Getting into the groove: Unusual features of peptide binding to MHC class I molecules and implications in vaccine design

The major histocompatibility complex presents antigenic peptides on the sur face of antigen presenting cells to T cell receptors. Recognition of peptid e-MHC by T cells initiates a cascade of signals in T cells which maintains a T cell dependent immune response. An understanding of the how peptides bi nd to MHC class I molecules is an important prerequisite in the design of v accines. Herein, we will discuss, with special emphasis on MUC1, unusual fe atures of MUC1 peptide binding to MHC class I, obtained from vaccine studie s including a MUC1 peptide mimic and the crystal structures of low and high affinity peptides lacking canonical anchor motifs in complex with H-2K(b).