Protective role of naturally occurring interleukin-17A-producing γδ T cells in the lung at the early stage of systemic candidiasis in mice

Infect Immun. 2011 Nov;79(11):4503-10. doi: 10.1128/IAI.05799-11. Epub 2011 Aug 29.

Abstract

Interleukin-17A (IL-17A)-producing γδ T cells differentiate in the fetal thymus and reside in the peripheral tissues, such as the lungs of naïve adult mice. We show here that naturally occurring γδ T cells play a protective role in the lung at a very early stage after systemic infection with Candida albicans. Selective depletion of neutrophils by in vivo administration of anti-Ly6G monoclonal antibody (MAb) impaired fungal clearance more prominently in the lung than in the kidney 24 h after intravenous infection with C. albicans. Rapid and transient production of IL-23 was detected in the lung at 12 h, preceding IL-17A production and the influx of neutrophils, which reached a peak at 24 h after infection. IL-17A knockout (KO) mice showed reduced infiltration of neutrophils concurrently with impaired fungal clearance in the lung after infection. The major source of IL-17A was the γδ T cell population in the lung, and Cδ KO mice showed little IL-17A production and reduced neutrophil infiltration after infection. Early IL-23 production in a TLR2/MyD88-dependent manner and IL-23-triggered tyrosine kinase 2 (Tyk2) signaling were essential for IL-17A production by γδ T cells. Thus, our study demonstrated a novel role of naturally occurring IL-17A-producing γδ T cells in the first line of host defense against C. albicans infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism
  • Animals
  • CARD Signaling Adaptor Proteins
  • Candidiasis / immunology*
  • Interleukin-17 / genetics
  • Interleukin-17 / metabolism*
  • Interleukin-23 / genetics
  • Interleukin-23 / metabolism
  • Lung / cytology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Myeloid Differentiation Factor 88 / genetics
  • Myeloid Differentiation Factor 88 / metabolism
  • Neutrophils / physiology
  • Receptors, Antigen, T-Cell, gamma-delta* / metabolism
  • Specific Pathogen-Free Organisms
  • T-Lymphocyte Subsets / metabolism*
  • Toll-Like Receptor 2 / genetics
  • Toll-Like Receptor 2 / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • CARD Signaling Adaptor Proteins
  • Card9 protein, mouse
  • Interleukin-17
  • Interleukin-23
  • Myd88 protein, mouse
  • Myeloid Differentiation Factor 88
  • Receptors, Antigen, T-Cell, gamma-delta
  • Tlr2 protein, mouse
  • Toll-Like Receptor 2

Supplementary concepts

  • Systemic candidiasis