Circadian clocks guide dendritic cells into skin lymphatics
Stephan Holtkamp, Louise M. Ince, Coline Barnoud, Madeleine T. Schmitt, Flore Sinturel, Violetta Pilorz, Robert Pick, Stéphane Jemelin, Michael Mühlstädt, Wolf‐Henning Boehncke, Jasmin Weber, David Laubender, Julia Philippou‐Massier, Chien-Sin Chen, Leonie Holtermann, Dietmar Vestweber, Markus Sperandio, Barbara U. Schraml, Cornelia Halin, Charna Dibner, Henrik Oster, Jörg Renkawitz, Christoph Scheiermann
Abstract
Abstract Migration of leukocytes from the skin to lymph nodes (LNs) via afferent lymphatic vessels (LVs) is pivotal for adaptive immune responses 1,2 . Circadian rhythms have emerged as important regulators of leukocyte trafficking to LNs via the blood 3,4 . Here, we demonstrate that dendritic cells (DCs) have a circadian migration pattern into LVs, which peaks during the rest phase in mice. This migration pattern is determined by rhythmic gradients in the expression of the chemokine CCL21 and of adhesion molecules in both mice and humans. Chronopharmacological targeting of the involved factors abrogates circadian migration of DCs. We identify cell-intrinsic circadian oscillations in skin lymphatic endothelial cells (LECs) and DCs that cogovern these rhythms, as their genetic disruption in either cell type ablates circadian trafficking. These observations indicate that circadian clocks control the infiltration of DCs into skin lymphatics, a process that is essential for many adaptive immune responses and relevant for vaccination and immunotherapies.