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.
Copyright © 2021 Tang, Lu and Yu.