T Cell Function + Therapy
Cellular immunotherapy or adoptive T cell therapy involves the isolation and ex vivo expansion of tumor-specific T cells. The tumor-specific T cells are then infused into patients with cancer. There are many forms of adoptive T cell therapy being used for cancer treatment, such as culturing tumor infiltrating lymphocytes (TIL) and isolating and expanding one particular T cell clone. Chimeric antigen receptor (CAR) T cell therapy is when T cells are genetically engineered to express a synthetic receptor that binds a tumor antigen. Dramatic clinical responses and high rates of complete remission have been observed in the setting of CAR T cell therapy of hematopoietic malignancies.
Our approach has been to utilize T cells taken directly from the patient’s blood after they have received a cancer vaccine. We have found by “priming” rare tumor antigen specific T cells first, with active immunization, we are much more able to expand those T cells in the laboratory to greater numbers for therapeutic infusion. A unique aspect to our approach for adoptive T cell therapy is the use of tumor-specific CD4+ Th1 cells which may enhance anti-tumor efficacy. Adoptive T cell therapy strategies have largely focused on the infusion of tumor antigen specific cytotoxic T cells (CTL) which can directly kill tumor cells. However, CD4+ Th cells have a broader functionality. Th can activate antigen-specific effector cells and recruit cells of the innate immune system such as macrophages and dendritic cells to assist in antigen presentation (APC). Moreover, antigen primed Th cells can directly activate tumor antigen-specific CTL.