Frontiers in Immunology (Oct 2021)

Role of Eosinophils in Intestinal Inflammation and Fibrosis in Inflammatory Bowel Disease: An Overlooked Villain?

  • Inge Jacobs,
  • Matthias Ceulemans,
  • Lucas Wauters,
  • Lucas Wauters,
  • Christine Breynaert,
  • Christine Breynaert,
  • Séverine Vermeire,
  • Séverine Vermeire,
  • Bram Verstockt,
  • Bram Verstockt,
  • Tim Vanuytsel,
  • Tim Vanuytsel

DOI
https://doi.org/10.3389/fimmu.2021.754413
Journal volume & issue
Vol. 12

Abstract

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Eosinophils are leukocytes which reside in the gastrointestinal tract under homeostatic conditions, except for the esophagus which is normally devoid of eosinophils. Research on eosinophils has primarily focused on anti-helminth responses and type 2 immune disorders. In contrast, the search for a role of eosinophils in chronic intestinal inflammation and fibrosis has been limited. With a shift in research focus from adaptive to innate immunity and the fact that the eosinophilic granules are filled with inflammatory mediators, eosinophils are becoming a point of interest in inflammatory bowel diseases. In the current review we summarize eosinophil characteristics and recruitment as well as the current knowledge on presence, inflammatory and pro-fibrotic functions of eosinophils in inflammatory bowel disease and other chronic inflammatory conditions, and we identify research gaps which should be covered in the future.

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