STRUCTURAL BASIS OF T CELL RECOGNITION

Abstract

▪ Abstract Exciting breakthroughs in the last two years have begun to elucidate the structural basis of cellular immune recognition. Crystal structures have been determined for full-length and truncated forms of αβ T cell receptor (TCR) heterodimers, both alone and in complex with their peptide-MHC (pMHC) ligands or with anti-TCR antibodies. In addition, a truncated CD8 coreceptor has been visualized with a pMHC. Aided in large part by the substantial body of knowledge accumulated over the last 25 years on antibody structure, a number of general conclusions about TCR structure and its recognition of antigen can already be derived from the relatively few TCR structures that have been determined. Small, but important, variations between TCR and antibody structures bear on their functional differences as well as on their specific antigen recognition requirements. As observed in antibodies, canonical CDR loop structures are already emerging for some of the TCR CDR loops. Highly similar docking orientations of...