Interleukin-17A Interweaves the Skeletal and Immune Systems

Front Immunol. 2021 Feb 4:11:625034. doi: 10.3389/fimmu.2020.625034. eCollection 2020.

Abstract

The complex crosstalk between the immune and the skeletal systems plays an indispensable role in the maintenance of skeletal homeostasis. Various cytokines are involved, including interleukin (IL)-17A. A variety of immune and inflammatory cells produces IL-17A, especially Th17 cells, a subtype of CD4+ T cells. IL-17A orchestrates diverse inflammatory and immune processes. IL-17A induces direct and indirect effects on osteoclasts. The dual role of IL-17A on osteoclasts partly depends on its concentrations and interactions with other factors. Interestingly, IL-17A exerts a dual role in osteoblasts in vitro. IL-17A is a bone-destroying cytokine in numerous immune-mediated bone diseases including postmenopausal osteoporosis (PMOP), rheumatoid arthritis (RA), psoriatic arthritis (PsA) and axial spondylarthritis (axSpA). This review will summarize and discuss the pathophysiological roles of IL-17A on the skeletal system and its potential strategies for application in immune-mediated bone diseases.

Keywords: axial spondyloarthritis; interleukin-17A; osteoblasts; osteoclasts; osteoimmunology; postmenopausal osteoporosis; psoriatic arthritis; rheumatoid arthritis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Arthritis, Psoriatic / genetics
  • Arthritis, Psoriatic / immunology*
  • Arthritis, Rheumatoid / genetics
  • Arthritis, Rheumatoid / immunology*
  • Cytokines / metabolism
  • Humans
  • Interleukin-17 / metabolism*
  • Osteoblasts / metabolism*
  • Osteoclasts / metabolism*
  • Osteoporosis, Postmenopausal / genetics
  • Osteoporosis, Postmenopausal / immunology*
  • Signal Transduction / immunology
  • Spondylarthritis / genetics
  • Spondylarthritis / immunology*
  • Th17 Cells / immunology

Substances

  • Cytokines
  • IL17A protein, human
  • Interleukin-17