Murdoch Children's Research Institute, Parkville, Victoria, Australia.
Department of Microbiology and Immunology, University of Melbourne, Melbourne, Victoria, Australia.
Nat Rev Immunol. 2020 Dec;20(12):756-770. doi: 10.1038/s41577-020-0345-y. Epub 2020 Jun 24.
T cell lineages are defined by specialized functions and differential expression of surface antigens, cytokines and transcription factors. Conventional CD4 and CD8 T cells are the best studied of the T cell subsets, but 'unconventional' T cells have emerged as being more abundant and influential than has previously been appreciated. Key subsets of unconventional T cells include natural killer T (NKT) cells, mucosal-associated invariant T (MAIT) cells and γδ T cells; collectively, these make up ~10% of circulating T cells, and often they are the majority of T cells in tissues such as the liver and gut mucosa. Defects and deficiencies in unconventional T cells are associated with autoimmunity, chronic inflammation and cancer, so it is important to understand how their development is regulated. In this Review, we describe the thymic development of NKT cells, MAIT cells and γδ T cells and highlight some of the key differences between conventional and unconventional T cell development.
T 细胞谱系由表面抗原、细胞因子和转录因子的特异性功能和差异表达来定义。传统的 CD4 和 CD8 T 细胞是 T 细胞亚群中研究最多的，但“非常规”T 细胞的丰度和影响力比以前认为的要大。非常规 T 细胞的主要亚群包括自然杀伤 T（NKT）细胞、黏膜相关不变 T（MAIT）细胞和 γδ T 细胞；这些细胞共同构成了约 10%的循环 T 细胞，并且它们通常是肝脏和肠道黏膜等组织中 T 细胞的主要组成部分。非常规 T 细胞的缺陷和不足与自身免疫、慢性炎症和癌症有关，因此了解它们的发育如何受到调控非常重要。在这篇综述中，我们描述了 NKT 细胞、MAIT 细胞和 γδ T 细胞的胸腺发育，并强调了传统和非常规 T 细胞发育之间的一些关键差异。
