Insertion/deletion-related polymorphisms in the human T cell receptor β gene complex

Abstract

The TCR, a heterodimer comprised of an α and β chain, mediates the corecognition of antigen and MHC molecules by T cells. The α and ⇆b chains of the TCR are encoded in gene complexes that include segments corresponding to the V, J, D, and C regions of the receptor chains (1-3). Diversity, which characterizes T cell responses, is generated by rearrangement of TCR gene segments in the course of T cell maturation (4). Somatic mutation appears to play little or no role in the diversity of the TCR, thus enhancing the importance of polymorphism in the germline genes (5-7). Genetic polymorphism reported to date in human TCR-β genes has been limited relative to that described for some mouse strains in which significant deletions occur within the TCR-β complex (8-10). In the current report, we show that areas of insertion/deletion are likewise present within the human TCR-β gene complex.