Barreiro, OlgaCibrian, DanayClemente, CristinaÁlvarez, DavidMoreno, VanessaValiente, IñigoBernad, AntonioVestweber, DietmarArroyo, Alicia GMartin, Pilarvon Andrian, Ulrich H.Sanchez Madrid, Francisco2017-10-302017-10-3020162050-084Xhttp://hdl.handle.net/20.500.12105/5218Heterogeneity and functional specialization among skin-resident macrophages are incompletely understood. In this study, we describe a novel subset of murine dermal perivascular macrophages that extend protrusions across the endothelial junctions in steady-state and capture blood-borne macromolecules. Unlike other skin-resident macrophages that are reconstituted by bone marrow-derived progenitors after a genotoxic insult, these cells are replenished by an extramedullary radio-resistant and UV-sensitive Bmi1(+) progenitor. Furthermore, they possess a distinctive anti-inflammatory transcriptional profile, which cannot be polarized under inflammatory conditions, and are involved in repair and remodeling functions for which other skin-resident macrophages appear dispensable. Based on all their properties, we define these macrophages as Skin Transendothelial Radio-resistant Anti-inflammatory Macrophages (STREAM) and postulate that their preservation is important for skin homeostasis.engVoRhttp://creativecommons.org/licenses/by/4.0/CD103(+) DENDRITIC CELLSRESIDENT MACROPHAGESIN-VIVOACTIVATED MACROPHAGESEXPRESSION PROFILESBLOOD-VESSELSKUPFFER CELLSLYMPH-NODESSTEM-CELLSRNA-SEQAtribución 4.0 Internacional27304075510.7554/eLife.15251ELIFEopen access