[An anti-P-gp/anti-CD3 bispecific antibody cytotoxic to human multidrug resistant KB cells].
OBJECTIVE
To study the specific cytotoxicity mediated by anti-P-gp/anti-CD(3) diabodies in multidrug resistant solid tumor using P-gp as target.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Gao
Ying-dai
YD
State Key Laboratory of Experimental Hematology, Institute of Hematology, Chinese Academy of Medical Sciences, Peking Union Medical College, Tianjin 300020, China.
Xiong
Dong-sheng
DS
Yang
Ming
M
Xu
Yuan-fu
YF
Shao
Xiao-feng
XF
Peng
Hui
H
Fan
Dong-mei
DM
Yang
Chun-zheng
CZ
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000276:immunology*; D000818:Animals; D018033:Antibodies, Bispecific / Q000276:immunology / Q000627:therapeutic use*; D017252:CD3 Complex / Q000276:immunology*; D018432:Drug Resistance, Multiple / Q000276:immunology; D019008:Drug Resistance, Neoplasm / Q000276:immunology*; D005260:Female; D006801:Humans; D007624:KB Cells; D051379:Mice; D008819:Mice, Nude; D009374:Neoplasms, Experimental / Q000628:therapy*; D015202:Protein Engineering / Q000379:methods; D011994:Recombinant Proteins / Q000627:therapeutic use; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018033:Antibodies, Bispecific; D017252:CD3 Complex; D011994:Recombinant Proteins