Synergy between dendritic cell-based vaccine and anti-CD137 monoclonal antibody in the treatment of mouse renal cell carcinoma

Therapeutic efficacy of dendritic cell-based vaccine for renal cell carcinoma remains limited. In this study, we investigated whether anti-CD137 monoclonal antibody is capable of potentiating anti-tumor effect of dendritic cellbased vaccine. Experimental study. Research laboratory. Balb/c mice [8-10 weeks old]. A renal cell carcinoma model was established by subcutaneous injection of Renca tumor cells into Balb/c mice on day 0. After three days, tumor-bearing mice were treated with Renca tumor lysate-pulsed dendritic cells [i.e., dendritic cell-based vaccine], anti-CD137 monoclonal antibody, or combination of Renca tumor lysate-pulsed dendritic cells with anti-CD137 monoclonal antibody. Mice were killed on day 20 after tumor cell inoculation, and spleens were harvested for analysis of anti-tumor immune responses. The anti-tumor immune responses were analyzed by measuring proliferation and activity of T cells, which have the ability to kill tumor cells. The anti-tumor effect was assessed by measuring tumor size. The combination therapy with Renca tumor lysatepulsed dendritic cells and anti-CD137 antibody significantly increased T-cell proliferation and activity, and significantly inhibited tumor growth, compared with a single treatment with Renca tumor lysate-pulsed dendritic cells or anti-CD137 antibody. These results suggest that combination therapy can enhance anti-tumor effect by increasing T-cell proliferation and activity