Genomic Organization and Polymorphism of the T Cell Receptor

Abstract

The genes encoding the two forms of TcK, αβ, and γδ have now been cloned and largely characterized in both the human and murine systems. They are distinct from the immunoglobulin genes, although their basic genomic organization and mechanisms of recombination are similar to those of the B cell antigen-recognition genes. A model is presented for explaining the interaction between the TcR αβ chains and antigens bound to major histocompatibility complex (MHC) molecules. Just as the TcR αβ chains, the γδ chains may also recognize antigen on the surface of other cells, although this has so far been reported only in one instance. The proliferative and cytotoxic responses expressed by this γδ cell line are toward an allogcnic target cell. Further experiments are needed for determining whether γδ cells can also recognize foreign antigens in association with self-MHC encoded molecules. © 1990 Academic Press Inc.