Characterization of the diversity of T cell receptor-y6 complementary determinant region 3 in human peripheral blood by Immune Repertoire Sequencing

gamma delta T cells function as sentinels in early host response to infections and malignancies. Although gamma delta T cells are regarded as innate immune cells and recognize antigens in a non-MHC restricted manner, they possess a huge diversity of complementary determinant region 3 (CDR3) of T cell receptor (TCR) generated by the rearrangement of germ-line gene V-(D)-J-Cfragments. However, the detailed characteristics of the TCR gamma delta CDR3 repertoire remain unclear. A comprehensive analysis would answer fundamental questions about the diversity of the TCR gamma delta CDR3 repertoire and elucidate the mechanism underlying gamma delta T cell recognition of pathogens and tumor antigens. In this study, we used Immune Repertoire Sequencing (IR-SEQ) to analyze the diversity of TCR-gamma delta CDR3 repertoires from 30 healthy donors. The results show that IR-SEQ had sufficient repeatability to analyze the TCR gamma delta CDR3 repertoire. The diversity of TCR gamma delta CDR3 repertoire is quite dispersed and individually different. The TCR delta chain (TRD) repertoire displayed more diversity and less sharing among individuals compared with TCR chain (TRG). To our knowledge, this is the first study to use IR-SEQ to characterize the repertoire of TCR gamma delta CDR3 in human peripheral blood yS T cells by using IR-SEQ Our findings provide a basic understanding of the diversity of TCR gamma delta repertoire in the physiological condition, which provides a clue to the underlying mechanism of 'gamma delta T cell recognition of pathogens and tumor antigens. (C) 2017 Elsevier B.V. All rights reserved.