Fungi Take Control of Lymphocyte Recirculation Jasper J. Koning, Reina E. Mebius  Immunity  Volume 44, Issue 2, Pages 211-213 (February 2016) DOI: 10.1016/j.immuni.2016.01.017 Copyright © 2016 Elsevier Inc. Terms and Conditions

Figure 1 Gut DCs Migrate to Skin-Draining Lymph Nodes and Affect Lymphocyte Recirculation Migration of lymphocytes from the blood into the lymph nodes requires proper functioning of specialized blood vessels, so-called high endothelial venules (HEVs). The maturation of HEVs occurs neonatally and depends on signals derived from dendritic cells (DCs). Germ-free mice have reduced cellularity in skin- and gut-draining lymph nodes (LNs) and show reduced maturation of HEVs, suggesting an important role for commensal flora in the development of LNs after birth. In this issue, Zhang et al. show that shortly after birth, a specific subset of gut-derived DCs, expressing CD103, CD11b, and RALDH2, which they call neo-migratory DCs, migrates via gut-draining mesenteric LNs (mLNs) to peripheral (inguinal) LNs (iLNs). Upon arrival in peripheral lymph nodes, these neo-migratory DCs induce maturation of HEVs and, in addition, induce gut homing molecules on lymphocytes, possibly to build up the lymphocyte repertoire in gut-associated tissues. Although the presence of these neo-mi DCs in lamina propria is independent of commensal microbiota, their phenotype depends on vitamin A, their migration is induced by commensal fungi, and their homing depends on mucosal addressins expressed on HEVs. Figure made by G. Kraal. Immunity 2016 44, 211-213DOI: (10.1016/j.immuni.2016.01.017) Copyright © 2016 Elsevier Inc. Terms and Conditions