Margolis D, Yassai M, Hletko A, McOlash L, Gorski J
Blood Research Institute, The Blood Center of Southeastern Wisconsin, Milwaukee 53226, USA.
J Immunol. 1997 Jul 15;159(2):529-33.
Analysis of TCR rearrangement profiles of well-defined thymocyte populations in a number of individual thymi provides evidence for a new pathway of lineage commitment. In all of the thymi analyzed, alphabeta thymocytes have rearrangements in the delta locus that are enhanced for out-of-frame rearrangements. Thus, not only did alphabeta thymocytes pass through a stage in differentiation that included delta rearrangement, but they also constitute a population that was relatively unsuccessful at these rearrangements. Interestingly, in some thymi, gammadelta thymocytes have out-of-frame beta rearrangements. This represents a novel pathway in which delta and beta rearrangement happens concurrently. In this pathway, selection favors whichever gene is in frame, thus improving the chances of generating useful T cells. In other thymi, gammadelta cells showed no obvious beta gene rearrangement, indicating a sequential rearrangement. Thus, alphabeta/gammadelta lineage commitment can follow at least two distinct pathways in different individuals.
对多个个体胸腺中明确的胸腺细胞群体的TCR重排谱进行分析，为谱系定向的新途径提供了证据。在所有分析的胸腺中，αβ胸腺细胞在δ基因座上发生重排，其中框外重排增强。因此，αβ胸腺细胞不仅经历了包括δ重排在内的分化阶段，而且它们还构成了在这些重排中相对不成功的群体。有趣的是，在一些胸腺中，γδ胸腺细胞存在框外β重排。这代表了一种δ和β重排同时发生的新途径。在这条途径中，选择有利于任何一个处于读框内的基因，从而提高产生有用T细胞的机会。在其他胸腺中，γδ细胞未显示明显的β基因重排，表明是顺序重排。因此，αβ/γδ谱系定向在不同个体中至少可以遵循两条不同的途径。
