IL-7 derived from lymph node fibroblastic reticular cells is dispensable for naive T cell homeostasis but crucial for central memory T cell survival
Knop L, Deiser K, Bank U, Witte A, Mohr J, Philipsen L, Fehling H, Müller A, Kalinke U, Schüler T
Erschienen in
European Journal of Immunology: Volume 50, Issue 6, Page 846-857
Abstract
The survival of peripheral T cells is dependent on their access to peripheral LNs (pLNs) and stimulation by IL-7. In pLNs fibroblastic reticular cells (FRCs) and lymphatic endothelial cells (LECs) produce IL-7 suggesting their contribution to the IL-7-dependent survival of T cells. However, IL-7 production is detectable in multiple organs and is not restricted to pLNs. This raises the question whether pLN-derived IL-7 is required for the maintenance of peripheral T cell homeostasis. Here, we show that numbers of naive T cells (T(N) ) remain unaffected in pLNs and spleen of mice lacking Il7 gene activity in pLN FRCs, LECs, or both. In contrast, frequencies of central memory T cells (T(CM) ) are reduced in FRC-specific IL-7 KO mice. Thus, steady state IL-7 production by pLN FRCs is critical for the maintenance of T(CM) , but not T(N) , indicating that both T cell subsets colonize different ecological niches in vivo.
In PubMed öffnen