Nitta Takeshi, Suzuki Harumi
Department of Immunology and Pathology, Research Institute, National Center for Global Health and Medicine, Chiba, 272-8516, Japan.
Cell Mol Life Sci. 2016 Mar;73(5):1021-37. doi: 10.1007/s00018-015-2107-8. Epub 2016 Jan 29.
The thymus provides a specialized microenvironment in which a variety of stromal cells of both hematopoietic and non-hematopoietic origin regulate development and repertoire selection of T cells. Recent studies have been unraveling the inter- and intracellular signals and transcriptional networks for spatiotemporal regulation of development of thymic stromal cells, mainly thymic epithelial cells (TECs), and the molecular mechanisms of how different TEC subsets control T cell development and selection. TECs are classified into two functionally different subsets: cortical TECs (cTECs) and medullary TECs (mTECs). cTECs induce positive selection of diverse and functionally distinct T cells by virtue of unique antigen-processing systems, while mTECs are essential for establishing T cell tolerance via ectopic expression of peripheral tissue-restricted antigens and cooperation with dendritic cells. In addition to reviewing the role of the thymic stroma in conventional T cell development, we will discuss recently discovered novel functions of TECs in the development of unconventional T cells, such as natural killer T cells and γδT cells.
胸腺提供了一个特殊的微环境，在这个微环境中，各种造血和非造血来源的基质细胞调节T细胞的发育和库的选择。最近的研究一直在揭示胸腺基质细胞（主要是胸腺上皮细胞，即TECs）发育的时空调节的细胞间和细胞内信号以及转录网络，以及不同TEC亚群控制T细胞发育和选择的分子机制。TECs分为两个功能不同的亚群：皮质TECs（cTECs）和髓质TECs（mTECs）。cTECs凭借独特的抗原加工系统诱导不同的和功能不同的T细胞进行阳性选择，而mTECs通过外周组织限制性抗原的异位表达以及与树突状细胞的合作对于建立T细胞耐受性至关重要。除了回顾胸腺基质在传统T细胞发育中的作用外，我们还将讨论TECs在非传统T细胞（如自然杀伤T细胞和γδT细胞）发育中最近发现的新功能。
