MRC Centre for Immune Regulation, Institute for Biomedical Research, Medical School, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK,
Curr Top Microbiol Immunol. 2014;373:19-47. doi: 10.1007/82_2013_320.
The development of CD4(+) helper and CD8(+) cytotoxic T-cells expressing the αβ form of the T-cell receptor (αβTCR) takes place in the thymus, a primary lymphoid organ containing distinct cortical and medullary microenvironments. While the cortex represents a site of early T-cell precursor development, and the positive selection of CD4(+)8(+) thymocytes, the thymic medulla plays a key role in tolerance induction, ensuring that thymic emigrants are purged of autoreactive αβTCR specificities. In recent years, advances have been made in understanding the development and function of thymic medullary epithelial cells, most notably the subset defined by expression of the Autoimmune Regulator (Aire) gene. Here, we summarize current knowledge of the developmental mechanisms regulating thymus medulla development, and examine the role of the thymus medulla in recessive (negative selection) and dominant (T-regulatory cell) tolerance.
CD4(+)辅助和 CD8(+)细胞毒性 T 细胞表达 αβ 形式的 T 细胞受体（αβTCR）的发育发生在胸腺中，胸腺是包含独特皮质和髓质微环境的主要淋巴器官。虽然皮质代表早期 T 细胞前体发育和 CD4(+)8(+)胸腺细胞的阳性选择的部位，但胸腺髓质在诱导耐受方面起着关键作用，确保胸腺迁出物清除自身反应性的 αβTCR 特异性。近年来，人们在理解胸腺髓质上皮细胞的发育和功能方面取得了进展，特别是表达自身免疫调节剂（Aire）基因的亚群。在这里，我们总结了调节胸腺髓质发育的发育机制的最新知识，并研究了胸腺髓质在隐性（阴性选择）和显性（T 调节细胞）耐受中的作用。
