Characterization of complementary determinant region 3δ in human MutS homologue 2-specific γδ T cells.

gamma delta T cells function as sentinels in early host responses to infections and malignancies. Previously, we found ectopically expressed human MutS homologue 2 (hMSH2), recognized by gamma delta T cells, triggered a gamma delta T cell-mediated cytolysis to tumor cells. However, the characteristics of hMSH2-specific gamma delta T. cells are not fully understood. In this study, we investigated the complementary determinant region (CDR) 3 delta diversity of hMSH2-specific gamma delta T cells. We found that the CDR3 delta sequences of hMSH2-specific gamma delta T cells displayed limited diversity, while the length and germline gene usage showed no differences compared with whole CDR3 delta immune repertoire. There are more hydrophilic amino acids in P/N insert of hMSH2-specific gamma delta T cells including the more conserved amino acid at the position 97. Our results offer clues to understanding antigen recognition pattern of gamma delta T cells to stress-induced hMSH2 of tumor cells and also the mechanism of gamma delta T cell-mediated tumor immune surveillance.