Epstein Barr virus-induced 3 (EBI3) together with IL-12 negatively regulates T helper 17-mediated immunity to Listeria monocytogenes infection

PLoS Pathog. 2013 Sep;9(9):e1003628. doi: 10.1371/journal.ppat.1003628. Epub 2013 Sep 19.

Abstract

Although the protective functions by T helper 17 (Th17) cytokines against extracellular bacterial and fungal infection have been well documented, their importance against intracellular bacterial infection remains unclear. Here, we investigated the contribution of Th17 responses to host defense against intracellular bacteria Listeria monocytogenes and found that Th17 cell generation was suppressed in this model. Unexpectedly, mice lacking both p35 and EBI3 cleared L. monocytogenes as efficiently as wild-type mice, whereas p35-deficient mice failed to do so. Furthermore, both innate cells and pathogen-specific T cells from double-deficient mice produced significantly higher IL-17 and IL-22 compared to wild-type mice. The bacterial burden in the liver of double-deficient mice treated with anti-IL-17 was significantly increased compared to those receiving a control Ab. Transfer of Th17 cells specific for listeriolysin O as well as administration of IL-17 and IL-22 significantly suppressed bacterial growth in p35-deficient mice, indicating the critical contribution of Th17 responses to host defense against the intracellular pathogen in the absence of IL-12 and proper Th1 responses. Our findings unveil a novel immune evasion mechanism whereby the intracellular bacteria exploit IL-27EBI3 to suppress Th17-mediated protective immunity.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Bacterial Load
  • CD8-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / microbiology
  • CD8-Positive T-Lymphocytes / pathology
  • CD8-Positive T-Lymphocytes / transplantation
  • Cells, Cultured
  • Down-Regulation*
  • Gene Expression Regulation
  • Immune Evasion
  • Immunity, Cellular*
  • Immunity, Innate
  • Interleukin-12 Subunit p35 / genetics
  • Interleukin-12 Subunit p35 / metabolism*
  • Interleukin-17 / genetics
  • Interleukin-17 / metabolism
  • Interleukin-22
  • Interleukins / genetics
  • Interleukins / metabolism
  • Listeria monocytogenes / growth & development
  • Listeria monocytogenes / immunology*
  • Listeria monocytogenes / isolation & purification
  • Listeriosis / immunology*
  • Listeriosis / microbiology
  • Listeriosis / pathology
  • Listeriosis / therapy
  • Liver / immunology
  • Liver / microbiology
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Minor Histocompatibility Antigens
  • Receptors, Cytokine / genetics
  • Receptors, Cytokine / metabolism*
  • Spleen / immunology
  • Spleen / metabolism
  • Spleen / microbiology
  • Spleen / pathology
  • Th17 Cells / immunology*
  • Th17 Cells / metabolism
  • Th17 Cells / microbiology
  • Th17 Cells / pathology

Substances

  • Ebi3 protein, mouse
  • Il12a protein, mouse
  • Interleukin-12 Subunit p35
  • Interleukin-17
  • Interleukins
  • Minor Histocompatibility Antigens
  • Receptors, Cytokine