THE HUMAN T-CELL RECEPTOR IN HEALTH AND DISEASE

The T cell antigen receptor (TCR) recognizes antigen in the form of short peptides bound to a major histocompatibility (MHC) molecule. This review provides a synopsis of the current state of knowledge of the structure and function of the receptor and its possible role in human disease. Analysis of the T cell receptor usage of T-cell lines and clones recognizing the same peptide-MHC complex is beginning to shed light onto the structural basis of the TCR-peptide-MHC complex. Also, it is now apparent that there are two mechanisms by which the TCR can interact with the MHC molecule, either through classical peptide interactions or through superantigens. Finally, we review the role of specific TCRs in human disease. Current evidence in this area is difficult to interpret; however, it is likely that TCR-mediated disease susceptibility exists, and its basis at either a germline or somatic level will soon be clarified.