The human T cell receptor δ (TCR δ) gene encodes one component of the TCR -γδ-CD3 complex found on subsets of peripheral blood and thymic T cells. Human TCR δ diversity was estimated by characterizing rearangements in TCR γδ cell lines and determining the stucures of complementary DNA clones representing functional and nonfunctional transcripts in these cell lines. One Vδ segment and one Jδ segment were identified in all functional tanscripts, although a distinct Jδ segment was idetified in a truncated tansript. Further, one Dδ element was identified, and evidence for the use of an additional Dδ dement was obtained. Thus human TCR δ genes appear to use a limited number of germline elements. However, the apparent use of two Dδ elements in tandem coupled with imprecise joining and extensive incorporation of N nucleotides generates unprecedented variability in the junctional region.
ASJC Scopus subject areas