Stephens Geoffrey L, Andersson John, Shevach Ethan M
Cellular Immunology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
J Immunol. 2007 Jun 1;178(11):6901-11. doi: 10.4049/jimmunol.178.11.6901.
Expression of the transcription factor FoxP3 is the hallmark of regulatory T cells that play a crucial role in dampening immune responses. A comparison of the development and phenotype of FoxP3(+) T cells in relation to the expression of conventional MHC molecules facilitated the identification of several distinct lineages of naive and effector/memory populations of Foxp3(+) T cells. One subpopulation of effector/memory Foxp3(+) T cells develops in the thymic medulla, whereas the second is thymic independent. Both lineages display a distinct activated phenotype, undergo extensive steady-state proliferation, home to sites of acute inflammation, and are unique in their capacity to mediate Ag-nonspecific suppression of T cell activation directly ex vivo. Effector FoxP3(+) T cells may act as a sentinel of tolerance, providing a first line of defense against potentially harmful responses by rapidly suppressing immunity to peripheral self-Ags.
转录因子FoxP3的表达是调节性T细胞的标志，调节性T细胞在抑制免疫反应中起关键作用。通过比较FoxP3(+) T细胞的发育和表型与传统MHC分子的表达，有助于鉴定出Foxp3(+) T细胞的几个不同的幼稚和效应/记忆群体谱系。效应/记忆Foxp3(+) T细胞的一个亚群在胸腺髓质中发育，而第二个亚群不依赖胸腺。这两个谱系都表现出独特的活化表型，经历广泛的稳态增殖，归巢到急性炎症部位，并且其独特之处在于能够在体外直接介导对T细胞活化的抗原非特异性抑制。效应性FoxP3(+) T细胞可能作为耐受性的哨兵，通过快速抑制对外周自身抗原的免疫反应，提供针对潜在有害反应的第一道防线。
