Regulation of thymus size by competition for stromal niches among early T cell progenitors
Regulation of thymus size by competition for stromal niches among early T cell progenitors
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DOI：
10.4049/jimmunol.173.3.1604
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发表时间：
2004-08-01
影响因子：
4.4
通讯作者：
Petrie, HT
中科院分区：
文献类型：
--
作者：
Prockop, SE;Petrie, HT
胸腺T细胞产生的特征在于非自我更新的骨髓源性祖细胞的分化波。限制新祖细胞募集、胸腺内前体扩增和胸腺大小的因素仍然是个谜，但据信是由一个反馈回路控制的，该回路响应于淋巴细胞构成和对基质小生境的竞争。在这项研究中，我们表明，竞争基质龛确实发生，但仅限于细胞在早期CD 4（-）8（-）前体分化阶段。器官的总体大小由早期前体细胞扩增的限制和第二个细胞内在限制决定，第二个细胞内在限制是祖细胞向CD 4（+）8（+）阶段过渡的扩增。与不对称使用骨髓来源的祖细胞重建胸腺内池一起，这些过程促进了新T细胞的连续产生，同时保持相对稳定的器官大小。
Thymic T cell production is characterized by differentiating waves of non-self-renewing, bone marrow-derived progenitors. The factors constraining new progenitor recruitment, intrathymic precursor expansion, and thymus size remain enigmatic, but are believed to be controlled by a feedback loop responding to lymphoid cellularity and competition for stromal niches. In this study, we show that competition for stromal niches does occur, but is solely limited to cells at the early CD4(-)8(-) precursor stages of differentiation. The overall size of the organ is determined both by this limitation on early precursor expansion, and by a second, cell-intrinsic limit on expansion of progenitor cells transiting to the CD4(+)8(+) stage. Together with asymmetric use of marrow-derived progenitors to reconstitute the intrathymic pool, these processes facilitate continuous generation of new T cells while maintaining a relatively stable organ size.