Other sources of IL-17: Invariant natural killer T cells

Abstract

Interleukin-17 (IL-17) plays a major role in various models of immune-mediated tissue injury, including organ-specific autoimmunity, allergic disorders and microbial infections. Th17 cells are currently the most thoroughly characterized source of IL-17 credited for causing and sustaining the tissue damage mediated by this cytokine. Similarly to their Th1 and Th2 counterpart, Th17 cells depend on specific factors for their differentiation from naïve T cell precursors, before acquiring their typical cytokine profile. However, this is not the case for all IL-17-producing cells, particu- larly for a subset of invariant natural killer T cells, termed iNKT17, which are ready to produce this cytokine immediately upon stimulation, in keeping with their capacity to intervene during early stages of the inflammatory response.