The role of recombinant bacille Calmette-Guérin expressing recombinant human B7-2 on PBMC against bladder cancer cells / 肿瘤研究与临床

ABSTRACT

Objective To investigate the expression of IFN-α of the peripheral blood monocytes (PBMC) stimulated by bacille Calmeue-Guérin (BCG) expressing recombinant human B7-2, and the antitumor effect of BCG activated killer cells(BAK). Methods Expression of human B7-2 was detected by SDS-PAGE and ELISA. Recombinant BCG and wild-type BCG were used to stimulate PBMC in different concentrations in vitro. Supernatant was collected at various time points and IFN-α was detected by an enzyme-linked immunosorbent assay (ELISA). MTT assay was used to observe the effects of recombinant BCG on proliferation of T cell, and LDH assay was used to study antitumor cytotoxicity of BAK cells. Results The concentration of human B7-2 in culture was 3.8 U/ml by ELISA. Compared with wild-type BCG, recombinant BCG can induce more IFN-α. The results of the LDH release assay showed that the anti-tumor activity of BAK cells stimulated by recombinant BCG was 2.14 fold higher than that of wild-type BCG. Conclusion The expression of IFN-α in PBMC stimulated by recombinant BCG is higher than that stimulated by wild-type BCG, suggesting that enhanced antitumor activity of BAK when bladder cancer cells could be enchanced by using recombinant BCG.