Principal Investigator Jianzhu Chen
CD8 T cells are critical for the clearance of virus infection as well as tumor cells. Harnessing the power of CD8 immunity to kill tumor cells has been a long-term goal of cancer immunotherapy. We have developed a mouse model in which CD8 T cell response and tolerance to a spontaneous prostate cancer can be monitored in detail. We have shown that tumor-specific CD8 T cells can be activated in tumor-bearing mice by virus infection. Although the resulting effector CD8 T cells infiltrate prostate tumor and remain functional in the tumor tissue for several days, eventually the T cells are inactivated or tolerized by the persistent expression of tumor antigen and the tumor environment. Interestingly, a population of tumor-specific CD8 T cell persists in the tumor tissue, analogous to the tumor-infiltrating lymphocytes in human. We are investigating the basis for the persistence of tumor-specific CD8 T cells in the tumor tissue and developing approaches to delay the tolerance induction and reactivate the tumor-specific CD8 T cells. Findings from these studies may help develop more effective cancer immunotherapy.