CONFORMATIONAL-CHANGES IN MHC CLASS-I MOLECULES - ANTIBODY, T-CELL RECEPTOR, AND NK CELL RECOGNITION IN ON HLA-B7 MODEL SYSTEM

In this article we review the role of MHC conformation, including pept ide-induced MHC conformation, in forming antibody (Ab), T-cell recepto r (TCR), and natural killer (NK) cell receptor epitopes. Abs recognize conformational major histocompatibility (MHC) epitopes that often are influenced by the identity of MHC-bound peptide. Diverse TCRs recogni ze a common docking site on peptide/MHC complexes and directly contact peptide. Human NK cell inhibitory receptors (KIR) appear to recognize limited regions of the HLA alpha(1) helix, DX9(+) KIR specifically fo cus on KLA-B residues 82 and 83. However, NK cells recognize much broa der regions of HLA class I molecules and are sensitive to bound peptid es. Thus, several classes of lymphocyte receptors are peptide-specific . Peptide specificity could be the result of direct contact with the r eceptor, or to conformational shifts in MHC residues that interact wit h both receptor and bound peptide.