Th17 cells and IL-17 receptor signaling are essential for mucosal host defense against oral candidiasis

J Exp Med. 2009 Feb 16;206(2):299-311. doi: 10.1084/jem.20081463. Epub 2009 Feb 9.

Abstract

The commensal fungus Candida albicans causes oropharyngeal candidiasis (OPC; thrush) in settings of immunodeficiency. Although disseminated, vaginal, and oral candidiasis are all caused by C. albicans species, host defense against C. albicans varies by anatomical location. T helper 1 (Th1) cells have long been implicated in defense against candidiasis, whereas the role of Th17 cells remains controversial. IL-17 mediates inflammatory pathology in a gastric model of mucosal candidiasis, but is host protective in disseminated disease. Here, we directly compared Th1 and Th17 function in a model of OPC. Th17-deficient (IL-23p19(-/-)) and IL-17R-deficient (IL-17RA(-/-)) mice experienced severe OPC, whereas Th1-deficient (IL-12p35(-/-)) mice showed low fungal burdens and no overt disease. Neutrophil recruitment was impaired in IL-23p19(-/-) and IL-17RA(-/-), but not IL-12(-/-), mice, and TCR-alphabeta cells were more important than TCR-gammadelta cells. Surprisingly, mice deficient in the Th17 cytokine IL-22 were only mildly susceptible to OPC, indicating that IL-17 rather than IL-22 is vital in defense against oral candidiasis. Gene profiling of oral mucosal tissue showed strong induction of Th17 signature genes, including CXC chemokines and beta defensin-3. Saliva from Th17-deficient, but not Th1-deficient, mice exhibited reduced candidacidal activity. Thus, the Th17 lineage, acting largely through IL-17, confers the dominant response to oral candidiasis through neutrophils and antimicrobial factors.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acquired Immunodeficiency Syndrome / complications*
  • Animals
  • CD4-Positive T-Lymphocytes / immunology*
  • Candidiasis, Oral / etiology*
  • Candidiasis, Oral / immunology*
  • Disease Susceptibility / immunology*
  • Flow Cytometry
  • Gene Expression Profiling
  • Humans
  • Interleukin-12 Subunit p35 / genetics
  • Interleukin-12 Subunit p35 / immunology
  • Interleukin-17 / genetics
  • Interleukin-17 / immunology*
  • Interleukin-22
  • Interleukin-23 Subunit p19 / genetics
  • Interleukin-23 Subunit p19 / immunology
  • Interleukins / deficiency
  • Mice
  • Mice, Knockout
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • Interleukin-12 Subunit p35
  • Interleukin-17
  • Interleukin-23 Subunit p19
  • Interleukins