Construction of human naive phage antibody library and primary screening of the gab antibodies against gp96 / 中国综合临床

ABSTRACT

Objective To construct a naive human Fab fragment phage display library,from which the anti-gp96 antibodies may be panned by the gp96 purified from the tissue of urothelial carcinoma in the urinary bladder and provide a basis to new therapy for the malignant tumors.Methods Peripheral blood lymphocytes were isolated from 800 ml of blood,which was obtained from four healthy blood donors.The heavy chain Fd and light chain cDNA synthesized from the total RNA of lympbocytes were amplified by PCR with variable regions 5' and 3' primers of heavy and light chain, and the amplification products were ligated into the phagemid vector pComb3, then the ligated sample was transformed into competent E.coli XL1-Blue by electroperation.The transformed cells were infected with VCSM13 helper phage to yield recombinant phage antibody Fabs.The phagemids abstracted from amplified E.coli were cut with endonucleases such as Sac Ⅰ,Xba Ⅰ,Xho Ⅰ and Spe Ⅰ, and both the phage antibody Fabs and phage-raids abstracted from amplified E.coil were amplified by PCR to monitor the insertion of the genes of light chain or heavy chain Fd fragment.The gp96 purified from the urothelial carcinoma tissue of the bladder by affinity chromatog-raphy on eoncanavalin-A sephnrose and DEAE-sephnrose ion exchange chromatography were utilized as antigens to process three rounds of panning to the original Fab antibody library.Results The quantity of total RNA and cDNA were qualified.By combination of light chain and heavy chain genes, an antibody library containing 6.6×106 clones was obtained, and both the cutting of enzymes and PCR showed that there were the genes of light chain or heavy chain Fd fragment in the phagemids.The gp96 protein was obtained from urothelial carcinoma tissue in the urinary bladder.After having been panned by gp96, the original antibody library gained enrichment by 68 times.Conclusion Utilizing the technology of phage surface display, specific antibody can be gained from the human naive Fab phage display library,which can be used for immunological therapy for tumors.