[Human tumor-rejection antigens and peptides from genes to clinical research]

One of the most significant advances in the field of modern tumor immunology is the identification of genes encoding tumor-rejection antigens that are recognized by human leukocyte antigen (HLA) class I-restricted and tumor-specific cytotoxic T lymphocytes (CTLs). Several peptides encoded by these genes are now under clinical trial as cancer vaccines, and major tumor regression has been observed in some melanoma patients. These results indicate that identification of the peptides capable of inducing CTLs may provide a new modality of cancer therapy. We investigated tumor-rejection antigens from epithelial cancers, and reported 7 genes encoding tumor-rejection antigens and peptides available for specific immunotherapy of HLA-A26 or -A24 patients with epithelial cancers. Furthermore, we identified more than 10 genes encoding tumor-rejection antigens and peptides available for specific immunotherapy of HLA-A2 patients with epithelial cancers. Therefore these new antigens and peptides could be applicable to the treatment of numerous epithelial cancer patients worldwide. Phase I clinical trials of cancer vaccine with these peptides for epithelial cancer patients are in progress at our university. Basic and clinical research will provide new insights for a better understanding of the molecular basis of T cell-mediated recognition of cancer cells and be important for the development of cancer vaccines.