The obsession of T cell receptors with MHC (ML06).

The αβreceptors on T cells (TCRs) nearly always recognize peptides from antigens bound to host major histocompatibility complex proteins (MHC). We and others have found some of the residues on TCRs that control their ability to react with MHC. The same TCR residues are used to bind both MHCI and MHCII. This property of TCRs have been inherited through evolution since in the case we test here, a TCR variable region from shark confers the same specificity for MHC on a mouse TCR as the endogenous mouse variable region does. The TCR amino acids we have studied confer generic reactivity with MHC on the TCR, that is, they contribute to binding to MHC regardless of the class or allele. However, TCRs in any individual are biased by positive selection to react only with MHC alleles present in their host. We are now trying to find out what portions of the TCR control specificity for MHC. Our results on this subject will be discussed. [ABSTRACT FROM PUBLISHER]