Inflammatory migration-associated skin-like CD103+ ILC2s impact lung immunity 9270

Description Group 2 innate lymphoid cells (ILC2s) are tissue-resident cells with transcriptional signatures imprinted by tissues in which they reside. Post-inflammatory expansion, migration and protective roles in distant organs have been described for small intestinal and bone marrow ILC2s, but whether additional barrier ILC2s perform similar roles is unknown. We show that skin ILC2s (skILC2s) expand after infestation by commensal hair-follicle mites, enter the blood and adapt to lung residence while enabling new innate sources of IL-13 and IL-17A. We use immunohistochemistry to define positioning of newly recruited ex-skILCs and challenges with migratory helminths and influenza to demonstrate impacts on lung host defense. Redistribution of barrier ILC2s educated by exposure to microbiota and foreign antigens may be an intrinsic property of the innate immune system designed to enhance internal organ responses during transition to the post-birth environment.