KR100220356B1 - A method for selecting superagonists, antagonists and super antagonists of human interleukin-6 based receptor complex three dimensional modelling - Google Patents

Abstract

The ligands belonging to the group of cytokines similar to interleukin-6 (IL-6), namely oncostatin M (OSM), leukemia inhibitory factor (LIF), neurotrophic factor (CNTF), and interleukin 11 It is known that gp130, a protein molecule, induces the formation of a receptor complex that is part of it. The present invention

- the process of comparing the amino acid sequence of bovine granulocyte colony stimulating factor (bG-CSF) with the sequence of interleukin-6 hormone; And

Based on the above comparison, a three-dimensional model of the hormone capable of identifying a residue forming a site (site 1) interacting with a specific receptor and a site constituting a site (site 2) interacting with gp130, respectively An antagonist, and a superantagonist of human interleukin-6.

The present invention relates to the identification of such sites in human interleukin-6 and to variants (superagonists and superantagonists) having greater affinity for specific receptors than wild-type hormones, or variants in which the affinity for gp130 is reduced or eliminated (Antagonists and super antagonists). The figure is a schematic diagram showing the method applied to identify regions 1 and 2 in the case of human interleukin-6.

The present invention also describes the use of the superantagonist as a low dose inhibitor for the acquisition of certain superagonists and superantagonists of interleukin-6 and the growth of human myeloma cells dependent on wild-type interleukin-6.

Description

Selection method of human superannot, superantagonist and superantagonist of human interleukin-6 based on three-dimensional modeling of receptor complex

1 is a schematic diagram showing a method applied to identify regions 1 and 2 in the case of human interleukin-6; FIG.

Figure 2 is a graph showing the effect of the three super antagonists according to the invention, Sant 3, Sant 4 and Sant 5, with increasing concentration, over the antagonist Tyr31Asp / Gly35Phe / Ser118Arg / Val121Asp .

The present invention relates to a method for screening superagens, antagonists and superantagonists of human interleukin-6 (hereinafter also referred to as hIL-6 or IL-6) based on three-dimensional modeling.

As is well known, Genentec Inc., International Patent Publication No. 92/21029 teaches methods for determining agonists or antagonists of growth hormones and ligands that are similar in structural form. When potential agonists and antagonists are contacted with receptors for their hormones, a ternary complex is formed that consists of potential agonists or antagonists and two receptors for antagonistic or antagonistic hormones. The dimerization of the receptor induced by the ligand molecule leads to the conclusion that the ligand has two different interaction sites (site 1 and site 2), and on the basis of which mutagenesis is used to generate an agonist or antagonist It is possible.

The ligands belonging to the group of cytokines similar to interleukin-6 (IL-6), namely oncostatin M (OSM), leukemia inhibitory factor (LIF), moyya neurotrophic factor (CNTF), interleukin 11 It is known that gp130, a protein molecule, induces the formation of a receptor complex that is part of it. In this receptor complex, a specific receptor for each of the above cytokines and gp130, a membrane protein molecule, always exist as a common element. Thus, in this class of hormones, it can be hypothesized that sites 1 and 2 bind to two different molecules. That is, site 1 binds to a specific receptor and site 2 binds to gp130. Identification of the two sites is possible by constructing a three-dimensional model of the receptor complex based on the functional similarity between the sequence of the human growth hormone (hGH) receptor and the receptor sequence for the hormone, as will be more apparent from the following description. Isolation of variants (superagonists or superantagonists) with greater affinity for specific receptors than wild-type hormones is done by the construction of a filament phage library, such as M13, that contains the hormone for both wild type and mutant types .

According to the present invention, different residues in Helix A and C are identified as components of Site 2 due to, for example, differences between the three-dimensional model of IL-6 adopted in the present invention and the model adopted in WO 92/21029 . Actually, according to the present invention, the structure of the IL-6 model was used as a template, not the growth hormone, but the structure of another cytokine.

Modeling of human interleukin-6 molecules was performed as follows. From data available in the scientific literature it is known that the amino acid sequence of human interleukin-6 is similar to the sequence of the granulocyte colony stimulating factor (G-CSF). We have developed a three-dimensional model of human IL-6 from residues 16 to 184 using a three-dimensional structure of bovine granulocyte colony stimulating factor (bG-CSF) identified by X-ray crystallography as a template. First, the amino acid sequence of human IL-6 was aligned with the sequence of bG-CSF. Based on the alignment results obtained here, the amino acid residues in the bG-CSF three-dimensional structure were replaced with corresponding residues of human IL-6 using a molecular modeling program in a computerized interactive graphics unit. Adjustments were made by applying the selection conditions provided in the molecular modeling program at locations associated with deletion or insertion (suggesting different local structures within the interleukin-6 molecule).

The interaction between human interleukin-6 and its two receptors: the low affinity receptor gp80 (site 1) and the high affinity signaling receptor gp130 (site 2) from the three-dimensional model of the interleukin-6 based on the bG- And the two sites where it was made could be identified. The two sites were identified using the following procedure. From sequence comparisons it is known that all members of the hematopoietic receptor family are interrelated by the fact that they share a domain known as the cytokine binding domain. This sequence similarity also indicates that there is a high likelihood that structural similarity exists in corresponding portions of several receptors, including two interleukin-6 receptors, gp80 and gp130. The fact that cytokines binding to these receptors all have (or are presumed to have) a similar structure, i.e., a bundle of four helixes, suggests that the interaction between these cytokines and their receptors through the cytokine binding domain is biologically Strongly suggests that it would be very similar - even if not identical - in active complexes.

Considering that the three-dimensional structure of one of these receptor complexes (the complex formed by the extracellular domain of the growth hormone and the dimeric receptor for the growth hormone (eg, GHbp)) was determined by X-ray crystallography, The inventive human bG-CSF baseline model of interleukin-6 allows the identification of potential interactions between interleukin-6 and its two receptors gp80 (site 1) and gp130 (site 2). This is in accordance with the present invention to create a structural model of gp80 and gp130 based on the coordinates provided by the X-ray crystallographic structure of the growth hormone receptor, (See Fig. 1).

As is known, interleukin-6 is a polypeptide consisting of 184 amino acids belonging to the helical cytokine group as described above. Interleukin-6 is a multifunctional cytokine that is produced in various cell types. This serves as a differentiation and growth factor for cells of various families, such as, for example, cells belonging to the immune system, hepatocytes, kidney cells, hematopoietic stem cells, keratinocytes and neurons.

The production of superagonists of interleukin-6 will enable the use of therapeutic doses lower than those required in the case of wild-type interleukin-6 in the treatment of many serious diseases. Indeed, interleukin-6 has important and promising applications in the treatment of diseases associated with breast, leukemia and infectious diseases or disorders of bone marrow progenitor cells.

In addition, superagens of IL-6 can be used for in vitro expansion proliferation of hematopoietic progenitor cells in both bone marrow transplantation and gene therapy.

On the other hand, the production of the antagonist or superantagonist of human Interleukin-6 is associated with a number of diseases characterized by excessive production of interleukin-6, such as chronic autoimmune diseases, myeloma / plasma cell, postmenopausal osteoporosis, 6 < / RTI >

The superagonist, antagonist or superantagonist of interleukin-6 provided in the present invention can be administered parenterally, and a preferable dosage is 1-20 mg / day. In the specific case, the appropriate dosage may be determined according to the ordinary method of a person skilled in the art depending on the condition of the patient and the kind of the disease.

The method for screening a superagonist, antagonist or superantagonist of interleukin-6 according to the present invention comprises the following steps:

- comparing the amino acid sequence of bovine granulocyte colony stimulating factor (bG-CSF) with the sequence of said hormone; And

- a three-dimensional model of the hormone that allows the identification of residues that constitute the site (site 1) interacting with the specific receptor and the site of the site (site 2) interacting with gp130, respectively, formation.

For the screening of the superagonists of interleukin-6, the method according to the invention further comprises the following additional steps:

Preparation of a series of phage libraries containing a mutation of the wild-type residue of interleukin-6 (present in the form of a fusion product with the filament phage protein)

Helix A:

Ser 22, Glu 23, Asp 26, Arg 30, Leu 33, Ser 37, Arg 40, Glu 42;

Loop AB:

Ser 52, Ser 53, Ala 56, Leu 57, Glu 59, Asn 60, Leu 62, Leu 64, Pro 65, Lys 66, Met 67, Ala 68, Glu 69, Lys 70, Asp 71, Phe 74, Gln 75 , Ser 76;

Helix D:

Arg 179, Ala 180, Leu 181, Arg 182, Gln 183, Met 184, Ser 177, Leu 178, Arg 179, Leu 165, Arg 168, Ser 169, Lys 171, Glu 172, Phe 173, .

Screening of phages that belong to each individual phage library and exhibit greater affinity for specific receptors than wild-type interleukins from phage mixed groups expressing interleukin-6 mutants; And

Identification of optimal receptor-binding amino acid sequences or sequences by sequencing DNA extracted from selected phage particles.

In this case, a series of phage libraries containing a mutation of the wild-type residue of the interleukin-6 present as a fusion product with the M13 pIII protein can be prepared.

The selection method of the antagonist of interleukin-6 according to the present invention comprises the following steps together with the above procedures for molecular modeling of human IL-6 protein and its receptor chain:

- residues (Arg 30, Tyr 31, Gly 35, Ser 37, Ala 38, Ser 118, Lys 120, Val 121, Gln) that were found to form part of the interaction site with gp130 using conventional molecular biology techniques 124, Phe 125, Gln 127, Lys 128 and Lys 129);

- the biological activity of the mutant produced as described above to identify variants of interleukin-6 that are normal and have decreased or lost biological activity, and the affinity for the specific interleukin-6 receptor evaluation; And

- Evaluation of variants of the interleukin-6 as antagonists for the biological activity of wild-type interleukin-6 in human cell lines.

When the super antagonist of interleukin-6 is obtained by the combination of the mutation of the amino acid sequence resulting in the identified antagonist activity and the amino acid mutation which leads to an increase of the affinity of the specific receptor for interleukin-6.

In the method of obtaining the antagonist or superantagonist of interleukin-6, the mutagenesis of the above-identified mutants is carried out using molecular biology techniques selected from polymerase chain reaction, primer extension, oligonucleotide directed mutagenesis and combinations thereof Can be performed.

The present invention is not limited to the selection method of superogonist, antagonist or superantagonist of interleukin-6. Rather, the invention relates to a molecule obtained by the above screening method, namely a superagonist of IL-6, except molecules having three substitutions Gln175Ile / Ser176Arg / Gln183Ala, referred to as IL-6 IRA; The following substitution:

Tyr31Asp / Gly35Phe / Ser118Arg / Val121Asp (DFRD)

Tyr31Asp / Gly35Phe / Ser118Phe / Val121Asp (DFFD)

Tyr31Asp / Gly35Phe / Ser118Leu / Val121Asp (DFLD)

≪ / RTI > h antagonist of IL-6 except for three molecules with IL-6; Lt; / RTI > and 7 substitutions; 6 super-antagonist except for molecules with Tyr31Asp / Gly35Phe / Ser118Arg / Val121Asp / Gln175Ile / Ser176Arg / Gln183Ala.

The foregoing has outlined the subject matter of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to understand the objects, features, advantages and application methods of the present invention, detailed description of specific embodiments of the present invention will be given by way of the following examples.

[submission]

This plasmid was transformed with the plasmid pHENΔHIL-6 containing the nucleotide sequence encoding the amino acid sequence of the wild type human interleukin-6 from the restriction enzyme SalI recognition site to the restriction enzyme NotI recognition site. E. coli K12 bacteria were isolated on June 10, 1993 from The National Collection of Industrial and Marine Bacteria Ltd., Aberdeen, UK. (NCIMB) with accession no. NCIMB 40563. < tb > < TABLE >

[Example 1]

[Application of the method according to the invention for the screening of superagonists of interleukin-6 by mutation of amino acid residues in the AB loop]

This method uses a hybrid gene (SEQ ID NO: 1) which contains the entire coding region of hIL-6, which leads to the last 157 amino acids of the protein pIII of phage M13 and which directs the synthesized protein to the periplasmic space, ).

Through this structure, phagemid particles can be obtained that reveal the biologically active human interleukin-6, which folds properly on the surface.

Starting from the mutant IL-6 IRA (substituted Gln175Ile / Ser176Arg / Gln183Ala), which is described in WO 95/00852 and exhibits about 5-fold greater affinity for the receptor than the wild-type human Interleukin-6, the protein of filament phage M13 A phage library containing mutations of Asp71, Phe74, Gln75 and Ser76 residues of interleukin-6, present in the form of a fusion product with pIII, was prepared. This library was constructed using the primer extension method. The mutant oligonucleotide was IL-6 DFQS, a 95 nucleotide oligomer represented by SEQ ID NO: 2. Primer IL-6 DFQS introduces degeneration into codons encoding amino acids 71 (wild type Asp), 74 (wild type Phe), 75 (wild type Gln) and 76 (wild type Ser). The oligonucleotide IL-6 AB primer (SEQ ID NO: 3) was used as the primer for the primer extension reaction. The two oligonucleotides were annealed in vitro and the annealed oligonucleotides used as substrates in the primer extension reaction. The resulting double-stranded DNA fragment was then digested and ligated into the plasmid pHen hIL-6 to replace the wild-type sequence with the mutated one. The product of the ligation reaction was inserted into bacteria to yield approximately 3 million independent transformants. The transformed bacteria were infected with M13K07 helper bacteriophage to generate a phage library (phagemid library).

The library was screened by incubation with magnetic beads coated with monoclonal antibodies against shrIL-6R in the presence of shrIL-6R and shrgp130. Next, the phagemid population eluted at pH 3.6 was amplified in bacteria. After four rounds of selection-amplification, randomly selected phagemids were sequenced across the mutated region and the corresponding mutant interleukin-6 protein was produced in the periplasmic space of the appropriate bacterial strain and the interleukin-6 specific receptor Binding. Table 1 shows that variants of interleukin-6 with increased affinity for specific receptors can be screened using the method according to the invention.

[Example 2]

[Application of the method according to the present invention for obtaining a super antagonist of interleukin-6]

The four mutant Tyr31Asp / Gly35Phe / Ser118Arg / Val121Asp (DFRD) confer antagonist properties as described in WO 95/00852. These four mutations were combined with a mutation (described in Example 1) that could increase specific receptor binding capacity using molecular biology techniques called polymerase chain reaction (PCR). More specifically, the preparation of the mutant protein Sant3 in combination with a superbinding mutation on the helix D and AB regions of phagemid D3-7 (described in Example 1); Preparation of the mutant protein Sant 4 in combination with a superbinding mutation on the Helix D and AB regions of D 3-3 (as described in Example 1); Preparation of the mutant protein Sant 5 in combination with a superbinding mutation on the helix D and AB regions of phagemid D 4-20 (described in Example 1).

The ability to bind specific interleukin-6 receptor and to antagonize the biological activity of interleukin-6 in human liver carcinoma and myeloma cells in mutant proteins containing 9 amino acid substitutions (Sant 3 Sant 5) or 10 (Sant 4) . Table 2 and Figure 2 show the specific receptor binding properties of DFRD and Sant3, Sant4, and Sant5 to the concentration of mutants required to inhibit 50% of the interleukin-6 biological activity (expressed in ml of mutant / ml of culture medium) . (Liver cancer cells were stimulated with 4 ng wild-type interleukin-6 / culture medium, and myeloma cells were stimulated with 0.1 ng / ml culture medium of interleukin-6 because of higher sensitivity to wild-type interleukin-6).

As can be seen from the above table, the specific receptor binding ability of the parent mutant DFRD was increased at one time by the introduction of the amino acid substitution described in Example 1, and 50% of the wild type interleukin-6 biological activity in both cell lines tested The amount of antagonist required to inhibit was reduced, resulting in a highly effective and potent interleukin superantagonist.

[Sequence Table]

General information

(I) Applicant: Istisetto di Ricerche di Biologia Muller Kolarepi Angeletes. blood. a

(Ii) Title of the invention: Method for screening of superannot, antagonist and superantagonist of human interleukin-6 based on three-dimensional modeling of receptor complex

(Iii) Number of sequences: 3

(Iv) Communication address:

(A) Name: Societa Italia Brabanti

(B) Street Address: Piazza di Pietra, 39

City: Rome

(D) Country: Italy

(E) Postal Code: A-00186

(V) Computer readable form:

(A) Media type: floppy disk 3.5, 1.44 MBytes

(B) Computer: IBM PC compatible

(C) Operating system: PC-DOS / MS-DOS 6.22 edition

(D) Software: Microsoft Word 6.0

(Ⅷ) Attorney / Agent Information:

(A) Name: Dicerbo, Mario (PhD)

(C) Reference / document number: RM / X88471 / PC-DC

(Ⅸ) Telegraphic information

(A) Telephone: 06/6785941

(B) Fax: 06/6794692

(C) Telex: 612287 ROPAT

(1) Information on sequence identification number 1:

(I) Sequence characteristics:

(A) Length: 555 base pairs

(B) Type: Nucleic acid

(C) Number of strands: Single

(D) Phase: Linear

(Ii) Molecular form: DNA

(Iii) Home sequence: Not

(Iv) Antisense: Not

(V) Type of fragment: internal

(Ⅶ) Direct Source:

(A) Synthesis: Production in bacteria

(Ⅸ) Features:

(A) Name: IL-6 cDNA

(C) Identification method: Polyacrylamide gel

(Xi) Sequence listing: SEQ ID NO: 1

(2) Information on sequence identification number 2:

(I) Sequence characteristics:

(A) Length: 95 base pairs

(B) Type: Nucleic acid

(C) Number of strands: Single

(D) Phase: Linear

(Ii) Molecular form: synthetic DNA

(Iii) Home sequence: Not

(Iv) Antisense: Not

(V) Type of fragment: internal

(Ⅶ) Direct Source:

(A) Synthesis: oligonucleotide synthesizer

(Ⅸ) Features:

(A) Name: DFQS

(C) Identification method: Polyacrylamide gel

(Xi) Sequence Listing: SEQ ID NO: 2

(3) Information on sequence identification number 3:

(I) Sequence characteristics:

(A) Length: 72 base pairs

(B) Type: Nucleic acid

(C) Number of strands: Single

(D) Phase: Linear

(Ii) Molecular form: synthetic DNA

(Iii) Home sequence: Not

(Iv) Antisense: Correct

(V) Type of fragment: internal

(Ⅶ) Direct Source:

(A) Synthesis: oligonucleotide synthesizer

(Ⅸ) Features:

(A) Name: AB primer

(C) Identification method: Polyacrylamide gel

(Xi) Sequence listing: SEQ ID NO: 3

Claims (32)

(1) Phe74Tyr, Gln75Phe, Ser76Ile, Gln175Ile, Ser176Arg, Gln183Ala; (2) Phe74Tyr, Gln75Tyr, Ser76Val, Gln175Ile, Ser176Arg, Gln183Ala; (3) Gln75Tyr, Ser76Ile, Gln175Ile, Ser176Arg, Gln183Ala; (4) Gln75Tyr, Gln175Ile, Ser176Arg, Gln183Ala; (5) Gln75Tyr, Ser76Lys, Gln175Ile, Ser176Arg, Gln183Ala; (6) Gln75Tyr, Ser76Leu, Gln175Ile, Ser176Arg, Gln183Ala; (7) Gln75Phe, Ser76Ile, Glnl75Ile, Ser176Arg. Gln183Ala; Interleukin-6 receptor agonist having an amino acid sequence of wild-type interleukin-6 sequence containing a series of amino acid substitutions selected from the group consisting of SEQ ID NO: 7. An interleukin-6 receptor agonist according to claim 1 which contains a series of amino acid substitutions with Phe74Tyr, Gln75Phe, Ser76Ile, Gln175Ile, Ser176Arg, Gln183Ala. A composition for treating thrombocytopenia in a human comprising an interleukin-6 receptor agonist of claim 2 in a pharmaceutically acceptable carrier, vehicle or adjuvant. A composition for in vitro expansion of human hematopoietic progenitor cells for bone marrow transplantation, comprising an interleukin-6 receptor agonist of claim 2 in a pharmaceutically acceptable carrier, vehicle or adjuvant. 6. An interleukin-6 receptor agonist according to claim 1 which contains a series of amino acid substitutions with Phe74Tyr, Gln75Tyr, Ser76Val, Gln175Ile, Ser176Arg, Gln183Ala. A composition for the treatment of thrombocytopenia in a human comprising a interleukin-6 receptor agonist of claim 5 in a pharmaceutically acceptable carrier, vehicle or adjuvant. A composition for in vitro expansion of human hematopoietic progenitor cells for bone marrow transplantation comprising the interleukin-6 receptor agonist of claim 5 in a pharmaceutically acceptable carrier, vehicle or adjuvant. 7. An interleukin-6 receptor agonist according to claim 1 which contains a series of amino acid substitutions with Gln75Tyr, Ser76Ile, Gln175Ile, Ser176Arg, Gln183Ala. 8. A composition for treating thrombocytopenia in a human comprising an interleukin-6 receptor agonist of claim 8 in a pharmaceutically acceptable carrier, vehicle or adjuvant. A composition for in vitro expansion of human hematopoietic progenitor cells for bone marrow transplantation comprising the interleukin-6 receptor agonist of claim 8 in a pharmaceutically acceptable carrier, vehicle or adjuvant. 7. An interleukin-6 receptor agonist according to claim 1 which contains a series of amino acid substitutions with Gln75Tyr, Gln175Ile, Ser176Arg, Gln183Ala. 12. A composition for treating thrombocytopenia in a human comprising an interleukin-6 receptor agonist of claim 11 in a pharmaceutically acceptable carrier, vehicle or adjuvant. 11. A composition for in vitro expansion of human hematopoietic progenitor cells for bone marrow transplantation comprising an interleukin-6 receptor agonist of claim 11 in a pharmaceutically acceptable carrier, vehicle or adjuvant. 7. An interleukin-6 receptor agonist according to claim 1 which contains a series of amino acid substitutions with Gln75Tyr, Ser76Lys, Gln175Ile, Ser176Arg, Gln183Ala. 14. A composition for treating thrombocytopenia in a human comprising a therapeutically acceptable carrier, vehicle or adjuvant, the interleukin-6 receptor agonist of claim 14. A composition for in vitro expansion of human hematopoietic progenitor cells for bone marrow transplantation comprising the interleukin-6 receptor agonist of claim 14 in a pharmaceutically acceptable carrier, vehicle or adjuvant. 6. An interleukin-6 receptor agonist according to claim 1 which contains a series of amino acid substitutions with Gln75Tyr, Ser76Leu, Gln175Ile, Ser176Arg, Gln183Ala. 17. A composition for treating thrombocytopenia in a human comprising an interleukin-6 receptor agonist of claim 17 in a pharmaceutically acceptable carrier, vehicle or adjuvant. 17. A composition for in vitro expansion of human hematopoietic progenitor cells for bone marrow transplantation comprising the interleukin-6 receptor agonist of claim 17 in a pharmaceutically acceptable carrier, vehicle or adjuvant. 7. The composition of claim 1, wherein Gln75Phe, Ser76Ile, Glnl75Ile, Ser176Arg. Interleukin-6 receptor agonists containing a series of amino acid substitutions with Gln183Ala. 20. A composition for treating thrombocytopenia in a human comprising an interleukin-6 receptor agonist of claim 20 in a pharmaceutically acceptable carrier, vehicle or adjuvant. 20. A composition for in vitro expansion propagation of human hematopoietic progenitor cells for bone marrow transplantation comprising an interleukin-6 receptor agonist of claim 20 in a pharmaceutically acceptable carrier, vehicle or adjuvant. (1) Tyr31Asp, Gly35Phe, Gln75Tyr, Ser76Ile, Ser118Arg, Val121Asp, Gln175Ile, Ser176Arg, Gln183Ala; (2) Tyr31Asp, Gly35Phe, Phe74Tyr, Gln75Phe, Ser76Ile, Ser118Arg, Val121Asp, Gln75Ile, Ser176Arg, Gln183Ala; And (3) an interleukin-6 receptor antagonist having the amino acid sequence of a wild-type human interleukin-6, wherein the interleukin-6 receptor antagonist contains a series of amino acid substitutions selected from the group consisting of Tyr31Asp, Gly35Phe, Gln75Tyr, Ser76Lys, Ser118Arg, Val121Asp, Gln175Ile, Ser176Arg and Gln183Ala. 24. An interleukin-6 receptor antagonist according to claim 23, comprising a series of amino acid substitutions with Tyr31Asp, Gly35Phe, Gln75Tyr, Ser76Ile, Ser118Arg, Val121Asp, Gln175Ile, Ser176Arg, Gln183Ala. A composition for the treatment of a disease characterized by overproduction of interleukin-6, comprising an interleukin-6 receptor agonist of claim 24 in a pharmaceutically acceptable carrier, vehicle or adjuvant. 26. The composition of claim 25, wherein said disease is selected from the group consisting of multiple myeloma, rheumatoid arthritis, postmenopausal osteoporosis, and systemic lupus erythematosus. 24. An interleukin-6 receptor antagonist according to claim 23, comprising a series of amino acid substitutions with Tyr31Asp, Gly35Phe, Phe74Tyr, Gln75Phe, Ser76Ile, Ser118Arg, Val121Asp, Gln75Ile, Ser176Arg, Gln183Ala. A composition for the treatment of a disease characterized by overproduction of interleukin-6, comprising an interleukin-6 receptor agonist of claim 27 in a pharmaceutically acceptable carrier, vehicle or adjuvant. 29. The composition of claim 28, wherein the disease is selected from the group consisting of multiple myeloma, rheumatoid arthritis, postmenopausal osteoporosis and systemic lupus erythematosus. 24. An interleukin-6 receptor antagonist according to claim 23, comprising a series of amino acid substitutions consisting of Tyr31Asp, Gly35Phe, Gln75Tyr, Ser76Lys, Ser118Arg, Val121Asp, Gln175Ile, Ser176Arg, Gln183Ala. A composition for the treatment of a disease characterized by overproduction of interleukin-6, comprising an interleukin-6 receptor agonist of claim 30 in a pharmaceutically acceptable carrier, vehicle or adjuvant. 32. The composition of claim 31, wherein the disease is selected from the group consisting of multiple myeloma, rheumatoid arthritis, postmenopausal osteoporosis, and systemic lupus erythematosus.