Recognition of the product of a novel MHC TL region gene (27b) by a mouse gamma delta T cell receptor.

The gamma delta T cell receptor (TCR) derived from the mouse KN6 T cell hybridoma recognizes an autologous determinant encoded by a broadly expressed gene mapping in the TL region of the major histocompatibility complex (MHC). We have cloned the gene and demonstrated that it is a novel class I gene (designated 27b) belonging to a hitherto undescribed TL region gene cluster in strain C57BL/6. The BALB/c allele of 27b, gene T17c, is defective because it lacks an appropriate splice acceptor site, which explains the lack of recognition of BALB/c stimulator cells by the KN6 cells. We propose that gamma delta TCR and nonclassical MHC and MHC-related class I molecules have coevolved to recognize a conserved set of endogenous and foreign determinants.