Abstract:Objective:To construct a eukaryotic expression system of human anti-TROP2 antibody IgG by using human anti-TROP2 Fab antibody gene as template,so as to study its inhibition of pancreatic cancer cell proliferation. Methods:The recombinant expression vector of human anti-TROP2 antibody IgG,named as pWS-anti-TROP2,was established by amplifying the heavy chain and light chain genes of human anti-TROP2 antibody IgG,respectively. pWS-anti-TROP2 plasmids were transfected into CHO dhfr- cell lines,and the monoclonal cell strains with high antibody expression were harvested by MTX screening. Then,human anti-TROP2 antibody IgG was obtained using Protein G affinity purification. The identification and immunological characteristics of the human anti-TROP2 antibody IgG were analyzed by several methods,including sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE),Westent blotting assay,enzyme-linked immuno sorbent assay(ELISA),flow cytometry method(FCM) and immuno fluorescence assay. The inhibition function of human anti-TROP2 antibody IgG in proliferation of BxPC3 cells was analyzed by MTT assay. Results:The eukaryotic expression system of human anti-TROP2 antibody IgG was constructed successfully. Purified human anti-TROP2 antibody IgG was obtained. The molecular weight of light and heavy chains of human anti-TROP2 antibody IgG are consistent with expected results,the antibodies could bind to TROP2 protein specifically,and the antibody titer reached 1∶6 400. MTT assay demonstrated that human anti-TROP2 antibody IgG played a significant pole in inhibiting BxPC3 cell proliferation,and the inhibition ratio was gradually increased with prolonged time and increased antibody dose. Conclusion:In the study,the eukaryotic expression system of human anti-TROP2 antibody IgG was established successfully,and it was proved that the antibody could recognize native TROP2 protein on pancreatic cancer cell surface specificially and play an important role in inhibiting the proliferation of pancreatic cancer cells.