Anderson Graham, Jenkinson Eric J, Rodewald Hans-Reimer
MRC Centre for Immune Regulation, Institute for Biomedical Research, University of Birmingham, UK.
Eur J Immunol. 2009 Jul;39(7):1694-9. doi: 10.1002/eji.200939379.
Thymic epithelial cells (TEC) are essential components of the thymus that guide and control the development and TCR repertoire selection of T cells. Previously, TEC have been considered as postmitotic cells that, once generated during ontogeny, were maintained in their mature state. Recently, it has become clear that TEC can be generated from common or committed medullary and cortical TEC progenitor cells in ontogeny, that stages of immature and mature TEC are phenotypically separable, and that TEC undergo a rapid turnover in a matter of a few weeks. All of these findings strongly suggest that in the adult thymus mature TEC are constantly regenerated from a pool of stem or progenitor cells, a view that renders the thymus structure potentially much more dynamic than previously thought. However, the identity of "thymus stem cells" is elusive, and developmental stages of TEC development are only beginning to be elucidated.
胸腺上皮细胞（TEC）是胸腺的重要组成部分，可引导和控制T细胞的发育以及T细胞受体库的选择。以前，TEC被认为是有丝分裂后细胞，一旦在个体发育过程中产生，就会维持在成熟状态。最近，已经明确在个体发育过程中，TEC可由常见的或定向的髓质和皮质TEC祖细胞产生，不成熟和成熟TEC阶段在表型上是可分离的，并且TEC在几周内会经历快速更新。所有这些发现都强烈表明，在成年胸腺中，成熟TEC不断地从干细胞或祖细胞池中再生，这一观点使胸腺结构的动态性可能比以前认为的要大得多。然而，“胸腺干细胞”的身份难以捉摸，TEC发育的阶段才刚刚开始得到阐明。
