Absence of interleukin-17 receptor a signaling prevents autoimmune inflammation of the joint and leads to a Th2-like phenotype in collagen-induced arthritis

Arthritis Rheumatol. 2014 Feb;66(2):340-9. doi: 10.1002/art.38229.

Abstract

Objective: Interleukin-17A (IL-17A) signals through the IL-17 receptor (IL-17R) A/C heterodimer. IL-17RA serves as a common receptor subunit for several IL-17 cytokine family members. Lack of IL-17RA signaling may therefore have additional effects beyond those of lack of IL-17A alone. The present study was undertaken to determine the role of IL-17RA signaling in autoimmune arthritis.

Methods: Disease incidence and severity were scored in type II collagen-treated wild-type, IL-17RA-deficient, and IL-23p19-deficient mice. T helper cell profiles and humoral immune responses were analyzed at several time points. Pathogenicity of T cells and total splenocytes was determined by in vitro functional assay. IL-17RA signaling was blocked in vivo in mice with antigen-induced arthritis (AIA).

Results: Comparable to the findings in IL-23p19-deficient mice, IL-17RA-deficient mice were completely protected against the development of collagen-induced arthritis (CIA). However, IL-17RA-deficient mice exhibited an increased number of IL-4-producing CD4+ T cells, distinct from IL-17A+CD4+ T cells. This was associated with fewer plasma cells, lower production of pathogenic IgG2c antibody, and increased production of IgG1 antibody. Both isolated CD4+ T cells and total splenocytes from IL-17RA-deficient mice had a reduced ability to induce IL-6 production by synovial fibroblasts in the setting of CIA, in a functional in vitro assay. Furthermore, blocking of IL-17RA signaling in AIA reduced synovial inflammation.

Conclusion: These results demonstrate that absence of IL-17RA leads to a Th2-like phenotype characterized by IL-4 production and suggest that IL-17RA signaling plays a critical role in the regulation of IL-4 in CIA and the development of autoimmune inflammation of the joint.

MeSH terms

  • Animals
  • Arthritis, Experimental / pathology*
  • Arthritis, Experimental / physiopathology
  • Autoimmune Diseases / physiopathology
  • Autoimmune Diseases / prevention & control*
  • CD4-Positive T-Lymphocytes / metabolism
  • CD4-Positive T-Lymphocytes / pathology
  • Disease Models, Animal
  • Inflammation / physiopathology
  • Inflammation / prevention & control*
  • Interleukin-17 / metabolism
  • Interleukin-23 Subunit p19 / deficiency
  • Interleukin-23 Subunit p19 / genetics
  • Interleukin-23 Subunit p19 / physiology
  • Interleukin-4 / metabolism
  • Joints / pathology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Phenotype*
  • Plasma Cells / pathology
  • Receptors, Interleukin-17 / deficiency*
  • Receptors, Interleukin-17 / genetics
  • Receptors, Interleukin-17 / physiology
  • Severity of Illness Index
  • Signal Transduction / physiology*
  • Th2 Cells / pathology*

Substances

  • Il17ra protein, mouse
  • Interleukin-17
  • Interleukin-23 Subunit p19
  • Receptors, Interleukin-17
  • Interleukin-4