摘要
Theγδcells are a unique population of T lymphocytes that combine innate-like features and adaptive-type responses and play an important role in the early host response to infections and malignancies.Different fromαβT cells,γδT cells recognize a limited set of antigens,which are shared by a variety of microbial pathogens and tumor cells in a non-MHC restricted manner;1 thus,these cells use the TCR in a manner similar to a pattern recognition receptor(PRR).Moreover,whereasαβT cells require antigen-and cytokine-driven clonal expansion,γδT cells are equipped with immediate effector functions.1 However,the potentialγδrepertoire with junctional diversity is estimated at∼10^(18),which is much greater than theαβrepertoire(∼10^(16)),thus raising questions concerning the forces governing the selection of such a huge TCR repertoire during ontogeny and whether and how theγδTCR repertoire is shaped under physiological and pathological conditions.
