AU766507B2

AU766507B2 - Novel chimpanzee erythropoietin (CHEPO) polypeptides and nucleic acids encoding the same

Info

Publication number: AU766507B2
Application number: AU47047/00A
Authority: AU
Inventors: Frederic De Sauvage; Dennis J. Henner
Original assignee: Genentech Inc
Current assignee: Genentech Inc
Priority date: 1999-05-07
Filing date: 2000-05-05
Publication date: 2003-10-16
Anticipated expiration: 2020-05-05
Also published as: WO2000068376A1; JP2002543784A; JP3660880B2; AU4704700A; WO2000068376A8; EP1177285A1; IL145785A0; MXPA01011264A; WO2000068376B1

Description

NOVEL CHIMPANZEE ERYTHROPOIETIN (CHEPO) POLYPEPTIDES AND NUCLEIC ACIDS ENCODING THE SAME FIELD OF THE INVENTION The present invention relates generally to the identification and isolation of novel chimpanzee erythropoietin polypeptides, nucleic acid molecules encoding those polypeptides and to the recombinant production of those polypeptides.

BACKGROUND OF THE INVENTION All references, including any patents or patent applications, cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents forms part of the common general knowledge in the art, in Australia or in any other country.

Erythropoiesis, the production of red blood cells, occurs continuously throughout the human life span to offset cell destruction. Erythropoiesis is a very precisely controlled physiological mechanism enabling sufficient numbers of red blood cells to be available in the blood for proper tissue oxygenation, but not so many that the cells would impede circulation. The formation of red blood cells occurs in the bone marrow and is under control of the hormone, erythropoietin.

Erythropoietin, an acidic glycoprotein is approximately 34,000 dalton molecular weight, may occur in three forms: alpha, beta and asialo. The alpha and beta forms different slightly in carbohydrate components have the same potency, biological activity and molecular weight. The asialo form is an alpha or beta form with the terminal carbohydrate (sialic acid) removed. Erythropoietin is present in a very low concentrations in plasma when the body is in a healthy state wherein tissues receive sufficient oxygenation from the existing number of erythrocytes. This normal low concentration is enough to stimulate .replacement of red blood cells which are lost normally through aging.

o *The amount of erythropoietin in the circulation is increased under conditions of hypoxia when oxygen transport by blood cells in the circulation is reduced. Hypoxia may be caused by loss of large S 30 amounts of blood through hemorrhage, destruction of red blood cells by over-exposure to radiation, reduction in oxygen intake due to high altitudes or prolonged unconsciousness, or various forms of anemia.

In response to tissues undergoing hypoxic stress, erythropoietin will increase red blood cell production by stimulating the conversion of primitive precursor cells in the bone marrow into proerythroblasts which subsequently mature, synthesize hemoglobin and are released into the circulation as red blood cells. When 35 the number of red blood cells in circulation is greater than needed for normal tissue oxygen requirements, erythropoietin in circulation is decreased.

8 H:\gabriela\kccp\speci\47047.00.doc 13/05/03 1 Because erythropoietin is essential in the process of red blood cell formation, the hormone has potential useful application in both the diagnosis and treatment of blood disorders characterized by low or defective red blood cell production. See, generally, Pennathur-Das, et al., Blood 63(5):1168-71 (1984) and Haddy, Am. Jour. Ped. Hematol. Oncol., 4:191-196 (1982) relating to erythropoietin in possible therapies for sickle cell disease, and Eschbach et al., J. Clin. Invest. 74(2):434-441 (1984), describing a therapeutic regimen for uremic sheep based on in vivo response to erythropoietin-rich plasma infusions and proposing a dosage of 10 U EOP/kg per day for 15-40 days as corrective of anemia of the type associated with chronic renal failure. See also, Krane, Henry Ford Hosp. Med. 31(3):177-181 (1983).

We describe herein the identification and characterization of a novel erythropoietin polypeptide derived from the chimpanzee, designated herein as "CHEPO".

SUMMARY OF THE INVENTION A cDNA clone has been identified that has homology to nucleic acid encoding human erythropoietin that encodes a novel chimpanzee erythropoietin polypeptide, designated in the present application as "CHEPO".

In a first aspect, the invention provides a chimeric molecule comprising a CHEPO polypeptide comprising amino acid residues 1 to 193 or 28 to 193 of Figure 2 (SEQ ID NO: 2) fused to an Fc region of an immunoglobulin; or a polypeptide sequence encoded by nucleotides 1 to 579 or 82 to 579 of Figure 2 (SEQ ID NO: or any one of amino acid sequences having SEQ ID Nos: 18 to 23, 25 to 31 or 33 given below; or any one of amino acid sequences having SEQ ID Nos: 34 to 49 given below, fused to an Fc region of an immunoglobulin.

APPRLICDSRVLERYLLEAKEAENITTGCAEHCSLNENITVPDTKVNFYAWKRNXSXQQAV

EVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAQKEAISPPDAASA

::25 APLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:18);

APPRLICDSRVLERYLLEAKEAENITTGCAEHCSLNENITVPDTKVNFYAWKRNXSXQQAV

EVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAKKEAISPPDAASA

APLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:19);

APPRLICDSRVLERYLLEAKEAENITTGCAEHCSLNENITVPDTKVNFYAWKRNXTXQQA

0 VEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAQKEAISPPDAAS AAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID

APPRLICDSRVLERYLLEAKEAENITTGCAEHCSLNENITVPDTKVNFYAWKRNXTXQQA

VEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAKKEAISPPDAAS

AAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:21); -2- H:\Juanita\Keep\patent\47047.00.doc 27/08/03 APPRLICDSRVLERYLLEAKEAENI7FrGCAEHCSLNENITVPDTKVNFYAWKRMNXSX

QAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAQKEAISPP

DAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:22);

APPRLICDSRVLERYLLEAKEAENITTGCAEHGSLNENITVPDTKVNFYAWKRMNXSX

QAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTrLLRALGAKKEAISPP DAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:23);

APPRIICDSRVLERYLLEAKEAENITTGCAEHCSLNENITVPDTKVNFYAWKRMNXTX

QAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLPTLLRALGAKKEAISPP

DAASAAPLRTITADTFRXLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID

APPRLICDSRVLERYLLEAKEAENITTGGAEHCSLNENITVPDTKVNFYAWKRMENXS

XAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAQKEAISPP

DAASAAPLRTITADTFRXLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:26); APPRLICDSRVLERYLLEAKEAENITITGCAEHCSLNENITVrPDTKVNFYAWKRMENXS

XAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAKKEAISPP

DAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:27);

APPRLICDSRVLERYLLEAKEAENI'TTGCAEHCSLNENITVPDTKVNFYAWKRMENXT

XA VEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAQKEAISPP' DAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:28);

APPRLICDSRVLERYLLEAKEAENITTGCAEHCSLNENITVPDTKVNFYAWKRMENXT

XAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTI'LLRALGAKKEAISPP

DAASAAjPLRTITADTFRKILFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO :29);

APPRLICDSRVLERYLLEAKEAENITTGCAEHCSLNENITVPDTKVNFYAWKRMEVNX

SXVEVWQGLALLSEAVLRGQALLXTNSSQPWEPLQLHVDKAVSGLRSLTTLLR-ALGAQKEAISPP

DAASAAPLRTITADTFRXLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID

APPRLICDSRVLERYLLEAKEAENITTGCAEHCSLNENITVPDTKVNFYAWKRMEVNX

SXVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTI7LLRALGAKKEAISPP DAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:3 1);

APPRLICDSRVLERYLLEAKEAENITTGCAEHCSLNENITVPDTKVNFYAWKRMEVNX

TXVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAKKEAISPP

DAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:33), wherein X is *~*any amino acid except for proline.

-2a- H:\Juanita\Kep\patelt4747.O.doc 27/08/03

MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTGCAE

HCSLNENITVPDTKVNFYAWKRNXSXQQAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL

HVDKAVSGLRSLTTLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTG

EACRTGDR (SEQ ID NO:34);

MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENI'TGCAE

HCSLNENITVPDTKVNFYAWKRNXSXQQAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL

HVDKAVSGLRSLTTLLRALGAKKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTG

EACRTGDR (SEQ ID

MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTGCAE

HCSLNENITVPDTKVNFYAWKRNXTXQQAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL

HVDKAVSGLRSLTTLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTG

EACRTGDR (SEQ ID NO:36);

MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTGCAE

HCSLNENITVPDTKVNFYAWKRNXTXQQAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL

HVDKAVSGLRSLTTLLRALGAKKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTG

EACRTGDR (SEQ ID NO:37);

MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTGCAE

HCSLNENITVPDTKVNEYAWKRMNXSXQAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL

HVDKAVSGLRSLTTLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTG

EACRTGDR (SEQ ID NO:3 8);

MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTGCAE

HCSLNENITVPDTKVNFYAWKRMNXSXQAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL

HVDKAVSGLRSLTTLLRALGAKKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTG

EACRTGDR (SEQ ID NO:39); 25 MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENIF-fGCAE

HCSLNENITVPDTKVNFYAWKRMNXTXQAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL

HVDKAVSGLRSLTTLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTG

EACRTGDR (SEQ ID MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITfGCAE

HCSLNENITVPDTKVNFYAWKRMNXTXQAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL

HVDKAVSGLRSLYI'LLRALGAKKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTG

O..o EACRTGDR (SEQ ID NO:41);

MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTGCAE

0HCSLNENITVPDTKVNFYAWKRMENXSXAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL

HVDKAVSGLRSLTTLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTG

0 o. EACRTGDR (SEQ ID NO:42);

MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTGCAE

HCSLNENITVPDTKVNFYAWKRMENXSXAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL

-2b- H:\Juanita\Keep\patent4747.00.doc 27/08/03

HVDKAVSGLRSLTTLLRALGAKKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTG

EACRTGDR (SEQ ID NO:43);

MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLIGDSRVLERYLLEAKEAENITTGCAE

HCSLNENITVPDTKVNFYAWKRMENXTXAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL

HVDKAVSGLRSLTTLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTG

EACRTGDR (SEQ ID NO:44);-

MGVHEGPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENIFFGCAE

HCSLNENITVPDTKVNFYAWKRMENXTXAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL

HVDKAVSGLRSLTFTLLRALGAKKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTG

EACRTGDR (SEQ ID

MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRICDSRVLERYLLEAKEAENITTGCAE

HCSLNENITVPDTKVNFYAWKRMEVNXSXVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL

HVDKAVSGLRSLTTLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTG

EACRTGDR (SEQ ID NO:46); MGVHEGPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTrGCAE

HCSLNENITVPDTKVNFYAWKRMEVNXSXVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL

HVDKAVSGLRSLTTLLRALGAKKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTG

EACRTGDR (SEQ ID NO:47);

MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITYTGCAE

HCSLNENITVPDTKVNFYAWKRMEVNXTXVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL

HVDKAVSGLRSLTTLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTG

EAGRTGDR (SEQ ID NO:48); and

MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTGCAE

.9....HCSLNENITVPDTKVNFYAWKRMEVNXTXVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQL HVDKAVSGLRSLTI7LLRALGAKKEAISPPDAASAAPLRTITADTFRKIFRVYSNFLRGKLKLYTG EACRTGDR (SEQ ID NO:49), wherein X is any amino acid except for proline.

Preferably the CHEPO polypeptide is substituted in place of at least one variable region within the immunoglobulin. More preferably the chimeric molecule is a dimer.

Preferably the immunoglobulin is an IgG molecule.

3 0 Preferably the immunoglobulin Fc region comprises the hinge, CH2 and CH3 regions of IgGi molecule. More preferably the immunoglobulin Fc region comprises the hinge, CHI, CH2 and CH3 regions of an IgG 1 molecule.

In one embodiment, the invention provides an isolated nucleic acid molecule comprising a nucleotide sequence that encodes a CHEPO polypeptide.

In one aspect, the isolated nucleic acid molecule comprises a nucleotide sequence having at least about 80% nucleic acid sequence identity, alternatively at least about 8 1% nucleic acid sequence identity, alternatively at least about 82% nucleic acid sequence identity, altemnatively at least about 83% -2c- H;'Juanita\Kcep\patent\47047.00.doc 27/08/03 nucleic acid sequence identity, alternatively at least about 84% nucleic acid sequence identity, alternatively at least about 85% nucleic acid sequence identity, alternatively at least about 86% nucleic acid sequence identity, alternatively at least about 87% nucleic acid sequence identity, alternatively at least about 88% nucleic acid sequence identity, alternatively at least about 89% nucleic acid sequence identity, alternatively at least about 90% nucleic acid sequence identity, alternatively at least about 91% nucleic acid sequence identity, alternatively at least about 92% nucleic acid sequence identity, alternatively at least about 93% nucleic acid sequence identity, alternatively at least about 94% nucleic acid sequence identity, alternatively at least about 95% nucleic acid sequence identity, alternatively at least about 96% nucleic acid sequence identity, alternatively at least about 97% nucleic acid sequence identity, alternatively at least about 98% nucleic acid sequence identity and alternatively at least about 99% nucleic acid sequence identity to a DNA molecule encoding a CHEPO polypeptide having the sequence of amino acid residues from about 1 or about 28 to about 193, inclusive, of Figure 3 (SEQ ID NOS:2 and or the complement of the DNA molecule of(a).

In another aspect, the isolated nucleic acid molecule comprises a nucleotide sequence encoding a CHEPO polypeptide having the sequence of amino acid residues from about 1 or about 28 to about 193, inclusive, of Figure 3 (SEQ ID NOS:2 and or the complement of the nucleotide sequence of(a).

In other aspects, the isolated nucleic acid molecule comprises a nucleotide sequence having at least about 80% nucleic acid sequence identity, alternatively at least about 81% nucleic acid sequence identity, alternatively at least about 82% nucleic acid sequence identity, alternatively at least about 83% nucleic acid sequence identity, alternatively at least about 84% nucleic acid sequence identity, alternatively at least about 85% nucleic acid sequence identity, alternatively at least about 86% nucleic acid sequence identity, alternatively at least about 87% nucleic acid sequence identity, alternatively at least about 88% nucleic acid sequence identity, alternatively at least about 89% nucleic acid sequence identity, alternatively at least about 90% nucleic acid sequence identity, alternatively at least about 91% nucleic acid sequence identity, alternatively at least about 92% nucleic acid sequence identity, alternatively at least about 93% nucleic acid sequence identity, alternatively at least about 94% nucleic acid sequence identity, alternatively at least about 95% nucleic acid sequence identity, alternatively at least about 96% nucleic acid sequence identity, alternatively at least about 97% nucleic acid sequence 30 identity, alternatively at least about 98% nucleic acid sequence identity and alternatively at least about S°99% nucleic acid sequence identity to a DNA molecule having the sequence of nucleotides from S° °about 1 or about 82 to about 579, inclusive, of Figure 2 (SEQ ID NO:3), or the complement of the DNA molecule of(a).

.2d- -2d- H:\Juanita\Kecp\patent\47047.00.doc 27/08/03 WO 00/68376 PCT/US00/12370 In another aspect, the isolated nucleic acid molecule comprises the nucleotide sequence of from about 1 or about 82 to about 579, inclusive, of Figure 2 (SEQ ID NO:3), or the complement of the nucleotide sequence of In another aspect, the invention concerns an isolated nucleic acid molecule which encodes an active CHEPO polypeptide as defined below comprising a nucleotide sequence that hybridizes to the complement of a nucleic acid sequence that encodes amino acids 1 or about 28 to about 193, inclusive, of Figure 3 (SEQ ID NOS:2 and Preferably, hybridization occurs under stringent hybridization and wash conditions.

In yet another aspect, the invention concerns an isolated nucleic acid molecule which encodes an active CHEPO polypeptide as defined below comprising a nucleotide sequence that hybridizes to the complement of the nucleic acid sequence between about nucleotides 1 or about 82 and about 579, inclusive, of Figure 2 (SEQ ID NO:3). Preferably, hybridization occurs under stringent hybridization and wash conditions.

In a further aspect, the invention concerns an isolated nucleic acid molecule which is produced by hybridizing a test DNA molecule under stringent conditions with a DNA molecule encoding a CHEPO polypeptide having the sequence of amino acid residues from about 1 or about 28 to about 193, inclusive, of Figure 3 (SEQ ID NOS:2 and or the complement of the DNA molecule of and, if the test DNA molecule has at least about an 80% nucleic acid sequence identity, alternatively at least about 81% nucleic acid sequence identity, alternatively at least about 82% nucleic acid sequence identity, alternatively at least about 83% nucleic acid sequence identity, alternatively at least about 84% nucleic acid sequence identity, alternatively at least about 85% nucleic acid sequence identity, alternatively at least about 86% nucleic acid sequence identity, alternatively at least about 87% nucleic acid sequence identity, alternatively at least about 88% nucleic acid sequence identity, alternatively at least about 89% nucleic acid sequence identity, alternatively at least about 90% nucleic acid sequence identity, alternatively at least about 91% nucleic acid sequence identity, alternatively at least about 92% nucleic acid sequence identity, alternatively at least about 93% nucleic acid sequence identity, alternatively at least about 94% nucleic acid sequence identity, alternatively at least about 95% nucleic acid sequence identity, alternatively at least about 96% nucleic acid sequence identity, alternatively at least about 97% nucleic acid sequence identity, alternatively at least about 98% nucleic acid sequence identity and alternatively at least about 99% nucleic acid sequence identity to or and isolating the test DNA molecule.

In another aspect, the invention concerns an isolated nucleic acid molecule comprising a nucleotide sequence encoding a polypeptide scoring at least about 80% positives, alternatively at least about 81% positives, alternatively at least about 82% positives, alternatively at least about 83% positives, alternatively at least about 84% positives, alternatively at least about 85% positives, alternatively at least about 86% positives, alternatively at least about 87% positives, alternatively at least about 88% positives, alternatively at least about 89% positives, alternatively at least about positives, alternatively at least about 91% positives, alternatively at least about 92% positives, alternatively at least about 93% positives, alternatively at least about 94% positives, alternatively at least about 95% positives, alternatively at least about 96% positives, alternatively at least about 97% positives, alternatively at least about 98% positives and alternatively at least about 99% positives when compared with the amino acid sequence of residues about 1 or about 28 to 193, inclusive, of Figure 3 (SEQ ID NOS:2 and or the complement of the nucleotide sequence of WO 00/68376 PCTUSO/12370 In a specific aspect, the invention provides an isolated nucleic acid molecule comprising DNA encoding a CHEPO polypeptide without the N-terminal signal sequence and/or the initiating methionine, or is complementary to such encoding nucleic acid molecule. The signal peptide has been tentatively identified as extending from about amino acid position 1 to about amino acid position 27 in the sequence of Figure 3 (SEQ ID NOS:2 and It is noted, however, that the C-terminal boundary of the signal peptide may vary, but most likely by no more than about 5 amino acids on either side of the signal peptide C-terminal boundary as initially identified herein, wherein the C-terminal boundary of the signal peptide may be identified pursuant to criteria routinely employed in the art for identifying that type of amino acid sequence element Nielsen et al., Prot. Eng. 10:1-6 (1997) and von Heinje et al., Nucl. Acids. Res. 14:4683-4690 (1986)). Moreover, it is also recognized that, in some cases, cleavage of a signal sequence from a secreted polypeptide is not entirely uniform, resulting in more than one secreted species. These polypeptides, and the polynucleotides encoding them, are contemplated by the present invention. As such, for purposes of the present application, the signal peptide of the CHEPO polypeptide shown in Figure 3 (SEQ ID NOS:2 and 5) extends from amino acids 1 to X of Figure 3 (SEQ ID NOS:2 and wherein X is any amino acid from 23 to 32 of Figure 3 (SEQ ID NOS:2 and Therefore, mature forms of the CHEPO polypeptide which are encompassed by the present invention include those comprising amino acids X to 193 of Figure 3 (SEQ ID NOS:2 and wherein X is any amino acid from 23 to 32 of Figure 3 (SEQ ID NOS:2 and 5) and variants thereof as described below.

Isolated nucleic acid molecules encoding these polypeptides are also contemplated.

Another embodiment is directed to fragments of a CHEPO polypeptide coding sequence that may find use as, for example, hybridization probes or for encoding fragments of a CHEPO polypeptide that may optionally encode a polypeptide comprising a binding site for an anti-CHEPO antibody. Such nucleic acid fragments are usually at least about nucleotides in length, alternatively at least about 30 nucleotides in length, alternatively at least about 40 nucleotides in length, alternatively at least about 50 nucleotides in length, alternatively at least about 60 nucleotides in length, alternatively at least about 70 nucleotides in length, alternatively at least about 80 nucleotides in length, alternatively at least about 90 nucleotides in length, alternatively at least about 100 nucleotides in length, alternatively at least about 110 nucleotides in length, alternatively at least about 120 nucleotides in length, alternatively at least about 130 nucleotides in length, alternatively at least about 140 nucleotides in length, alternatively at least about 150 nucleotides in length, alternatively at least about 160 nucleotides in length, alternatively at least about 170 nucleotides in length, alternatively at least about 180 nucleotides in length, alternatively at least about 190 nucleotides in length, alternatively at least about 200 nucleotides in length, alternatively at least about 250 nucleotides in length, alternatively at least about 300 nucleotides in length, alternatively at least about 350 nucleotides in length, alternatively at least about 400 nucleotides in length, alternatively at least about 450 nucleotides in length, alternatively at least about 500 nucleotides in length, alternatively at least about 600 nucleotides in length, alternatively at least about 700 nucleotides in length, alternatively at least about 800 nucleotides in length, alternatively at least about 900 nucleotides in length and alternatively at least about 1000 nucleotides in length, wherein in this context the term about means the referenced nucleotide sequence length plus or minus 10% of that referenced length. In a preferred embodiment, the nucleotide sequence fragment is derived from 3 5 any coding region of the nucleotide sequence shown in Figure 1 (SEQ ID NO:1). It is noted that novel fragments of a CHEPO polypeptide-encoding nucleotide sequence may be determined in a routine manner by aligning the CHEPO WO 00/68376 PCT/US00/12370 polypeptide-encoding nucleotide sequence with other known nucleotide sequences using any of a number of well known sequence alignment programs and determining which CHEPO polypeptide-encoding nucleotide sequence fragment(s) are novel. All of such CHEPO polypeptide-encoding nucleotide sequences are contemplated herein and can be determined without undue experimentation. Also contemplated are the CHEPO polypeptide fragments encoded by these nucleotide molecule fragments, preferably those CHEPO polypeptide fragments that comprise a binding site for an anti-CHEPO antibody.

In another embodiment, the invention provides a vector comprising a nucleotide sequence encoding CHEPO or its variants. The vector may comprise any of the isolated nucleic acid molecules hereinabove identified.

A host cell comprising such a vector is also provided. By way of example, the host cells may be CHO cells, E.

coil, or yeast. A process for producing CHEPO polypeptides is further provided and comprises culturing host cells under conditions suitable for expression of CHEPO and recovering CHEPO from the cell culture.

In another embodiment, the invention provides isolated CHEPO polypeptide encoded by any of the isolated nucleic acid sequences hereinabove identified.

In a specific aspect, the invention provides isolated native sequence CHEPO polypeptide, which in certain embodiments, includes an amino acid sequence comprising residues from about 1 or about 28 to about 193 of Figure 3 (SEQ ID NOS:2 and In another aspect, the invention concerns an isolated CHEPO polypeptide, comprising an amino acid sequence having at least about 80% amino acid sequence identity, alternatively at least about 81% amino acid sequence identity, alternatively at least about 82% amino acid sequence identity, alternatively at least about 83% amino acid sequence identity, alternatively at least about 84% amino acid sequence identity, alternatively at least about 85% amino acid sequence identity, alternatively at least about 86% amino acid sequence identity, alternatively at least about 87% amino acid sequence identity, alternatively at least about 88% amino acid sequence identity, alternatively at least about 89% amino acid sequence identity, alternatively at least about 90% amino acid sequence identity, alternatively at least about 91% amino acid sequence identity, alternatively at least about 92% amino acid sequence identity, alternatively at least 2 5 about 93% amino acid sequence identity, alternatively at least about 94% amino acid sequence identity, alternatively at least about 95% amino acid sequence identity, alternatively at least about 96% amino acid sequence identity, alternatively at least about 97% amino acid sequence identity, alternatively at least about 98% amino acid sequence identity and alternatively at least about 99% amino acid sequence identity to the sequence of amino acid residues from about 1 or about 28 to about 193, inclusive, of Figure 3 (SEQ ID NOS:2 and In a further aspect, the invention concerns an isolated CHEPO polypeptide comprising an amino acid sequence scoring at least about 80% positives, alternatively at least about 81% positives, alternatively at least about 82% positives, alternatively at least about 83% positives, alternatively at least about 84% positives, alternatively at least about positives, alternatively at least about 86% positives, alternatively at least about 87% positives, alternatively at least about 88% positives, alternatively at least about 89% positives, alternatively at least about 90% positives, alternatively at least about 91% positives, alternatively at least about 92% positives, alternatively at least about 93% positives, alternatively at least about 94% positives, alternatively at least about 95% positives, alternatively at least about 96% positives, WO 00/68376 PCT/USOO/12370 alternatively at least about 97% positives, alternatively at least about 98% positives and alternatively at least about 99% positives when compared with the amino acid sequence of residues from about 1 or about 28 to about 193, inclusive, of Figure 3 (SEQ ID NOS:2 and In a specific aspect, the invention provides an isolated CHEPO polypeptide without the N-terminal signal sequence andlor the initiating methionine and is encoded by a nucleotide sequence that encodes such an amino acid sequence as hereinbefore described. Processes for producing the same are also herein described, wherein those processes comprise culturing a host cell comprising a vector which comprises the appropriate encoding nucleic acid molecule under conditions suitable for expression of the CHEPO polypeptide and recovering the CHEPO polypeptide from the cell culture.

In yet another aspect, the invention concerns an isolated CHEPO polypeptide, comprising the sequence of amino acid residues from about 1 or about 28 to about 193, inclusive, of Figure 3 (SEQ ID NOS:2 and or a fragment thereof which is biologically active or sufficient to provide a binding site for an anti-CHEPO antibody, wherein the identification of CHEPO polypeptide fragments that possess biological activity or provide a binding site for an anti-CHEPO antibody may be accomplished in a routine manner using techniques which are well known in the art. Preferably, the CHEPO fragment retains a qualitative biological activity of a native CHEPO polypeptide.

In a still further aspect, the invention provides a polypeptide produced by hybridizing a test DNA molecule under stringent conditions with a DNA molecule encoding a CHEPO polypeptide having the sequence of amino acid residues from about 1 or about 28 to about 193, inclusive, of Figure 3 (SEQ ID NOS:2 and or the complement of the DNA molecule of and if the test DNA molecule has at least about an 80% nucleic acid sequence identity, alternatively at least about 81% nucleic acid sequence identity, alternatively at least about 82% nucleic acid sequence identity, alternatively at least about 83% nucleic acid sequence identity, alternatively at least about 84% nucleic acid sequence identity, alternatively at least about 85% nucleic acid sequence identity, alternatively at least about 86% nucleic acid sequence identity, alternatively at least about 87% nucleic acid sequence identity, alternatively at least about 88% nucleic acid sequence identity, alternatively at least about 89% nucleic acid sequence identity, alternatively at least about nucleic acid sequence identity, alternatively at least about 91% nucleic acid sequence identity, alternatively at least about 92% nucleic acid sequence identity, alternatively at least about 93% nucleic acid sequence identity, alternatively at least about 94% nucleic acid sequence identity, alternatively at least about 95% nucleic acid sequence identity, alternatively at least about 96% nucleic acid sequence identity, alternatively at least about 97% nucleic acid sequence identity, alternatively at least about 98% nucleic acid sequence identity and alternatively at least about 99% nucleic acid sequence identity to or (ii) culturing a host cell comprising the test DNA molecule under conditions suitable for expression of the polypeptide, and (iii) recovering the polypeptide from the cell culture.

In another embodiment, the invention provides chimeric molecules comprising a CHEPO polypeptide fused to a heterologous polypeptide or amino acid sequence, wherein the CHEPO polypeptide may comprise any CHEPO polypeptide, variant or fragment thereof as hereinbefore described. An example of such a chimeric molecule comprises a CHEPO polypeptide fused to an epitope tag sequence or a Fc region of an immunoglobulin.

WO 00/68376 PCTIUSO/12370 In another embodiment, the invention provides an antibody as defined below which specifically binds to a CHEPO polypeptide as hereinbefore described. Optionally, the antibody is a monoclonal antibody, an antibody fragment or a single chain antibody.

In yet another embodiment, the invention concerns agonists and antagonists of a native CHEPO polypeptide as defined below. In a particular embodiment, the agonist or antagonist is an anti-CHEPO antibody or a small molecule.

In a further embodiment, the invention concerns a method of identifying agonists or antagonists to a CHEPO polypeptide which comprise contacting the CHEPO polypeptide with a candidate molecule and monitoring a biological activity mediated by said CHEPO polypeptide. Preferably, the CHEPO polypeptide is a native CHEPO polypeptide.

In a still further embodiment, the invention concerns a composition of matter comprising a CHEPO polypeptide, or an agonist or antagonist of a CHEPO polypeptide as herein described, or an anti-CHEPO antibody, in combination with a carrier. Optionally, the carrier is a pharmaceutically acceptable carrier.

Another embodiment of the present invention is directed to the use of a CHEPO polypeptide, or an agonist or antagonist thereof as herein described, or an anti-CHEPO antibody, for the preparation of a medicament useful in the treatment of a condition which is responsive to the CHEPO polypeptide, an agonist or antagonist thereof or an anti-CHEPO antibody.

Yet another embodiment of the present invention is directed to CHEPO polypeptides having altered glycosylation patterns in one or more regions of the polypeptide as compared to the native sequence CHEPO polypeptide, preferably in the region surrounding and/or including amino acid position 84 in the CHEPO amino acids sequence shown in Figure 3 (SEQ ID NDS:2 and In various embodiments, CHEPO variant polypeptides are prepared using well known techniques so as to create an N- or 0-linked glycosylation site at or near amino acid position 84 in the CHEPO polypeptide sequence. For example, CHEPO polypeptides contemplated by the present invention include those where amino acids 81-84 of the CHEPO amino acid sequence shown in Figure 3 (SEQ ID NOS:2 and 5) Met-Glu-Val-Arg; SEQ ID NO:6) are replaced by the amino acid sequence Asn-X-Ser-X (SEQ 10 NO:7) or Asn-X-Thr-X (SEQ ID NO:8), where X is any amino acid except for Pro; amino acids 82-85 of the CHEPO amino acid sequence shown in Figure 3 (SEQ ID NOS:2 and 5) Glu-Val-Arg- Gin; SEQ ID NO:9) are replaced by the amino acid sequence Asn-X-Ser-X (SEQ ID NO:7) or Asn-X-Thr-X (SEQ ID NO:8), where X is any amino acid except for Pro; amino acids 83-86 of the CHEPO amino acid sequence shown in Figure 3 (SEQ ID NOS:2 and 5) Val-Arg-Gln-GIn; SEQ ID NO:10) are replaced by the amino acid sequence Asn-X-Ser-X (SEQ ID NO:7) or Asn-X-Thr-X (SEQ ID NO:8), where X is any amino acid except for Pro; or amino acids 84-87 of the CHEPO amino acid sequence shown in Figure 3 (SEQ ID NOS:2 and 5) Arg-Gln.Gln-Ala; SEQ ID NO: 11) are replaced by the amino acid sequence Asn-X-Ser-X (SEQ ID NO:7) or Asn-X-Thr-X (SEQ ID NO:8), where X is any amino acid except for Pro, thereby creating an N-glycosylation site at those positions. Nucleic acids encoding these variant polypeptides are also contemplated herein as are vectors and host cells comprising those nucleic acids.

BRIEF DESCRIPTION OF THE DRAWINGS Figures 1A-C show a nucleotide sequence (SEQ ID NO:1) of an isolated genomic DNA molecule containing a nucleotide sequence (nucleotides 134-146, 667-812, 1071-1157, 1760-1939 and 2074-2226, exclusive of others) encoding native sequence CHEPO. Also presented in the genomic sequence are the locations of the start codon, exons and introns as well as the amino acid sequence (SEQ ID NO:2) encoded by the coding sequence of SEQ ID NO:1.

Figure 2 shows the cDNA sequence of the CHEPO molecule (SEQ ID NO:3) and the amino acid sequence encoded thereby (SEQ ID NO:2).

Figure 3 shows a comparison of the human erythropoietin amino acid sequence (human) (SEQ ID NO:4) and that of the chimp erythropoietin (CHEPO) described herein, wherein the amino acid designated at amino acid position 142 of the CHEPO sequence is either glutamine (SEQ ID NO:2) or lysine (SEQ ID Figure 4 illustrates the stimulation of proliferation of human erythropoietin receptor-expressing Ba/F3 cells in response to recombinant human erythropoietin and CHEPO-IgGl.

Closed squares: recombinant human erythropoietin Open squares: CHEPO IgG Figure 5 shows the effect of CHEPO-IgG1 on stimulation of CD34 human bone marrow cells, as assessed by fluorescence-activated cell sorting (FACS) analysis.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS I. Definitions For the purposes of this specification it will be clearly understood that the word "comprising" means "including but not limited to", and that the word "comprises" has a corresponding meaning.

The terms "CHEPO polypeptide", "CHEPO protein" and "CHEPO" when used herein encompass native sequence CHEPO and CHEPO polypeptide variants (which are further defined herein). The CHEPO polypeptide may be isolated from a variety of sources, such as from human tissue types or from another source, or prepared by recombinant and/or synthetic methods.

25 A "native sequence CHEPO" comprises a polypeptide having the same amino acid sequence as a CHEPO derived from nature. Such native sequence CHEPO can be isolated from nature or can be produced by recombinant and/or synthetic means. The term "native sequence CHEPO" specifically encompasses naturally-occurring truncated or secreted forms an extracellular domain sequence), naturally-occurring variant forms alternatively spliced forms) and naturally-occurring allelic variants of the CHEPO. In one embodiment of the invention, the native sequence CHEPO is a mature or full-length native sequence CHEPO comprising amino acids 1 to 193 of Figure 3 (SEQ ID NOS:2 and Also, while the CHEPO polypeptides disclosed in Figure 3 (SEQ ID NOS:2 and 5) is shown to begin with the methionine residue designated herein as amino acid position 1, it is conceivable and possible that another Smethionine residue located either upstream or downstream from amino acid position 1 in Figure 3 (SEQ ID 35 NOS:2 and 5) may be employed as the starting amino acid residue for the CHEPO polypeptide.

S• "CHEPO variant polypeptide" means an active CHEPO polypeptide as defined below having at least about 80% amino acid sequence identity with the amino acid sequence of residues 1 or about 28 to S13/05/03 *H7***7 H:\gabrila\kcp\spcci\7047.00.doc 13/05/03 193 of the CHEPO polypeptide shown in Figure 3 (SEQ ID NOS:2 and X to 193 of the CHEPO polypeptide shown in Figure 3 (SEQ ID NOS:2 and wherein X is any amino acid residue from 23 to 32 of Figure 3 (SEQ ID NOS:2 and 5) or another specifically derived fragment of the amino acid sequence shown in Figure 3 (SEQ ID NOS:2 and Such CHEPO variant polypeptides include, for instance, CHEPO polypeptides wherein one or more amino acid residues are added, or deleted, at the N- and/or Cterminus, as well as within one or more internal domains, of the sequence of Figure 3 (SEQ ID NOS:2 and Ordinarily, a CHEPO variant polypeptide will have at least about 80% amino acid sequence identity, alternatively at least about 81% amino acid sequence identity, alternatively at least about 82% amino acid sequence identity, alternatively at least about 83% amino acid sequence identity, alternatively at least about 84% amino acid sequence identity, alternatively at least about 85% amino acid sequence identity, alternatively at least about 86% amino acid sequence identity, alternatively at least about 87% amino acid sequence identity, alternatively at least about 88% amino acid sequence identity, alternatively H:\gabriela\kep\speci\47047.00.doc 13/05/03 WO 00/68376 PCT/USOO/2370 at least about 89% amino acid sequence identity, alternatively at least about 90% amino acid sequence identity, alternatively at least about 91% amino acid sequence identity, alternatively at least about 92% amino acid sequence identity, alternatively at least about 93% amino acid sequence identity, alternatively at least about 94% amino acid sequence identity, alternatively at least about 95% amino acid sequence identity, alternatively at least about 96% amino acid sequence identity, alternatively at least about 97% amino acid sequence identity, alternatively at least about 98% amino acid sequence identity and alternatively at least about 99% amino acid sequence identity with residues 1 or about 28 to 193 of the CHEPO polypeptide shown in Figure 3 (SEQ ID NOS:2 and X to 193 of the CHEPO polypeptide shown in Figure 3 (SEQ ID NOS:2 and wherein X is any amino acid residue from 23 to 32 of Figure 3 (SEQ ID NOS:2 and 5) or another specifically derived fragment of the amino acid sequence shown in Figure 3 (SEQ D10 NOS:2 and CHEPO variant polypeptides do not encompass the native CHEPO polypeptide sequence. Ordinarily, CHEPO variant polypeptides are at least about 10 amino acids in length, alternatively at least about 20 amino acids in length, alternatively at least about 30 amino acids in length, alternatively at least about 40 amino acids in length, alternatively at least about amino acids in length, alternatively at least about 60 amino acids in length, alternatively at least about 70 amino acids in length, alternatively at least about 80 amino acids in length, alternatively at least about 90 amino acids in length, alternatively at least about 100 amino acids in length, alternatively at least about 150 amino acids in length, alternatively at least about 200 amino acids in length, alternatively at least about 300 amino acids in length, or more.

"Percent amino acid sequence identity" with respect to the CHEPO polypeptide sequences identified herein is defined as the percentage of amino acid residues in a candidate sequence that are identical with the amino acid residues in a CHEPO sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity, and not considering any conservative substitutions as part of the sequence identity. Alignment for purposes of determining percent amino acid sequence identity can be achieved in various ways that are within the skill in the art, for instance, using publicly available computer software such as BLAST, BLAST.2, ALIGN, ALIGN-2 or Megalign (DNASTAR) software. Those skilled in the art can determine appropriate parameters for measuring alignment, including any algorithms needed to achieve maximal alignment over the full-length of the sequences being compared. For purposes herein, however, amino acid sequence identity values are obtained as described below by using the sequence comparison computer program AUGN-2, wherein the complete source code for the ALIGN.2 program is provided in Table 1 below. The ALIGN-2 sequence comparison computer program was authored by Genentech, Inc. and the source code shown in Table 1 has been filed with user documentation in the U.S. Copyright Office, Washington 20559, where it is registered under U.S. Copyright Registration No. TXU510087. The ALIGN-2 program is publicly available through Genentech, Inc., South San Francisco, California or may be compiled from the source code provided in Table 1. The ALIGN-2 program should be compiled for use on a UNIX operating system, preferably digital UNIX V4.0D. All sequence comparison parameters are set by the ALIGN-2 program and do not vary.

For purposes herein, the amino acid sequence identity of a given amino acid sequence A to, with, or against a given amino acid sequence B (which can alternatively be phrased as a given amino acid sequence A that has or comprises a certain amino acid sequence identity to, with, or against a given amino acid sequence B) is calculated as follows: WO 00/68376 PCT/US00/12370 100 times the fraction X/Y where X is the number of amino acid residues scored as identical matches by the sequence alignment program ALIGN-2 in that program s alignment of A and B, and where Y is the total number of amino acid residues in B. It will be appreciated that where the length of amino acid sequence A is not equal to the length of amino acid sequence B, the amino acid sequence identity of A to B will not equal the amino acid sequence identity of B to A. As examples of amino acid sequence identity calculations, Tables 2 and 3 below demonstrate how to calculate the amino acid sequence identity of the amino acid sequence designated Comparison Protein to the amino acid sequence designated PRO.

Unless specifically stated otherwise, all amino acid sequence identity values used herein are obtained as described above using the ALIGN-2 sequence comparison computer program. However, amino acid sequence identity may also be determined using the sequence comparison program NCBI-BLAST2 (Altschul et al., Nucleic Acids Res.

25:3389-3402 (1997)). The NCBI-BLAST2 sequence comparison program may be downloaded from http://www.ncbi.nlm.nih.gov or otherwise obtained from the National Institute of Health, Bethesda, MD. NCBI-BLAST2 uses several search parameters, wherein all of those search parameters are set to default values including, for example, unmask yes, strand all, expected occurrences 10, minimum low complexity length 1515, multi-pass e-value 0.01, constant for multi-pass 25, dropoff for final gapped alignment 25 and scoring matrix BLOSUM62.

In situations where NCBI-BLAST2 is employed for amino acid sequence comparisons, the amino acid sequence identity of a given amino acid sequence A to, with, or against a given amino acid sequence B (which can alternatively be phrased as a given amino acid sequence A that has or comprises a certain amino acid sequence identity to, with, or against a given amino acid sequence B) is calculated as follows: 100 times the fraction X/Y where X is the number of amino acid residues scored as identical matches by the sequence alignment program NCBI- BLAST2 in that program s alignment of A and B, and where Y is the total number of amino acid residues in B. It will be appreciated that where the length of amino acid sequence A is not equal to the length of amino acid sequence B, the amino acid sequence identity of A to B will not equal the amino acid sequence identity of B to A.

"CHEPO variant polynucleotide" or CHEPO variant nucleic acid sequence means a nucleic acid molecule which encodes an active CHEPO polypeptide as defined below and which has at least about 80% nucleic acid sequence identity 3 0 with either a nucleic acid sequence which encodes residues 1 or about 28 to 193 of the CHEPO polypeptide shown in Figure 3 (SEQ ID NOS:2 and a nucleic acid sequence which encodes residues X to 193 of the CHEPO polypeptide shown in Figure 3 (SEQ ID NOS:2 and wherein X is any amino acid residue from 23 to 32 of Figure 3 (SEQ ID NOS:2 and 5) or a nucleic acid sequence which encodes another specifically derived fragment of the amino acid sequence shown in Figure 3 (SEQ 10 NOS:2 and Ordinarily, a CHEPO variant polynucleotide will have at least about 80% nucleic 3 5 acid sequence identity, alternatively at least about 81 nucleic acid sequence identity, alternatively at least about 82% nucleic acid sequence identity, alternatively at least about 83% nucleic acid sequence identity, alternatively at least about WO 00/68376 PCT/US00/12370 84% nucleic acid sequence identity, alternatively at least about 85% nucleic acid sequence identity, alternatively at least about 86% nucleic acid sequence identity, alternatively at least about 87% nucleic acid sequence identity, alternatively at least about 88% nucleic acid sequence identity, alternatively at least about 89% nucleic acid sequence identity, alternatively at least about 90% nucleic acid sequence identity, alternatively at least about 91% nucleic acid sequence identity, alternatively at least about 92% nucleic acid sequence identity, alternatively at least about 93% nucleic acid sequence identity, alternatively at least about 94% nucleic acid sequence identity, alternatively at least about 95% nucleic acid sequence identity, alternatively at least about 96% nucleic acid sequence identity, alternatively at least about 97% nucleic acid sequence identity, alternatively at least about 98% nucleic acid sequence identity and alternatively at least about 99% nucleic acid sequence identity with either a nucleic acid sequence which encodes residues 1 or about 28 to 193 of the CHEPO polypeptide shown in Figure 3 (SEQ ID NOS:2 and a nucleic acid sequence which encodes residues X to 193 of the CHEPO polypeptide shown in Figure 3 (SEQ ID NOS:2 and wherein X is any amino acid residue from 23 to 32 of Figure 3 (SEQ ID NOS:2 and 5) or a nucleic acid sequence which encodes another specifically derived fragment of the amino acid sequence shown in Figure 3 (SEQ ID NOS:2 and CHEPO polynucleotide variants do not encompass the native CHEPO nucleotide sequence.

Ordinarily, CHEPO variant polynucleotides are at least about 30 nucleotides in length, alternatively at least about nucleotides in length, alternatively at least about 90 nucleotides in length, alternatively at least about 120 nucleotides in length, alternatively at least about 150 nucleotides in length, alternatively at least about 180 nucleotides in length, alternatively at least about 210 nucleotides in length, alternatively at least about 240 nucleotides in length, alternatively at least about 270 nucleotides in length, alternatively at least about 300 nucleotides in length, alternatively at least about 450 nucleotides in length, alternatively at least about 600 nucleotides in length, alternatively at least about 900 nucleotides in length, or more.

"Percent nucleic acid sequence identity" with respect to the CHEPO polypeptide-encoding nucleic acid sequences identified herein is defined as the percentage of nucleotides in a candidate sequence that are identical with the nucleotides in a CHEPO polypeptide-encoding nucleic acid sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity. Alignment for purposes of determining percent nucleic acid sequence identity can be achieved in various ways that are within the skill in the art, for instance, using publicly available computer software such as BLAST, BLAST.2, ALIGN, ALIGN-2 or Megalign (DNASTAR) software. Those skilled in the art can determine appropriate parameters for measuring alignment, including any algorithms needed to achieve maximal alignment over the full-length of the sequences being compared. For purposes herein, however, nucleic acid sequence identity values are obtained as described below by using the sequence comparison computer program ALIGN-2, wherein the complete source code for the ALIGN-2 program is provided in Table 1. The ALIGN-2 sequence comparison computer program was authored by Genentech, Inc. and the source code shown in Table 1 has been filed with user documentation in the U.S. Copyright Office, Washington 20559, where it is registered under U.S. Copyright Registration No.

TXU510087. The ALIGN-2 program is publicly available through Genentech, Inc., South San Francisco, California or may be compiled from the source code provided in Table 1. The ALIGN-2 program should be compiled for use on a UNIX WO 00/68376 PCT/US00/12370 operating system, preferably digital UNIX V4.0D. All sequence comparison parameters are set by the ALIGN-2 program and do not vary.

For purposes herein, the nucleic acid sequence identity of a given nucleic acid sequence C to, with, or against a given nucleic acid sequence 0 (which can alternatively be phrased as a given nucleic acid sequence C that has or comprises a certain nucleic acid sequence identity to, with, or against a given nucleic acid sequence 0) is calculated as follows: 100 times the fraction WIZ where W is the number of nucleotides scored as identical matches by the sequence alignment program ALIGN-2 in that program s alignment of C and D, and where Z is the total number of nucleotides in D. It will be appreciated that where the length of nucleic acid sequence C is not equal to the length of nucleic acid sequence D, the nucleic acid sequence identity of C to 0 will not equal the nucleic acid sequence identity of D to C. As examples of nucleic acid sequence identity calculations, Tables 4 and 5 below demonstrate how to calculate the nucleic acid sequence identity of the nucleic acid sequence designated Comparison DNA to the nucleic acid sequence designated PRO-DNA.

Unless specifically stated otherwise, all nucleic acid sequence identity values used herein are obtained as described above using the ALIGN-2 sequence comparison computer program. However, nucleic acid sequence identity may also be determined using the sequence comparison program NCBI-BLAST2 (Altschul et al., Nucleic Acids Res.

In situations where NCBI-BLAST2 is employed for sequence comparisons, the nucleic acid sequence identity of a given nucleic acid sequence C to, with, or against a given nucleic acid sequence D (which can alternatively be phrased as a given nucleic acid sequence C that has or comprises a certain nucleic acid sequence identity to, with, or against a given nucleic acid sequence D) is calculated as follows: 100 times the fraction W/Z where W is the number of nucleotides scored as identical matches by the sequence alignment program NCBI-BLAST2 in that program s alignment of C and D, and where Z is the total number of nucleotides in D. It will be appreciated that where the length of nucleic acid sequence C is not equal to the length of nucleic acid sequence D, the nucleic acid sequence identity of C to D will not equal the nucleic acid sequence identity of D to C.

In other embodiments, CHEPO variant polynucleotides are nucleic acid molecules that encode an active CHEPO polypeptide and which are capable of hybridizing, preferably under stringent hybridization and wash conditions, to WO 00/68376 PCTIUSOO/12370 nucleotide sequences encoding the full-length CHEPO polypeptide shown in Figure 3 (SEQ ID NOS:2 and CHEPO variant polypeptides may be those that are encoded by a CHEPO variant polynucleotide.

The term "positives", in the context of the amino acid sequence identity comparisons performed as described above, includes amino acid residues in the sequences compared that are not only identical, but also those that have similar properties. Amino acid residues that score a positive value to an amino acid residue of interest are those that are either identical to the amino acid residue of interest or are a preferred substitution (as defined in Table 6 below) of the amino acid residue of interest.

For purposes herein, the value of positives of a given amino acid sequence A to, with, or against a given amino acid sequence B (which can alternatively be phrased as a given amino acid sequence A that has or comprises a certain positives to, with, or against a given amino acid sequence B) is calculated as follows: 100 times the fraction X/Y where X is the number of amino acid residues scoring a positive value as defined above by the sequence alignment program ALIGN-2 in that program s alignment of A and B, and where Y is the total number of amino acid residues in B. It will be appreciated that where the length of amino acid sequence A is not equal to the length of amino acid sequence B, the positives of A to B will not equal the positives of B to A.

"Isolated," when used to describe the various polypeptides disclosed herein, means polypeptide that has been identified and separated andlor recovered from a component of its natural environment. Preferably, the isolated polypeptide is free of association with all components with which it is naturally associated. Contaminant components of its natural environment are materials that would typically interfere with diagnostic or therapeutic uses for the polypeptide, and may include enzymes, hormones, and other proteinaceous or non-proteinaceous solutes. In preferred embodiments, the polypeptide will be purified to a degree sufficient to obtain at least 15 residues of N-terminal or internal amino acid sequence by use of a spinning cup sequenator, or to homogeneity by SOS-PAGE under non-reducing or reducing conditions using Coomassie blue or, preferably, silver stain. Isolated polypeptide includes polypeptide in situ within recombinant cells, since at least one component of the CHEPO natural environment will not be present. Ordinarily, however, isolated polypeptide will be prepared by at least one purification step.

An "isolated" nucleic acid molecule encoding a CHEPO polypeptide is a nucleic acid molecule that is identified and separated from at least one contaminant nucleic acid molecule with which it is ordinarily associated in the natural source of the CHEPO-encoding nucleic acid. Preferably, the isolated nucleic is free of association with all components with which it is naturally associated. An isolated CHEPO-encoding nucleic acid molecule is other than in the form or setting in which it is found in nature. Isolated nucleic acid molecules therefore are distinguished from the CHEPO-encoding nucleic acid molecule as it exists in natural cells. However, an isolated nucleic acid molecule encoding a CHEPO polypeptide includes CHEPO-encoding nucleic acid molecules contained in cells that ordinarily express CHEPO where, for example, the 3 5 nucleic acid molecule is in a chromosomal location different from that of natural cells.

WO 00/68376 PCTIUSOO/12370 The term "control sequences" refers to DNA sequences necessary for the expression of an operably linked coding sequence in a particular host organism. The control sequences that are suitable for prokaryotes, for example, include a promoter, optionally an operator sequence, and a ribosome binding site. Eukaryotic cells are known to utilize promoters, polyadenylation signals, and enhancers.

Nucleic acid is "operably linked" when it is placed into a functional relationship with another nucleic acid sequence. For example, DNA for a presequence or secretory leader is operably linked to DNA for a polypeptide if it is expressed as a preprotein that participates in the secretion of the polypeptide; a promoter or enhancer is operably linked to a coding sequence if it affects the transcription of the sequence; or a ribosome binding site is operably linked to a coding sequence if it is positioned so as to facilitate translation. Generally, "operably linked" means that the DNA sequences being linked are contiguous, and, in the case of a secretory leader, contiguous and in reading phase. However, enhancers do not have to be contiguous. Linking is accomplished by ligation at convenient restriction sites. If such sites do not exist, the synthetic oligonucleotide adaptors or linkers are used in accordance with conventional practice.

The term "antibody" is used in the broadest sense and specifically covers, for example, single anti-CHEPO monoclonal antibodies (including agonist, antagonist, and neutralizing antibodies), anti-CHEPO antibody compositions with polyepitopic specificity, single chain anti-CHEPO antibodies, and fragments of anti-CHEPO antibodies (see below). The term "monoclonal antibody" as used herein refers to an antibody obtained from a population of substantially homogeneous antibodies, ie., the individual antibodies comprising the population are identical except for possible naturally-occurring mutations that may be present in minor amounts.

"Stringency" of hybridization reactions is readily determinable by one of ordinary skill in the art, and generally is an empirical calculation dependent upon probe length, washing temperature, and salt concentration. In general, longer probes require higher temperatures for proper annealing, while shorter probes need lower temperatures. Hybridization generally depends on the ability of denatured DNA to reanneal when complementary strands are present in an environment below their melting temperature. The higher the degree of desired homology between the probe and hybridizable sequence, the higher the relative temperature which can be used. As a result, it follows that higher relative temperatures would tend to make the reaction conditions more stringent, while lower temperatures less so. For additional details and explanation of stringency of hybridization reactions, see Ausubel et al, Current Protocols in Molecular Biology, Wiley Interscience Publishers, (1995).

"Stringent conditions" or "high stringency conditions", as defined herein, may be identified by those that: (1) employ low ionic strength and high temperature for washing, for example 0.015 M sodium chloridel0.0015 M sodium citratel0.1 sodium dodecyl sulfate at 50 C; employ during hybridization a denaturing agent, such as formamide, for example, 50% (vlv) formamide with 0.1% bovine serum albuminl0.1% FicolllO.1% polyvinylpyrrolidone/50mM sodium phosphate buffer at pH 6.5 with 750 mM sodium chloride, 75 mM sodium citrate at 42 C; or employ 50% formamide, x SSC (0.75 M NaCI, 0.075 M sodium citrate), 50 mM sodium phosphate (pH 0.1% sodium pyrophosphate, 5 x Denhardt s solution, sonicated salmon sperm DNA (50 glml), 0.1% SDS, and 10% dextran sulfate at 42 C, with washes at 42 C in 0.2 x SSC (sodium chloridelsodium citrate) and 50% formamide at 55 C, followed by a high-stringency wash consisting of 0.1 x SSC containing EDTA at 55 C.

WO 00/68376 PCT/USOO/12370 "Moderately stringent conditions" may be identified as described by Sambrook et Molecular Cloning: A Laboratory Manual, New York: Cold Spring Harbor Press, 1989, and include the use of washing solution and hybridization conditions temperature, ionic strength and %SOS) less stringent that those described above. An example of moderately stringent conditions is overnight incubation at 37 C in a solution comprising: 20% formamide, 5 x SSC (150 mM NaCI, 15 mM trisodium citrate), 50 mM sodium phosphate (pH 5 x Denhardt s solution, 10% dextran sulfate, and mg/ml denatured sheared salmon sperm DNA, followed by washing the filters in 1 x SSC at about 37-50 C. The skilled artisan will recognize how to adjust the temperature, ionic strength, etc. as necessary to accommodate factors such as probe length and the like.

The term "epitope tagged" when used herein refers to a chimeric polypeptide comprising a CHEPO polypeptide fused to a "tag polypeptide". The tag polypeptide has enough residues to provide an epitope against which an antibody can be made, yet is short enough such that it does not interfere with activity of the polypeptide to which it is fused. The tag polypeptide preferably also is fairly unique so that the antibody does not substantially cross-react with other epitopes.

Suitable tag polypeptides generally have at least six amino acid residues and usually between about 8 and 50 amino acid residues (preferably, between about 10 and 20 amino acid residues).

As used herein, the term "immunoadhesin" designates antibody-like molecules which combine the binding specificity of a heterologous protein (an "adhesin") with the effector functions of immunoglobulin constant domains.

Structurally, the immunoadhesins comprise a fusion of an amino acid sequence with the desired binding specificity which is other than the antigen recognition and binding site of an antibody is "heterologous"), and an immunoglobulin constant domain sequence. The adhesin part of an immunoadhesin molecule typically is a contiguous amino acid sequence comprising at least the binding site of a receptor or a ligand. The immunoglobulin constant domain sequence in the immunoadhesin may be obtained from any immunoglobulin, such as lgG.1, lgG.2, IgG-3, or lgG-4 subtypes, IgA (including IgA-1 and IgA-2), IgE, IgD or IgM.

"Active" or "activity" for the purposes herein refers to form(s) of CHEPO which retain a biological andlor an immunological activity of native or naturally-occurring CHEPO, wherein biological activity refers to a biological function (either inhibitory or stimulatory) caused by a native or naturally-occurring CHEPO other than the ability to induce the production of an antibody against an antigenic epitope possessed by a native or naturally-occurring CHEPO and an immunological activity refers to the ability to induce the production of an antibody against an antigenic epitope possessed by a native or naturally-occurring CHEPO. Preferred biological activities includes, for example, the ability to regulate red blood cell production, to bind to receptors on the surface of committed progenitor cells of the bone marrow andlor other 3 0 hematopoietic tissues andlor to induce proliferation andlor terminal maturation of erythroid cells.

The term "antagonist" is used in the broadest sense, and includes any molecule that partially or fully blocks, inhibits, or neutralizes a biological activity of a native CHEPO polypeptide disclosed herein. In a similar manner, the term "agonist" is used in the broadest sense and includes any molecule that mimics a biological activity of a native CHEPO polypeptide disclosed herein. Suitable agonist or antagonist molecules specifically include agonist or antagonist antibodies or antibody fragments, fragments or amino acid sequence variants of native CHEPO polypeptides, peptides, small organic molecules, etc. Methods for identifying agonists or antagonists of a CHEPO polypeptide may comprise contacting a WO 00/68376 PCTIUSOO/12370 CHEPO polypeptide with a candidate agonist or antagonist molecule and measuring a detectable change in one or more biological activities normally associated with the CHEPO polypeptide.

"Treatment" refers to both therapeutic treatment and prophylactic or preventative measures, wherein the object is to prevent or slow down (lessen) the targeted pathologic condition or disorder. Those in need of treatment include those already with the disorder as well as those prone to have the disorder or those in whom the disorder is to be prevented.

"Chronic" administration refers to administration of the agent(s) in a continuous mode as opposed to an acute mode, so as to maintain the initial therapeutic effect (activity) for an extended period of time. Intermittent administration is treatment that is not consecutively done without interruption, but rather is cyclic in nature.

"Mammal" for purposes of treatment refers to any animal classified as a mammal, including humans, domestic and farm animals, and zoo, sports, or pet animals, such as dogs, cats, cattle, horses, sheep, pigs, goats, rabbits, etc.

Preferably, the mammal is human.

Administration "in combination with" one or more further therapeutic agents includes simultaneous (concurrent) and consecutive administration in any order.

"Carriers" as used herein include pharmaceutically acceptable carriers, excipients, or stabilizers which are nontoxic to the cell or mammal being exposed thereto at the dosages and concentrations employed. Often the physiologically acceptable carrier is an aqueous pH buffered solution. Examples of physiologically acceptable carriers include buffers such as phosphate, citrate, and other organic acids; antioxidants including ascorbic acid; low molecular weight (less than about 10 residues) polypeptide; proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, arginine or lysine; monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugar alcohols such as mannitol or sorbitol; salt-forming counterions such as sodium; andlor nonionic surfactants such as TWEEN, polyethylene glycol (PEG), and PLURONICS.

"Antibody fragments" comprise a portion of an intact antibody, preferably the antigen binding or variable region of the intact antibody. Examples of antibody fragments include Fab, Fab', and Fv fragments; diabodies; linear antibodies (Zapata et al., Protein Eno. 8(10): 1057-1062 [1995]); single-chain antibody molecules; and multispecific antibodies formed from antibody fragments.

Papain digestion of antibodies produces two identical antigen-binding fragments, called "Fab" fragments, each with a single antigen-binding site, and a residual "Fc" fragment, a designation reflecting the ability to crystallize readily.

Pepsin treatment yields an fragment that has two antigen-combining sites and is still capable of cross-linking antigen.

"Fv" is the minimum antibody fragment which contains a complete antigen-recognition and -binding site. This region consists of a dimer of one heavy- and one light-chain variable domain in tight, non-covalent association. It is in this configuration that the three CORs of each variable domain interact to define an antigen-binding site on the surface of the VH-VL dimer. Collectively, the six CDRs confer antigen-binding specificity to the antibody. However, even a single variable domain (or half of an Fv comprising only three CDRs specific for an antigen) has the ability to recognize and bind antigen, although at a lower affinity than the entire binding site.

WO 00/68376 PCTIUSOO/12370 The Fab fragment also contains the constant domain of the light chain and the first constant domain (CH1) of the heavy chain. Fab fragments differ from Fab fragments by the addition of a few residues at the carboxy terminus of the heavy chain CH1 domain including one or more cysteines from the antibody hinge region. Fab'-SH is the designation herein for Fab' in which the cysteine residue(s) of the constant domains bear a free thiol group. antibody fragments originally were produced as pairs of Fab' fragments which have hinge cysteines between them. Other chemical couplings of antibody fragments are also known.

The "light chains" of antibodies (immunoglobulins) from any vertebrate species can be assigned to one of two clearly distinct types, called kappa and lambda, based on the amino acid sequences of their constant domains.

Depending on the amino acid sequence of the constant domain of their heavy chains, immunoglobulins can be assigned to different classes. There are five major classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM, and several of these may be further divided into subclasses (isotypes), IgG1, IgG2, IgG3, IgG4, IgA, and lgA2.

"Single-chain Fv" or "sFv" antibody fragments comprise the VH and VL domains of antibody, wherein these domains are present in a single polypeptide chain. Preferably, the Fv polypeptide further comprises a polypeptide linker between the VH and VL domains which enables the sFv to form the desired structure for antigen binding. For a review of sFv, see Pluckthun in The Pharmacology of Monoclonal Antibodies, vol. 113, Rosenburg and Moore eds., Springer-Verlag, New York, pp. 269-315 (1994).

The term "diabodies" refers to small antibody fragments with two antigen-binding sites, which fragments comprise a heavy-chain variable domain (VH) connected to a light-chain variable domain (VL) in the same polypeptide chain (VH VL). By using a linker that is too short to allow pairing between the two domains on the same chain, the domains 2 0 are forced to pair with the complementary domains of another chain and create two antigen-binding sites. Diabodies are described more fully in, for example, EP 404,097; WO 93111161; and Hollinger et al., Proc. Natl. Acad. Sci. USA, 90:6444- 6448(1993).

An "isolated" antibody is one which has been identified and separated andlor recovered from a component of its natural environment. Contaminant components of its natural environment are materials which would interfere with diagnostic or therapeutic uses for the antibody, and may include enzymes, hormones, and other proteinaceous or nonproteinaceous solutes. In preferred embodiments, the antibody will be purified to greater than 95% by weight of antibody as determined by the Lowry method, and most preferably more than 99% by weight, to a degree sufficient to obtain at least 15 residues of N-terminal or internal amino acid sequence by use of a spinning cup sequenator, or to homogeneity by SOS-PAGE under reducing or nonreducing conditions using Coomassie blue or, preferably, silver stain.

Isolated antibody includes the antibody in situ within recombinant cells since at least one component of the antibody's natural environment will not be present. Ordinarily, however, isolated antibody will be prepared by at least one purification step.

The word "label" when used herein refers to a detectable compound or composition which is conjugated directly or indirectly to the antibody so as to generate a "labeled" antibody. The label may be detectable by itself radioisotope 3 5 labels or fluorescent labels) or, in the case of an enzymatic label, may catalyze chemical alteration of a substrate compound or composition which is detectable.

WO 00/68376 PCTIUSOO/12370 By "solid phase" is meant a non-aqueous matrix to which the antibody of the present invention can adhere.

Examples of solid phases encompassed herein include those formed partially or entirely of glass controlled pore glass), polysaccharides agarose), polyacrylamides, polystyrene, polyvinyl alcohol and silicones. In certain embodiments, depending on the context, the solid phase can comprise the well of an assay plate; in others it is a purification column an affinity chromatography column). This term also includes a discontinuous solid phase of discrete particles, such as those described in U.S. Patent No. 4,275,149.

A "liposome" is a small vesicle composed of various types of lipids, phospholipids and/or surfactant which is useful for delivery of a drug (such as a CHEPO polypeptide or antibody thereto) to a mammal. The components of the liposome are commonly arranged in a bilayer formation, similar to the lipid arrangement of biological membranes.

A small molecule is defined herein to have a molecular weight below about 500 Daltons.

WO 00/68376 PTUO/27 PCT[USOO/12370 Table 1 "C-C increased from 12 to Zis average of EB.

"B is average of ND match with stop is stop-stop 0; J (joker) match 0 #define -M -8 1* value of a match with a stop *1 int -day12611261 PABCBE FG HIJKLM NOPBRSTUVWXYZ/J I* A 2, 0, 0,4, 1, 1, 1, 0, 0}, I* B 0, 3, 0, 1, 0, 0, 0, 1), 1* C *1 I* D 0, 4, 1, 0, 0,0, 2), E 0, 0, 0,0, 3).

I* F *1 1, 2, 0, 0, I* G *1 1, 1, 1, 0, 01, 1- H *1 1, 0, 0, 3, 0, 0, 2), I* I 4/ 5, 2, 0, 0 ,4,S 0,0, 0, 0, 00,0, 0,0, 0,0, 0,0,M, 0,0, 0, 0,0,0, 0,0, 0,0, 0}, K *1 0, 0,-2t 0, 0, 1, 3, 0, 0, 0,-2Z-3, 0), 1 'I 2, 6, 0, /4 M *1 2, 0,0, 4, 0, 2,4, 1} I* N 0, 2Z-4, 2, 1,4, 0, 2Z-2, 0, 2,_Me-1, 1, 0, 1, 0, 1 I*P *1 6, 0, 0, 1, 0, 0), I- a1 0, 2, 0, 4, 0,4, 3), /4 R I 0, 0, 1, 6, 2,0,4,0), I* S *1 1, 0, L1, 0, 2, 1, 0), I-T 1, 0, 0, 0, 1, 1, 3, 0, 0).

r U/ 0, 0,0, 0,0, 0,0, 0, 0,0,0, 0, 0,0, 0,0, 0, 0,0, 0,0), /4 V 4, 2, 0, 0, 0,-2,-21, /4 W *1 0,-6,17, 0, X 0, 0,0, 0, 0,0, 0 0, 0,f0 0 0,0, 0,0, 0,0, 0,0, 0,0, 0, WO 00/68376 PCT/USOO/12370 1* Y *1 0, 0,10,41, I' Z -1 2, 0, 0, 0, 3, 0, 0, a, OA-, 41 WO 00/68376 WO 0068376PCT/USOO/12370 Table 1 (cant) #include stdio.h #finclude ctype.h #define MAXJMP #def ine MAXGAP24 #define JMPS #define MX #define OMAT #define DM15 #define DINSO #define IJINS1 #define PINSO #define PINS 1 struct imp short unsigned short 16 1* max jumps in a diag 1/ I* don't continue to penalize gaps larger than this1 1024 1* max imps in an path *1 4 I' save if theres at least MM- bases since last imp *1 I* value of matching bases *1 I* penalty for mismatched bases *1 I* penalty for a gap *1 I* penalty per base I* penalty for a gap *1 I* penalty per residue nIMAXJMPJ; I* size of imp (neg for dely) *1 x[MAXJMPJ; I* base no. of imp in seq x *1 I* limits seq to 2'16-1 *1 struct diag int long short struct imp struct path{ mnt si short n mnt x~ score; offset: ijmp: ip; P* score at last jmp *1 I* offset of prey block *1 I* current imp index I* list of imps *1 PC; I* number of leading spaces IJMPSJ; P* size of jmp (gap) *1 [JMPSI; 1* lc of imp (last elem before gap) WO 00/68376 PTUO/27 PCT/USOO/12370 char char char char int int ilt int int ilt int int int long struct struct *ofile; namex[21; *prog; *seqxt2J; dmax; dmaxO; dna; endgaps; gapx, gapy; lenD, leni; ngapx, ngapy; smax; *xbm; offset; *dx; pp[21; I* output file name 'I I* seq names: getseqsO *1 I* prog name for err msgs I* seqs: getseqs) *1 1* best diag: nw() I* final diag *1 I* set if dna: main() .1 I* set if penalizing end gaps '1 I* total gaps in seqs1 I* seq lens I* total size of gaps I* max score: nwo .1 I* bitmap for matching1 1' current offset in imp file *1 I* holds diagonals *I 1* holds path for seqs *1 char char *callocO, *malloco, *indexO, *strcpyo; *getseqO. *g_calloco; WO 00/68376 PCTfUSOO/12370 Table 1 (cant) I* Needleman-Wunsch alignment program *usage: progs fulel file2 where fulel and fite2 are two dna ar two protein sequences.

The sequences can be in upper- or lower-case an may contain ambiguity Any lines beginning with are ignored Max file length is 65535 (limited by unsigned short x in the imp struct) *A sequence with 1/3 or more of its elements ACGTU is assumed to be DNA *Output is in the file "align.out" "The program may create a tmp file in Itmp to hold info about traceback.

Original version developed under BSD 4.3 on a vax 8650 *j #include "nwh" #include "day.h" static _dbval[261- 1,14,2,13,0,0,4,11,0,0,12,0,3,1 5,0,0,0,5,6,8,8,7,9,0,1,0 static _pbvalI26J 1, 2 1(1< 4, 8, 16, 32, 64, 128, 256, OxFFFFFFF, 1 10, 1 11, 1 12, 1 13, 1 14, 15,1 <16, 1 <<17,1 <18, 1< <19,1 <20, 1 <<21,1 <2Z, 1 23. 1 24, 1 25 1(1 I1(1 main(ac, av) main int ac; char *avfl; prog av[0l; if (ac fprintf(stderr,"usage: %s file 1 file2ln", prog); fprintf(stderr,"where file 1 and file2 are two dna or two protein sequences.1n"); WO 00/68376 PTUO/27 PCT[USOO/12370 f printf (stderr,"The sequences can be in upper- or Iawer-caseln"); f printf (stderr,'Any lines beginning with or 'are ig nored~n"); f printf(stderr,"Output is in the file I"align.outl"ini); exit(1): namexiOl av[ll; namexI ii avI2J; seqxlOl getseq(namex[0J, &lenO); seqx[1J getseq(namexl, &lenl); xbm (dna)? -dbval _pbval; endgaps 0; 1* 1 to penalize endgaps1 ofile "align.out"; 1* output file *1 nwo; 1* fill in the matrix, get the possible jmps readjmpso; I* get the actual imps printo; I* print stats, alignment cleanup(0); 1* unlink any tmp files *1 WO 00/68376 PTUO/27 PCT/USOO/12370 Table 1 (cant) I* do the alignment, return best score: mainO dna: values in Fitch and Smith, PNAS, 80, 1382-1386, 1983 "pro: PAM 250 values When scores are equal, we prefer mismatches to any gap, prefer "a new gap to extending an ongoing gap, and prefer a gap in seqx to a gap in seq y.

nwO char int int int int int register register register register *px, *py; *ndely, *dely; ndelx, delx; *tmp; mis; insO, insil; id; i; *Colo, *Coll; xx, yy; 1* seqs and ptrs *I I* keep track of dely I* keep track of delx *1 I* for swapping rowO, rowi I* score for each type I* insertion penalties *1 I* diagonal index 'I I* imp index '1 I* score for curr, last row I* index into seqs *1 dx (struct diag calloc("to get diags", lenO+lenl 1, sizeof(struct diag)); ndely (int I)g calloc("to get ndely", leni 1, sizeof (int)); dely (int calloc("*to get dely", leni 1, sizeaf(int)); Colo (mt calloc("to get Colo", leni 1, sizeof(int)); coil (int *)g_calloc("to get Coll", leni 1, sizeaf(int)); insO (dna)? DINSO PINSO; insi (dna)? IJINS1 PINS 1; smax -10000; if (endgaps) for (colOlOl delylOl ins0, yy 1; yy leni1; yy clO~yyJ dely[yy] colO[yy-1J insi; ndelylyyJ yy; WO 00/68376 WO 0068376PCTUSOO/12370 c0la[OJ 0; I' Waterman Bull Math Biol 84 *I for (yy 1; yy -len1; yy dely[yy] -insO; 1* fill in match matrix for (px seqx[0J, xx 1; xx lenO; px xx I* initialize first entry in cal *1 if (endgaps){ if (xx 1) coll[0] -delx (ins0+insl); else coll[0J deix colOjO] insi; ndelx xx; 'else{ call [01 0; deix ins0; ndelx 0; WO 00/68376 PTUO/27 PCT/USOO/12370 Table 1 (cant for (py -seqx[l],yy 1; yy -enl;py yy mis colO[YY.1J; if (dna) mis (xbml*px-'A'&xbmlpy'A')? DMAT: DMIS; else mis _day[* px-IAl][py'AJ; 1* update penalty for del in x seq; favor new del over ongong del ignore MAXGAP if weighting endgaps if (endgaps IIndelylyyl MAXGAP){ if (colIyyj insO dely[yyl){ delylvy] colO~yyJ (ins0 +ins 1); ndely[yyJ 1; }else dely[yyj insi; ndelylyy]+ }else{ if (colOjyyJ (insO +ins 1) delylyy])( dely[yyJ colO[yyJ (insO+insl); ndelyfyyj 1; }else ndely[yy] 3 0 1* update penalty for del in y seq; *favor new del over ongong del if (endgaps I ndelx MAXGAP){ if (calll[yy- 11 insO delx){ delx colllyy-11I (ins0+insl); ndelx 1; WO 00/68376 PTUOI27 PCTIUSOO/12370 I else I deix insi; ndelx }else I if (col yy- 1J (ins ins 1) deix){ deix col1[yy 1J (ins insl)1 ndelx 1; }else ndelx I* pick the maximum score; we're favoring mis over any del and deix aver dely WO 00/68376 PTUO/27 PCT/USOO/12370 Table 1 (cant) id xx -yy leni 1; if (mis deix mis delylyyJ) colllyyJ mis; else if (deix dely[yyl){ Coll yyl deix; ii dxlidlimp; if (dx[idJ.jp.n[0J U!na I I (ndelx MAXJMP xx dx[id].ip.xlij MX) IImis dxlidl.scare +JINSO)) dxlidl.iimp if +i MAXJMP){ writeimps(id); ii dxfidl.iimp 0; dxlidJ.affset offset; offset sizeof(struct imp) sizedf (offset); dxfidJ.ip.n[ijj ndelx; dx[idj.ip.xlijJ xx; dxlidJ.score deix; else{ if CdxidJ.jp.n[0J (!dna I collivy] delylyyj; ii dx[idl.ijmp; (ndely[yyl MAXJMP xx dxlidJ.ip.xfij MX) mis dx[idJ.score +DINSO)){ dx[idJ.ijmp if MAXJMP){ writejmps(id); ii dx[idJ.ijmp 0; dxlidl.offset offset; offset sizeaf(struct imp) sizeof (offset); dxtidl.Ip.nhijl *ndelylyyl; WO 00/68376PC'SO/20 PCTfUSOO/12370 dx[idl.jp.xlij xx; dxlidJ.score delylvyl; if (xx lenO yy leni){ 1* last col *1 if (endgaps) coil [yyl insO+insl (Ienl -yy); if (callivyl] smax){ smax collyyl; dmax id; if (endgaps xx lenO) col Iyy. 11 insO insi1 (IenO.xx); if (call[yy-l1I smax) smax coll[yy-lJ; dmax id; tmp Colo; Colo coil; coil tmp; e(chrIdl) (void) free((char Indely); (void) free((char *)Colo); (void) free((char )coil);} WO 00/68376 PTUO/27 PCT/USOO/12370 Table 1 (cont) *printO only routine visible outside this module static: *getmatO trace back best path, count matches: print() *pr aligno print alignment of described in array p1]: printo dumpblockO dump a block of lines with numbers, stars: pralign() numso put out a number line: dumpblocko *putlineo put out a line (name, [numi, seq. [numil: dumpblock() *starso- -put a line of stars: dumpblocko *stripnameo strip any path and prefix from a seq name #include "nw.h" #def ine SPC #define PLINE #define P SPC 1* maximum output line 1* space between name or num and seq *1 1* set output line length 1* output file *1 extern int

FILE

printo _dayf 2811261; olen; *fx; print int Ix, ly, firstgap. lastgap; 1* overlap *1 if ((fx fopen(ofile, 0) fprintf(stderr,"%s: can't write prog, ofile); cleanup( 1): fprintf(fx, first sequence: %s (length namex[0J, lenD); fprintf(fx, second sequence: %s (length namexil], leni); olen WO 00/68376 PTUO/27 PCTIUSOO/12370 lx lenO; ly leni; firstgap lastgap 0; if (dmax leni 1) 1* leading gap in x1 ppIOJ.spc firstgap lenil dmax 1; ly pp[0J.spc; else if (dmax leni 1) I* leading gap in y ppfll.spc firstgap dmax (leni 1); lx ppIlJ .spc; if (dmaxO lenO 1) 1*P trailing gap in x *1 lastgap lenO -dmax0 -1; Ix lastgap; else if (dmaxO lenO 1) 1*P trailing gap in y lastgap dmaxO (lenO 1); ly lastgap; getmat(Ix, ly, firstgap, lastgap); pralignfl; WO 00/68376PUISOI27 PCr/USOO/12370 Table 1 (cant) *trace back the best path, count matches static getmat(Ix, ly, firstgap, lastgap) int lx, ly; mnt firstgap, lastgap; getmat 1* "core" (minus endgaps) I* leading trailing overlap int char double register register char nm, A0 ii, sizo, sizi; outx[321; pct; n1N; p0 *p1; I* get total matches, score io il sizo SOz 0; p0 seqx[01 +i pp~lJ.spc; p1 seqx[l1J pp[0).spc; nO pp~lJ.spc 1; n1 pp[01.spc 1; nm 0: while p1 if (sizO) ni siz0**; else if (sizl){ p0+ n0+ siz 1else{ WO 00/68376 PCTIUSOOI1 2370 if (xbm[ pO-'A'1&xbm[*p1 -'A1I) nm+ if (nO ppIOI.x[iO]) sizO ppIOJ.n[iO if (ni pll.x~i1) sizi ppl I 1; I* pct homology: "if penalizing endgaps, base is the shorter seq "else, knock off overhangs and take shorter core if (endgaps) Ix (lenO leni)? lena: leni; else lx (Ix ly)? Ix: ly; pct 100.*double)nml(douhle)x; fprintf(fx, fprintf(fx, %d match%s in an overlap of %.2f percent similarityln", nm, (nm Ix, pct); WO 00/68376 WO 0068376PCTUSOO/12370 Table I (cant) fprintf(fx, gaps in first sequence: gapx); getmat if (gapx) (void) sprintf(outx, ngapx, (dna)? "base":" residue", (ngapx fprintf(fx,"%s", outx); fprintf(fx, gaps in second sequence: gapy); if (gapy) (void) sprintf(outx, ngapy, (dna)? "base":"residue", (ngapy fprintf(fx,'%s", outx); if (dna) fprintf(fx, "In score: %d (match mismatch gap penalty %d %d per base)~n, smax, IJMAT, OMIS, IJINSO, BINS 1); else 2 0 fprintf(fx, "In score: %d (Dayhoff PAM 250 matrix, gap penalty %d %d per residue)~n", sinax, PINSO. PINS 1); if (endgaps) fprintf(fx, 2 5 <endgaps penalized, left endgap: %d right endgap: %d firstgap, (dna)? "base" residue', (firstgap lastgap, (dna)? "base" :"residue", (Iastgap 1) else fprintf(fx, <endgaps not penalizedln"); static nm; I' matches in care for checking *1 static Imax; I" lengths of stripped file names static iijt21; I" imp index for a path *1 3 5 static nc[2J; 1* number at start of current line *1 static ni[21; current elem number for gapping WO 00/68376 static static char static char static char static char PCTIUSOO/12370 siz[2J; ps[2J; po[21; out[2][PLINEJ; stariPLINEJ; I* ptr to current element *1 I' ptr to next output char slat *1 output line *1 I* set by starsO *1 *print alignment of described in struct path pp[J static pr_aligno pr-align int int register nn; char count more; for (i 0, Imax i< 2; i+ rm stripname(namex[i); if (nn Imax) Imax nn; nclil 1; nifi] 1; sizli] ii a; psliJ seqxli]; Po~i] autfh]; WO 00/68376 PTUOI27 PCTIUSOO/12370 Table 1 (cant) far Inn nm 0, more 1; mare;) for(i mare 0;i *do we have mare of this sequence? if (!*ps[il) continue; p _align more+ if (pplil.spc) leading space1 *Pali]++ ppliJ.spc..; else if (sizl) I in a gap *po~iJ++ -Y siz[il.-; else{ 1* we're putting a seq element Pali] *psliJ; if (islower(*ps[i)) ps[iI toupper(*psi); poti] ps[ij+ are we at next gap for this seq? if (nifi] pp[iJ.x[ijDiJJ){ we need to merge all gaps *at this location WO 00/68376 WO 0068376PCT/USOO/12370 sizfi] pplil.n[ijtiJ 1; while (nihi] pp[iJ.x[ijiJ]) sizi pplij.nhijj+ 1; il+J4 if olen Ij I!more nn){ dumpblocko; for (i 0; i 2; pofl] out[i]; nn 0; dump a block of lines, including numbers, stars: pr_aligno static dumpblocko register i: dumpblock for (i 0; i 2; i+ *PONi- lo' WO 00/68376 WO 0068376PCIUSOOI12370 Table 1 (cant) dumpblock (void) putc('In', fx); for (i i< 2; if (*outil (oGuti oi) {i] if (i 0) nums(i); if 0 0 *out~l]1) starsO; putline(i); if 0i 0 oCut[lJ) fprintf(fx, star); if (i -1) nums(i); 1 *put out a number line: dumpblockO static nums(ix) nums mnt ix; I' index in outfi holding seq line *1 char nline[PLINE); register i, j; register char *pn, *px, *py; for (pn nMine, i 0; i lmax PSPC; i pn *pn for 0i nctix), py outlix]; *py; py pn if (py p p else WO 00/68376 PCTIUSOO/12370 if 10 -0 II(i 1 nclixj M-1) for (px pn; j; jI 10, px.-) *px i%10 if 0i <0) *px else

II

pn fo nclixl i for (pn nWine; pn; pn +4) (void) putc(*pn, fx); (void) putc(In', fx); 1 *put out a line (name, [num], seq. dumpblackO static putline(ix) putline int ix;{ WO 00/68376 PCT/USOO/12370 Table 1 (cant) putline int i; register char *px; for (px namexlixj, i 0; *px px (void) putc(*px, fx); for(; i lmax PSPC; i+ (void) putc(' fx); I* these count from 1: nil] is current element (from 1) nc[J is number at start of cuff ent line for (px outlix]; -px; px (void) putc(*px&Ox7F, fx); (void) putc('In', fx);

I*

*put a line of stars (seqs always in outlOl. outil dumpblocko static starsO stars int i; register char *PO, *P1. cx, *px; if ('out[01 I outO] POOi) ')I !*out~lJI (Guqll (po0l) return; px star; for (i lmax PSPC; i: i-) *px+ WO 00/68376 WO 0068376PCT/USOOI1237O for (pO -out[OJ, pl outtll; p0 pj; pl if (isafpha(*pO) isalpha(*p1)) if (xbm*pO.'A'J&xbmfpl.'A'J){ cx- 1*1 else if (!dna day[*pO.A'][*pl.A'J 0) CX else else cx-; cx; px px 1, WO 00/68376 WO 0068376PCT/USOO/12370 Table 1 (cont) *strip path or prefix from pn, return len: pralign() static stripname(pn) char *pn; 1* file name (may be path) *1 register char px. *py; 0 py 0; for (px pn; *px; px if (*px P py px 1; if (py) (void) strcpy(pn. py); return(stren(pn)); stripname WO 00/68376 WO 0068376PCT/USOO/12370 Table 1 (cant) cleanupO cleanup any tmp file getseq() read in seq, set dna, len, maxlen g calloco calloco with error checkin readimpso)- get the good jmps, from tmp file if necessary writejmpso write a filled array of imps to a tmp file: nw() #include "nw.h" #finclude <syslfile.h> *iname "Itmp/homgXXXXXX"; I* tmp file for jmps *1 mnt cleanupo; long IseekO; 1* cleanup tmp file *I remove any tmp file if we blow cleanup(i) int i; cleanup if (fj) (void) unlink(iname); exit(i); 3 0 *read, return ptr to seq, set dna, len, maxlen skip lines starting with', 7' or *seq in upper or lower case

*I

char 3 5 getseq(file. len) char *file; I* file name *1 getseq WO 00/68376 WO 0068376PCT/USOO/12370 iot lIen; 1* seq len *1 char Iine[1O24I, *pseq; register char *px, *py; iot natgc, tien; FILE *fp; if ((fp f open(f ile,"rl) 0){ fprintf(stderr,"%s: can't read prog, file); exit(l); tlen natgc 0; while (fgets(line, 1024, fp)){ if (lfine I line line continue; for (px line; *px px if (isupper(*px) I I islower(ipx)) tlen if ((pseq malloc((unsigned)(tlen+6))) 0){ fprintf(stderr,"%s: mallocO failed to get %d bytes for prog, tlen+6, file); exit(l): pseq~j0 pseq[ll pseq[2] pseql31 WO 00/68376 PTUOI27 PCTIUSOO/12370 Table I (cant) getseq py pseq 4; l1en dlen; rewind(fp); while (f gets(Iine, 1024, f if (*line line ine continue; for (px line; *px I In'; px+ if (isupper(*px)) *px; else if (islower('px)) *py toupper(*px); if (index("ATGCU",-(py1))) natgc+ py+ -1, py 1, (void) fclose(fp); dna natgc (tlenI3); return(pseq char gcalloc(msg, nx, sz) gcalloc char *Msg; 1P program, calling routine *1 int nx, sz; 1* number and size of elements char *px, *callocO; if ((px callo c((u ns igned)nx, (unsigned)sz)) 0){ if (*msg) fprintf(stderr, g-callocO failed %s sz-%dfn", prog, msg, nx, sz); exit(l); WO 00/68376 WO 0068376PCT/USOO/12370 return(px); get final jmps from dxlI or tmp file, set pp[J, reset dmax: maino *1 readimps() read imps int fd 1; int siz, AO il; register i, j, xx; if (fj) (void) fclose(fj); if ((fd openfjname, 0_RDONLY, 0){ fprintf(stderr, %Ns: can't openo %sin", prog, jname); cleanup(1); for 0 iO i 1 0, dmax0 dmax, xx IenO; while for (j dx[dmaxi.ijmp; i> 0 dxldmaxl.ip.xl xx; WO 00/68376 WO 0068376PCTIUSOO/12370 Table 1 (cant) readimps if (j 0 dxldmax].offset fj) (void) Iseek(fd, dx[dmaxl.offset, 0); (void) read(f d, (char *)&dxldmax].jp, sizeof(struct imp)); (void) read(fd, (char *)&dx~dmax].offset, sizeof(dx[dmax].off set)), dxldmaxl.ijmp MAXJMP-1; else break; if (i -JMPS){ fprintf(stderr, too many gaps in alignmentln", prog); clean up( 1); if (j 0) siz dxldmaxJ.jp.nfjl; xx dx[dmaxJ.jp.x[jJ; dmax siz; if (siz 0) I* gap in second seq pp[1l.n[ilJ *siz; xx siz; I* id xx -yy leni 1 PP11I1x4il xx dmax leni 1; gapy ngapy siz; I* ignore MAXGAP when doing endgaps siz (-siz MAXGAP jjendgaps)? -siz :MAXGAP; else if (siz 0) I* gap in first seq1 pp[01.n[i0J siz; ppIOJ.x[i0J xx; gapx+ ngapx siz; WO 00/68376 PTUO/27 PCT/USOO/12370 P* ignore MAXGAP when doing endgaps *1 siz (siz MAXGAP jIendgaps)? siz: MAXGAP; break; I* reverse the order of imps for (j 0, i iO; j+ i- PP[0J.nljJ; PP[O].niJ] ppIOJ.niO]; pp[OJ.niiO] i i- ppIOJ.Xlj]; PPIOJ.XtjJ pp[OJbxioI; pp[OJ.x[iOJ i for (j 0, il--;ji il; j+ il.-) i- pp~l pp~l J.n~jJ ppllJ.n~il I; pp~l J.n[ill i- pp[1J.Xulj; pp~lJ.x[] pp[1J.x~ilJ; pp~lJ.x~ilI i if (fd >-O0) (void) close(fd); if (fj) (void) unlink(jname); fj 0; offset 0; WO 00/68376 PTUO/27 PCTfUSOO/12370 Table 1 (cant) write a filled imp struct offset of the prey one (if any): nwo *1 writeimps(ix) int writejmps char *mktempo; if (upfj{ if (mktemp(jname) 0){ fprintf(stderr, can't mktempO prog, iname); cleanup(1); if ((fj f op en~iname, 0){ fprintf(stderr, can't write Usrn', prog, iname); exit( 1); (void) f write((char *)&dx[ixJ.ip, sizeof(struct imp), 1, fj); (void) fwrite((char *)&dxlixl.offset, sizeof(dxf ixj.off set), 1, fj); WO 00/68376 PCT/US00/12370 Table 2

PRO

Comparison Protein

XXXXXXXXXXXXXXX

XXXXXYYYYYYY

(Length 15 amino acids) (Length 12 amino acids) amino acid sequence identity (the number of identically matching amino acid residues between the two polypeptide sequences as determined by ALIGN-2) divided by (the total number of amino acid residues of the PRO polypeptide) divided by 15 33.3% WO 00/68376 PCT/USOOI12370 Table 3

PRO

Comparison Protein

XXXXXXXXXX

XXXXXYYYYYYZZYZ

(Length 10 amino acids) (Length 15 amino acids) amino acid sequence identity (the number of identically matching amino acid residues between the two polypeptide sequences as determined by ALIGN-2) divided by (the total number of amino acid residues of the PRO polypeptide) divided by 10 WO 00/68376 PCT/USOO/12370 Table 4

PRO-DNA

Comparison DNA

NNNNNNNNNNNNNN

NNNNNNLLLLLLLLLL

(Length 14 nucleotides) (Length 16 nucleotides) nucleic acid sequence identity (the number of identically matching nucleotides between the two nucleic acid sequences as determined by ALIGN-2) divided by (the total number of nucleotides of the PRO-DNA nucleic acid sequence) 6 divided by 14 42.9% WO 00/68376 PCT/USOO/12370 Table

PRO-DNA

Comparison DNA

NNNNNNNNNNNN

NNNNLLLVV

(Length 12 nucleotides) (Length 9 nucleotides) nucleic acid sequence identity (the number of identically matching nucleotides between the two nucleic acid sequences as determined by ALIGN-2) divided by (the total number of nucleotides of the PRO-DNA nucleic acid sequence) 4 divided by 12 33.3% WO 00/68376 PCTIUSOO/12370 II. Compositions and Methods of the Invention A. Full-length CHEPO Polypeptide The present invention provides newly identified and isolated nucleotide sequences encoding polypeptides referred to in the present application as CHEPO. In particular, DNA encoding a CHEPO polypeptide has been identified and isolated, as disclosed in further detail in the Examples below.

B. CHEPO Variants In addition to the full-length native sequence CHEPO polypeptides described herein, it is contemplated that CHEPO variants can be prepared. CHEPO variants can be prepared by introducing appropriate nucleotide changes into the CHEPO DNA, andlor by synthesis of the desired CHEPO polypeptide. Those skilled in the art will appreciate that amino acid changes may alter post-translational processes of the CHEPO, such as changing the number or position of glycosylation sites or altering the membrane anchoring characteristics.

Variations in the native full-length sequence CHEPO or in various domains of the CHEPO described herein, can be made, for example, using any of the techniques and guidelines for conservative and non-conservative mutations set forth, for instance, in U.S. Patent No. 5,364,934. Variations may be a substitution, deletion or insertion of one or more codons encoding the CHEPO that results in a change in the amino acid sequence of the CHEPO as compared with the native sequence CHEPO. Optionally the variation is by substitution of at least one amino acid with any other amino acid in one or more of the domains of the CHEPO. Guidance in determining which amino acid residue may be inserted, substituted or deleted without adversely affecting the desired activity may be found by comparing the sequence of the CHEPO with that of homologous known protein molecules and minimizing the number of amino acid sequence changes made in regions of high homology. Amino acid substitutions can be the result of replacing one amino acid with another amino acid having similar structural andlor chemical properties, such as the replacement of a leucine with a serine, conservative amino acid replacements. Insertions or deletions may optionally be in the range of about 1 to 5 amino acids. The variation allowed may be determined by systematically making insertions, deletions or substitutions of amino acids in the sequence and testing the resulting variants for activity exhibited by the full-length or mature native sequence.

CHEPO polypeptide fragments are provided herein. Such fragments may be truncated at the N-terminus or Cterminus, or may lack internal residues, for example, when compared with a full length native protein. Certain fragments lack amino acid residues that are not essential for a desired biological activity of the CHEPO polypeptide.

CHEPO fragments may be prepared by any of a number of conventional techniques. Desired peptide fragments may be chemically synthesized. An alternative approach involves generating CHEPO fragments by enzymatic digestion, by treating the protein with an enzyme known to cleave proteins at sites defined by particular amino acid residues, or by digesting the DNA with suitable restriction enzymes and isolating the desired fragment. Yet another suitable technique involves isolating and amplifying a DNA fragment encoding a desired polypeptide fragment, by polymerase chain reaction (PCR). Oligonucleotides that define the desired termini of the DNA fragment are employed at the 5' and 3' primers 3 5 in the PCR. Preferably, CHEPO polypeptide fragments share at least one biological andlor immunological activity with the native CHEPO polypeptides shown in Figure 3 (SEQ ID NOS:2 and WO 00/68376 PCT/US00/12370 In particular embodiments, conservative substitutions of interest are shown in Table 6 under the heading of preferred substitutions. If such substitutions result in a change in biological activity, then more substantial changes, denominated exemplary substitutions in Table 6, or as further described below in reference to amino acid classes, are introduced and the products screened.

Table 6 Original Residue Ala (A) Arg (R) Asn (N) Asp (D) Cys(C) Gin (Q) Glu (E) Gly (G) His (H) lie (I) Leu (L) Lys(K) Met (M) Phe (F) Pro (P) Ser(S) Thr(T) Trp (W) Tyr(Y) Val(V) Exemplary Substitutions val; leu; ile lys; gin; asn gin; his; lys; arg glu ser asn asp pro; ala asn; gin; lys; arg leu; val; met; ala; phe; norleucine norleucine; ile; val; met; ala; phe arg; gin; asn leu; phe; ile leu; val; ile; ala; tyr ala thr ser Preferred Substitutions val lys tyr; phe trp; phe; thr; ser ile; leu; met; phe; ala; norleucine Substantial modifications in function or immunological identity of the CHEPO polypeptide are accomplished by selecting substitutions that differ significantly in their effect on maintaining the structure of the polypeptide backbone in the area of the substitution, for example, as a sheet or helical conformation, the charge or hydrophobicity of the WO 00/68376 PCT/USO/12370 molecule at the target site, or the bulk of the side chain. Naturally occurring residues are divided into groups based on common side-chain properties: hydrophobic: norleucine, met, ala, val, leu, ile; neutral hydrophilic: cys, ser, thr; acidic: asp, glu; basic: asn, gin, his, lys, arg; residues that influence chain orientation: gly, pro; and aromatic: trp, tyr, phe.

Non-conservative substitutions will entail exchanging a member of one of these classes for another class. Such substituted residues also may be introduced into the conservative substitution sites or, more preferably, into the remaining (non-conserved) sites.

The variations can be made using methods known in the art such as oligonucleotide-mediated (site-directed) mutagenesis, alanine scanning, and PCR mutagenesis. Site-directed mutagenesis [Carter et al., Nucl. Acids Res. 13:4331 (1986); Zoller et al., Nucl. Acids Res., 10:6487 (1987)], cassette mutagenesis [Wells et al., Gene, 34:315 (1985)], restriction selection mutagenesis [Wells et al., Philos. Trans. R. Soc. London SerA, 317:415 (1986)] or other known techniques can be performed on the cloned DNA to produce the CHEPO variant DNA.

Scanning amino acid analysis can also be employed to identify one or more amino acids along a contiguous sequence. Among the preferred scanning amino acids are relatively small, neutral amino acids. Such amino acids include alanine, glycine, serine, and cysteine. Alanine is typically a preferred scanning amino acid among this group because it eliminates the side-chain beyond the beta-carbon and is less likely to alter the main-chain conformation of the variant [Cunningham and Wells, Science, 244: 1081-1085 (1989)]. Alanine is also typically preferred because it is the most common amino acid. Further, it is frequently found in both buried and exposed positions [Creighton, The Proteins, (W.H.

Freeman Co., Chothia, J. Mol. Biol., 150:1 (1976)]. If alanine substitution does not yield adequate amounts of variant, an isoteric amino acid can be used.

C. Modifications of CHEPO Covalent modifications of CHEPO are included within the scope of this invention. One type of covalent modification includes reacting targeted amino acid residues of a CHEPO polypeptide with an organic derivatizing agent that is capable of reacting with selected side chains or the N- or C- terminal residues of the CHEPO. Derivatization with bifunctional agents is useful, for instance, for crosslinking CHEPO to a water-insoluble support matrix or surface for use in the method for purifying anti-CHEPO antibodies, and vice-versa. Commonly used crosslinking agents include, 1,1bis(diazoacetyl)-2-phenylethane, glutaraldehyde, N-hydroxysuccinimide esters, for example, esters with 4-azidosalicylic acid, homobifunctional imidoesters, including disuccinimidyl esters such as 3,3'-dithiobis(succinimidylpropionate), bifunctional maleimides such as bis-N-maleimido-1,8-octane and agents such as methyl-3-[(p-azidophenyl)dithio]propioimidate.

WO 00/68376 PCT/USOO/12370 Other modifications include deamidation of glutaminyl and asparaginyl residues to the corresponding glutamyl and aspartyl residues, respectively, hydroxylation of proline and lysine, phosphorylation of hydroxyl groups of seryl or threonyl residues, methylation of the -amino groups of lysine, arginine, and histidine side chains Creighton, Proteins: Structure and Molecular Properties, W.H. Freeman Co., San Francisco, pp. 79-86 (1983)], acetylation of the N-terminal amine, and amidation of any C-terminal carboxyl group.

Another type of covalent modification of the CHEPO polypeptide included within the scope of this invention comprises altering the native glycosylation pattern of the polypeptide. "Altering the native glycosylation pattern" is intended for purposes herein to mean deleting one or more carbohydrate moieties found in native sequence CHEPO (either by removing the underlying glycosylation site or by deleting the glycosylation by chemical and/or enzymatic means), andlor adding one or more glycosylation sites that are not present in the native sequence CHEPO. In addition, the phrase includes qualitative changes in the glycosylation of the native proteins, involving a change in the nature and proportions of the various carbohydrate moieties present.

Addition of glycosylation sites to the CHEPO polypeptide may be accomplished by altering the amino acid sequence. The alteration may be made, for example, by the addition of, or substitution by, one or more serine or threonine residues to the native sequence CHEPO (for 0-linked glycosylation sites). The CHEPO amino acid sequence may optionally be altered through changes at the DNA level, particularly by mutating the DNA encoding the CHEPO polypeptide at preselected bases such that codons are generated that will translate into the desired amino acids.

Another means of increasing the number of carbohydrate moieties on the CHEPO polypeptide is by chemical or enzymatic coupling of glycosides to the polypeptide. Such methods are described in the art, in WO 87105330 published 11 September 1987, and in Aplin and Wriston, CRC Crit. Rev. Biochem., pp. 259-306 (1981).

Removal of carbohydrate moieties present on the CHEPO polypeptide may be accomplished chemically or enzymatically or by mutational substitution of codons encoding for amino acid residues that serve as targets for glycosylation. Chemical deglycosylation techniques are known in the art and described, for instance, by Hakimuddin, et al., Arch. Biochem. Biophys., 259:52 (1987) and by Edge et al., Anal. Biochem., 118:131 (1981). Enzymatic cleavage of carbohydrate moieties on polypeptides can be achieved by the use of a variety of endo- and exo-glycosidases as described by Thotakura et al., Meth. Enzymol., 138:350 (1987).

Another type of covalent modification of CHEPO comprises linking the CHEPO polypeptide to one of a variety of nonproteinaceous polymers, polyethylene glycol (PEG), polypropylene glycol, or polyoxyalkylenes, in the manner set forth in U.S. Patent Nos. 4,640,835; 4,496,689; 4,301,144; 4,670,417; 4,791,192 or 4,179,337.

The CHEPO of the present invention may also be modified in a way to form a chimeric molecule comprising CHEPO fused to another, heterologous polypeptide or amino acid sequence.

In one embodiment, such a chimeric molecule comprises a fusion of the CHEPO with a tag polypeptide which provides an epitope to which an anti-tag antibody can selectively bind. The epitope tag is generally placed at the aminoor carboxyl- terminus of the CHEPO. The presence of such epitope-tagged forms of the CHEPO can be detected using an antibody against the tag polypeptide. Also, provision of the epitope tag enables the CHEPO to be readily purified by affinity purification using an anti-tag antibody or another type of affinity matrix that binds to the epitope tag. Various tag WO 00/68376 PCT/USOO/12370 polypeptides and their respective antibodies are well known in the art. Examples include poly-histidine (poly-his) or polyhistidine-glycine (poly-his-gly) tags; the flu HA tag polypeptide and its antibody 12CA5 [Field et al., Mol. Cell. Biol., 8:2159- 2165 (1988)]; the c-myc tag and the 8F9, 3C7, 6E10, G4, B7 and 9E10 antibodies thereto [Evan et al., Molecular and Cellular Biology. 5:3610-3616 (1985)]; and the Herpes Simplex virus glycoprotein D (gD) tag and its antibody [Paborsky et al., Protein Engineering, 3(6):547-553 (1990)]. Other tag polypeptides include the Flag-peptide [Hopp et al., BioTechnology, 6:1204-1210 (1988)]; the KT3 epitope peptide [Martin et al., Science 255:192-194 (1992)]; an -tubulin epitope peptide [Skinner et al., J. Biol. Chem., 266:15163-15166 (1991)]; and the T7 gene 10 protein peptide tag [Lutz- Freyermuth et al., Proc. Natl. Acad. Sci. USA, 87:6393-6397 (1990)].

In an alternative embodiment, the chimeric molecule may comprise a fusion of the CHEPO with an immunoglobulin or a particular region of an immunoglobulin. For a bivalent form of the chimeric molecule (also referred to as an immunoadhesin), such a fusion could be to the Fc region of an IgG molecule. The Ig fusions preferably include the substitution of a soluble (transmembrane domain deleted or inactivated) form of a CHEPO polypeptide in place of at least one variable region within an Ig molecule. In a particularly preferred embodiment, the immunoglobulin fusion includes the hinge, CH2 and CH3, or the hinge, CH1, CH2 and CH3 regions of an IgG1 molecule. For the production of immunoglobulin fusions see also US Patent No. 5,428,130 issued June 27, 1995.

D. Preparation of CHEPO The description below relates primarily to production of CHEPO by culturing cells transformed or transfected with a vector containing CHEPO nucleic acid. It is, of course, contemplated that alternative methods, which are well known in the art, may be employed to prepare CHEPO. For instance, the CHEPO sequence, or portions thereof, may be produced by direct peptide synthesis using solid-phase techniques [see, Stewart et al., Solid-Phase Peptide Synthesis, W.H.

Freeman Co., San Francisco, CA (1969); Merrifield, J. Am. Chem. Soc., 85:2149-2154 (1963)]. In vitro protein synthesis may be performed using manual techniques or by automation. Automated synthesis may be accomplished, for instance, using an Applied Biosystems Peptide Synthesizer (Foster City, CA) using manufacturer's instructions. Various portions of the CHEPO may be chemically synthesized separately and combined using chemical or enzymatic methods to produce the full-length CHEPO.

1. Isolation of DNA Encoding CHEPO DNA encoding CHEPO may be obtained from a cDNA library prepared from tissue believed to possess the CHEPO mRNA and to express it at a detectable level. Accordingly, human CHEPO DNA can be conveniently obtained from a cDNA library prepared from human tissue, such as described in the Examples. The CHEPO-encoding gene may also be obtained from a genomic library or by known synthetic procedures automated nucleic acid synthesis).

Libraries can be screened with probes (such as antibodies to the CHEPO or oligonucleotides of at least about bases) designed to identify the gene of interest or the protein encoded by it. Screening the cDNA or genomic library with the selected probe may be conducted using standard procedures, such as described in Sambrook et al., Molecular Cloning: A Laboratory Manual (New York: Cold Spring Harbor Laboratory Press, 1989). An alternative means to isolate WO 00/68376 PCT/USOO/12370 the gene encoding CHEPO is to use PCR methodology [Sambrook et al., supra Dieffenbach et al., PCR Primer: A Laboratory Manual (Cold Spring Harbor Laboratory Press, 1995)].

The Examples below describe techniques for screening a cDNA library. The oligonucleotide sequences selected as probes should be of sufficient length and sufficiently unambiguous that false positives are minimized. The oligonucleotide is preferably labeled such that it can be detected upon hybridization to DNA in the library being screened.

Methods of labeling are well known in the art, and include the use of radiolabels like 32 P-labeled ATP, biotinylation or enzyme labeling. Hybridization conditions, including moderate stringency and high stringency, are provided in Sambrook et al., supra.

Sequences identified in such library screening methods can be compared and aligned to other known sequences deposited and available in public databases such as GenBank or other private sequence databases. Sequence identity (at either the amino acid or nucleotide level) within defined regions of the molecule or across the full-length sequence can be determined using methods known in the art and as described herein.

Nucleic acid having protein coding sequence may be obtained by screening selected cDNA or genomic libraries using the deduced amino acid sequence disclosed herein for the first time, and, if necessary, using conventional primer extension procedures as described in Sambrook et al., supra, to detect precursors and processing intermediates of mRNA that may not have been reverse-transcribed into cDNA.

2. Selection and Transformation of Host Cells Host cells are transfected or transformed with expression or cloning vectors described herein for CHEPO production and cultured in conventional nutrient media modified as appropriate for inducing promoters, selecting transformants, or amplifying the genes encoding the desired sequences. The culture conditions, such as media, temperature, pH and the like, can be selected by the skilled artisan without undue experimentation. In general, principles, protocols, and practical techniques for maximizing the productivity of cell cultures can be found in Mammalian Cell Biotechnology: a Practical Approach, M. Butler, ed. (IRL Press, 1991) and Sambrook et al., supra.

Methods of eukaryotic cell transfection and prokaryotic cell transformation are known to the ordinarily skilled artisan, for example, CaCI 2 CaP0 4 liposome-mediated and electroporation. Depending on the host cell used, transformation is performed using standard techniques appropriate to such cells. The calcium treatment employing calcium chloride, as described in Sambrook et al., supra, or electroporation is generally used for prokaryotes. Infection with Agrobacterium tumefaciens is used for transformation of certain plant cells, as described by Shaw et al., Gene, 23:315 (1983) and WO 89105859 published 29 June 1989. For mammalian cells without such cell walls, the calcium phosphate precipitation method of Graham and van der Eb, Virology 52:456-457 (1978) can be employed. General aspects of mammalian cell host system transfections have been described in U.S. Patent No. 4,399,216. Transformations into yeast are typically carried out according to the method of Van Solingen et al., J. Bact. 130:946 (1977) and Hsiao et al., Proc.

Natl. Acad. Sci. (USA) 76:3829 (1979). However, other methods for introducing DNA into cells, such as by nuclear 3 5 microinjection, electroporation, bacterial protoplast fusion with intact cells, or polycations, polybrene, polyornithine, WO 00/68376 PCT/US00/12370 may also be used. For various techniques for transforming mammalian cells, see Keown et al., Methods in Enzymology, 185:527.537 (1990) and Mansour et al., Nature, 336:348-352 (1988).

Suitable host cells for cloning or expressing the DNA in the vectors herein include prokaryote, yeast, or higher eukaryote cells. Suitable prokaryotes include but are not limited to eubacteria, such as Gram-negative or Gram-positive organisms, for example, Enterobacteriaceae such as E. coli. Various E coli strains are publicly available, such as E. coli K12 strain MM294(ATCC 31,446); E. coliX1776 (ATCC 31,537);E. co'strain W3110 (ATCC 27,325) and K5 772 (ATCC 53,635). Other suitable prokaryotic host cells include Enterobacteriaceae such as Escherichia, E. coli, Enterobacter, Erwinia, Klebsiella, Proteus, Salmonella, Salmonella typhimurium, Serratia, Serratia marcescans, and Shigella, as well as Bacilli such as B. subtilis and B. licheniformis B. licheniformis 41P disclosed in 00 266,710 published 12 April 1989), Pseudomonas such as P. aeruginosa, and Streptomyces. These examples are illustrative rather than limiting.

Strain W3110 is one particularly preferred host or parent host because it is a common host strain for recombinant DNA product fermentations. Preferably, the host cell secretes minimal amounts of proteolytic enzymes. For example, strain W3110 may be modified to effect a genetic mutation in the genes encoding proteins endogenous to the host, with examples of such hosts including E. coliW3110 strain 1A2, which has the complete genotype tonA E. col W3110 strain 9E4, which has the complete genotype tonA ptr3; E. coliW3110 strain 27C7 (ATCC 55,244), which has the complete genotype tonA ptr3phoA E15 (argF.lac/169 degP ompTkar; E. coliW3110 strain 3706, which has the complete genotype tonA ptr3 phoA E15 (argF.lac)169 degP ompT rbs7 ilvG kal; E. coli W3110 strain 40B4, which is strain 3706 with a nonkanamycin resistant degP deletion mutation; and an E. coli strain having mutant periplasmic protease disclosed in U.S.

Patent No. 4,946,783 issued 7 August 1990. Alternatively, in vitro methods of cloning, PCR or other nucleic acid polymerase reactions, are suitable.

In addition to prokaryotes, eukaryotic microbes such as filamentous fungi or yeast are suitable cloning or expression hosts for CHEP0-encoding vectors. Saccharomyces cerevisiae is a commonly used lower eukaryotic host microorganism. Others include Schizosaccharomycespombe (Beach and Nurse, Nature. 290:140 [1981]; EP 139,383 published 2 May 1985); Kluyveromyces hosts Patent No. 4,943,529; Fleer et al., Bio/Technology. 9:968-975 (1991)) such as, K. lactis (MW98-8C, CBS683, CBS4574; Louvencourt et J. Bacteriol., 737 [1983]), K. fragilis (ATCC 12,4241 K. bulgaicus (ATCC 16,045), K. wickeramii(ATCC 24,178), K. waltii(ATCC 56,500), K. drosophilarum (ATCC 36,906; Van den Berg etal., Bio/Technology, 8:135 (1990)), K. thermotolerans, and K. marxianus;yarrowia (EP 402,226); Pichia pastoris (EP 183,070; Sreekrishna etal., J. Basic Microbiol. 28: 265-278 [1988]); Candida; Tichoderma reesia (EP 244,234); Neurospora crassa (Case etal., Proc. Natl. Acad. Sci. USA, 76: 5259-5263 [19791); Schwanniomyces such as 3 0 Schwanniomyces occidentalis (EP 394,538 published 31 October 1990); and filamentous fungi such as, Neurospora, Penicillium, Tolypocladium (WO 91100357 published 10 January 1991), and Aspergillus hosts such as A. nidulans (Ballance etal., Biochem. Biophys. Res. Commun., 112: 284-289 11983]; Tilburn etal., Gene 26: 205-221 [1983]; Yelton et al, Proc. Natl. Acad. Sci. USA 81: 1470-1474 [1984]) and A. niger (Kelly and Hynes, EMBO J.4: 475-479 [1985]).

Methylotropic yeasts are suitable herein and include, but are not limited to, yeast capable of growth on methanol selected from the genera consisting of Hansenula, Candida, Kloeckera, Pichia, Sacchammyces, Torulopsis, and Rhodotorula. A list WO 00/68376 PCT/USOO/12370 of specific species that are exemplary of this class of yeasts may be found in C. Anthony, The Biochemistry of Methylotrophs, 269 (1982).

Suitable host cells for the expression of glycosylated CHEPO are derived from multicellular organisms. Examples of invertebrate cells include insect cells such as Drosophila S2 and Spodoptera Sf9, as well as plant cells. Examples of useful mammalian host cell lines include Chinese hamster ovary (CHO) and COS cells. More specific examples include monkey kidney CV1 line transformed by SV40 (COS-7, ATCC CRL 1651); human embryonic kidney line (293 or 293 cells subcloned for growth in suspension culture, Graham et al., J. Gen Virol. 36:59 (1977)); Chinese hamster ovary cellsl-DHFR (CHO, Urlaub and Chasin, Proc. Natl. Acad. Sci. USA, 77:4216 (1980)); mouse sertoli cells (TM4, Mather, Biol. Reprod.

23:243-251 (1980)); human lung cells (W138, ATCC CCL 75); human liver cells (Hep G2, HB 8065); and mouse mammary tumor (MMT 060562, ATCC CCL51). The selection of the appropriate host cell is deemed to be within the skill in the art.

3. Selection and Use of a Replicable Vector The nucleic acid cDNA or genomic DNA) encoding CHEPO may be inserted into a replicable vector for cloning (amplification of the DNA) or for expression. Various vectors are publicly available. The vector may, for example, be in the form of a plasmid, cosmid, viral particle, or phage. The appropriate nucleic acid sequence may be inserted into the vector by a variety of procedures. In general, DNA is inserted into an appropriate restriction endonuclease site(s) using techniques known in the art. Vector components generally include, but are not limited to, one or more of a signal sequence, an origin of replication, one or more marker genes, an enhancer element, a promoter, and a transcription termination sequence. Construction of suitable vectors containing one or more of these components employs standard ligation techniques which are known to the skilled artisan.

The CHEPO may be produced recombinantly not only directly, but also as a fusion polypeptide with a heterologous polypeptide, which may be a signal sequence or other polypeptide having a specific cleavage site at the N.

terminus of the mature protein or polypeptide. In general, the signal sequence may be a component of the vector, or it may be a part of the CHEPO-encoding DNA that is inserted into the vector. The signal sequence may be a prokaryotic signal sequence selected, for example, from the group of the alkaline phosphatase, penicillinase, Ipp, or heat-stable enterotoxin II leaders. For yeast secretion the signal sequence may be, the yeast invertase leader, alpha factor leader (including Saccharomyces and Kluyveromyces -factor leaders, the latter described in U.S. Patent No. 5,010,182), or acid phosphatase leader, the C. albicans glucoamylase leader (EP 362,179 published 4 April 1990), or the signal described in WO 90/13646 published 15 November 1990. In mammalian cell expression, mammalian signal sequences may be used to direct secretion of the protein, such as signal sequences from secreted polypeptides of the same or related species, as well as viral secretory leaders.

Both expression and cloning vectors contain a nucleic acid sequence that enables the vector to replicate in one or more selected host cells. Such sequences are well known for a variety of bacteria, yeast, and viruses. The origin of replication from the plasmid pBR322 is suitable for most Gram-negative bacteria, the 2 plasmid origin is suitable for yeast, and various viral origins (SV40, polyoma, adenovirus, VSV or BPV) are useful for cloning vectors in mammalian cells.

WO 00/68376 PCT/US00/12370 Expression and cloning vectors will typically contain a selection gene, also termed a selectable marker. Typical selection genes encode proteins that confer resistance to antibiotics or other toxins, ampicillin, neomycin, methotrexate, or tetracycline, complement auxotrophic deficiencies, or supply critical nutrients not available from complex media, the gene encoding D-alanine racemase for Bacilli.

An example of suitable selectable markers for mammalian cells are those that enable the identification of cells competent to take up the CHEPO-encoding nucleic acid, such as DHFR or thymidine kinase. An appropriate host cell when wild-type DHFR is employed is the CHO cell line deficient in DHFR activity, prepared and propagated as described by Urlaub et al., Proc. Natl. Acad. Sci. USA, 77:4216 (1980). A suitable selection gene for use in yeast is the trpl gene present in the yeast plasmid YRp7 [Stinchcomb et al., Nature 282:39 (1979); Kingsman et al., Gene, 7:141 (1979); Tschemper et al., Gene, 10:157 (1980). The trpl gene provides a selection marker for a mutant strain of yeast lacking the ability to grow in tryptophan, for example, ATCC No. 44076 or PEP4-1 [Jones, Genetics 85:12(1977)].

Expression and cloning vectors usually contain a promoter operably linked to the CHEPO-encoding nucleic acid sequence to direct mRNA synthesis. Promoters recognized by a variety of potential host cells are well known. Promoters suitable for use with prokaryotic hosts include the -lactamase and lactose promoter systems [Chang et al., Nature 275:615 (1978); Goeddel et al., Nature, 281:544 (1979)1, alkaline phosphatase, a tryptophan (trp) promoter system [Goeddel, Nucleic Acids Res., 8:4057 (1980); EP 36,776], and hybrid promoters such as the tac promoter [deBoer et al., Proc. Natl. Acad. Sci. USA, 80:21-25 (1983)]. Promoters for use in bacterial systems also will contain a Shine-Dalgarno sequence operably linked to the DNA encoding CHEPO.

Examples of suitable promoting sequences for use with yeast hosts include the promoters for 3-phosphoglycerate kinase [Hitzeman et al., J. Biol. Chem., 255:2073 (1980)] or other glycolytic enzymes [Hess et al., J. Adv. Enzyme Ren., 7:149 (1968); Holland, Biochemistry, 17:4900 (1978)], such as enolase, glyceraldehyde-3-phosphate dehydrogenase, hexokinase, pyruvate decarboxylase, phosphofructokinase, glucose-6-phosphate isomerase, 3-phosphoglycerate mutase, pyruvate kinase, triosephosphate isomerase, phosphoglucose isomerase, and glucokinase.

Other yeast promoters, which are inducible promoters having the additional advantage of transcription controlled by growth conditions, are the promoter regions for alcohol dehydrogenase 2, isocytochrome C, acid phosphatase, degradative enzymes associated with nitrogen metabolism, metallothionein, glyceraldehyde-3-phosphate dehydrogenase, and enzymes responsible for maltose and galactose utilization. Suitable vectors and promoters for use in yeast expression are further described in EP 73,657.

CHEPO transcription from vectors in mammalian host cells is controlled, for example, by promoters obtained from 3 0 the genomes of viruses such as polyoma virus, fowlpox virus (UK 2,211,504 published 5 July 1989), adenovirus (such as Adenovirus bovine papilloma virus, avian sarcoma virus, cytomegalovirus, a retrovirus, hepatitis-B virus and Simian Virus (SV40), from heterologous mammalian promoters, the actin promoter or an immunoglobulin promoter, and from heat-shock promoters, provided such promoters are compatible with the host cell systems.

Transcription of a DNA encoding the CHEPO by higher eukaryotes may be increased by inserting an enhancer sequence into the vector. Enhancers are cis-acting elements of DNA, usually about from 10 to 300 bp, that act on a promoter to increase its transcription. Many enhancer sequences are now known from mammalian genes (globin, elastase, WO 00/68376 PCTIUSOO/12370 albumin, -fetoprotein, and insulin). Typically, however, one will use an enhancer from a eukaryotic cell virus. Examples include the SV40 enhancer on the late side of the replication origin (bp 100-270), the cytomegalovirus early promoter enhancer, the polyoma enhancer on the late side of the replication origin, and adenovirus enhancers. The enhancer may be spliced into the vector at a position 5' or 3' to the CHEPO coding sequence, but is preferably located at a site 5' from the promoter.

Expression vectors used in eukaryotic host cells (yeast, fungi, insect, plant, animal, human, or nucleated cells from other multicellular organisms) will also contain sequences necessary for the termination of transcription and for stabilizing the mRNA. Such sequences are commonly available from the 5' and, occasionally untranslated regions of eukaryotic or viral DNAs or cDNAs. These regions contain nucleotide segments transcribed as polyadenylated fragments in the untranslated portion of the mRNA encoding CHEPO.

Still other methods, vectors, and host cells suitable for adaptation to the synthesis of CHEPO in recombinant vertebrate cell culture are described in Gething et al., Nature, 293:620-625 (1981); Mantei et al., Nature, 281:40-46 (1979); EP 117,060; and EP 117,058.

4. Detecting Gene AmplificationlExpression Gene amplification andlor expression may be measured in a sample directly, for example, by conventional Southern blotting, Northern blotting to quantitate the transcription of mRNA [Thomas, Proc. Natl. Acad. Sci. USA, 77:5201-5205 (1980)], dot blotting (DNA analysis), or in situ hybridization, using an appropriately labeled probe, based on the sequences provided herein. Alternatively, antibodies may be employed that can recognize specific duplexes, including DNA duplexes, RNA duplexes, and DNA-RNA hybrid duplexes or DNA-protein duplexes. The antibodies in turn may be labeled and the assay may be carried out where the duplex is bound to a surface, so that upon the formation of duplex on the surface, the presence of antibody bound to the duplex can be detected.

Gene expression, alternatively, may be measured by immunological methods, such as immunohistochemical staining of cells or tissue sections and assay of cell culture or body fluids, to quantitate directly the expression of gene product. Antibodies useful for immunohistochemical staining andlor assay of sample fluids may be either monoclonal or polyclonal, and may be prepared in any mammal. Conveniently, the antibodies may be prepared against a native sequence CHEPO polypeptide or against a synthetic peptide based on the DNA sequences provided herein or against exogenous sequence fused to CHEPO DNA and encoding a specific antibody epitope.

5. Purification of Polyoeotide Forms of CHEPO may be recovered from culture medium or from host cell lysates. If membrane-bound, it can be released from the membrane using a suitable detergent solution Triton-X 100) or by enzymatic cleavage. Cells employed in expression of CHEPO can be disrupted by various physical or chemical means, such as freeze-thaw cycling, sonication, mechanical disruption, or cell lysing agents.

It may be desired to purify CHEPO from recombinant cell proteins or polypeptides. The following procedures are exemplary of suitable purification procedures: by fractionation on an ion-exchange column; ethanol precipitation; reverse WO 00/68376 PCT/USOO/12370 phase HPLC; chromatography on silica or on a cation-exchange resin such as DEAE; chromatofocusing; SDS-PAGE; ammonium sulfate precipitation; gel filtration using, for example, Sephadex G-75; protein A Sepharose columns to remove contaminants such as IgG; and metal chelating columns to bind epitope-tagged forms of the CHEPO. Various methods of protein purification may be employed and such methods are known in the art and described for example in Deutscher, Methods in Enzvmology, 182 (1990); Scopes, Protein Purification: Principles and Practice, Springer-Verlag, New York (1982). The purification step(s) selected will depend, for example, on the nature of the production process used and the particular CHEPO produced.

E. Uses for CHEPO Nucleotide sequences (or their complement) encoding CHEPO have various applications in the art of molecular biology, including uses as hybridization probes, in chromosome and gene mapping and in the generation of anti-sense RNA and DNA. CHEPO nucleic acid will also be useful for the preparation of CHEPO polypeptides by the recombinant techniques described herein.

The full-length native sequence CHEPO cDNA (SEQ 10 NO:3), or portions thereof, may be used as hybridization probes for a cDNA library to isolate the full-length CHEPO cDNA or to isolate still other cDNAs (for instance, those encoding naturally-occurring variants of CHEPO or CHEPO from other species) which have a desired sequence identity to the CHEPO sequence disclosed in Figure 2 (SEQ ID NO:3). Optionally, the length of the probes will be about 20 to about bases. The hybridization probes may be derived from at least partially novel regions of the nucleotide sequence of SEQ ID NO:3 wherein those regions may be determined without undue experimentation or from genomic sequences including promoters, enhancer elements and introns of native sequence CHEPO. By way of example, a screening method will comprise isolating the coding region of the CHEPO gene using the known DNA sequence to synthesize a selected probe of about 40 bases. Hybridization probes may be labeled by a variety of labels, including radionucleotides such as "P or 3S, or enzymatic labels such as alkaline phosphatase coupled to the probe via avidin/biotin coupling systems. Labeled probes having a sequence complementary to that of the CHEPO gene of the present invention can be used to screen libraries of human cONA, genomic DNA or mRNA to determine which members of such libraries the probe hybridizes to. Hybridization techniques are described in further detail in the Examples below.

Any EST sequences disclosed in the present application may similarly be employed as probes, using the methods disclosed herein.

Other useful fragments of the CHEPO nucleic acids include antisense or sense oligonucleotides comprising a singe-stranded nucleic acid sequence (either RNA or DNA) capable of binding to target CHEPO mRNA (sense) or CHEPO DNA (antisense) sequences. Antisense or sense oligonucleotides, according to the present invention, comprise a fragment of the coding region of CHEPO DNA. Such a fragment generally comprises at least about 14 nucleotides, preferably from about 14 to 30 nucleotides. The ability to derive an antisense or a sense oligonucleotide, based upon a cONA sequence encoding a given protein is described in, for example, Stein and Cohen (Cancer Res. 48:2659, 1988) and van der Krol et al. (ioTechniques 6:958, 1988).

WO 00/68376 PCT/USOO/12370 Binding of antisense or sense oligonucleotides to target nucleic acid sequences results in the formation of duplexes that block transcription or translation of the target sequence by one of several means, including enhanced degradation of the duplexes, premature termination of transcription or translation, or by other means. The antisense oligonucleotides thus may be used to block expression of CHEPO proteins. Antisense or sense oligonucleotides further comprise oligonucleotides having modified sugar-phosphodiester backbones (or other sugar linkages, such as those described in WO 91106629) and wherein such sugar linkages are resistant to endogenous nucleases. Such oligonucleotides with resistant sugar linkages are stable in vivo capable of resisting enzymatic degradation) but retain sequence specificity to be able to bind to target nucleotide sequences.

Other examples of sense or antisense oligonucleotides include those oligonucleotides which are covalently linked to organic moieties, such as those described in WO 90110048, and other moieties that increases affinity of the oligonucleotide for a target nucleic acid sequence, such as poly-(L-lysine). Further still, intercalating agents, such as ellipticine, and alkylating agents or metal complexes may be attached to sense or antisense oligonucleotides to modify binding specificities of the antisense or sense oligonucleotide for the target nucleotide sequence.

Antisense or sense oligonucleotides may be introduced into a cell containing the target nucleic acid sequence by any gene transfer method, including, for example, CaPO 4 -mediated DNA transfection, electroporation, or by using gene transfer vectors such as Epstein-Barr virus. In a preferred procedure, an antisense or sense oligonucleotide is inserted into a suitable retroviral vector. A cell containing the target nucleic acid sequence is contacted with the recombinant retroviral vector, either in vivo or ex vivo. Suitable retroviral vectors include, but are not limited to, those derived from the murine retrovirus M-MuLV, N2 (a retrovirus derived from M-MuLV), or the double copy vectors designated DCT5A, DCT5B and OCT5C (see WO 90113641).

Sense or antisense oligonucleotides also may be introduced into a cell containing the target nucleotide sequence by formation of a conjugate with a ligand binding molecule, as described in WO 91104753. Suitable ligand binding molecules include, but are not limited to, cell surface receptors, growth factors, other cytokines, or other ligands that bind to cell surface receptors. Preferably, conjugation of the ligand binding molecule does not substantially interfere with the ability of the ligand binding molecule to bind to its corresponding molecule or receptor, or block entry of the sense or antisense oligonucleotide or its conjugated version into the cell.

Alternatively, a sense or an antisense oligonucleotide may be introduced into a cell containing the target nucleic acid sequence by formation of an oligonucleotide-lipid complex, as described in WO 90110448. The sense or antisense oligonucleotide-lipid complex is preferably dissociated within the cell by an endogenous lipase.

The probes may also be employed in PCR techniques to generate a pool of sequences for identification of closely related CHEPO coding sequences.

Nucleotide sequences encoding a CHEPO can also be used to construct hybridization probes for mapping the gene which encodes that CHEPO and for the genetic analysis of individuals with genetic disorders. The nucleotide sequences provided herein may be mapped to a chromosome and specific regions of a chromosome using known techniques, such as in situ hybridization, linkage analysis against known chromosomal markers, and hybridization screening with libraries.

WO 00/68376 PCT/USO/12370 When the coding sequences for CHEPO encode a protein which binds to another protein (example, where the CHEPO is a receptor), the CHEPO can be used in assays to identify the other proteins or molecules involved in the binding interaction. By such methods, inhibitors of the receptorligand binding interaction can be identified. Proteins involved in such binding interactions can also be used to screen for peptide or small molecule inhibitors or agonists of the binding interaction. Also, the receptor CHEPO can be used to isolate correlative ligand(s). Screening assays can be designed to find lead compounds that mimic the biological activity of a native CHEPO or a receptor for CHEPO. Such screening assays will include assays amenable to high-throughput screening of chemical libraries, making them particularly suitable for identifying small molecule drug candidates. Small molecules contemplated include synthetic organic or inorganic compounds. The assays can be performed in a variety of formats, including protein-protein binding assays, biochemical screening assays, immunoassays and cell based assays, which are well characterized in the art.

Nucleic acids which encode CHEPO or its modified forms can also be used to generate either transgenic animals or "knock out" animals which, in turn, are useful in the development and screening of therapeutically useful reagents. A transgenic animal a mouse or rat) is an animal having cells that contain a transgene, which transgene was introduced into the animal or an ancestor of the animal at a prenatal, an embryonic stage. A transgene is a DNA which is integrated into the genome of a cell from which a transgenic animal develops. In one embodiment, cDNA encoding CHEPO can be used to clone genomic DNA encoding CHEPO in accordance with established techniques and the genomic sequences used to generate transgenic animals that contain cells which express DNA encoding CHEPO. Methods for generating transgenic animals, particularly animals such as mice or rats, have become conventional in the art and are described, for example, in U.S. Patent Nos. 4,736,866 and 4,870,009. Typically, particular cells would be targeted for CHEPO transgene incorporation with tissue-specific enhancers. Transgenic animals that include a copy of a transgene encoding CHEPO introduced into the germ line of the animal at an embryonic stage can be used to examine the effect of increased expression of DNA encoding CHEPO. Such animals can be used as tester animals for reagents thought to confer protection from, for example, pathological conditions associated with its overexpression. In accordance with this facet of the invention, an animal is treated with the reagent and a reduced incidence of the pathological condition, compared to untreated animals bearing the transgene, would indicate a potential therapeutic intervention for the pathological condition.

Alternatively, non-human homologues of CHEPO can be used to construct a CHEPO "knock out" animal which has a defective or altered gene encoding CHEPO as a result of homologous recombination between the endogenous gene encoding CHEPO and altered genomic DNA encoding CHEPO introduced into an embryonic stem cell of the animal. For example, cDNA encoding CHEPO can be used to clone genomic DNA encoding CHEPO in accordance with established techniques. A portion of the genomic DNA encoding CHEPO can be deleted or replaced with another gene, such as a gene encoding a selectable marker which can be used to monitor integration. Typically, several kilobases of unaltered flanking DNA (both at the 5' and 3' ends) are included in the vector [see Thomas and Capecchi, Cell, 51:503 (1987) for a description of homologous recombination vectors]. The vector is introduced into an embryonic stem cell line by electroporation) and cells in which the introduced DNA has homologously recombined with the endogenous DNA are selected [see Li et al., Cell, 69:915 (1992)]. The selected cells are then injected into a blastocyst of an animal a mouse or rat) to form aggregation chimeras [see Bradley, in Teratocarcinomas and Embryonic Stem Cells: A Practical WO 00/68376 PCT/USOO/12370 Approach, E. J. Robertson, ed. (IRL, Oxford, 1987), pp. 113-1521. A chimeric embryo can then be implanted into a suitable pseudopregnant female foster animal and the embryo brought to term to create a "knock out" animal. Progeny harboring the homologously recombined DNA in their germ cells can be identified by standard techniques and used to breed animals in which all cells of the animal contain the homologously recombined DNA. Knockout animals can be characterized for instance, for their ability to defend against certain pathological conditions and for their development of pathological conditions due to absence of the CHEPO polypeptide.

Nucleic acid encoding the CHEPO polypeptides may also be used in gene therapy. In gene therapy applications, genes are introduced into cells in order to achieve in viva synthesis of a therapeutically effective genetic product, for example for replacement of a defective gene. "Gene therapy" includes both conventional gene therapy where a lasting effect is achieved by a single treatment, and the administration of gene therapeutic agents, which involves the one time or repeated administration of a therapeutically effective DNA or mRNA. Antisense RNAs and DNAs can be used as therapeutic agents for blocking the expression of certain genes in vivo. It has already been shown that short antisense oligonucleotides can be imported into cells where they act as inhibitors, despite their low intracellular concentrations caused by their restricted uptake by the cell membrane. (Zamecnik et al, Proc. Natl. Acad. Sci. USA 83, 41434146 [1986]). The oligonucleotides can be modified to enhance their uptake, e.g. by substituting their negatively charged phosphodiester groups by uncharged groups.

There are a variety of techniques available for introducing nucleic acids into viable cells. The techniques vary depending upon whether the nucleic acid is transferred into cultured cells in vitro, or in vivo in the cells of the intended host.

Techniques suitable for the transfer of nucleic acid into mammalian cells in vitro include the use of liposomes, 2 0 electroporation, microinjection, cell fusion, DEAE-dextran, the calcium phosphate precipitation method, etc. The currently preferred in vivo gene transfer techniques include transfection with viral (typically retroviral) vectors and viral coat proteinliposome mediated transfection (Dzau et al., Trends in Biotechnology 11 205-210 11993]). In some situations it is desirable to provide the nucleic acid source with an agent that targets the target cells, such as an antibody specific for a cell surface membrane protein or the target cell, a ligand for a receptor on the target cell, etc. Where liposomes are employed, proteins which bind to a cell surface membrane protein associated with endocytosis may be used for targeting andlor to facilitate uptake, e.g. capsid proteins or fragments thereof tropic for a particular cell type, antibodies for proteins which undergo internalization in cycling, proteins that target intracellular localization and enhance intracellular half-life.

The technique of receptor-mediated endocytosis is described, for example, by Wu et al, J. Biol. Chem. 262, 4429-4432 (1987); and Wagner et al, Proc. Natl. Acad. Sci. USA 87, 3410-3414 (1990). For review of gene marking and gene therapy protocols see Anderson et al, Science 256, 808-813 (1992).

The CHEPO polypeptides described herein may also be employed as molecular weight markers for protein electrophoresis purposes.

The nucleic acid molecules encoding the CHEPO polypeptides or fragments thereof described herein are useful for chromosome identification. In this regard, there exists an ongoing need to identify new chromosome markers, since relatively few chromosome marking reagents, based upon actual sequence data are presently available. Each CHEPO nucleic acid molecule of the present invention can be used as a chromosome marker.

WO 00/68376 PCTIUSOO/12370 The CHEPO polypeptides and nucleic acid molecules of the present invention may also be used for tissue typing, wherein the CHEPO polypeptides of the present invention may be differentially expressed in one tissue as compared to another. CHEPO nucleic acid molecules will find use for generating probes for PCR, Northern analysis, Southern analysis and Western analysis.

The CHEPO polypeptides described herein may also be employed as therapeutic agents. The CHEPO polypeptides of the present invention can be formulated according to known methods to prepare pharmaceutically useful compositions, whereby the CHEPO product hereof is combined in admixture with a pharmaceutically acceptable carrier vehicle.

Therapeutic formulations are prepared for storage by mixing the active ingredient having the desired degree of purity with optional physiologically acceptable carriers, excipients or stabilizers (Remington's Pharmaceutical Sciences 16th edition, Osol, A. Ed. (1980)), in the form of lyophilized formulations or aqueous solutions. Acceptable carriers, excipients or stabilizers are nontoxic to recipients at the dosages and concentrations employed, and include buffers such as phosphate, citrate and other organic acids; antioxidants including ascorbic acid; low molecular weight (less than about 10 residues) polypeptides; proteins, such as serum albumin, gelatin or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone, amino acids such as glycine, glutamine, asparagine, arginine or lysine; monosaccharides, disaccharides and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugar alcohols such as mannitol or sorbitol; salt-forming counterions such as sodium; andlor nonionic surfactants such as TWEEN

M

PLURONICS

M

or PEG.

The formulations to be used for in vivo administration must be sterile. This is readily accomplished by filtration through sterile filtration membranes, prior to or following lyophilization and reconstitution.

Therapeutic compositions herein generally are placed into a container having a sterile access port, for example, an intravenous solution bag or vial having a stopper pierceable by a hypodermic injection needle.

The route of administration is in accord with known methods, e.g. injection or infusion by intravenous, intraperitoneal, intracerebral, intramuscular, intraocular, intraarterial or intralesional routes, topical administration, or by sustained release systems.

Dosages and desired drug concentrations of pharmaceutical compositions of the present invention may vary depending on the particular use envisioned. The determination of the appropriate dosage or route of administration is well within the skill of an ordinary physician. Animal experiments provide reliable guidance for the determination of effective doses for human therapy. Interspecies scaling of effective doses can be performed following the principles laid down by Mordenti, J. and Chappell, W. "The use of interspecies scaling in toxicokinetics" In Toxicokinetics and New Drug Oevelopment, Yacobi et al, Eds., Pergamon Press, New York 1989, pp. 42-96.

When in vivo administration of a CHEPO polypeptide or agonist or antagonist thereof is employed, normal dosage amounts may vary from about 10 ng/kg to up to 100 mg/kg of mammal body weight or more per day, preferably about 1 glkglday to 10 mglkglday, depending upon the route of administration. Guidance as to particular dosages and methods of delivery is provided in the literature; see, for example, U.S. Pat. Nos. 4,657,760; 5,206,344; or 5,225,212. It is 3 5 anticipated that different formulations will be effective for different treatment compounds and different disorders, that WO 00/68376 PCT/USOO/12370 administration targeting one organ or tissue, for example, may necessitate delivery in a manner different from that to another organ or tissue.

Where sustained-release administration of a CHEPO polypeptide is desired in a formulation with release characteristics suitable for the treatment of any disease or disorder requiring administration of the CHEPO polypeptide, microencapsulation of the CHEPO polypeptide is contemplated. Microencapsulation of recombinant proteins for sustained release has been successfully performed with human growth hormone (rhGH), interferon- (rhlFN-), interleukin-2, and MN Johnson et Nat. Med. 2: 795-799 (1996); Yasuda. Biomed. Ther., 27: 1221-1223 (1993); Hora et al., BiolTechnoloyv, 8: 755-758 (1990); Cleland, "Design and Production of Single Immunization Vaccines Using Polylactide Polyglycolide Microsphere Systems," in Vaccine Design: The Subunit and Adiuvant Approach, Powell and Newman, eds, (Plenum Press: New York, 1995), pp. 439462; WO 97103692, WO 96140072, WO 96107399; and U.S Pat. No. 5,654,010.

The sustained-release formulations of these proteins were developed using poly-lactic-coglycolic acid (PLGA) polymer due to its biocompatibility and wide range of biodegradable properties. The degradation products of PLGA, lactic and glycolic acids, can be cleared quickly within the human body. Moreover, the degradability of this polymer can be adjusted from months to years depending on its molecular weight and composition. Lewis, "Controlled release of bioactive agents from lactidelglycolide polymer," in: M. Chasin and R. Langer Biodegradable Polymers as Drug Delivery Systems (Marcel Dekker: New York, 1990), pp. 1-41.

This invention encompasses methods of screening compounds to identify those that mimic the CHEPO polypeptide (agonists) or prevent the effect of the CHEPO polypeptide (antagonists). Screening assays for antagonist drug candidates are designed to identify compounds that bind or complex with the CHEPO polypeptides encoded by the genes identified herein, or otherwise interfere with the interaction of the encoded polypeptides with other cellular proteins. Such screening assays will include assays amenable to high-throughput screening of chemical libraries, making them particularly suitable for identifying small molecule drug candidates.

The assays can be performed in a variety of formats, including protein-protein binding assays, biochemical screening assays, immunoassays, and cell-based assays, which are well characterized in the art. All assays for antagonists are common in that they call for contacting the drug candidate with a CHEPO polypeptide encoded by a nucleic acid identified herein under conditions and for a time sufficient to allow these two components to interact.

In binding assays, the interaction is binding and the complex formed can be isolated or detected in the reaction mixture. In a particular embodiment, the CHEPO polypeptide encoded by the gene identified herein or the drug candidate is immobilized on a solid phase, on a microtiter plate, by covalent or non-covalent attachments. Non-covalent attachment generally is accomplished by coating the solid surface with a solution of the CHEPO polypeptide and drying.

Alternatively, an immobilized antibody, a monoclonal antibody, specific for the CHEPO polypeptide to be immobilized can be used to anchor it to a solid surface. The assay is performed by adding the non-immobilized component, which may be labeled by a detectable label, to the immobilized component, the coated surface containing the anchored component. When the reaction is complete, the non-reacted components are removed, by washing, and complexes 3 5 anchored on the solid surface are detected. When the originally non-immobilized component carries a detectable label, the detection of label immobilized on the surface indicates that complexing occurred. Where the originally non-immobilized WO 00/68376 PCT/US00/12370 component does not carry a label, complexing can be detected, for example, by using a labeled antibody specifically binding the immobilized complex.

If the candidate compound interacts with but does not bind to a particular CHEPO polypeptide encoded by a gene identified herein, its interaction with that polypeptide can be assayed by methods well known for detecting protein-protein interactions. Such assays include traditional approaches, such as, cross-linking, co-immunoprecipitation, and copurification through gradients or chromatographic columns. In addition, protein-protein interactions can be monitored by using a yeast-based genetic system described by Fields and co-workers (Fields and Song, Nature (London), 340: 245-246 (1989); Chien et Proc. Natl. Acad. Sci. USA 88: 9578-9582 (1991)) as disclosed by Chevray and Nathans, Proc. Natl.

Acad. Sci. USA 89: 5789-5793 (1991). Many transcriptional activators, such as yeast GAL4, consist of two physically discrete modular domains, one acting as the ONA-binding domain, the other one functioning as the transcription-activation domain. The yeast expression system described in the foregoing publications (generally referred to as the "two-hybrid system") takes advantage of this property, and employs two hybrid proteins, one in which the target protein is fused to the ONA-binding domain of GAL4, and another, in which candidate activating proteins are fused to the activation domain.

The expression of a GAL1-IacZ reporter gene under control of a GAL4-activated promoter depends on reconstitution of GAL4 activity via protein-protein interaction. Colonies containing interacting polypeptides are detected with a chromogenic substrate for -galactosidase. A complete kit (MATCHMAKER

T

for identifying protein-protein interactions between two specific proteins using the two-hybrid technique is commercially available from Clontech. This system can also be extended to map protein domains involved in specific protein interactions as well as to pinpoint amino acid residues that are crucial for these interactions.

Compounds that interfere with the interaction of a gene encoding a CHEPO polypeptide identified herein and other intra- or extracellular components can be tested as follows: usually a reaction mixture is prepared containing the product of the gene and the intra- or extracellular component under conditions and for a time allowing for the interaction and binding of the two products. To test the ability of a candidate compound to inhibit binding, the reaction is run in the absence and in the presence of the test compound. In addition, a placebo may be added to a third reaction mixture, to serve as positive control. The binding (complex formation) between the test compound and the intra- or extracellular component present in the mixture is monitored as described hereinabove. The formation of a complex in the control reaction(s) but not in the reaction mixture containing the test compound indicates that the test compound interferes with the interaction of the test compound and its reaction partner.

To assay for antagonists, the CHEPO polypeptide may be added to a cell along with the compound to be screened for a particular activity and the ability of the compound to inhibit the activity of interest in the presence of the CHEPO polypeptide indicates that the compound is an antagonist to the CHEPO polypeptide. Alternatively, antagonists may be detected by combining the CHEPO polypeptide and a potential antagonist with membrane-bound CHEPO polypeptide receptors or recombinant receptors under appropriate conditions for a competitive inhibition assay. The CHEPO polypeptide can be labeled, such as by radioactivity, such that the number of CHEPO polypeptide molecules bound to the receptor can be used to determine the effectiveness of the potential antagonist. The gene encoding the receptor can be identified by numerous methods known to those of skill in the art, for example, ligand panning and FACS sorting. Coligan etal., Current WO 00/68376 PCTIUSOO/12370 Protocols in Immun. Chapter 5 (1991). Preferably, expression cloning is employed wherein polyadenylated RNA is prepared from a cell responsive to the CHEPO polypeptide and a cONA library created from this RNA is divided into pools and used to transfect COS cells or other cells that are not responsive to the CHEPO polypeptide. Transfected cells that are grown on glass slides are exposed to labeled CHEPO polypeptide. The CHEPO polypeptide can be labeled by a variety of means including iodination or inclusion of a recognition site for a site-specific protein kinase. Following fixation and incubation, the slides are subjected to autoradiographic analysis. Positive pools are identified and sub-pools are prepared and re-transfected using an interactive sub-pooling and re-screening process, eventually yielding a single clone that encodes the putative receptor.

As an alternative approach for receptor identification, labeled CHEPO polypeptide can be photoaffinity-linked with cell membrane or extract preparations that express the receptor molecule. Cross-linked material is resolved by PAGE and exposed to X-ray film. The labeled complex containing the receptor can be excised, resolved into peptide fragments, and subjected to protein micro-sequencing. The amino acid sequence obtained from micro- sequencing would be used to design a set of degenerate oligonucleotide probes to screen a cONA library to identify the gene encoding the putative receptor.

In another assay for antagonists, mammalian cells or a membrane preparation expressing the receptor would be incubated with labeled CHEPO polypeptide in the presence of the candidate compound. The ability of the compound to enhance or block this interaction could then be measured.

More specific examples of potential antagonists include an oligonucleotide that binds to the fusions of immunoglobulin with CHEPO polypeptide, and, in particular, antibodies including, without limitation, poly- and monoclonal antibodies and antibody fragments, single-chain antibodies, anti-idiotypic antibodies, and chimeric or humanized versions of such antibodies or fragments, as well as human antibodies and antibody fragments. Alternatively, a potential antagonist may be a closely related protein, for example, a mutated form of the CHEPO polypeptide that recognizes the receptor but imparts no effect, thereby competitively inhibiting the action of the CHEPO polypeptide.

Another potential CHEPO polypeptide antagonist is an antisense RNA or DNA construct prepared using antisense technology, where, an antisense RNA or ONA molecule acts to block directly the translation of mRNA by hybridizing to targeted mRNA and preventing protein translation. Antisense technology can be used to control gene expression through triple-helix formation or antisense ONA or RNA, both of which methods are based on binding of a polynucleotide to ONA or RNA. For example, the 5' coding portion of the polynucleotide sequence, which encodes the mature CHEPO polypeptides herein, is used to design an antisense RNA oligonucleotide of from about 10 to 40 base pairs in length. A ONA oligonucleotide is designed to be complementary to a region of the gene involved in transcription (triple helix see Lee et al, Nucl. Acids Res., 3073 (1979); Cooney et al., Science 241: 456 (1988); Dervan et al., Science, 251: 1360 (1991)), thereby preventing transcription and the production of the CHEPO polypeptide. The antisense RNA oligonucleotide hybridizes to the mRNA in vivo and blocks translation of the mRNA molecule into the CHEPO polypeptide (antisense Okano, Neurochem., 56: 560 (1991); Oligodeoxynucleotides as Antisense Inhibitors of Gene Expression (CRC Press: Boca Raton, FL, 1988). The oligonucleotides described above can also be delivered to cells such that the antisense RNA or DNA may be expressed in vivo to inhibit production of the CHEPO polypeptide. When antisense DNA is used, WO 00/68376 PCT/USOO/12370 oligodeoxyribonucleotides derived from the translation-initiation site, between about -10 and +10 positions of the target gene nucleotide sequence, are preferred.

Potential antagonists include small molecules that bind to the active site, the receptor binding site, or growth factor or other relevant binding site of the CHEPO polypeptide, thereby blocking the normal biological activity of the CHEPO polypeptide. Examples of small molecules include, but are not limited to, small peptides or peptide-like molecules, preferably soluble peptides, and synthetic non-peptidyl organic or inorganic compounds.

Ribozymes are enzymatic RNA molecules capable of catalyzing the specific cleavage of RNA. Ribozymes act by sequence-specific hybridization to the complementary target RNA, followed by endonucleolytic cleavage. Specific ribozyme cleavage sites within a potential RNA target can be identified by known techniques. For further details see, Rossi, Current Biology, 4:469-471 (1994), and PCT publication No. WO 97133551 (published September 18, 1997).

Nucleic acid molecules in triple-helix formation used to inhibit transcription should be single-stranded and composed of deoxynucleotides. The base composition of these oligonucleotides is designed such that it promotes triplehelix formation via Hoogsteen base-pairing rules, which generally require sizeable stretches of purines or pyrimidines on one strand of a duplex. For further details see, PCT publication No. WO 97133551, supra.

These small molecules can be identified by any one or more of the screening assays discussed hereinabove andlor by any other screening techniques well known for those skilled in the art.

F. Anti-CHEPO Antibodies The present invention further provides anti-CHEPO antibodies. Exemplary antibodies include polyclonal, monoclonal, humanized, bispecific, and heteroconjugate antibodies.

1. Polyclonal Antibodies The anti-CHEPO antibodies may comprise polyclonal antibodies. Methods of preparing polyclonal antibodies are known to the skilled artisan. Polyclonal antibodies can be raised in a mammal, for example, by one or more injections of an immunizing agent and, if desired, an adjuvant. Typically, the immunizing agent andlor adjuvant will be injected in the mammal by multiple subcutaneous or intraperitoneal injections. The immunizing agent may include the CHEPO polypeptide or a fusion protein thereof. It may be useful to conjugate the immunizing agent to a protein known to be immunogenic in the mammal being immunized. Examples of such immunogenic proteins include but are not limited to keyhole limpet hemocyanin, serum albumin, bovine thyroglobulin, and soybean trypsin inhibitor. Examples of adjuvants which may be employed include Freund's complete adjuvant and MPL-TOM adjuvant (monophosphoryl Lipid A, synthetic trehalose dicorynomycolate). The immunization protocol may be selected by one skilled in the art without undue experimentation.

2. Monoclonal Antibodies The anti-CHEPO antibodies may, alternatively, be monoclonal antibodies. Monoclonal antibodies may be prepared using hybridoma methods, such as those described by Kohler and Milstein, Nature, 256:495 (1975). In a hybridoma method, a mouse, hamster, or other appropriate host animal, is typically immunized with an immunizing agent to elicit WO 00/68376 PCT/US00/12370 lymphocytes that produce or are capable of producing antibodies that will specifically bind to the immunizing agent.

Alternatively, the lymphocytes may be immunized in vitro.

The immunizing agent will typically include the CHEPO polypeptide or a fusion protein thereof. Generally, either peripheral blood lymphocytes ("PBLs") are used if cells of human origin are desired, or spleen cells or lymph node cells are used if non-human mammalian sources are desired. The lymphocytes are then fused with an immortalized cell line using a suitable fusing agent, such as polyethylene glycol, to form a hybridoma cell [Goding, Monoclonal Antibodies: Principles and Practice, Academic Press, (1986) pp. 59-1031. Immortalized cell lines are usually transformed mammalian cells, particularly myeloma cells of rodent, bovine and human origin. Usually, rat or mouse myeloma cell lines are employed. The hybridoma cells may be cultured in a suitable culture medium that preferably contains one or more substances that inhibit the growth or survival of the unfused, immortalized cells. For example, if the parental cells lack the enzyme hypoxanthine guanine phosphoribosyl transferase (HGPRT or HPRT), the culture medium for the hybridomas typically will include hypoxanthine, aminopterin, and thymidine ("HAT medium"), which substances prevent the growth of HGPRT-deficient cells.

Preferred immortalized cell lines are those that fuse efficiently, support stable high level expression of antibody by the selected antibody-producing cells, and are sensitive to a medium such as HAT medium. More preferred immortalized cell lines are murine myeloma lines, which can be obtained, for instance, from the Salk Institute Cell Distribution Center, San Diego, California and the American Type Culture Collection, Manassas, Virginia. Human myeloma and mouse-human heteromyeloma cell lines also have been described for the production of human monoclonal antibodies [Kozbor, J. Immunol., 133:3001 (1984); Brodeur et al., Monoclonal Antibody Production Techniques and Applications, Marcel Dekker, Inc., New York, (1987) pp. 51-631.

The culture medium in which the hybridoma cells are cultured can then be assayed for the presence of monoclonal antibodies directed against CHEPO. Preferably, the binding specificity of monoclonal antibodies produced by the hybridoma cells is determined by immunoprecipitation or by an in vitro binding assay, such as radioimmunoassay (RIA) or enzymelinked immunoabsorbent assay (ELISA). Such techniques and assays are known in the art. The binding affinity of the monoclonal antibody can, for example, be determined by the Scatchard analysis of Munson and Pollard, Anal. Biochem..

107:220 (1980).

After the desired hybridoma cells are identified, the clones may be subcloned by limiting dilution procedures and grown by standard methods [Goding, supral. Suitable culture media for this purpose include, for example, Dulbecco's Modified Eagle's Medium and RPMI-1640 medium. Alternatively, the hybridoma cells may be grown in vivo as ascites in a mammal.

The monoclonal antibodies secreted by the subclones may be isolated or purified from the culture medium or ascites fluid by conventional immunoglobulin purification procedures such as, for example, protein A-Sepharose, hydroxylapatite chromatography, gel electrophoresis, dialysis, or affinity chromatography.

The monoclonal antibodies may also be made by recombinant ONA methods, such as those described in U.S.

Patent No. 4,816,567. DNA encoding the monoclonal antibodies of the invention can be readily isolated and sequenced using conventional procedures by using oligonucleotide probes that are capable of binding specifically to genes encoding the heavy and light chains of murine antibodies). The hybridoma cells of the invention serve as a preferred source WO 00/68376 PCTIUSOO/12370 of such DNA. Once isolated, the DNA may be placed into expression vectors, which are then transfected into host cells such as simian COS cells, Chinese hamster ovary (CHO) cells, or myeloma cells that do not otherwise produce immunoglobulin protein, to obtain the synthesis of monoclonal antibodies in the recombinant host cells. The DNA also may be modified, for example, by substituting the coding sequence for human heavy and light chain constant domains in place of the homologous murine sequences Patent No. 4,816,567; Morrison et al., supra] or by covalently joining to the immunoglobulin coding sequence all or part of the coding sequence for a non-immunoglobulin polypeptide. Such a nonimmunoglobulin polypeptide can be substituted for the constant domains of an antibody of the invention, or can be substituted for the variable domains of one antigen-combining site of an antibody of the invention to create a chimeric bivalent antibody.

The antibodies may be monovalent antibodies. Methods for preparing monovalent antibodies are well known in the art. For example, one method involves recombinant expression of immunoglobulin light chain and modified heavy chain.

The heavy chain is truncated generally at any point in the Fc region so as to prevent heavy chain crosslinking.

Alternatively, the relevant cysteine residues are substituted with another amino acid residue or are deleted so as to prevent crosslinking.

In vitro methods are also suitable for preparing monovalent antibodies. Oigestion of antibodies to produce fragments thereof, particularly, Fab fragments, can be accomplished using routine techniques known in the art.

3. Human and Humanized Antibodies The anti-CHEPO antibodies of the invention may further comprise humanized antibodies or human antibodies.

Humanized forms of non-human murine) antibodies are chimeric immunoglobulins, immunoglobulin chains or fragments thereof (such as Fv, Fab, Fab', F(ab') 2 or other antigen-binding subsequences of antibodies) which contain minimal sequence derived from non-human immunoglobulin. Humanized antibodies include human immunoglobulins (recipient antibody) in which residues from a complementary determining region (CDR) of the recipient are replaced by residues from a CDR of a non-human species (donor antibody) such as mouse, rat or rabbit having the desired specificity, affinity and capacity.

In some instances, Fv framework residues of the human immunoglobulin are replaced by corresponding non-human residues. Humanized antibodies may also comprise residues which are found neither in the recipient antibody nor in the imported CDR or framework sequences. In general, the humanized antibody will comprise substantially all of at least one, and typically two, variable domains, in which all or substantially all of the COR regions correspond to those of a non-human immunoglobulin and all or substantially all of the FR regions are those of a human immunoglobulin consensus sequence.

The humanized antibody optimally also will comprise at least a portion of an immunoglobulin constant region typically that of a human immunoglobulin [Jones et al., Nau 321:522-525 (1986); Riechmann et al., Nature 332:323-329 (1988); and Presta, Curr. Op. Struct. Biol., 2:593-596 (1992)].

Methods for humanizing non-human antibodies are well known in the art. Generally, a humanized antibody has one or more amino acid residues introduced into it from a source which is non-human. These non-human amino acid residues are often referred to as "import" residues, which are typically taken from an "import" variable domain.

Humanization can be essentially performed following the method of Winter and co-workers [Jones et aL, Nature, 321:522- WO 00/68376 PCTIUSOO/12370 525 (1986); Riechmann et al., Nature, 332:323-327 (1988); Verhoeyen et al., Science, 239:1534-1536 (1988)], by substituting rodent CDRs or COR sequences for the corresponding sequences of a human antibody. Accordingly, such "humanized" antibodies are chimeric antibodies Patent No. 4,816,567), wherein substantially less than an intact human variable domain has been substituted by the corresponding sequence from a non-human species. In practice, humanized antibodies are typically human antibodies in which some CDR residues and possibly some FR residues are substituted by residues from analogous sites in rodent antibodies.

Human antibodies can also be produced using various techniques known in the art, including phage display libraries [Hoogenboom and Winter, J. Mol. Biol., 227:381 (1991); Marks et al., J. Mol. Biol., 222:581 (1991)1. The techniques of Cole et al. and Boemer et al. are also available for the preparation of human monoclonal antibodies (Cole et al., Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, p. 77 (1985) and Boerner et al., J. Immunol., 147(1):86-95 (1991)]. Similarly, human antibodies can be made by introducing of human immunoglobulin loci into transgenic animals, mice in which the endogenous immunoglobulin genes have been partially or completely inactivated. Upon challenge, human antibody production is observed, which closely resembles that seen in humans in all respects, including gene rearrangement, assembly, and antibody repertoire. This approach is described, for example, in U.S. Patent Nos. 5,545,807; 5,545,806; 5,569,825; 5,625,126; 5,633,425; 5,661,016, and in the following scientific publications: Marks et al., Bio/Technoloyv 10 779-783 (1992); Lonberg etal., Nature 368 856.859 (1994); Morrison, Nature 368, 812-13 (1994); Fishwild etal., Nature Biotechnology 14 845-51 (1996); Neuberger, Nature Biotechnology 14 826 (1996); Lonberg and Huszar, Intern. Rev. Immunol. 13 65-93 (1995).

4. Bispecific Antibodies Bispecific antibodies are monoclonal, preferably human or humanized, antibodies that have binding specificities for at least two different antigens. In the present case, one of the binding specificities is for the CHEPO, the other one is for any other antigen, and preferably for a cell-surface protein or receptor or receptor subunit.

Methods for making bispecific antibodies are known in the art. Traditionally, the recombinant production of bispecific antibodies is based on the co-expression of two immunoglobulin heavy-chain/light-chain pairs, where the two heavy chains have different specificities [Milstein and Cuello, Nature, 305:537-539 (1983)]. Because of the random assortment of immunoglobulin heavy and light chains, these hybridomas (quadromas) produce a potential mixture of ten different antibody molecules, of which only one has the correct bispecific structure. The purification of the correct molecule is usually accomplished by affinity chromatography steps. Similar procedures are disclosed in WO 93108829, published 13 May 1993, and in Traunecker et al., EMBO J. 10:3655-3659 (1991).

Antibody variable domains with the desired binding specificities (antibody-antigen combining sites) can be fused to immunoglobulin constant domain sequences. The fusion preferably is with an immunoglobulin heavy-chain constant domain, comprising at least part of the hinge, CH2, and CH3 regions. It is preferred to have the first heavy-chain constant region (CH1) containing the site necessary for light-chain binding present in at least one of the fusions. DNAs encoding the immunoglobulin heavy-chain fusions and, if desired, the immunoglobulin light chain, are inserted into separate WO 00/68376 PCTIUSOO/12370 expression vectors, and are co-transfected into a suitable host organism. For further details of generating bispecific antibodies see, for example, Suresh et al., Methods in Enzvmology, 121:210 (1986).

According to another approach described in WO 96127011, the interface between a pair of antibody molecules can be engineered to maximize the percentage of heterodimers which are recovered from recombinant cell culture. The preferred interface comprises at least a part of the CH3 region of an antibody constant domain. In this method, one or more small amino acid side chains from the interface of the first antibody molecule are replaced with larger side chains tyrosine or tryptophan). Compensatory cavities of identical or similar size to the large side chain(s) are created on the interface of the second antibody molecule by replacing large amino acid side chains with smaller ones alanine or threonine). This provides a mechanism for increasing the yield of the heterodimer over other unwanted end-products such as homodimers.

Bispecific antibodies can be prepared as full length antibodies or antibody fragments F(ab )2 bispecific antibodies). Techniques for generating bispecific antibodies from antibody fragments have been described in the literature.

For example, bispecific antibodies can be prepared can be prepared using chemical linkage. Brennan et al., Science 229:81 (1985) describe a procedure wherein intact antibodies are proteolytically cleaved to generate F(ab fragments. These fragments are reduced in the presence of the dithiol complexing agent sodium arsenite to stabilize vicinal dithiols and prevent intermolecular disulfide formation. The Fab fragments generated are then converted to thionitrobenzoate (TNB) derivatives. One of the Fab -TNB derivatives is then reconverted to the Fab -thiol by reduction with mercaptoethylamine and is mixed with an equimolar amount of the other Fab -TNB derivative to form the bispecific antibody. The bispecific antibodies produced can be used as agents for the selective immobilization of enzymes.

Fab fragments may be directly recovered from E. coli and chemically coupled to form bispecific antibodies.

Shalaby et al., J. Exp. Med. 175:217-225 (1992) describe the production of a fully humanized bispecific antibody F(ab molecule. Each Fab fragment was separately secreted from E coliand subjected to directed chemical coupling in vitro to form the bispecific antibody. The bispecific antibody thus formed was able to bind to cells overexpressing the ErbB2 receptor and normal human T cells, as well as trigger the lytic activity of human cytotoxic lymphocytes against human breast tumor targets.

Various technique for making and isolating bispecific antibody fragments directly from recombinant cell culture have also been described. For example, bispecific antibodies have been produced using leucine zippers. Kostelny etal., J. Immunol. 148(5):1547-1553 (1992). The leucine zipper peptides from the Fos and Jun proteins were linked to the Fab portions of two different antibodies by gene fusion. The antibody homodimers were reduced at the hinge region to form monomers and then re-oxidized to form the antibody heterodimers. This method can also be utilized for the production of antibody homodimers. The diabody technology described by Hollinger etal., Proc. Natl. Acad. Sci. USA 90:6444-6448 (1993) has provided an alternative mechanism for making bispecific antibody fragments. The fragments comprise a heavy-chain variable domain (VH) connected to a light-chain variable domain by a linker which is too short to allow pairing between the two domains on the same chain. Accordingly, the VH and Vt domains of one fragment are forced to 3 5 pair with the complementary Vt and V, domains of another fragment, thereby forming two antigen-binding sites. Another WO 00/68376 PCTIUSOO/12370 strategy for making bispecific antibody fragments by the use of single-chain Fv (sFv) dimers has also been reported. See, Gruber etal., J. ImmunoL 152:5368 (1994).

Antibodies with more than two valencies are contemplated. For example, trispecific antibodies can be prepared. Tutt et al., J. Immunol. 147:60 (1991).

Exemplary bispecific antibodies may bind to two different epitopes on a given CHEPO polypeptide herein.

Alternatively, an anti-CHEPO polypeptide arm may be combined with an arm which binds to a triggering molecule on a leukocyte such as a T-cell receptor molecule CD2, CD3, CD28, or B7), or Fc receptors for IgG (Fc such as Fc RI (CD64), Fc RII (CD32) and Fc RIII (CD16) so as to focus cellular defense mechanisms to the cell expressing the particular CHEPO polypeptide. Bispecific antibodies may also be used to localize cytotoxic agents to cells which express a particular CHEPO polypeptide. These antibodies possess a CHEPO-binding arm and an arm which binds a cytotoxic agent or a radionuclide chelator, such as EOTUBE, OPTA, DOTA, or TETA. Another bispecific antibody of interest binds the CHEPO polypeptide and further binds tissue factor (TF).

Heteroconiugate Antibodies Heteroconjugate antibodies are also within the scope of the present invention. Heteroconjugate antibodies are composed of two covalently joined antibodies. Such antibodies have, for example, been proposed to target immune system cells to unwanted cells Patent No. 4,676,980], and for treatment of HIV infection [WO 91100360; WO 921200373; EP 030891. It is contemplated that the antibodies may be prepared in vitro using known methods in synthetic protein chemistry, including those involving crosslinking agents. For example, immunotoxins may be constructed using a disulfide 2 0 exchange reaction or by forming a thioether bond. Examples of suitable reagents for this purpose include iminothiolate and methyl-4-mercaptobutyrimidate and those disclosed, for example, in U.S. Patent No. 4,676,980.

6. Effector Function Engineering It may be desirable to modify the antibody of the invention with respect to effector function, so as to enhance, the effectiveness of the antibody in treating cancer. For example, cysteine residue(s) may be introduced into the Fc region, thereby allowing interchain disulfide bond formation in this region. The homodimeric antibody thus generated may have improved internalization capability andlor increased complement-mediated cell killing and antibody-dependent cellular cytotoxicity (ADCC). See Caron et J. Exp Med., 176: 1191-1195 (1992) and Shopes, J. Immunol., 148: 2918-2922 (1992). Homodimeric antibodies with enhanced anti-tumor activity may also be prepared using heterobifunctional crosslinkers as described in Wolff et al Cancer Research, 53:2560-2565 (1993). Alternatively, an antibody can be engineered that has dual Fc regions and may thereby have enhanced complement lysis and ADCC capabilities. See Stevenson et al., Anti-Cancer Drua Design, 3: 219-230 (1989).

WO 00/68376 PCTUSO/12370 7. Immunoconiuqates The invention also pertains to immunoconjugates comprising an antibody conjugated to a cytotoxic agent such as a chemotherapeutic agent, toxin an enzymatically active toxin of bacterial, fungal, plant, or animal origin, or fragments thereof), or a radioactive isotope a radioconjugate).

Chemotherapeutic agents useful in the generation of such immunoconjugates have been described above.

Enzymatically active toxins and fragments thereof that can be used include diphtheria A chain, nonbinding active fragments of diphtheria toxin, exotoxin A chain (from Pseudomonas aeruginosa), ricin A chain, abrin A chain, modeccin A chain, alpha-sarcin, Aleurites fordi7 proteins, dianthin proteins, Phytolaca americana proteins (PAPI, PAPII, and PAP-S), momordica charantia inhibitor, curcin, crotin, sapaonaria officinalis inhibitor, gelonin, mitogellin, restrictocin, phenomycin, enomycin, and the tricothecenes. A variety of radionuclides are available for the production of radioconjugated antibodies. Examples include 21 2 Bi 3 n, soY, and '"Re.

Conjugates of the antibody and cytotoxic agent are made using a variety of bifunctional protein-coupling agents such as N-succinimidyl-3-(2-pyridyldithiol) propionate (SPDP), iminothiolane bifunctional derivatives of imidoesters (such as dimethyl adipimidate HCL), active esters (such as disuccinimidyl suberate), aldehydes (such as glutaraldehyde), bis-azido compounds (such as bis (p-azidobenzoyl) hexanediamine), bis-diazonium derivatives (such as bis-(pdiazoniumbenzoyl)-ethylenediamine), diisocyanates (such as tolyene 2,6-diisocyanate), and bis-active fluorine compounds (such as 1,5-difluoro-2,4-dinitrobenzene). For example, a ricin immunotoxin can be prepared as described in Vitetta et a., Science, 238: 1098 (1987). Carbon-14-labeled 1-isothiocyanatobenzyl-3-methyldiethylene triaminepentaacetic acid (MX- DTPA) is an exemplary chelating agent for conjugation of radionucleotide to the antibody. See W094111026.

In another embodiment, the antibody may be conjugated to a "receptor" (such streptavidin) for utilization in tumor pretargeting wherein the antibody-receptor conjugate is administered to the patient, followed by removal of unbound conjugate from the circulation using a clearing agent and then administration of a "ligand" avidin) that is conjugated to a cytotoxic agent a radionucleotide).

8. Immunoliposomes The antibodies disclosed herein may also be formulated as immunoliposomes. Liposomes containing the antibody are prepared by methods known in the art, such as described in Epstein et Proc. Natl. Acad. Sci. USA 82: 3688 (1985); Hwang et Proc. Natl Acad. Sci. USA, 77: 4030 (1980); and U.S. Pat. Nos. 4,485,045 and 4,544,545. Liposomes with enhanced circulation time are disclosed in U.S. Patent No. 5,013,556.

3 0 Particularly useful liposomes can be generated by the reverse-phase evaporation method with a lipid composition comprising phosphatidylcholine, cholesterol, and PEG-derivatized phosphatidylethanolamine (PEG-PE). Liposomes are extruded through filters of defined pore size to yield liposomes with the desired diameter. Fab' fragments of the antibody of the present invention can be conjugated to the liposomes as described in Martin et al, J. Biol. Chem. 257: 286-288 (1982) via a disulfide-interchange reaction. A chemotherapeutic agent (such as Ooxorubicin) is optionally contained within the liposome. See Gabizon etal., J. National Cancer Inst. 81(19): 1484 (1989).

WO 00/68376 PCTIUSOO/12370 9. Pharmaceutical Compositions of Antibodies Antibodies specifically binding a CHEPO polypeptide identified herein, as well as other molecules identified by the screening assays disclosed hereinbefore, can be administered for the treatment of various disorders in the form of pharmaceutical compositions.

If the CHEPO polypeptide is intracellular and whole antibodies are used as inhibitors, internalizing antibodies are preferred. However, lipofections or liposomes can also be used to deliver the antibody, or an antibody fragment, into cells.

Where antibody fragments are used, the smallest inhibitory fragment that specifically binds to the binding domain of the target protein is preferred. For example, based upon the variable-region sequences of an antibody, peptide molecules can be designed that retain the ability to bind the target protein sequence. Such peptides can be synthesized chemically andlor produced by recombinant ONA technology. See, Marasco et Proc. Natl. Acad. Sci. USA, 90: 7889-7893 (1993). The formulation herein may also contain more than one active compound as necessary for the particular indication being treated, preferably those with complementary activities that do not adversely affect each other. Alternatively, or in addition, the composition may comprise an agent that enhances its function, such as, for example, a cytotoxic agent, cytokine, chemotherapeutic agent, or growth-inhibitory agent. Such molecules are suitably present in combination in amounts that are effective for the purpose intended.

The active ingredients may also be entrapped in microcapsules prepared, for example, by coacervation techniques or by interfacial polymerization, for example, hydroxymethylcellulose or gelatin-microcapsules and poly-(methylmethacylate) microcapsules, respectively, in colloidal drug delivery systems (for example, liposomes, albumin microspheres, microemulsions, nano-particles, and nanocapsules) or in macroemulsions. Such techniques are disclosed in Remington's Pharmaceutical Sciences, supra.

The formulations to be used for in vivo administration must be sterile. This is readily accomplished by filtration through sterile filtration membranes.

Sustained-release preparations may be prepared. Suitable examples of sustained-release preparations include semipermeable matrices of solid hydrophobic polymers containing the antibody, which matrices are in the form of shaped articles, films, or microcapsules. Examples of sustained-release matrices include polyesters, hydrogels (for example, poly(2-hydroxyethyl-methacrylate), or poly(vinylalcohol)), polylactides Pat. No. 3,773,919), copolymers of L-glutamic acid and ethyl-L-glutamate, non-degradable ethylene-vinyl acetate, degradable lactic acid-glycolic acid copolymers such as the LUPRON OEPOT T (injectable microspheres composed of lactic acid-glycolic acid copolymer and leuprolide acetate), and poly-0-(-)-3-hydroxybutyric acid. While polymers such as ethylene-vinyl acetate and lactic acid-glycolic acid enable release of molecules for over 100 days, certain hydrogels release proteins for shorter time periods. When encapsulated antibodies remain in the body for a long time, they may denature or aggregate as a result of exposure to moisture at 37 C, resulting in a loss of biological activity and possible changes in immunogenicity. Rational strategies can be devised for stabilization depending on the mechanism involved. For example, if the aggregation mechanism is discovered to be WO 00/68376 PCr[USOO/12370 intermolecular S-S bond formation through thio-disulfide interchange, stabilization may be achieved by modifying sulfhydryl residues, lyophilizing from acidic solutions, controlling moisture content, using appropriate additives, and developing specific polymer matrix compositions.

G. Uses for anti-CHEPO Antibodies The anti-CHEPO antibodies of the invention have various utilities. For example, anti-CHEPO antibodies may be used in diagnostic assays for CHEPO, detecting its expression in specific cells, tissues, or serum. Various diagnostic assay techniques known in the art may be used, such as competitive binding assays, direct or indirect sandwich assays and immunoprecipitation assays conducted in either heterogeneous or homogeneous phases [Zola, Monoclonal Antibodies: A Manual of Techniques, CRC Press, Inc. (1987) pp. 147-158]. The antibodies used in the diagnostic assays can be labeled with a detectable moiety. The detectable moiety should be capable of producing, either directly or indirectly, a detectable signal. For example, the detectable moiety may be a radioisotope, such as 3 H, 1 4 C, 32, 3 5 S, or 1251, a fluorescent or chemiluminescent compound, such as fluorescein isothiocyanate, rhodamine, or luciferin, or an enzyme, such as alkaline phosphatase, beta-galactosidase or horseradish peroxidase. Any method known in the art for conjugating the antibody to the detectable moiety may be employed, including those methods described by Hunter et al., Nature 144:945 (1962); Oavid et aL, Biochemistry 13:1014 (1974); Pain et aL., J. Immunol. Meth. 40:219 (1981); and Nygren, J. Histochem. and Cytochem., 30:407 (1982).

Anti-CHEPO antibodies also are useful for the affinity purification of CHEPO from recombinant cell culture or natural sources. In this process, the antibodies against CHEPO are immobilized on a suitable support, such a Sephadex resin or filter paper, using methods well known in the art. The immobilized antibody then is contacted with a sample containing the CHEPO to be purified, and thereafter the support is washed with a suitable solvent that will remove substantially all the material in the sample except the CHEPO, which is bound to the immobilized antibody. Finally, the support is washed with another suitable solvent that will release the CHEPO from the antibody.

The following examples are offered for illustrative purposes only, and are not intended to limit the scope of the present invention in any way.

2 5 All patent and literature references cited in the present specification are hereby incorporated by reference in their entirety.

EXAMPLES

Commercially available reagents referred to in the examples were used according to manufacturer's instructions unless otherwise indicated. The source of those cells identified in the following examples, and throughout the specification, by ATCC accession numbers is the American Type Culture Collection, Manassas, VA.

WO 00/68376 PCTIUSOO/12370 EXAMPLE 1 Isolation of Nucleic Acid Encoding CHEPO Genomic DNA was isolated from two chimpanzee cell lines (ATCC CRL1609 and CRL1857) using a Qiagen kit (cat#10262) as recommended by the manufacturer's instructions. The chimp Epo gene was then obtained on 3 separate fragments by PCR using 1 g of genomic DNA as template and the following primer pairs: EPO.F: 5'.ACCGCGCCCCCTGGACAG.3' (SEQ ID NO:12) EPO.INT1.R: 5'-CATCCACTTCTCCGGCCAAACTTCA-3' (SEQ ID NO:13) EPO.INT1F: 5'TTTGGCCGGAGAAGTGGATGC.3' (SEQ ID NO:14) EPO.INT4R: 5'TCACTCACTCACTCATTCATTCATTCATTCA-3' (SEQ 10 EPO.INT4F: 5'-GTTGAATGAATGATTGAATGAATGAGTGA-3' (SEQ 10 NO:16) EPO.R: 5'.GCACTGGAGTGTCCATGGGACAG-3 (SEQ ID NO:17) Each PCR reaction contained 5 1 of 1Ox PCR Buffer (Perkin Elmer), 1 I dNTP (20mM), 1 g genomic ONA, 1 I of each primer, 11 of Taq polymerase (Clontech) and HO to bring the total volume to 50 1. The reaction was first denatured for 4 min. at 94 C then amplified for 40 cycles of 1 min. at 94 C, 1 min. at 65 C or 66 C then extended for 1 min. at 72 C.

A last extension step of 5 min. at 72 C was performed. The reaction was then analyzed on agarose gel. PCR product of 500bp, 1200bp and 750bp were observed for each PCR product, respectively. The PCR reactions were then purified using a Wizard kit (Promega cat A7170) then directly sequenced. ONA sequencing of the PCR products was done using an Applied Biosystems 377 ONA Sequencer (PE/Applied Biosystems, Foster City, CA). The chemistry used was DYE Terminator Cycle Sequencing with dRhodamine and BIG DYE terminators (PEIApplied Biosystems, Foster City, CA).

Sequence assembly and editing done with Sequencher software (Gene Codes, Ann Arbor, MI).

The 5 coding exons were identified by homology with the human erythropoietin sequence and assembled into a predicted full length cONA. The coding region of CHEPO cONA is 579 nucleotides long (Figure 1) and encodes a predicted protein of 193 amino acids (Figure There are 3 putative signal cleavage sites predicted after amino acid residue 22, 24 and 27. In accordance with the N-terminus of human Epo, the latest one is likely to correspond to the cleavage site for chimp Epo. The hydrophobic 27 amino acid signal peptide is followed by a 166 amino acid long mature protein containing 3 potential N-glycosylation sites. A single nucleotide polymorphism is present in the predicted sequence obtained from CRL1609 and changes the protein sequence at amino acid position 142 from a Q to a K. Alignment of the chimp Epo protein with the human sequence indicates a single change at amino acid position 84 (Figure 3).

EXAMPLE 2 Use of CHEPO cDNA as a hybridization probe The following method describes use of a nucleotide sequence encoding CHEPO as a hybridization probe.

WO 00/68376 PCrUSO/12370 DNA comprising the coding sequence of full-length or mature CHEPO (as shown in Figure 2, SEQ ID NO:3) is employed as a probe to screen for homologous DNAs (such as those encoding naturally-occurring variants of CHEPO) in human tissue cDNA libraries or human tissue genomic libraries.

Hybridization and washing of filters containing either library DNAs is performed under the following high stringency conditions. Hybridization of radiolabeled CHEPO-derived probe to the filters is performed in a solution of formamide, 5x SSC, 0.1% SDS, 0.1% sodium pyrophosphate, 50 mM sodium phosphate, pH 6.8, 2x Denhardt's solution, and 10% dextran sulfate at 42°C for 20 hours. Washing of the filters is performed in an aqueous solution of 0.1x SSC and 0.1% SDS at 42C.

DNAs having a desired sequence identity with the DNA encoding full-length native sequence CHEPO can then be identified using standard techniques known in the art.

EXAMPLE 3 Expression of CHEPO in E. coli This example illustrates preparation of an unglycosylated form of CHEPO by recombinant expression in E. coli.

The DNA sequence encoding CHEPO (SEQ ID NO:3) is initially amplified using selected PCR primers. The primers should contain restriction enzyme sites which correspond to the restriction enzyme sites on the selected expression vector.

A variety of expression vectors may be employed. An example of a suitable vector is pBR322 (derived from E coli; see Bolivar et al., Gene 2:95 (1977)) which contains genes for ampicillin and tetracycline resistance. The vector is digested with restriction enzyme and dephosphorylated. The PCR amplified sequences are then ligated into the vector. The vector 2 0 will preferably include sequences which encode for an antibiotic resistance gene, a trp promoter, a polyhis leader (including the first six STII codons, polyhis sequence, and enterokinase cleavage site), the CHEPO coding region, lambda transcriptional terminator, and an argU gene.

The ligation mixture is then used to transform a selected E. coli strain using the methods described in Sambrook et al., supra. Transformants are identified by their ability to grow on LB plates and antibiotic resistant colonies are then selected. Plasmid DNA can be isolated and confirmed by restriction analysis and DNA sequencing.

Selected clones can be grown overnight in liquid culture medium such as LB broth supplemented with antibiotics.

The overnight culture may subsequently be used to inoculate a larger scale culture. The cells are then grown to a desired optical density, during which the expression promoter is turned on.

After culturing the cells for several more hours, the cells can be harvested by centrifugation. The cell pellet obtained by the centrifugation can be solubilized using various agents known in the art, and the solubilized CHEPO protein can then be purified using a metal chelating column under conditions that allow tight binding of the protein.

CHEPO may be expressed in E. cofin a poly-His tagged form, using the following procedure. The DNA encoding CHEPO is initially amplified using selected PCR primers. The primers will contain restriction enzyme sites which correspond to the restriction enzyme sites on the selected expression vector, and other useful sequences providing for efficient and 3 5 reliable translation initiation, rapid purification on a metal chelation column, and proteolytic removal with enterokinase.

The PCR-amplified, poly-His tagged sequences are then ligated into an expression vector, which is used to transform an WO 00/68376 PCTIUSOO/12370 E. colihost based on strain 52 (W3110 fuhA(tonA) Ion galE rpoHts(htpRts) clpP(laclq). Transformants are first grown in LB containing 50 mglml carbenicillin at 30 C with shaking until an 0.0.600 of 3-5 is reached. Cultures are then diluted 50-100 fold into CRAP media (prepared by mixing 3.57 g (NH 4 2 SO, 0.71 g sodium citrate 2H20, 1.07 g KCI, 5.36 g Difco yeast extract, 5.36 g Sheffield hycase SF in 500 mL water, as well as 110 mM MPOS, pH 7.3, 0.55% glucose and .7 mM MgS04) and grown for approximately 20-30 hours at 30 C with shaking. Samples are removed to verify expression by SDS-PAGE analysis, and the bulk culture is centrifuged to pellet the cells. Cell pellets are frozen until purification and refolding.

E. colipaste from 0.5 to 1 L fermentations (6-10 g pellets) is resuspended in 10 volumes in 7 M guanidine, mM Tris, pH 8 buffer. Solid sodium sulfite and sodium tetrathionate is added to make final concentrations of 0.1M and 0.02 M, respectively, and the solution is stirred overnight at 4 C. This step results in a denatured protein with all cysteine residues blocked by sulfitolization. The solution is centrifuged at 40,000 rpm in a Beckman Ultracentifuge for min. The supernatant is diluted with 3-5 volumes of metal chelate column buffer (6 M guanidine, 20 mM Tris, pH 7.4) and filtered through 0.22 micron filters to clarify. The clarified extract is loaded onto a 5 ml Qiagen Ni-NTA metal chelate column equilibrated in the metal chelate column buffer. The column is washed with additional buffer containing 50 mM imidazole (Calbiochem, Utrol grade), pH 7.4. The protein is eluted with buffer containing 250 mM imidazole. Fractions containing the desired protein are pooled and stored at 4 C. Protein concentration is estimated by its absorbance at 280 nm using the calculated extinction coefficient based on its amino acid sequence.

The proteins are refolded by diluting the sample slowly into freshly prepared refolding buffer consisting of: mM Tris, pH 8.6, 0.3 M NaCI, 2.5 M urea, 5 mM cysteine, 20 mM glycine and 1 mM EDTA. Refolding volumes are chosen so that the final protein concentration is between 50 to 100 micrograms/ml. The refolding solution is stirred gently at 4 C for 12-36 hours. The refolding reaction is quenched by the addition of TFA to a final concentration of 0.4% (pH of approximately Before further purification of the protein, the solution is filtered through a 0.22 micron filter and acetonitrile is added to 2-10% final concentration. The refolded protein is chromatographed on a Poros R1/H reversed phase column using a mobile buffer of 0.1% TFA with elution with a gradient of acetonitrile from 10 to 80%. Aliquots of fractions with A280 absorbance are analyzed on SDS polyacrylamide gels and fractions containing homogeneous refolded protein are pooled. Generally, the properly refolded species of most proteins are eluted at the lowest concentrations of acetonitrile since those species are the most compact with their hydrophobic interiors shielded from interaction with the reversed phase resin. Aggregated species are usually eluted at higher acetonitrile concentrations. In addition to resolving misfolded forms of proteins from the desired form, the reversed phase step also removes endotoxin 3 0 from the samples.

Fractions containing the desired folded CHEPO polypeptide are pooled and the acetonitrile removed using a gentle stream of nitrogen directed at the solution. Proteins are formulated into 20 mM Hepes, pH 6.8 with 0.14 M sodium chloride and 4% mannitol by dialysis or by gel filtration using G25 Superfine (Pharmacia) resins equilibrated in the formulation buffer and sterile filtered.

WO 00/68376 PCTIUS00/12370 EXAMPLE 4 Expression of CHEPO in mammalian cells This example illustrates preparation of a potentially glycosylated form of CHEPO by recombinant expression in mammalian cells.

The vector, pRK5 (see EP 307,247, published March 15, 1989), is employed as the expression vector.

Optionally, the CHEPO DNA is ligated into pRK5 with selected restriction enzymes to allow insertion of the CHEPO DNA using ligation methods such as described in Sambrook et al., supra. The resulting vector is called In one embodiment, the selected host cells may be 293 cells. Human 293 cells (ATCC CCL 1573) are grown to confluence in tissue culture plates in medium such as DMEM supplemented with fetal calf serum and optionally, nutrient components andlor antibiotics. About 10 g pRK5-CHEPO DNA is mixed with about 1 g DNA encoding the VA RNA gene [Thimmappaya et al., Cell, 31:543 (1982)] and dissolved in 500 I of 1 mM Tris-HCI, 0.1 mM EDTA, 0.227 M CaCI,. To this mixture is added, dropwise, 500 I of 50 mM HEPES (pH 7.35), 280 mM NaCI, 1.5 mM NaPO,, and a precipitate is allowed to form for 10 minutes at 25°C. The precipitate is suspended and added to the 293 cells and allowed to settle for about four hours at 37°C. The culture medium is aspirated off and 2 ml of 20% glycerol in PBS is added for seconds. The 293 cells are then washed with serum free medium, fresh medium is added and the cells are incubated for about 5 days.

Approximately 24 hours after the transfections, the culture medium is removed and replaced with culture medium (alone) or culture medium containing 200 Cilml 3 S-cysteine and 200 Ci/ml 35 S-methionine. After a 12 hour incubation, the conditioned medium is collected, concentrated on a spin filter, and loaded onto a 15% SDS gel. The processed gel may be dried and exposed to film for a selected period of time to reveal the presence of CHEPO polypeptide. The cultures containing transfected cells may undergo further incubation (in serum free medium) and the medium is tested in selected bioassays.

In an alternative technique, CHEPO may be introduced into 293 cells transiently using the dextran sulfate method described by Somparyrac et al., Proc. Natl. Acad. Sci., 12:7575 (1981). 293 cells are grown to maximal density in a spinner flask and 700 g pRK5-CHEPO ONA is added. The cells are first concentrated from the spinner flask by centrifugation and washed with PBS. The ONA-dextran precipitate is incubated on the cell pellet for four hours. The cells are treated with 20% glycerol for 90 seconds, washed with tissue culture medium, and re-introduced into the spinner flask containing tissue culture medium, 5 gIml bovine insulin and 0.1 gIml bovine transferrin. After about four days, the conditioned media is centrifuged and filtered to remove cells and debris. The sample containing expressed CHEPO can then be concentrated and purified by any selected method, such as dialysis andlor column chromatography.

In another embodiment, CHEPO can be expressed in CHO cells. The pRK5-CHEPO can be transfected into CHO cells using known reagents such as CaP04 or OEAE-dextran. As described above, the cell cultures can be incubated, and the medium replaced with culture medium (alone) or medium containing a radiolabel such as 3 "S-methionine. After determining the presence of CHEPO polypeptide, the culture medium may be replaced with serum free medium. Preferably, the cultures are incubated for about 6 days, and then the conditioned medium is harvested. The medium containing the expressed CHEPO can then be concentrated and purified by any selected method.

WO 00/68376 PCT/US00/12370 Epitope-tagged CHEPO may also be expressed in host CHO cells. The CHEPO may be subcloned out of the vector. The subclone insert can undergo PCR to fuse in frame with a selected epitope tag such as a poly-his tag into a Baculovirus expression vector. The poly-his tagged CHEPO insert can then be subcloned into a SV40 driven vector containing a selection marker such as DHFR for selection of stable clones. Finally, the CHO cells can be transfected (as described above) with the SV40 driven vector. Labeling may be performed, as described above, to verify expression. The culture medium containing the expressed poly-His tagged CHEPO can then be concentrated and purified by any selected method, such as by Ni'-chelate affinity chromatography.

CHEPO may also be expressed in CHO andlor COS cells by a transient expression procedure or in CHO cells by another stable expression procedure.

Stable expression in CHO cells is performed using the following procedure. The proteins are expressed as an IgG construct (immunoadhesin), in which the coding sequences for the soluble forms extracellular domains) of the respective proteins are fused to an IgG1 constant region sequence containing the hinge, CH2 and CH2 domains andlor is a poly-His tagged form.

Following PCR amplification, the respective DNAs are subcloned in a CHO expression vector using standard techniques as described in Ausubel et al., Current Protocols of Molecular Biology, Unit 3.16, John Wiley and Sons (1997).

CHO expression vectors are constructed to have compatible restriction sites 5 and 3 of the DNA of interest to allow the convenient shuttling of cDNA s. The vector used expression in CHO cells is as described in Lucas et al., Nucl. Acids Res.

24:9 (1774-1779 (1996), and uses the SV40 early promoter/enhancer to drive expression of the cDNA of interest and dihydrofolate reductase (DHFR). DHFR expression permits selection for stable maintenance of the plasmid following transfection.

Twelve micrograms of the desired plasmid DNA is introduced into approximately 10 million CHO cells using commercially available transfection reagents Superfect (Quiagen), Dosper or Fugene (Boehringer Mannheim). The cells are grown as described in Lucas et al., supra. Approximately 3 x 10 7 cells are frozen in an ampule for further growth and production as described below.

The ampules containing the plasmid DNA are thawed by placement into water bath and mixed by vortexing. The contents are pipetted into a centrifuge tube containing 10 mLs of media and centrifuged at 1000 rpm for 5 minutes. The supernatant is aspirated and the cells are resuspended in 10 mL of selective media (0.2 m filtered PS20 with 5% 0.2 m diafiltered fetal bovine serum). The cells are then aliquoted into a 100 mL spinner containing 90 mL of selective media.

After 1-2 days, the cells are transferred into a 250 mL spinner filled with 150 mL selective growth medium and incubated at 37°C. After another 2-3 days, 250 mL, 500 mL and 2000 mL spinners are seeded with 3 x 10' cells/mL The cell media is exchanged with fresh media by centrifugation and resuspension in production medium. Although any suitable CHO media may be employed, a production medium described in U.S. Patent No. 5,122,469, issued June 16, 1992 may actually be used. A 3L production spinner is seeded at 1.2 x 10" cells/mL On day 0, the cell number pH ie determined. On day 1, the spinner is sampled and sparging with filtered air is commenced. On day 2, the spinner is sampled, the temperature shifted to 33 0 C, and 30 mL of 500 g/L glucose and 0.6 mL of 10% antifoam 35% polydimethylsiloxane emulsion, Oow Corning 365 Medical Grade Emulsion) taken. Throughout the production, the pH is adjusted as necessary to keep it at WO 00/68376 PCT/USOO/12370 around 7.2. After 10 days, or until the viability dropped below 70%, the cell culture is harvested by centrifugation and filtering through a 0.22 m filter. The filtrate was either stored at 4'C or immediately loaded onto columns for purification.

For the poly-His tagged constructs, the proteins are purified using a Ni-NTA column (Qiagen). Before purification, imidazole is added to the conditioned media to a concentration of 5 mM. The conditioned media is pumped onto a 6 ml Ni- NTA column equilibrated in 20 mM Hepes, pH 7.4, buffer containing 0.3 M NaCI and 5 mM imidazole at a flow rate of ml/min. at 4°C. After loading, the column is washed with additional equilibration buffer and the protein eluted with equilibration buffer containing 0.25 M imidazole. The highly purified protein is subsequently desalted into a storage buffer containing 10 mM Hepes, 0.14 M NaCI and 4% mannitol, pH 6.8, with a 25 ml G25 Superfine (Pharmacia) column and stored at Immunoadhesin (Fc-containing) constructs are purified from the conditioned media as follows. The conditioned medium is pumped onto a 5 ml Protein A column (Pharmacia) which had been equilibrated in 20 mM Na phosphate buffer, pH 6.8. After loading, the column is washed extensively with equilibration buffer before elution with 100 mM citric acid, pH 3.5. The eluted protein is immediately neutralized by collecting 1 ml fractions into tubes containing 275 L of 1 M Tris buffer, pH 9. The highly purified protein is subsequently desalted into storage buffer as described above for the poly-His tagged proteins. The homogeneity is assessed by SDS polyacrylamide gels and by N-terminal amino acid sequencing by Edman degradation.

EXAMPLE Expression of CHEPO in Yeast The following method describes recombinant expression of CHEPO in yeast.

First, yeast expression vectors are constructed for intracellular production or secretion of CHEPO from the ADH2/GAPDH promoter. DNA encoding CHEPO and the promoter is inserted into suitable restriction enzyme sites in the selected plasmid to direct intracellular expression of CHEPO. For secretion, DNA encoding CHEPO can be cloned into the selected plasmid, together with DNA encoding the ADH2/GAPDH promoter, a native CHEPO signal peptide or other mammalian signal peptide, or, for example, a yeast alpha-factor or invertase secretory signallleader sequence, and linker sequences (if needed) for expression of CHEPO.

Yeast cells, such as yeast strain AB110, can then be transformed with the expression plasmids described above and cultured in selected fermentation media. The transformed yeast supernatants can be analyzed by precipitation with trichloroacetic acid and separation by SOS-PAGE, followed by staining of the gels with Coomassie Blue stain.

Recombinant CHEPO can subsequently be isolated and purified by removing the yeast cells from the fermentation medium by centrifugation and then concentrating the medium using selected cartridge filters. The concentrate containing CHEPO may further be purified using selected column chromatography resins.

EXAMPLE 6 Expression of CHEPO in Baculovirus-lnfected Insect Cells The following method describes recombinant expression of CHEPO in Baculovirus-infected insect cells.

WO 00/68376 PCTIUSOO/12370 The sequence coding for CHEPO is fused upstream of an epitope tag contained within a baculovirus expression vector. Such epitope tags include poly-his tags and immunoglobulin tags (like Fc regions of IgG). A variety of plasmids may be employed, including plasmids derived from commercially available plasmids such as pVL1393 (Novagen). Briefly, the sequence encoding CHEPO or the desired portion of the coding sequence of CHEPO such as the sequence encoding the extracellular domain of a transmembrane protein or the sequence encoding the mature protein if the protein is extracellular is amplified by PCR with primers complementary to the 5' and 3' regions. The 5' primer may incorporate flanking (selected) restriction enzyme sites. The product is then digested with those selected restriction enzymes and subcloned into the expression vector.

Recombinant baculovirus is generated by co-transfecting the above plasmid and BaculoGoldTM virus ONA (Pharmingen) into Spodoptera frugiperda cells (ATCC CRL 1711) using lipofectin (commercially available from GIBCO-BRL). After 4 5 days of incubation at 28 0 C, the released viruses are harvested and used for further amplifications.

Viral infection and protein expression are performed as described by O'Reilley et al., Baculovirus expression vectors: A Laboratory Manual, Oxford: Oxford University Press (1994).

Expressed poly-his tagged CHEPO can then be purified, for example, by Ni2*-chelate affinity chromatography as follows. Extracts are prepared from recombinant virus-infected Sf9 cells as described by Rupert et al., Nature. 362:175- 179 (1993). Briefly, Sf9 cells are washed, resuspended in sonication buffer (25 mL Hepes, pH 7.9; 12.5 mM MgCI,; 0.1 mM EDTA; 10% glycerol; 0.1% NP-40; 0.4 M KCI), and sonicated twice for 20 seconds on ice. The sonicates are cleared by centrifugation, and the supernatant is diluted 50-fold in loading buffer (50 mM phosphate, 300 mM NaCI, 10% glycerol, pH 7.8) and filtered through a 0.45 m filter. A Ni'-NTA agarose column (commercially available from Qiagen) is prepared with a bed volume of 5 mL, washed with 25 mL of water and equilibrated with 25 mL of loading buffer. The filtered cell extract is loaded onto the column at 0.5 mL per minute. The column is washed to baseline A28o with loading buffer, at which point fraction collection is started. Next, the column is washed with a secondary wash buffer (50 mM phosphate; 300 mM NaCI, 10% glycerol, pH which elutes nonspecifically bound protein. After reaching A 2 o baseline again, the column is developed with a 0 to 500 mM Imidazole gradient in the secondary wash buffer. One mL fractions are collected and analyzed by SOS-PAGE and silver staining or Western blot with Ni*-NTA-conjugated to alkaline phosphatase (Qiagen).

Fractions containing the eluted Hislo-tagged CHEPO are pooled and dialyzed against loading buffer.

Altematively, purification of the IgG tagged (or Fc tagged) CHEPO can be performed using known chromatography techniques, including for instance, Protein A or protein G column chromatography.

EXAMPLE 7 Preparation of Antibodies that Bind CHEPO This example illustrates preparation of monoclonal antibodies which can specifically bind CHEPO.

Techniques for producing the monoclonal antibodies are known in the art and are described, for instance, in Goding, suora. Immunogens that may be employed include purified CHEPO, fusion proteins containing CHEPO, and cells expressing recombinant CHEPO on the cell surface. Selection of the immunogen can be made by the skilled artisan without undue experimentation.

WO 00/68376 PCTIUSOO/12370 Mice, such as Balb/c, are immunized with the CHEPO immunogen emulsified in complete Freund's adjuvant and injected subcutaneously or intraperitoneally in an amount from 1-100 micrograms. Alternatively, the immunogen is emulsified in MPL-TDM adjuvant (Ribi Immunochemical Research, Hamilton, MT) and injected into the animal's hind foot pads. The immunized mice are then boosted 10 to 12 days later with additional immunogen emulsified in the selected adjuvant. Thereafter, for several weeks, the mice may also be boosted with additional immunization injections. Serum samples may be periodically obtained from the mice by retro-orbital bleeding for testing in ELISA assays to detect anti- CHEPO antibodies.

After a suitable antibody titer has been detected, the animals "positive" for antibodies can be injected with a final intravenous injection of CHEPO. Three to four days later, the mice are sacrificed and the spleen cells are harvested.

The spleen cells are then fused (using 35% polyethylene glycol) to a selected murine myeloma cell line such as P3X63AgU.1, available from ATCC, No. CRL 1597. The fusions generate hybridoma cells which can then be plated in 96 well tissue culture plates containing HAT (hypoxanthine, aminopterin, and thymidine) medium to inhibit proliferation of nonfused cells, myeloma hybrids, and spleen cell hybrids.

The hybridoma cells will be screened in an ELISA for reactivity against CHEPO. Determination of "positive" hybridoma cells secreting the desired monoclonal antibodies against CHEPO is within the skill in the art.

The positive hybridoma cells can be injected intraperitoneally into syngeneic Balbic mice to produce ascites containing the anti-CHEPO monoclonal antibodies. Alternatively, the hybridoma cells can be grown in tissue culture flasks or roller bottles. Purification of the monoclonal antibodies produced in the ascites can be accomplished using ammonium sulfate precipitation, followed by gel exclusion chromatography. Alternatively, affinity chromatography based upon binding of antibody to protein A or protein G can be employed.

EXAMPLE 8 Purification of CHEPO Polypeptides Using Specific Antibodies Native or recombinant CHEPO polypeptides may be purified by a variety of standard techniques in the art of protein purification. For example, pro-CHEPO polypeptide, mature CHEPO polypeptide, or pre-CHEPO polypeptide is purified by immunoaffinity chromatography using antibodies specific for the CHEPO polypeptide of interest. In general, an immunoaffinity column is constructed by covalently coupling the anti-CHEPO polypeptide antibody to an activated chromatographic resin.

Polyclonal immunoglobulins are prepared from immune sera either by precipitation with ammonium sulfate or by purification on immobilized Protein A (Pharmacia LKB Biotechnology, Piscataway, Likewise, monoclonal antibodies are prepared from mouse ascites fluid by ammonium sulfate precipitation or chromatography on immobilized Protein A.

Partially purified immunoglobulin is covalently attached to a chromatographic resin such as CnBr-activated SEPHAROSE

M

(Pharmacia LKB Biotechnology). The antibody is coupled to the resin, the resin is blocked, and the derivative resin is washed according to the manufacturer's instructions.

3 5 Such an immunoaffinity column is utilized in the purification of CHEPO polypeptide by preparing a fraction from cells containing CHEPO polypeptide in a soluble form. This preparation is derived by solubilization of the whole cell or of WO 00/68376 PCT/USOO/12370 a subcellular fraction obtained via differential centrifugation by the addition of detergent or by other methods well known in the art. Alternatively, soluble CHEPO polypeptide containing a signal sequence may be secreted in useful quantity into the medium in which the cells are grown.

A soluble CHEPO polypeptide-containing preparation is passed over the immunoaffinity column, and the column is washed under conditions that allow the preferential absorbance of CHEPO polypeptide high ionic strength buffers in the presence of detergent). Then, the column is eluted under conditions that disrupt antibody/CHEPO polypeptide binding a low pH buffer such as approximately pH 2-3, or a high concentration of a chaotrope such as urea or thiocyanate ion), and CHEPO polypeptide is collected.

EXAMPLE 9 Drug Screening This invention is particularly useful for screening compounds by using CHEPO polypeptides or binding fragment thereof in any of a variety of drug screening techniques. The CHEPO polypeptide or fragment employed in such a test may either be free in solution, affixed to a solid support, borne on a cell surface, or located intracellularly. One method of drug screening utilizes eukaryotic or prokaryotic host cells which are stably transformed with recombinant nucleic acids expressing the CHEPO polypeptide or fragment. Drugs are screened against such transformed cells in competitive binding assays. Such cells, either in viable or fixed form, can be used for standard binding assays. One may measure, for example, the formation of complexes between CHEPO polypeptide or a fragment and the agent being tested. Alternatively, one can examine the diminution in complex formation between the CHEPO polypeptide and its target cell or target receptors caused by the agent being tested.

Thus, the present invention provides methods of screening for drugs or any other agents which can affect a CHEPO polypeptide-associated disease or disorder. These methods comprise contacting such an agent with an CHEPO polypeptide or fragment thereof and assaying for the presence of a complex between the agent and the CHEPO polypeptide or fragment, or (ii) for the presence of a complex between the CHEPO polypeptide or fragment and the cell, by methods well known in the art. In such competitive binding assays, the CHEPO polypeptide or fragment is typically labeled. After suitable incubation, free CHEPO polypeptide or fragment is separated from that present in bound form, and the amount of free or uncomplexed label is a measure of the ability of the particular agent to bind to CHEPO polypeptide or to interfere with the CHEPO polypeptidelcell complex.

Another technique for drug screening provides high throughput screening for compounds having suitable binding affinity to a polypeptide and is described in detail in WO 84103564, published on September 13, 1984. Briefly stated, large numbers of different small peptide test compounds are synthesized on a solid substrate, such as plastic pins or some other surface. As applied to a CHEPO polypeptide, the peptide test compounds are reacted with CHEPO polypeptide and washed.

Bound CHEPO polypeptide is detected by methods well known in the art. Purified CHEPO polypeptide can also be coated directly onto plates for use in the aforementioned drug screening techniques. In addition, non-neutralizing antibodies can be used to capture the peptide and immobilize it on the solid support.

This invention also contemplates the use of competitive drug screening assays in which neutralizing antibodies capable of binding CHEPO polypeptide specifically compete with a test compound for binding to CHEPO polypeptide or fragments thereof. In this manner, the antibodies can be used to detect the presence of any peptide which shares one or more antigenic determinants with CHEPO polypeptide.

EXAMPLE Rational Drug Design The goal of rational drug design is to produce structural analogs of biologically active polypeptide of interest a CHEPO polypeptide) or of small molecules with which they interact, agonists, antagonists, or inhibitors. Any of these examples can be used to fashion drugs which are more active or stable forms of the CHEPO polypeptide or which enhance or interfere with the function of the CHEPO polypeptide in vivo Hodgson, Bio/Technologv, 9: 19-21 (1991)).

In one approach, the three-dimensional structure of the CHEPO polypeptide, or of an CHEPO polypeptide-inhibitor complex, is determined by x-ray crystallography, by computer modeling or, most typically, by a combination of the two approaches. Both the shape and charges of the CHEPO polypeptide must be ascertained to elucidate the structure and to determine active site(s) of the molecule. Less often, useful information regarding the structure of the CHEPO polypeptide may be gained by modeling based on the structure of homologous proteins. In both cases, relevant structural information is used to design analogous CHEPO polypeptide-like molecules or to identify efficient inhibitors. Useful examples of rational drug design may include molecules which have improved activity or stability as shown by Braxton and Wells, Biochemistry, 31:7796-7801 (1992) or which act as inhibitors, agonists, or antagonists of native peptides as shown by Athauda et al., J. Biochem., 113:742-746 (1993).

It is also possible to isolate a target-specific antibody, selected by functional assay, as described i 25 above, and then to solve its crystal structure. This approach, in principle, yields a pharmacore upon which subsequent drug design can be based. It is possible to bypass protein crystallography altogether by generating anti-idiotypic antibodies (anti-ids) to a functional, pharmacologically active antibody. As a S* mirror image of a mirror image, the binding site of the anti-ids would be expected to be an analog of the original receptor. The anti-id could then be used to identify and isolate peptides from banks of chemically or biologically produced peptides. The isolated peptides would then act as the pharmacore.

EXAMPLE 11 Preparation of a CHEPO-Immunoadhesin °In order to construct a CHEPO polypeptide having an enhanced in vivo half-life, a CHEPO 35 immunoadhesin molecule was constructed as follows.

A. Assembly of CHEPO cDNA H:\gab ppi7047 .do 130503 H:\gabricla\keep\speci\47047.00.doc 13/05/03 The chimpanzee Epo (CHEPO) gene was cloned as described in Example 1.

An expression construct containing the CHEPO gene under the control of the CMV promoter was generated by amplifying the CHEPO gene from chimp genomic DNA with the following forward and reverse primers: Eco-CHEPO.F: 5'-CGGAATTCATGGGGGTGCACGAATGTCCTGCCTGGC-3' (SEQ ID NO: and Xba-CHEPO.R: 5'-GCTCTAGACTCATCTGTCCCCTGTCCTGCAGG-3' (SEQ ID NO: 51).

The forward primer corresponds to the coding region of Exon 1 fused in frame to the beginning of Exon 2. The reverse primer corresponds to the carboxy terminus of Exon 5, including the stop codon.

The -1.6 kb PCR product therefore corresponds to the CHEPO gene, beginning with the the ATG of Exon 1 and ending with the Stop codon of Exon 5, and without Intron 1. The PCR product was subcloned into pRK5 after digestion with the restriction enzymes, EcoRI and XbaI, and transformed into bacteria. DNA isolated from 4 independent clones was subjected to DNA sequencing. DNA from one clone with the correct sequence was selected (clone and transfected by the calcium phosphate method into 293 cells. Total RNA was isolated from a 10 cm plate of transfected cells using RNA STAT-60 (Tel- Test Inc., Friendswood, TX) following instructions from the manufacturer. After ethanol precipitation, the RNA pellet was resuspended in 250 [l DEPC-treated water and with a Perkin-Elmer GeneAmp RNA PCR core kit was subjected to reverse transcription, resulting in CHEPO cDNA. The CHEPO cDNA was then amplified using Eco-CHEPO.F and Xba-CHEPO.R as primers. Upon separation of the amplified products by gel electrophoresis, several bands were detected. A DNA band of the predicted size for the correctly spliced CHEPO gene (approximately 0.5 kb) was isolated from the gel and subcloned into pRK5 after digestion with the restriction enzymes, EcoRI and XbaI, and transformed into bacteria. DNA isolated from clones were subjected to DNA sequencing. A clone, clone 3H3, with the correct sequence was selected for further study.

B. Construction of CHEPO-IgG 1 The following method describes construction of a CHEPO-IgG immunoadhesin. The coding region of CHEPO was amplified from clone 3H3, described above, with Pfu polymerase using Eco- CHEPO.F as the forward primer and the following reverse primer: BstE2.CHEPO.R: 5'-GTCCGGGTGACCCCTCTGTCCCCTGTCCTGCAGGC-3' (SEQ ID NO: 52) The BstE2.CHEPO.R primer corresponds to the carboxy terminus of Exon 5 of the CHEPO sequence with the 5' end of the primer beginning immediately upstream of the stop codon of Exon The PCR product was digested with the restriction enzymes, EcoRI and BstE2, and subcloned into Sthe vector, pBSSK-CH2CH3, in frame with human IgGl-Fc to create pBSSK-CH2CH3-CHEPO-IgG1.

35 DNA isolated from bacterial clones expressing the vector containing the CHEPO-IgGI fusion, pBSSK- CH2CH3-CHEPO-IgG1 was subjected to DNA sequencing. One clone with the correct sequence was selected for further study. DNA from clone #3 was digested with the restriction enzymes, EcoRI and XbaI, H:\gabla\kp\pcc 3/05/03 H:\gabriela\kecpspeci\47047.00.doc 13/05/03 to release the CHEPO-IgGI product. The digested product encoding CEPO-IgGI was subcloned into generating pRK5-CHEPO-IgGl. pRK5-CHEPO-IgGI was transiently transfected in 293 cells by the calcium phosphate method, described above, and CHEPO-IgGI was purified from the conditioned media using methods that involve protein A chromatography.

EXAMPLE 12 Biological activity of CHEPO-IgG 1 The biological activity of CHEPO-IgG1 was evaluated by three independent assays, measuring the ability of CHEPO-IgG 1 to stimulate 1) the proliferation of Ba/F3-EpoR cells 2) the production of erythroid colonies from human bone marrow cells, and 3) the formation of immature and mature erythroid cells in liquid cultures of bone marrow cells.

A DNA fragment corresponding to the entire coding sequence of human EPO receptor (EpoR) was obtained by PCR and cloned into pRK5-tkneo (a pRK5 vector containing the tymidine kinase (tk)-neo marker) to create a vector designated pRK5-tkneo EpoR. After linearization by digestion with restriction enzymes, the pRK5-tkneo EpoR construct was introduced into Ba/F3 cells by electroporation (250 Volts, 960 Neomycin resistant cells, expressing the pRK5-tkneo EpoR construct, were selected in 2 mg/ml G418, and individual clones were obtained by limiting dilutions.

A. Stimulation of proliferation of Ba/F3-EpoR cells Clones expressing EpoR from the pRK5-tkneo EpoR construct were analyzed for their responses to recombinant human Epo (rhEpo) (Amgen) or chimpanzee-IgG1 (CHEPO-IgGI), prepared as described in the previous example, in a biological assay measuring stimulation of proliferation of Ba/F3-EpoR cells.

The cells were developed internally. Briefl, the entire ORF of human EpoR was amplified by PCR and subcloned into a pRK5tkneo vector (Holmes, Science, 253: 1278-1280 (1991)). The construct was S 25 linearized with NotI and electroporated into Ba/F3 cells. Clones resistant to neomycin were obtained by limiting dilutions and were tested for their ability to proliferate in response to rhEpo. The best responder *e was selected for further studies. Stimulation of proliferation of Ba/F3-EpoR cells in response to rhEpo and CHEPO-IgGI, respectively, was measured by the extent of incorporation of H]-thymidine into the cellular DNA. Cells were initially starved of IL-3 for 16 hours, and subsequently, seeded in 96 well plates at a density of 25,000 cells/well in media containing rhEpo or CHEPO-IgG1 at various concentrations.

After incubation for 22 hours, 1 PCi of 3 H]-thymidine/well were added to the wells, and the cells were incubated for an additional 6 hours before being harvested. Cell-incorporated radioactivity was determined in the presence of 40 pl of scintillation fluid (picroscint 20) using a Top Count Counter (Packard Instruments). The average of duplicate results from the assay are shown in Figure 4. The efficiency of 35 CHEPO-IgG1 in stimulating incorporation of tritiated thymidine in Ba/F3-EpoR cells were compared to the efficiency of stimulation by rhEpo (Figure 4) and indicated that the fusion of CHEPO to the Fc region of *an IgG1 molecule does not affect binding and activation of the Epo receptor.

\speci\4704 c H:\gabriclalkeep\speci\47047.00.doc 13/05/03 B. Stimulation of erythroid colonies in human bone marrow cells In an alternative assay for measuring the biological activity of the CHEPO-IgGI immunoadhesin, stimulation of the production of erythroid colonies by CHEPO-IgG 1 was monitored in human bone marrow cells. Fresh human bone marrow aspirates were obtained from healthy donors (Poietic Technologies, Gaithersburg, MD). The mononuclear fraction was enriched for CD34 by immunomagnetic positive selection. Methylcellulose cultures were initiated with 1000 cells in complete methylcellulose media without erythropoietin (Stem Cell Technologies, Vancuver, BC). Culture medium was later supplemented with 50 ng/mL rhEpo or CHEPO-IgG1 and 50 ng/ml of kit ligand which acts as a stem cell factor (also called scf), and synergizes in these assays with Epo to promote the formation of arythroid colonies.

After 12-14 days, colonies were enumerated and phenotyped on an inverted light microscope. The efficiency of CHEPO-IgG 1 in stimulating production of erythroid colonies from human bone marrow cells was measured and compared to the results from assays with rhEPO. Colony numbers from quadruplicate plates and repeated in two independent experiments are presented in the following Table 7.

TABLE7 Experiment #1 BFU-E CFU-GEMM CFU-GM Macrophage KL/rhEpo 88 0 0 0 KL/CHEPO-IgGI1 82 0 1 0 Experiment #2 BFU-E CFU-GEMM CFU-GM Macrophage KL/rhEpo 104 0 0 0 KL/CHEPO-IgG1 92 0 0 0 BFU-E: burst-forming unit erythroid 20 CFU-GEMM: colony-forming unit-granulocyte, erythroid, macrophage, megakaryocyte CFU-GM: colony-forming unit-glanulocyte-macrophage KL: kit ligand C. Stimulation of bone marrow cells in liquid culture The biological activity of CHEPO-IgG1 was assessed in a third assay, measuring stimulation of bone marrow cells in liquid culture. Twenty thousand CD34+ cells isolated as described above were cultured in IMDM/10%FCS in the presence of CF, 50 ng/ml of kit ligand (KL) and either 50 ng/mL rhEpo (Amgen) or CHEPO-IgG 1. 7-10 inch plates of culture cells were counted by a hematocytometer and subsequently assayed for expression of the erythroid cell surface markers CD36, CD71 and Glycophorin A.

S. 30 As shown in Table 8 and Figure 5, CHEPO-IgGI was as efficient as rhEPO in stimulating the formation of immature and mature erythroid cells in bone marrow liquid culture.

H:\gabricla\keepspcci\47047.00.doc 13/05/03 TABLE 8 Condition Total cellularity KL 2.50+05 KL/rhEPO 2.20E+06 KL/CHEPO-IgG1 2.06+06 KL: kit ligand By virtue of the present invention, sufficient amounts of the CHEPO polypeptide may be made available to perform such analytical studies as X-ray crystallography. In addition, knowledge of the CHEPO polypeptide amino acid sequence provided herein will provide guidance to those employing computer modeling techniques in place of or in addition to x-ray crystallography.

The foregoing written specification is considered to be sufficient to enable one skilled in the art to practice the invention as claimed. Various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description and fall within the scope of the appended claims.

r o H:\gabriela\keep\speci\47047.00.do 13/05/03

Claims

1. A chimeric molecule comprising a CHEPO polypeptide comprising amino acid residues I to 193 or 28 to 193 of Figure 2 (SEQ ID NO: 2) fused to an Fc region of an immunoglobulin; or a polypeptide sequence encoded by nucleotides I to 579 or 82 to 579 of Figure 2 (SEQ ID NO: or any one of amino acid sequences having SEQ ID NOS 18 to 23, 25 to 31 or 33; APPRLICDSRVLERYLLEAKEAENITTGCAEHCSLNENITVPDTKVNFYAWKRNXS XQQAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAQK EAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO: 18); APPRLICDSRVLERYLLEAKEAENITIGCAEHCSLNENITVPDTKVNFYAWKRNXS XQQAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAKK EAISPPDAASAAIPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO: 19); APPRLICDSRVLERYLLEAKEAENITJ7GCAEHCSLNENITVPDTKVNFYAWKRNXT XQQAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLR-ALGAQK EAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID APPRIICDSRVLERYLLEAKEAENITTGCAEHCSLNENITVPDTKVNFYAWKRNXT XQQAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAKK EAISPPDAASAALPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:21); APPRLICDSRVLERYLLEAKEAENIFI'GCAEHCSLNENITVPDTKVNFYAWKRMNX SXQAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTFILLRALGAQK EAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:22); APPRLICDSRVLERYLLEAKEAENI1TGCAEHCSLNENITVPDTKVNFYAWKRMNX SXQAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAKK 0% 0EAISPPDAASAALPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:23); APPRLICDSRVLERYLLEAKEAENITJTGCAEHCSLNENITVPDTKVNFYAWKRMNX TXQAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAKK EAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID APPRLICDSRVLERYLLEAKEAENITTGCAEHCSLNENITVPDTKVNFYAWKRMEN **:XSXAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAQK EAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:26); APPRLICDSRVLERYLLEAKEAENITTGCAEHCSLNENITVPDTKVNFYAWKRMEN XSXAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLr-rLLRALGAKK 35 EAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:27); -96- H:\uanita\Keep\patent\47047O00doc 27/08/03 APPRLICDSRVLERYLLEAKEAENII1GCAEHCSLNENITVPDTKVNFYAWKRMEN XTXAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAQK EAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:28); (11) APPRLICDSRVLERYLLEAKEAENITTGCAEHCSLNENITVPDTKVNFYAWKRMEN XTXAVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAK( EAISPPDAASAAPLRTJTADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:29); (12) APPRLICDSRVLERYLLEAKEAENITfrGGAEHCSLNENITVPDTKVNFYAWKAR4EV NXSXVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLT-rLLRALGAQK EAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID (13) APPRLICDSRVLERYLLEAKEAENITITGCAEHCSLNENITVPDTKVNFYAWKRMEV NXSXVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLT-rLLRALGAKK EAISPPDAASAAPLRTITADTFRKLFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:3 1); (14) APPRLICDSRVLERYLLEAKEAENITGCAEHCSLNENITVPDTKVNFYAWKRMEV NXTXVEVWQGLALLSEAVLRGQALLVNSSQPWEPLQLHVDKAVSGLRSLTTLLRALGAKK EAISPPDAASAAPLRTITADTFRKIFRVYSNFLRGKLKLYTGEACRTGDR (SEQ ID NO:33), wherein X is any amino, acid except for proline. any one of amnino, acid sequences 6) having SEQ ID NOS 34 to 49, fused to an Fc region of an im-munoglobulin. MGVHEGPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENIFTGC AEHCSLNENITVPDTKVNFYAWKRNXSXQQAVEVWQGLALLSEAVLRGQALLVNSSQPW EPLQLHVDAVSGLRSLTLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLR GKLKLYTGEACRTGDR (SEQ ID NO:34); MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENIWrGC AEHCSLNENITVPDTKVNFYAWKRNXSXQQAVEVWQGLALLSEAVLRGQALLVNSSQPw EPLQLHVDKAVSGLRSLTT-LLRALGAKKEAISPPDAASAAPLRTITADTFRKIFRVYSNFLR GKLKLYTGEACRTGDR (SEQ ID MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLIGDSRVLERYLLEAKEAENITTGC AEHCSLNENITVPDTKVNFYAWKRNXTXQQAVEVWQGLALLSEAVLRGQALLVNSSQPW EPLQLHVDKAVSGLRSLTTLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLR GKLKLYTGEACRTGDR ID(SEQ IDNO:3.JU; MGVHECPAWLWLLLSLLSLPLGLPVLGALPPRLICDSRVLERYLLEAKEAENITTGC AEHCSLNENITVPDTKVNFYAWKRNXTXQQAVEVWQGLALLSEAVLRGQALLVNSSQPW EPLQLHVDKAVSGLRSLT-TLLRALGAKKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLR GKLKLYTGEACRTGDR (SEQ ID NO:3 7); -96a- H:\Juanita\Kep\paent47O47.OO.doc 27/08/03 MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENIT-[GC AEHCSLNENITVPDTKVNFYAWKRMNXSXQAVEVWQGLALLSEAVLRGQALLVNSSQPW EPLQLHVDKAVSGLRSLTfTLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRG KLKLYTGEACRTGDR (SEQ ID NO:38); MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENIT-rGC AEHCSLNENITVPDTKVNFYAWKRMNXSXQAVEVWQGLALLSEAVLRGQALLVNSSQPW EPLQLHVDKAVSGLRSLTTrLLRALGAKKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRG KLKLYTGEACRTGDR (SEQ ID NO:39); MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTrGC AEHCSLNENITVPDTKVNFYAWKRMNXTXQAVEVWQGLALLSEAVLRGQALLVNSSQPW EPLQLHVDKAVSGLRSLT-rLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRG KLKLYTGEACRTGDR (SEQ ID MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTrGC AEHCSLNENITVPDTKVNFYAWKRMN'XTXQAVEVWQGLALLSEAVLRGQALLVNSSQPW EPLQLHVDKAVSGLRSLTFTLLRALGAKKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRG KLKLYTGEACRTGDR (SEQ ID NO:4 1); MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTGC AEHCSLNENITVPDTKVNFYAWKRMENXSXAVEVWQGLALLSEAVLRGQALLVNSSQPWE PLQLHVDKAVSGLRSLTTLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRG KLKLYTGEACRTGDR (SEQ ID NO:42); MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTGC AEHCSLNENITVPDTKVNFYAWKRMENXSXAVEVWQGLALLSEAVLRGQALLVNSSQPWE PLQLHVDKAVSGLRSLTTLLRALGAKKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRG KLKLYTGEACRTGDR (SEQ ID NO:43); 25 (11) MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTFGC AEHCSLNENITVPDTKVNFYAWKRMENXTXAVEVWQGLALLSEAVLRGQALLVNSSQPW EPLQLHVDKAVSGLRSLT-TLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRG KLKLYTGEACRTGDR (SEQ ID NO:44); (12) MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTGC AEHCSLNENITVPDTKVNFYAWKRMENXTXAVEVWQGLALLSEAVLRGQALLVNSSQPW EPLQLHVDKAVSGLRSLTFrLLRALGAKKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRG KLKLYTGEACRTGDR (SEQ ID MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTGC AEHCSLNENITVPDTKVNFYAWKRMEVNXSXVEVWQGLALLSEAVLRGQALLVNSSQPWE 35 PLQLHVDKAVSGLRSLTTLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRG KLKLYTGEACRTGDR (SEQ ID NO:46); -96b- H:\JuanitaKep~patcit\47047.OO.doc 27/08103 (14) MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTGC AEHCSLNENITVPDTKVNFYAWKRMEVNXSXVEVWQGLALLSEAVLRGQALLVNSSQPWE PLQLHVDKAVSGLRSLTTLLRALGAKKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRG KLKLYTGEACRTGDR (SEQ ID NO:47); (15) MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITGC AEHCSLNENITVPDTKVNFYAWKRMEVNXTXVEVWQGLALLSEAVLRGQALLVNSSQPW EPLQLHVDKAVSGLRSLTTLLRALGAQKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRG KLKLYTGEACRTGDR (SEQ ID NO:48); and (16) MGVHECPAWLWLLLSLLSLPLGLPVLGAPPRLICDSRVLERYLLEAKEAENITTGC AEHCSLNENITVPDTKVNFYAWKRMEVNXTXVEVWQGLALLSEAVLRGQALLVNSSQPW EPLQLHVDKAVSGLRSLTTLLRALGAKKEAISPPDAASAAPLRTITADTFRKLFRVYSNFLRG KLKLYTGEACRTGDR (SEQ ID NO:49), wherein X is any amino acid except for proline.

2. The chimeric molecule of claim 1, wherein the CHEPO polypeptide is substituted in place of at least one variable region within said immunoglobulin.

3. The chimeric molecule of claim 1 or claim 2, which is a dimer.

4. The chimeric molecule of any one of claims 1 to 3, wherein said immunoglobulin is an IgG molecule.

5. The chimeric molecule of any one of claims 1 to 4, wherein said immunoglobulin Fc region comprises the hinge, CH2, and CH3 regions of an IgG1 molecule. 25

6. The chimeric molecule of any one of claims 1 to 5, wherein said immunogobulin Fc region comprises the hinge, CH1, CH2, and CH3 regions of an IgG1 molecule.

7. A nucleic acid molecule encoding a chimeric molecule according to any one of claims 1 to 6.

8. A vector comprising a nucleic acid molecule according to claim 7.

9. A host cell comprising a vector according to claim 8.

10. A host cell according to claim 9, in which the cell is a CHO cell, an E. coli cell, or a yeast cell. 35

11. A process for producing a chimeric molecule according to any one of claims 1 to 6, comprising the separate culturing of the host cell of claim 10 under conditions suitable for expression of the molecule and recovering the molecule from the cell culture. -96c- H:Uuanita\Keep\patent47047.00.doc 27/08/03 m

12. A composition comprising a chimeric molecule according to any one of claims 1 to 6, together with a pharmaceutically or diagnostically acceptable carrier.

13. A chimeric molecule according to claim 1, substantially as herein described with reference to the examples and figures. Dated this 13 th day of May 2003 GENENTECH, INC. By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia e ,eee oooo eeee e eeoc H:\gabriela\kcep'sped47047.00doc 13/05/03