Postnatal expansion, maturation and functionality of MR1 T cells in humans

摘要: MR1-restricted T cells (MR1Ts) are a cell subset that recognizes and mediate host immune responses to broad array of microbial pathogens, including Mycobacterium tuberculosis. Here, we sought characterize development circulating human MR1T cells, defined by MR1-5-OP-RU tetramer labelling expression TRAV1-2/CD26/CD161. We analyzed postnatal expansion, maturation functionality peripheral blood in cohorts from three different geographic settings with TB vaccination practices, levels exposure infection M. Early after birth, frequencies tetramer-defined increased rapidly several fold. This coincided marked phenotypic changes, predominantly CD4+ TRAV1-2- phenotype neonates, TRAV1-2+CD8+ also expressed CD26 CD161. observed tetramer+ TNF upon mycobacterial stimulation were very low but ~10-fold the first year life. These functional MR1Ts all age groups tetramer+, TRAV1-2+ CD161, markers appeared signal this subset. age-associated was loss naïve on more than tetramer+TRAV1-2- non-MR1T cells. data suggest neonates have infrequent populations diverse attributes environment preferentially expands tetramer+TRAV1-2+ population which becomes predominant early during childhood.