Cell Reports (Aug 2016)

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

  • Konrad Aden,
  • Ateequr Rehman,
  • Maren Falk-Paulsen,
  • Thomas Secher,
  • Jan Kuiper,
  • Florian Tran,
  • Steffen Pfeuffer,
  • Raheleh Sheibani-Tezerji,
  • Alexandra Breuer,
  • Anne Luzius,
  • Marlene Jentzsch,
  • Robert Häsler,
  • Susanne Billmann-Born,
  • Olga Will,
  • Simone Lipinski,
  • Richa Bharti,
  • Timon Adolph,
  • Juan L. Iovanna,
  • Sarah L. Kempster,
  • Richard S. Blumberg,
  • Stefan Schreiber,
  • Burkhard Becher,
  • Mathias Chamaillard,
  • Arthur Kaser,
  • Philip Rosenstiel

DOI
https://doi.org/10.1016/j.celrep.2016.07.054
Journal volume & issue
Vol. 16, no. 8
pp. 2208 – 2218

Abstract

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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 (Il23RΔIEC) have reduced Reg3b expression, show a disturbed colonic microflora with an expansion of flagellated bacteria, and succumb to DSS colitis. Surprisingly, Il23RΔIEC mice show impaired mucosal IL-22 induction in response to IL-23. αThy-1 treatment significantly deteriorates colitis in Il23RΔIEC animals, which can be rescued by IL-22 application. Importantly, exogenous Reg3b administration rescues DSS-treated Il23RΔIEC 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.