Abstract
The major histocompatibility complex molecules bind and present short antigenic peptide fragments on the surface of antigen presenting cells to T-cell receptors. Recognition of peptide-MHC by cytotoxic T-cells initiates a cascade of signals to T-cells, which in turn destroy the antigen presenting cell. In the design of molecular vaccines for the treatment of diseases, an understanding of the 3-dimensional structure of MHC class I and is interaction with both peptide and T-cell receptor is an important prerequisite. In this review, we will discuss such crystal structures, as well as structures of glycopeptides and alternative T-cell antigens presented by MHC molecules.