Negative selection in the thymus includes semimature T cells.
Negative selection in the thymus includes semimature T cells.
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DOI：
10.1084/jem.185.2.263
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发表时间：
1997-01-20
期刊：
影响因子：
--
通讯作者：
Sprent J
中科院分区：
文献类型：
--
作者：
Kishimoto H;Sprent J
胸腺髓质在负选择（自身耐受诱导）中起着关键作用，并含有前往胸腺外环境的分化T细胞。然而，由于相对成熟，髓T细胞被认为超出了耐受诱导阶段。这一悖论通过发现髓质T细胞（CD 4 +8−胸腺细胞）包含两个不同的亚群而得到解决。表达完全成熟（HSAlo）表型的髓质胸腺细胞对耐受诱导具有强烈抗性，而具有半成熟（HSAhi）表型的细胞对耐受敏感。这些发现表明，从皮质到达髓质的分化的T细胞在获得完全成熟的耐受性抗性表型之前的短暂时间内对耐受诱导保持敏感。髓T细胞的半成熟亚群显示出对耐受诱导的独特要求;根据使用的条件，耐受这些细胞可能涉及Fas（CD 95）依赖性或Fas非依赖性途径。
The thymic medulla plays a key role in negative selection (self-tolerance induction) and contains differentiated T cells en route to the extrathymic environment. However, being relatively mature, medullary T cells are thought to be beyond the stage of tolerance induction. This paradox is resolved by the finding that medullary T cells (CD4+8− thymocytes) comprise two distinct subsets. Medullary thymocytes expressing a fully mature (HSAlo) phenotype are strongly resistant to tolerance induction, whereas cells with a semimature (HSAhi) phenotype are tolerance susceptible. These findings suggest that the differentiated T cells reaching the medulla from the cortex remain sensitive to tolerance induction for a brief period before acquiring a fully mature tolerance-resistant phenotype. The semimature subset of medullary T cells displays unique requirements for tolerance induction; depending upon the conditions used, tolerizing these cells can involve either a Fas (CD95)-dependent or a Fas-independent pathway.