title: Type I interferon signalling in the intestinal epithelium affects Paneth cells, microbial ecology and epithelial regeneration.
abstract: OBJECTIVE
  Intestinal epithelial cells (IECs) at the internal/external interface orchestrate the mucosal immune response. Paneth cells secrete antimicrobial peptides and inflammatory mediators, protect from pathogens and shape the commensal microbiota. Prompted by the genetic association of the locus harbouring the type I interferon (IFN) receptor (IFNAR1) with Crohn's disease, and a transcriptional signature for type I IFN signalling in Paneth cells, we studied the function of IFNAR1 in IECs.
  
  
  METHODS
  Type I IFN signalling was studied in mice with conditional deletion of Ifnar1 in IECs. Phenotype was characterised at baseline, and gut microbiota composition was assessed by 16S rDNA ribotyping. The role of IFNAR1 was also investigated in experimental colitis induced by dextran sodium sulfate (DSS) and colitis-associated cancer induced by DSS in conjunction with azoxymethane (AOM).
  
  
  RESULTS
  Ifnar1(-/-(IEC)) mice displayed expansion of Paneth cell numbers and epithelial hyperproliferation compared with Ifnar1-sufficient littermates. While Ifnar1(-/-(IEC)) mice did not exhibit spontaneous inflammation or increased severity in DSS colitis compared with Ifnar1(+/+(IEC)) mice, they exhibited an increased tumour burden in the AOM/DSS model. Both hyperproliferation and tumour promotion were dependent on the microbial flora, as the differences between genotypes were marked upon separately housing mice, but disappeared when Ifnar1(-/-(IEC)) and Ifnar1(+/+(IEC)) mice were co-housed. Accordingly, ribotyping revealed marked differences between Ifnar1(-/-(IEC)) and Ifnar1(+/+(IEC)) mice that where diminished upon co-housing.
  
  
  CONCLUSIONS
  IFNAR1 in IECs, and Paneth cells in particular, contributes to the regulation of the host-microbiota relationship, with consequences for intestinal regeneration and colitis-associated tumour formation.
authors.affiliation: Division of Gastroenterology & Hepatology, Department of Medicine, University of Cambridge, Cambridge, UK Department of Medicine I, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Tschurtschenthaler
authors.affiliation: Max Planck Institute for Evolutionary Biology, Plön, Germany Institute for Experimental Medicine, Christian-Albrechts-University of Kiel, Kiel, Germany.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Medicine II, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Fricke
authors.affiliation: Department of Medicine II, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Teresa M J
authors.initials: TM
authors.lastname: Fritz
authors.affiliation: Division of Gastroenterology & Hepatology, Department of Medicine, University of Cambridge, Cambridge, UK.
authors.forename: Lukas
authors.initials: L
authors.lastname: Niederreiter
authors.affiliation: Division of Gastroenterology & Hepatology, Department of Medicine, University of Cambridge, Cambridge, UK.
authors.forename: Timon E
authors.initials: TE
authors.lastname: Adolph
authors.affiliation: Department of Pathology, Academic Teaching Hospital Feldkirch, Feldkirch, Austria.
authors.forename: Edina
authors.initials: E
authors.lastname: Sarcevic
authors.affiliation: Max Planck Institute for Evolutionary Biology, Plön, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Künzel
authors.affiliation: Department of Pathology, Academic Teaching Hospital Feldkirch, Feldkirch, Austria.
authors.forename: Felix A
authors.initials: FA
authors.lastname: Offner
authors.affiliation: Division of Immunology, Paul-Ehrlich-Institute, Langen, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Kalinke
authors.affiliation: Max Planck Institute for Evolutionary Biology, Plön, Germany Institute for Experimental Medicine, Christian-Albrechts-University of Kiel, Kiel, Germany.
authors.forename: John F
authors.initials: JF
authors.lastname: Baines
authors.affiliation: Department of Medicine I, Innsbruck Medical University, Innsbruck, Austria Christian-Doppler Research Laboratory for Gut Inflammation, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Herbert
authors.initials: H
authors.lastname: Tilg
authors.affiliation: Division of Gastroenterology & Hepatology, Department of Medicine, University of Cambridge, Cambridge, UK Department of Medicine II, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Arthur
authors.initials: A
authors.lastname: Kaser
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides; D049109:Cell Proliferation / Q000235:genetics; D003092:Colitis / Q000209:etiology / Q000276:immunology; D003424:Crohn Disease / Q000235:genetics / Q000276:immunology / Q000473:pathology; D016264:Dextran Sulfate / Q000494:pharmacology; D020022:Genetic Predisposition to Disease; D020397:Goblet Cells / Q000378:metabolism / Q000473:pathology; D018928:Immunity, Mucosal / Q000235:genetics; D018836:Inflammation Mediators; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D064307:Microbiota; D019879:Paneth Cells / Q000378:metabolism / Q000473:pathology; D053633:Receptor, Interferon alpha-beta / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D023181:Antimicrobial Cationic Peptides; C508032:Ifnar1 protein, mouse; D018836:Inflammation Mediators; D047908:Intracellular Signaling Peptides and Proteins; D053633:Receptor, Interferon alpha-beta; D016264:Dextran Sulfate
keywords: EPITHELIAL PROLIFERATION; EXPERIMENTAL COLITIS; INTESTINAL EPITHELIUM; INTESTINAL GENE REGULATION; INTESTINAL MICROBIOLOGY