Cutting edge: secondary lymphoid organs are essential for maintaining the CD4, but not CD8, naive T cell pool

Z Dai, FG Lakkis - The Journal of Immunology, 2001 - journals.aai.org
Z Dai, FG Lakkis
The Journal of Immunology, 2001journals.aai.org
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 …
Abstract
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.
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