Human tumor antigens recognized by T cells and their implications for cancer immunotherapy

Recent clinical trials of immunotherapies indicate that tumor reactive autologous T cells are able to regress even advanced, large tumors in melanoma patients. For example, the adoptive transfer of CD8+ cytotoxic T lymphocytes (CTL) specifically targeted for identified tumor antigens following lymphodepletive treatment, such as fludarabine/cyclophosphamide administration and total body irradiation, led to objective tumor responses in more than 70% of patients with melanoma (Dudley et al. 2008). Immunological analyses on these tumor tissues demonstrated that administered T cells may eliminate tumor cells through direct killing and cytokine secretion. Therefore, CD8+ CTLs that recognize MHC class I positive cancer cells are important for in vivo tumor rejection.