doi:10.1016/j.celrep.2021.108757engLayunta, E.Jäverfelt, S.Dolan, B.Arike, L.Pelaseyed, T.IL-22 promotes the formation of a MUC17 glycocalyx barrier in the postnatal small intestine during weaningART-2021-135224The intestine is under constant exposure to chemicals, antigens, and microorganisms from the external environment. Apical aspects of transporting epithelial cells (enterocytes) form a brush-border membrane (BBM), shaped by packed microvilli coated with a dense glycocalyx. We present evidence showing that the glycocalyx forms an epithelial barrier that prevents exogenous molecules and live bacteria from gaining access to BBM. We use a multi-omics approach to investigate the function and regulation of membrane mucins exposed on the BBM during postnatal development of the mouse small intestine. Muc17 is identified as a major membrane mucin in the glycocalyx that is specifically upregulated by IL-22 as part of an epithelial defense repertoire during weaning. High levels of IL-22 at time of weaning reprogram neonatal postmitotic progenitor enterocytes to differentiate into Muc17-expressing enterocytes, as found in the adult intestine during homeostasis. Our findings propose a role for Muc17 in epithelial barrier function in the small intestine.2021http://zaguan.unizar.es/record/12809910.1016/j.celrep.2021.108757http://zaguan.unizar.es/record/128099oai:zaguan.unizar.es:128099Cell Reports 34, 7 (2021), 108757 [24 pp.]byhttp://creativecommons.org/licenses/by/3.0/es/info:eu-repo/semantics/openAccess