Epithelial IL-23R Signaling Licenses Protective IL-22 Responses in Intestinal Inflammation

Cell Rep. 2016 Aug 23;16(8):2208-2218. doi: 10.1016/j.celrep.2016.07.054. Epub 2016 Aug 11.

Abstract

A plethora of functional and genetic studies have suggested a key role for the IL-23 pathway in chronic intestinal inflammation. Currently, pathogenic actions of IL-23 have been ascribed to specific effects on immune cells. Herein, we unveil a protective role of IL-23R signaling. Mice deficient in IL-23R expression in intestinal epithelial cells (Il23R(ΔIEC)) have reduced Reg3b expression, show a disturbed colonic microflora with an expansion of flagellated bacteria, and succumb to DSS colitis. Surprisingly, Il23R(ΔIEC) mice show impaired mucosal IL-22 induction in response to IL-23. αThy-1 treatment significantly deteriorates colitis in Il23R(ΔIEC) animals, which can be rescued by IL-22 application. Importantly, exogenous Reg3b administration rescues DSS-treated Il23R(ΔIEC) mice by recruiting neutrophils as IL-22-producing cells, thereby restoring mucosal IL-22 levels. The study identifies a critical barrier-protective immune pathway that originates from, and is orchestrated by, IL-23R signaling in intestinal epithelial cells.

MeSH terms

  • Animals
  • Colitis / chemically induced
  • Colitis / drug therapy
  • Colitis / immunology*
  • Colitis / microbiology
  • Dextran Sulfate
  • Dysbiosis / drug therapy
  • Dysbiosis / immunology*
  • Dysbiosis / pathology
  • Epithelial Cells / drug effects
  • Epithelial Cells / immunology
  • Epithelial Cells / microbiology
  • Gene Expression Regulation
  • Granulocytes / drug effects
  • Granulocytes / immunology
  • Granulocytes / microbiology
  • Interleukin-22
  • Interleukin-23 / pharmacology
  • Interleukins / genetics
  • Interleukins / immunology*
  • Interleukins / pharmacology
  • Intestinal Mucosa / drug effects
  • Intestinal Mucosa / immunology*
  • Intestinal Mucosa / microbiology
  • Isoantibodies / pharmacology
  • Male
  • Mice
  • Mice, Knockout
  • Neutrophils / drug effects
  • Neutrophils / immunology
  • Neutrophils / microbiology
  • Pancreatitis-Associated Proteins / genetics
  • Pancreatitis-Associated Proteins / immunology
  • Pancreatitis-Associated Proteins / pharmacology
  • Receptors, Interleukin / deficiency
  • Receptors, Interleukin / genetics
  • Receptors, Interleukin / immunology*
  • Signal Transduction
  • Stem Cells / drug effects
  • Stem Cells / immunology
  • Stem Cells / microbiology

Substances

  • Interleukin-23
  • Interleukins
  • Isoantibodies
  • Pancreatitis-Associated Proteins
  • Receptors, Interleukin
  • Reg3b protein, mouse
  • anti-Thy antibody
  • interleukin-23 receptor, mouse
  • Dextran Sulfate