The structure and function of MHC molecules. Possible implications for the control of tumor growth by MHC-restricted T cells.

We briefly survey recent basic progress on the structure and function of MHC molecules. We call attention on a number of remaining unanswered questions, and focus on a few points which we think might be of importance in immune surveillance against tumors mediated by MHC restricted T cells. In particular, we discuss the possible peptidic nature of certain tumor antigens. Following these lines, we mention a recent approach for the in vivo activation of specific CTL.