IL-17 and IL-22: siblings, not twins

Trends Immunol. 2010 Sep;31(9):354-61. doi: 10.1016/ Epub 2010 Aug 4.


T helper (Th) cell subsets secrete cytokines that regulate other immune cells. Interleukin (IL)-17 and IL-22 belong to a new class of cytokines with predominant effects on epithelial cells. Thus, these cytokines are key molecules in several disease processes. IL-17 and IL-22 are released by leukocytes such as Th and natural killer cell populations. Both IL-17 and IL-22 induce an innate immune response in epithelial cells, but their functional spectra are generally distinct. IL-17 induces an inflammatory tissue response and is involved in the pathogenesis of several autoimmune diseases, whereas IL-22 is protective/regenerative. This review juxtaposes IL-17 and IL-22 and describes overlaps and differences regarding their cellular sources, biochemical structure, signaling cascades in target cells, and function.

Publication types

  • Review

MeSH terms

  • Animals
  • Autoimmunity
  • Epithelial Cells / immunology
  • Epithelial Cells / metabolism
  • Humans
  • Interleukin-17 / immunology*
  • Interleukin-17 / metabolism
  • Interleukins / immunology*
  • Interleukins / metabolism
  • Leukocytes / immunology
  • Leukocytes / metabolism
  • Signal Transduction


  • Interleukin-17
  • Interleukins
  • interleukin-22