I am interested in how the cellular immune system can be used to control cancer and/or viral diseases. In each case, the immune system should be able to use the foreign or abnormal proteins (antigens) expressed by altered cells as a means to detect and destroy them. Part of my efforts are aimed at gaining an understanding of factors which control recognition of tumor cell antigens by a particular subset of T lymphocytes known as CD8+ cytotoxic T lymphocytes (CTL) as well as the factors which control whether or not immunization with a complex antigen results in the efficient recruitment and expansion of CD8+ T cells specifically focused at discrete parts of the antigen protein. The model system employed in our studies has been the large tumor antigen (T ag) of the Simian virus 40 (SV40). The SV 40 T ag can convert normal mouse cells into cancerous cells. However, the presence of the T ag in the cancer cells provides targets (epitopes) that allow for their recognition and destruction by CD8+ T cells of the immune system. Multiple projects have investigated factors which control the immunogenic potential of the multiple epitopes found within the SV40 T ag protein. Other projects have examined how readily these epitope targets can mutate to allow T ag-transformed tumor cells to escape destruction by otherwise potent CTL. These research projects have been done in large part by undergraduate student researchers.