The increased protection and pathology in Mycobacterium tuberculosis-infected IL-27R-alpha-deficient mice is supported by IL-17A and is associated with the IL-17A-induced expansion of multifunctional T cells

Mucosal Immunol. 2018 Jul;11(4):1168-1180. doi: 10.1038/s41385-018-0026-3. Epub 2018 May 4.

Abstract

During Mycobacterium tuberculosis (Mtb) infection, mice lacking the IL-27R exhibit lower bacterial burdens but develop an immunopathological sequelae in comparison to wild-type mice. We here show that this phenotype correlates with an enhanced recruitment of antigen-specific CCR6+ CD4+ T cells and an increased frequency of IL-17A-producing CD4+ T cells. By comparing the outcome of Mtb infection in C57BL/6, IL-27R-deficient and IL-27R/IL-17A-double deficient mice, we observed that both the increased protection and elevated immunopathology are supported by IL-17A. Whereas IL-17A neither impacts the development of Tr1 cells nor the expression of PD1 and KLRG1 on T cells in IL-27R-deficient mice during infection, it regulates the presence of multifunctional T-cells in the lungs, co-expressing IFN-γ, IL-2 and TNF. Eventually, IL-17A supports Cxcl9, Cxcl10 and Cxcl13 expression and the granulomatous response in the lungs of infected IL-27R-deficient mice. Taken together, IL-17A contributes to protection in Mtb-infected IL-27R-deficient mice probably through a chemokine-mediated recruitment and strategic positioning of multifunctional T cells in granulomas. As IL-27 limits optimal antimycobacterial protection by inhibiting IL-17A production, blocking of IL-27R-mediated signaling may represent a strategy for improving vaccination and host-directed therapy in tuberculosis. However, because IL-27 also prevents IL-17A-mediated immunopathology, such intervention has to be tightly controlled.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Proliferation
  • Cytokines / metabolism
  • Granuloma / immunology*
  • Immunity, Innate
  • Inflammation Mediators / metabolism
  • Interleukin-17 / genetics
  • Interleukin-17 / metabolism*
  • Lung / immunology*
  • Lung / microbiology
  • Lymphocyte Activation
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mycobacterium tuberculosis / physiology*
  • Receptors, Cytokine / genetics
  • Receptors, Cytokine / metabolism*
  • Receptors, Interleukin
  • Tuberculosis / immunology*

Substances

  • Cytokines
  • Il27ra protein, mouse
  • Inflammation Mediators
  • Interleukin-17
  • Receptors, Cytokine
  • Receptors, Interleukin