An anti-P-gp/anti-CD3 bispecific antibody cytotoxic to human multidrug resistant KB cells
Gao, Y.-d.; Xiong, D.-s.; Yang, M.; Xu, Y.-f.; Shao, X.-f.; Peng, H.; Fan, D.-m.; Yang, C.-z.
Zhonghua Zhong Liu Za Zhi 27(11): 653-656
2005
ISSN/ISBN: 0253-3766 PMID: 16438884 Document Number: 589340
To study the specific cytotoxicity mediated by anti-P-gp/anti-CD(3) diabodies in multidrug resistant solid tumor using P-gp as target. The anti-P-gp/anti-CD(3) diabodies were secreted from E. coli strain 16C9 containing the expression plasmid PAYZDCP, grown at 30 degrees C in a shaker flask; the diabodies were purified by affinity chromatography and identified by SDS-PAGE; the effect of the anti-P-gp/anti-CD(3) diabody mediated lysis of P-gp-expressing tumor cells was assayed by (51)Cr release assay in vitro, and by human KB nude mouse xenograft models in vivo. The diabodies were generated by bacteria as a soluble functional form and purified by one-step affinity chromatography with a yield > 4 mg/L culture medium. In (51)Cr release assay, the diabodies targeted human activated T cells to lyse P-gp(+)-KB/MDR cells in a dose-dependent manner. It suggested that the diabody was able to induce an efficient lysis of the target cells by human T cells in vitro. When combined with activated human T cells, the diabody significantly inhibited the growth of KB/MDR, but had no effect on KB xenografts. The anti-P-gp/anti-CD(3) bispecific antibody is a potent agent for targeting human T lymphocytes to lyse solid tumor cells overexpressing P-gp in vitro and in vivo.