Dai Z, Lakkis F G
Sections of Nephrology and Immunobiology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA.
J Immunol. 2001 Dec 15;167(12):6711-5. doi: 10.4049/jimmunol.167.12.6711.
Despite declining thymic output with age, the peripheral naive T cell pool of an adult animal remains remarkably stable. Therefore, a central question in immunology is how the naive T cell pool is maintained. Here we show that the maintenance of the naive CD4, but not CD8, T cell population in the thymectomized adult mouse is dependent on the presence of secondary lymphoid tissues. This finding is explained by the inability of naive CD4 T cells to sustain normal levels of the survival molecule Bcl-2 or to undergo homeostatic proliferation in the absence of secondary lymphoid organs. Thus, naive CD4 T cells must traffic through secondary lymphoid organs to maintain a stable CD4 pool while naive CD8 T cells encounter their survival and proliferation signals outside the organized structures of secondary lymphoid tissues.
尽管随着年龄增长胸腺输出减少，但成年动物外周幼稚T细胞库仍保持显著稳定。因此，免疫学中的一个核心问题是幼稚T细胞库如何维持。在此我们表明，成年去胸腺小鼠中幼稚CD4而非CD8 T细胞群体的维持依赖于次级淋巴组织的存在。这一发现可解释为，在没有次级淋巴器官的情况下，幼稚CD4 T细胞无法维持存活分子Bcl-2的正常水平，也无法进行稳态增殖。因此，幼稚CD4 T细胞必须通过次级淋巴组织来维持稳定的CD4库，而幼稚CD8 T细胞在次级淋巴组织的组织结构之外获得其存活和增殖信号。
