Summary of the invention
Technical problem to be solved by this invention: the present invention aim to provide a kind of energy effectively, the human antibody of specific binding people CD26, and the expression with CD26 in preparation treatment, the disease that particularly overexpression is feature, the new purposes in the medicine of diagnosis CD26 variability expression disease.More particularly:
First object of the present invention is to provide antibody or its fragment in a kind of people of deriving from source, described antibody or its fragments specific are in conjunction with people CD26, preferred specific binding CD26 extracellular region, the aminoacid sequence of described antibody or its fragment comprises the monoclonal antibody in any region or the conjugate of its fragment or its fragment that is selected from 6 complementary determining regions containing SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:7, mono-group of sequence of SEQ ID NO:8, or the aminoacid sequence obtaining by amino-acid substitution or modification.
Preferably the aminoacid sequence of the antibody in the present invention or its fragment is containing the complementary determining region of the variable region of heavy chain just like sequence shown in SEQ ID NO:2, SEQ ID NO:3 and SEQ ID NO:4.
Preferably the aminoacid sequence of the antibody in the present invention or its fragment is containing the complementary determining region of the variable region of light chain just like sequence shown in SEQ ID NO:6, SEQ ID NO:7 and SEQ ID NO:8.
The more preferably antibody in the present invention or its fragment, the aminoacid sequence of its variable region of heavy chain contains following complementary determining region: the CDRH1 as shown in sequence SEQ ID NO:2, CDRH2 as shown in sequence SEQ ID NO:3, the CDRH3 as shown in sequence SEQ ID NO:4;
With and the aminoacid sequence of variable region of light chain contain following complementary determining region: the CDRL1 as shown in sequence SEQ ID NO:6, the CDRL2 as shown in sequence SEQ ID NO:7 and the CDRL3 as shown in sequence SEQ ID NO:8.
More preferably the antibody in the present invention or its fragment contain variable region of heavy chain sequence and variable region of light chain sequence as shown in SEQ ID NO:5 as shown in SEQ ID NO:1.
Second object of the present invention is to provide the single-chain antibody in a kind of people of deriving from source, and the aminoacid sequence of described single-chain antibody is as shown in SEQ ID NO:11.
The 3rd object of the present invention is to provide a kind of nucleotide sequence of the above-mentioned single-chain antibody of encoding, and described nucleotide sequence is as shown in SEQ ID NO:10.
The 4th object of the present invention is to provide a kind of expression vector that contains above-mentioned nucleotide sequence.
The 5th object of the present invention is to provide a kind of recombinant host bacterium that contains above-mentioned expression vector.
The 6th object of the present invention is to provide a kind of method of producing above-mentioned single-chain antibody, comprising:
1) under suitable condition, cultivate above-mentioned recombinant host bacterium and express antibody;
2) then from Host Strains purifying, collect antibody.
The 7th object of the present invention is to provide above-mentioned antibody or the new purposes of its fragment in the medicine of preparation treatment CD26 high expression level tumour.Can treat the disease that the expression with CD26, particularly overexpression are feature, and for diagnosis CD26 variability expression disease provides the method based on antibody, relative disease includes but not limited to autoimmune disease and cancer.
Invention further illustrates:
723 Nucleotide of the anti-CD26 single-chain antibody gene in total man source sequence total length in the present invention, expection has 241 amino acid.There are 115 amino acid whose variable region of heavy chain (SEQ ID NO:1) and 111 amino acid whose variable region of light chain (SEQ ID NO:5), between variable region of heavy chain and variable region of light chain, by 15 amino acid whose flexible peptides, connect (SEQ ID NO:9).
The expression vector that contains CD26 single-chain antibody gene of the present invention and Host Strains all belong to protection scope of the present invention.The primer pair of any fragment of amplification single-chain antibody gene of the present invention is also within protection scope of the present invention.
Beneficial effect of the present invention has:
Antibody in the present invention or its fragment have multifrequency nature, comprise in combination also and the ability of CD26.Particularly, the anti-CD26 single-chain antibody that the present invention obtains has high specific with CD26 and is combined, the external cell adhesion can inhibition tumor cell mediating by CD26, extracorporeal suppression tumor cell growth experiment result shows, the single-chain antibody that the present invention obtains is propagation and the Invasion and Metastasis of inhibition tumor cell obviously.
Accompanying drawing explanation
Fig. 1 is the structural representation of single-chain antibody ZHB-2cF9.VH represents variable region of heavy chain structural domain (SEQ ID NO:1), and VL represents variable region of light chain structural domain (SEQ ID NO:5), and Linker is for connecting VH, the flexible peptide of VL (SEQ ID NO:9).
Fig. 2 is the evaluation figure of CD26 extracellular region protein.A is the SDS-PAGE figure of albumen after purifying, and Lane1 is standard protein, and Lane2 is CD26 extracellular region protein after purifying (arrow indication); B is the Western Blot evaluation figure of CD26 extracellular region protein after purifying, Lane1 is standard protein, Lane2 is CD26 extracellular region protein after purifying (arrow indication), and primary antibodie is anti-CD26 mouse-anti (purchased from MBL), and two resist for the anti-mouse-HRP of rabbit antibody (purchased from life technology).
Fig. 3 A, Fig. 3 B are the ELISA measurement results that phage antibody is combined with CD26 extracellular region protein.Fig. 3 A is polyclone Phage-ELISA, and the coated concentration of CD26 extracellular region protein is 1 μ g/mL, and the phage of screening amplification is taken turns in dilution 4, hatch with the enzyme plate of coated CD26 extracellular region protein, anti-M13-HRP antibody is hatched again, measures 450nm, 650nm light absorption value, and with OD
450nm-OD
650nmas end value.Result shows, shows and has the phage of CD26 specific single-chain antibody to obtain obvious enrichment.Fig. 3 B is mono-clonal Phage-ELISA measurement result, selects in mono-clonal to 96 orifice plate and expresses phage antibody, hatches with the enzyme plate of coated CD26 extracellular region protein, and anti-M13-HRP antibody test result is measured OD
450nm-OD
650nmas end value, result shows that more than 90% mono-clonal and CD26 extracellular region protein produces positive keying action.
Fig. 4 is the evaluation figure of single-chain antibody ZHB-2cF9.A is the SDS-PAGE figure of the ZHB-2cF9 after ni-sepharose purification, and Lane2 is ZHB-2cF9 sample protein, and albumen arrow indication is target protein size strip; Lane1 is standard protein; B is the Western Blot evaluation figure of ZHB-2cF9 after purifying, and primary antibodie is anti-myc mouse-anti, and two resist the antibody for the anti-mouse-HRP of rabbit, and Lane1 is ZHB-2cF9 sample, and albumen arrow indication is target protein size strip, and Lane2 is standard protein.
Fig. 5 shows the Western Blot evaluation figure that single-chain antibody ZHB-2cF9 is combined with CD26 extracellular region protein.Primary antibodie is anti-myc mouse-anti, and two resist the antibody for the anti-mouse-HRP of rabbit.Lane1 is standard protein, and Lane2 is ZHB-2cF9 and CD26 extracellular region protein keying action, arrow indication shown with Fig. 2 in CD26 extracellular region protein band of the same size.Result shows that anti-CD26 single-chain antibody ZHB-2cF9 can specificity be combined with CD26 extracellular region protein.
Fig. 6 shows the immunofluorescence figure that single-chain antibody is combined with people's mesothelioma cell NCI-H2452.A is the immunofluorescence of ZHB-2cF9 and NCI-H2452 cell, and B is that negative control antibody is combined the negative findings detecting with NCI-H2452 cellular immunofluorescence, and antibody concentration is diluted to 10 μ g/mL by 5%MPBS.
Fig. 7 shows that single-chain antibody suppresses people's mesothelioma cell NCI-H2452 in conjunction with the detected result of ECM.Testing ECM used is fibronectin, and experiment is divided into Binding group, Blank group, antibody test group, the adhesion situation of the cell after investigation single-chain antibody effect 12h to fibronectin.
OD450(Binding group)-OD450(Blank group)=complete adherent cell value;
OD450(antibody test group)-OD450(Blank group) the cell adhesion value of=sample sets;
The negative control antibodies of IgG control;
The cell adhesion value of cell adhesion rate (%)=sample sets/complete adherent cell value
Result shows, compares with negative control IgG control, and ZHB-2cF9 and positive control scFv-YS110 all have obvious restraining effect to NCI-H2452 cell adhesion.
Fig. 8 shows the detected result of single-chain antibody to people's mesothelioma NCI-H2452 cell inhibitory effect.Cell is with 1 * 10
4the quantity in/hole is incubated in 96 orifice plates, at single-chain antibody ZHB-2cF9, scFv-YS110 and negative control antibody IgG(mouse) act on after 48h, adopt CCK-8 reagent react 30min, the absorbance of measuring 450nm, the proliferation inhibition rate of cell represents with the decrement % of OD450nm.Experimental result shows that ZHB-2cF9 and positive control scFv-YS110 all have obvious restraining effect to NCI-H2452, and is concentration dependent.
Fig. 9 shows the detected result of single-chain antibody to human colon carcinoma HCT116 cell inhibitory effect.Cell is with 8 * 10
4the quantity in/hole is incubated in 96 orifice plates, at single-chain antibody ZHB-2cF9, scFv-YS110 and negative control antibody IgG(mouse) act on after 48h, adopt CCK-8 reagent react 30min, the absorbance of measuring 450nm, the proliferation inhibition rate of cell represents with the decrement % of OD450nm.Experimental result shows that ZHB-2cF9 and positive control scFv-YS110 all have obvious restraining effect to NCI-H2452, and is concentration dependent.
Embodiment
Definition
" antibody " is can be by the immunoglobulin molecules of at least one antigen recognition site specific binding target antigen in variable region, and described target antigen is as sugar, polynucleotide, fat, polypeptide etc.This term not only comprises complete polyclone and monoclonal antibody, also comprises its fragment (for example Fab, Fab ', F(ab ') 2, Fv), single-chain antibody (scFv), its mutant, the fusion rotein that comprises antibody moiety and arbitrary comprise antigen recognition site other change the immunoglobulin molecules of configurations.Antibody comprises the antibody of arbitrary class, as IgG, IgA or IgM(or its subclass), and antibody does not need for arbitrary certain kinds.
As used herein, " single-chain antibody " refers to immunoglobulin heavy chain variable region (V
h) and variable region of light chain (V
l) the single chain fusion protein that is connected to form by 10~25 amino acid polypeptides, connection peptides (linker), is rich in glycine and Serine conventionally, is beneficial to stability and the snappiness of single-chain antibody.Mode of connection can be by V
ln end be connected to V
hc-terminal, or contrary.Although removed constant region and introduced linker, single-chain antibody has still retained the specificity of immunoglobulin (Ig) to antigen.
" chimeric antibody and humanized antibody ", in general refers to the antibody having combined from the region of more than species." chimeric antibody " comprising traditionally from the variable region of mouse (or in some situation for rat) with from people's constant region." humanized antibody " generally refers to inhuman (for example mouse) antibody formation, and it is the specific gomphosis immunoglobulin containing derived from non-human immunoglobulin minmal sequence, immunoglobulin chain or its fragment (for example Fv, Fab, Fab ', F(ab ')
2or other antigen zygote sequence of antibody).Generally speaking, in humanized antibody, except CDR, whole antibody is the polynucleotide encoding of being originated by people, or outside CDR, has identity with the antibody of the polynucleotide encoding of being originated by people.Some or all of CDR is the nucleic acid encoding of being originated by non-human being's body, and the lamella framework region that they are transplanted to people antibody variable region is to produce antibody, and the specificity of this antibody is determined by the CDR implanting.
As used herein, " human antibody " represents to have the antibody of the aminoacid sequence that the aminoacid sequence of the antibody producing with people is corresponding and/or the antibody of preparing by arbitrary technology of preparing human antibody known in the art or disclosed herein.Human antibody can produce by multiple technology known in the art.For example, human antibody is selected from phage library, and wherein said phage library is expressed human antibody.Human antibody also can be prepared by human immunoglobulin gene's seat (loci) is introduced to transgenic animal, the mouse that wherein said transgenic animal have for example partially or completely been put out a fire endogenous immunoglobulin gene.Prepared by the human B lymphocyte (this bone-marrow-derived lymphocyte can obtain or carry out in vitro immunity from individual) that alternatively, people's antibody can produce the antibody of anti-target antigen by immortalization.In some embodiments, human antibody is " total man source ", and this represents that antibody comprises people's heavy chain and light chain polypeptide.
The present invention is described now with the following Examples.The only object for illustrating of these embodiment is provided, the invention is not restricted to these embodiment, but comprise the institute obviously being produced by instruction provided herein, change.Be used for carrier construction and plasmid, plasmid is imported to host cell and gene, and the detailed description of the ordinary methods such as expression identification of gene product can obtain from various publications, < < molecular cloning experiment guide third edition > > for example.The per-cent relating in embodiment, wherein solid reagent is weight percentage, and liquid reagent is volume percent.
Part material source is illustrated in this:
Clone: HLF cell is people's undifferentiated liver cancer cell, available from JCRB cell bank (Japanese Collection of Research Bioresources Cell Bank).NCI-H2452, is people's mesothelioma cell, available from cell bank/Shanghai Inst. of Life Science, CAS cell resource center of typical case's culture collection council of the Chinese Academy of Sciences.HCT116, is human colon cancer cell, available from cell bank/Shanghai Inst. of Life Science, CAS cell resource center of typical case's culture collection council of the Chinese Academy of Sciences.
(GIBCO, Cat#31800022 add NaHCO to the reagent such as substratum and damping fluid: RPMI-1640
31.5g/L, glucose2.5g/L, Sodium Pyruvate0.11g/L), 90%; High-quality foetal calf serum, (GIBCO) 10%.
2YT substratum: 1L includes Trptone (OXID) 16g, Yeast Extract (OXID) 10g, NaCl5g.
2YT-AK substratum: 2YT is containing 100 μ g/mL penbritins and 50 μ g/mL kantlex.
2YT-AG substratum: 2YT is containing 100 μ g/mL penbritins and 2% glucose.
10 * PBS:(is purchased from Beijing Suo Laibao, Cat#P1022).
5%MPBS or 2%MPBS: the PBS. that contains 5% or 2% skim-milk (OXID)
0.1%PBST: contain 0.1%Tween20(purchased from Beijing Suo Laibao) PBS.
2%BSA: contain 2%BSA(purchased from MP Biomedicals) PBS
Amp: penbritin (purchased from the raw work in Shanghai).
Kan: kantlex (purchased from the raw work in Shanghai).
IPTG:(is purchased from Amresco).
Other common reagent example hydrochloric acids, NaCl, Tris, glycine etc. are purchased from Chemical Reagent Co., Ltd., Sinopharm Group.
Bacterial strain: TG1, intestinal bacteria (available from Chinese microorganism strain net); HB2151, intestinal bacteria (available from Chinese microorganism strain net)
Plasmid: p3XFLAG-CMV9(is purchased from Sigma-Aldrich); PHEN2 (available from Medical Research Council (UK))
The preparation of embodiment 1 CD26 extracellular region protein
The object of this research is by Transfected Recombinant Plasmid eukaryotic cell, G418 resistance screening acquisition stable cell strain, and secreting, expressing CD26 extracellular region protein, goes out CD26 extracellular region protein through affinity chromatography separation and purification.
CD26 extracellular region gene is the synthetic gene that is selected from region, amino acid 29-766 position " Extracellular " in Uniprot:P27487 sequence, CD26 extracellular region gene is connected into plasmid p3XFLAG-CMV9, restriction enzyme site is Hind III, Xba I, construction recombination plasmid (J. Pehanorm Brooker. molecular cloning experiment guide. the third edition. the .2002.P68 of Science Press).
Adopt Lipofectamine LTX Reagent(purchased from Invitrogen) also method proceeds to HLF cell by the recombinant plasmid containing CD26 extracellular region gene to specifications.According to stably transfected cell line construction process (Current Protocols in Molecular Biology, P9.5.5) obtain CD26 extracellular region stable expression cell strain, be designated as HLF-4D9, serum-free is cultivated in a large number, secreting, expressing CD26 extracellular region protein, this albumen is with Flag label, adopt ANTI-FLAG M2 Affinity Gel(purchased from Sigma-Aldrich), serum-free culture supernatant is carried out to purifying and obtain CD26 extracellular region protein sterling, SDS-PAGE(Fig. 2 A) analyze and Western Blot (agriculture of J.S. Boneface. fine works Cell Biology Experiment guide. the .2007.P177 of Science Press) identify (Fig. 2 B), primary antibodie is anti-CD26 mouse-anti (purchased from MBL), two resist for the anti-mouse-HRP of rabbit antibody (purchased from life technology).
Result as shown in Figure 2, Fig. 2 A is the evaluation figure of SDS-PAGE to purifying protein, through a step affinity chromatography, obtain the wall scroll band (Lane2) of the pure level of electrophoresis target protein size, Fig. 2 B carries out Western Blot evaluation figure to the albumen of purifying, band shown in Lane2 and SDS-PAGE qualification result albumen are in the same size, show CD26 extracellular region gene through clone's restructuring transfecting eukaryotic cells and express, after purifying, obtaining the pure level of electrophoresis CD26 extracellular region protein.
The separation of the embodiment 2 anti-CD26 single-chain antibodies in total man source
This single-chain antibody, from people's single-chain antibody phage display library, adopts the affine screening of solid phase of CD26 extracellular region protein to obtain, and this people's single-chain antibody phage display library is built by the Jiangsu red biotechnology Chuan Yao of crowd research institute company limited.The heavy chain of antibody and the phage display library of variable region of light chain that this contains the generation of people's cell build from human peripheral lymphocyte, by using the special primer of antibody variable gene to carry out first run amplification, two take turns amplification adopts heavy chain variable region of light chain to flexibly connect peptide gene and be connected to form single-chain antibody gene, and ScFv gene cloning is entered in plasmid pHEN2 to transform e. coli tg1, obtain 10
8p.f.u. phage single-chain antibody is shown storehouse.(doubly put forth energy in Shen. recombinant antibodies. and the .2005.P107 of Science Press)
This single-chain antibody library Primary spawn, to logarithm growth stage, is infected with M13K07 helper phage, in 2YT-AK substratum, 30 ℃ of shaking table overnight incubation.4%PEG/2.5M NaCl precipitation for phage, and be resuspended in PBS and measure antibody library titre, obtaining titre is 10
11the phage antibody library of p.f.u.(Zhen Yongsu. antibody engineering medicine. the .2002.P51 of Chemical Industry Press) with PBS dilution CD26 extracellular region protein to 50 μ g/mL; Be coated with to enzyme plate (Maxi-sorp96, Nunc), blank hole (not containing CD26 extracellular region protein) is set simultaneously, seal subsequently.Phage antibody library is suspended in to 2%MPBS, gets 100 μ L and join in the blank well of sealing, room temperature is placed after 60min, joins in the hole of containing CD26 extracellular region protein, and room temperature is placed 2h; 0.1%PBST and PBS wash respectively 10 times, add 100 μ L0.1M hydrochloric acid (being adjusted to pH2.2 with glycine), room temperature vibration 10min, 15 μ L1M Tris(pH9.0) for neutralizing rapidly the phage eluting; The e. coli tg1 of the phage-infect 5mL logarithmic phase after neutralization, get 100uL, do 100 times of serial dilutions 1~3 time, then, by serial dilution thing paving TYE solid medium (containing 100 μ g/mL Amp and 1% glucose), remaining bacterium liquid adds 20mL to contain 2 * 10 again
10the 2YT-AG of M13K07 helper phage increases and prepares phage library, for next round screening process, carries out altogether 4 and takes turns screening.
The antibody fragment that is illustrated in phage particle surface is called as phage antibody, this experiment first identifies that by polyclone Phage-ELISA 4 take turns the enrichment condition of CD26 specific phage antibody after screening, after by mono-clonal Phage-ELISA, further identify the phage antibody of picking out high-affinity.
The evaluation of polyclone Phage-ELISA, envelope antigen i.e. 1 μ g/mL CD26 extracellular region protein, to enzyme plate, after sealing, is got the every phage of taking turns the rear acquisition of screening of 10 μ L, and 2%MPBS joins in antigen coated enzyme bar after diluting.Incubated at room 90min, adds mouse-anti M13 phage-HRP antibody (purchased from Yi Qiao Divine Land, Beijing biotech company) incubated at room 1h after washing, after washing, add 100 μ L TMB nitrite ions (purchased from AMRESCO).After incubated at room 10min, 1M dilute sulphuric acid termination reaction.Measure OD
450and OD
650, and with OD
450-OD
650as last detected result.As shown in Figure 3A, the coated enzyme plate of the BSA of usining is as negative control, and along with screening wheel number increases, the combination enhancing of phage antibody and CD26 extracellular region protein, shows to have obtained obvious enrichment with the phage of CD26 specific antibody.
Mono-clonal Phage-ELISA is identified, on the titer determination flat board of random choose third round fourth round screening process, picking mono-clonal is in 96 hole microbial culture plates (purchased from Corning), 2YT substratum (containing 100 μ g/mL Amp and 1% glucose) has been added in every hole, 37 ℃ are cultured to logarithmic phase, and every hole adds 10
937 ℃ of standing infection 30min of p.f.u.M13K07 helper phage, cultivate 1h for 37 ℃.The centrifugal 10min of 1800g, abandons supernatant.Bacterial sediment is resuspended in to 200 μ L2YT-AK substratum, 30 ℃ of shaking table overnight incubation.The culture supernatant containing phage that the centrifugal 10min of 1800g next day obtains, 20%MPBS incubated at room 1h with 1/10 volume, join in the enzyme plate that is coated with recombinant C D26 extracellular region protein, ELISA identifies (method and reagent are identified with polyclone Phage-ELISA) again.Measure OD
450and OD
650, and with OD
450-OD
650as last detected result.Select the clone that reading is high and carry out determined dna sequence.Fig. 3 B has shown the detected result of part mono-clonal phage E LSIA, and more than 90% mono-clonal shows positive keying action, further shows to take turns screening by 4, with the phage of CD26 specific antibody, has obtained obvious enrichment.Therefrom select 50 mono-clonal order-checkings that reading is high, obtain the single-chain antibody (be designated as ZHB-2cF9) of nucleotide coding sequence as shown in SEQ ID NO:10.The aminoacid sequence of corresponding single-chain antibody ZHB-2cF9 is SEQ ID NO:11.
Solubility expression and the separation and purification of the anti-CD26 single-chain antibody of embodiment 3
PHEN2 is a difunctional phagemid vector, has an amber type terminator codon (Amber) TAG between detection of expression label (c-my tag) and coat protein gene.If phage-infect amber mutation (SupE) inhibition type bacterial strain, as TG1, TAG codon is translated into L-glutamic acid, and sequence can be readed over translation, and antibody fragment and coat protein p3 amalgamation and expression are in phage surface; When the non-amber mutation inhibition of phage-infect type bacterial strain, as HB2151, translation stops at TAG place, can obtain the antibody fragment that solvable type is expressed.Antibody fragment C end, with 6 * His tag and c-myc tag, is beneficial to purifying and detects and identify.ZHB-2cF9 single-chain antibody adopts the solubility expression in colibacillus periplasm space, and purifying adopts high osmose process to extract cell periplasm protein, and the one step separation and purification of recycling affinity chromatography obtains the higher target protein of purity.
The little extraction reagent kit of employing plasmid extracts the plasmid (being designated as 2cF9-pHEN2) that contains coding single-chain antibody ZHB-2cF9 gene from thalline TG1, be used for transforming the sub-intestinal bacteria HB2151 of non-inhibition, transform and adopt Calcium Chloride Method preparation and transformed competence colibacillus intestinal bacteria HB2151(J. Pehanorm Brooker. molecular cloning experiment guide. the third edition. the .2002.P96 of Science Press), after gained transforms, bacterial strain is designated as HB2151-2cF9.
HB2151-2cF9 in 2YT-AG substratum, 37 ℃ of (OD while being cultured to logarithmic phase
600=0.8), add the IPTG of final concentration 1mM, 30 ℃ of inductions are spent the night (16~20h), express soluble single-chain antibody ZHB-2cF9.6000rpm, 4 ℃ of centrifugal 15min, collect thalline, hypertonic solution (50mM Tris-HCl, 20% sucrose, 1mM EDTA, pH8.0) resuspended thalline, slowly stir 1h, 4 ℃, the centrifugal 10min of 10000g, pour out supernatant and carry out affinity chromatography (purchased from GE), purification step carries out according to the Standard Operating Procedure of GE, adopt the level pad (Tris50mM that contains 5mM imidazoles, NaCl500mM, pH7.5) balance 1mL nickel post, loading after 10 column volumes, again adopt the foreign protein of non-specific binding on the level pad washing nickel post that contains 5mM imidazoles, with the level pad that contains 50mM imidazoles, wash non-specific foreign protein, finally with the level pad wash-out target protein that contains 100mM imidazoles.15%SDS-PAGE detects the sample of collecting, and Western Blot further identifies single-chain antibody, and primary antibodie is anti-c-myc mouse-anti (brilliant biological purchased from grace), and two resist the antibody for the anti-mouse-HRP of rabbit.Fig. 4 A show after purifying in sample, contain target protein size strip (arrow indication), Western Blot(Fig. 4 B) qualification result is consistent with SDS-PAGE, show to have obtained good purifying through nickel post one step affinity chromatography ZHB-2cF9 single-chain antibody.
The Immunoblot that the anti-CD26 single-chain antibody of embodiment 4 is combined with CD26 extracellular region protein identifies
This experiment purpose is in order to verify the anti-CD26 single-chain antibody ZHB-2cF9 of screening acquisition and the specific binding effect of CD26 extracellular region protein.Recombinant C D26 extracellular region protein carries out SDS-PAGE electrophoresis, and the half-dried method 1h that turns, is transferred to NC film (purchased from Millipore) by albumen; Transfer printing finishes, by film room temperature sealing 1h in 5%MPBS; With 5%MPBS dilution ZHB-2cF9 single-chain antibody to 1 μ g/mL, incubated at room 1h, TBS washing 3 times; With mouse anti-Myc antibody (brilliant biological purchased from grace) incubated at room 1h, TBS washing 3 times; With the anti-mouse-HRP of rabbit bis-is anti-, hatch gel imaging instrument (ImageQuant LAS4000 after 1h, GE) exposure, result as shown in Figure 5, has obvious band at CD26 extracellular region target protein size place, shows that anti-CD26 single-chain antibody ZHB-2cF9 can specificity be combined with CD26 extracellular region protein.
The immunofluorescence of embodiment 5 soluble single-chain antibody ZHB-2cF9 and people's mesothelioma cell NCI-H2452
CD26 is at people's mesothelioma cell NCI-H2452 cell surface high expression level (Inamoto et al. (2007) Clin Cancer Res, 13,4191-200), this experiment is tested and appraised ZHB-2cF9 and is combined situation with the immunofluorescence of NCI-H2452 cell, the single-chain antibody ZHB-2cF9 that further checking screening obtains can be combined with the NCI-H2452 of high expression level CD26 cell-specific, prove simultaneously ZHB-2cF9 can with the CD26 specific binding of cell surface.
By people's mesothelioma cell NCI-H2452 digestion, centrifugal rear resuspended, 1 * 10
5coated 24 orifice plates in/hole are by cell attachment 12h, and 4% paraformaldehyde is fixed, and PBS washes 3 times, 5%MPBS room temperature sealing 1h.PBS washes 3 times, different holes add respectively antibody ZHB-2cF9 or negative control antibody IgG(mouse) (purchased from life technology), hatch 2h for 37 ℃, with PBS washing 3 times, ZHB-2cF9 antibody hole adds mouse-anti myc-FITC antibody (purchased from Sigma-Aldrich), control antibodies hole adds sheep anti mouse fluorescence two anti-(purchased from life technology), hatch 1h for 37 ℃, PBS washing 3 times, fluorescent microscope (Olympus) is observed and takes pictures, result as shown in Figure 6 ZHB-2cF9 single-chain antibody and NCI-H2452 has obvious fluorescence developing, and control antibodies is without obvious fluorescence developing, the single-chain antibody ZHB-2cF9 that shows screening acquisition can be combined with the NCI-H2452 of high expression level CD26 cell-specific, further proof ZHB-2cF9 can with the CD26 specific binding of cell surface.
The adherence inhibition effect of the anti-CD26 single-chain antibody of embodiment 6 to people's mesothelioma cell NCI-H2452
CD26 is by the combination with extracellular matrix protein (ECM), the adhesive attraction of mediation tumour cell, fibronectin is one of common ECM, CD26 and the effect of fibronectin generation specific binding, thereby the adhesion of mediated cell, and this keying action can be blocked by anti-CD 26 antibodies (Inamoto et al. (2007) Clin Cancer Res, 13,4191-200), thus blocking-up tumour cell adhesive attraction.
The humanized antibody of the anti-CD26 mono-clonal mouse-anti of YS110 WeiY's Therapeutics company exploitation, has carried out the clinical experiment of anti-CD26 high expression level tumour at present.According to the heavy chain of YS110 antibody and chain variable region gene sequence (CN101282994), the single-chain antibody pattern of complete synthesis structure YS110, scFv-YS110 is as the positive control of this experiment, the same ZHB-2cF9 of Expression and purification process.
Adhesion experiment adopts 24 orifice plates, five groups of parallel laboratory tests, 4 every group multiple holes, wherein one group is blank group (Blank), directly with 2%BSA sealing, all the other four groups with 20~25 ℃ of coated 90min of 10 μ g/mL fibronectin (purchased from BD Biosciences) room temperatures.PBS adds 2%BSA37 ℃ of sealing 1h after washing 3 times.Simultaneously by 10 * 10
5individual NCI-H2452 cell is washed and after 3 times, is divided into five groups of equivalent with PBS, three groups is antibody test group, cell is respectively with the ZHB-2cF9 containing 50 μ g/mL, positive control scFv-YS110, negative control antibody IgG(mouse) RPMI-1640 medium treatment 2h, other two groups is that control group (Binding group, Blank group) is used with test group containing after the RPMI-1640 medium treatment 2h of equivalent PBS, decile adds in five groups of 24 orifice plates after sealing, and incubator continues to cultivate 12h.With PBS hole flushing 3 times, wash the cell not adhering to off, every hole adds the CCK-8(of 270 μ L RPMI-1640 and 30 μ L purchased from colleague's chemistry institute), 37 ℃ are continued to cultivate 30min, at microplate reader 450nm wavelength place, measure absorbance value (OD value), the size of OD value is directly proportional to viable cell quantity, calculates accordingly the adhesion rate of cell.Cell adhesion rate (%)=and [OD(antibody test group)-OD(Blank group)]/[OD(Binding group)-OD(Blank group)].Fig. 7 shows, cell after processing with scFv-YS110 and ZHB-2cF9 declines to the adhesion of fibronectin, negative control antibody IgG(mouse) do not affect cell adhesion, show that ZHB-2cF9 can suppress the combination of CD26 to ECM, suppress the tumor cell adhesion effect that CD26 mediates, suppressed the Invasion and Metastasis to other organs of tumour cell.
The inhibited proliferation of the anti-CD26 single-chain antibody of embodiment 7 to people's mesothelioma cell NCI-H2452
By NCI-H2452 cell 1 * 10
496 porocyte culture plates are inoculated in/hole, and former substratum is replaced with 1% calf serum substratum (containing effect antibody) after cultivation 12h in 100 μ L/ holes.Cultured cells is divided into three groups, and the corresponding effect antibody adding is respectively: the single-chain antibody ZHB-2cF9 of different concns, positive control scFv-YS110 and negative control antibody IgG(mouse).Effect antibody final concentration is grouped into 0,0.1,1.0,10 μ g/mL, 5 the every group multiple holes of experiment.Incubator continues to cultivate 48h, after observation of cell upgrowth situation, every hole adds the CCK-8(of 10 μ L purchased from colleague's chemistry institute), 37 ℃ are continued to cultivate 30min, at microplate reader 450nm wavelength place, measure absorbance value (OD value), the size of OD value is directly proportional to viable cell quantity, calculates accordingly the inhibiting rate of single-chain antibody ZHB-2cF9 on cell proliferation.As shown in Figure 8, ZHB-2cF9 and positive control scFv-YS110 all have obvious restraining effect to NCI-H2452, and be concentration dependent, the activity of ZHB-2cF9 and positive control is suitable, negative control IgG does not have obvious restraining effect to NCI-H2452, show that ZHB-2cF9 can have restraining effect to the mesothelioma cell proliferation of high expression level CD26, can be used as the potential medicine of CD26 high expression level tumour, and than positive control scFv-YS110, ZHB-pA12 is full humanized antibody, has eliminated the impact of foreign protein on human immune system.
The inhibited proliferation of the anti-CD26 single-chain antibody of embodiment 8 to human colon cancer cell HCT116
Except people's mesothelioma cell NCI-H2452, colon carcinoma cell line HCT116(Abe et al. (2011) the BMC Cancer of high expression level CD26,2011,11:51) be also used to investigate the proliferation inhibiting effect of single-chain antibody to cell.
By HCT116 cell 8 * 10
496 porocyte culture plates are inoculated in/hole, and former substratum is replaced with 1% calf serum substratum (containing effect antibody) after cultivation 12h in 100 μ L/ holes.Cultured cells is divided into three groups, and the corresponding effect antibody adding is respectively: the single-chain antibody ZHB-2cF9 of different concns, positive control scFv-YS110 and negative control antibody IgG(mouse).Effect antibody final concentration is grouped into 0,0.1,1.0,10 μ g/mL, 5 the every group multiple holes of experiment.Incubator continues to cultivate 48h, after observation of cell upgrowth situation, every hole adds the CCK-8(of 10 μ L purchased from colleague's chemistry institute), 37 ℃ are continued to cultivate 30min, at microplate reader 450nm wavelength place, measure absorbance value (OD value), the size of OD value is directly proportional to viable cell quantity, calculates accordingly the inhibiting rate of single-chain antibody ZHB-2cF9 on cell proliferation.As shown in Figure 9, ZHB-2cF9 and positive control scFv-YS110 all have obvious restraining effect to HCT116, and be concentration dependent, the activity of ZHB-2cF9 and positive control is suitable, negative control IgG does not have obvious restraining effect to HCT116, show that ZHB-2cF9 can have restraining effect to the Colon Cancer Cells of high expression level CD26, proving again ZHB-2cF9 can be used as the potential medicine of CD26 high expression level tumour, and than positive control scFv-YS110, ZHB-pA12 is full humanized antibody, has eliminated the impact of foreign protein on human immune system.