Type 17 T helper cells-origins, features and possible roles in rheumatic disease

Type 17 T helper (T(H)17) cells are a population of CD4(+) effector T cells that are distinct from T(H)1 and T(H)2 cells owing to their ability to produce interleukin (IL)-17. Although T(H)1 and T(H)2 cells are similar in mice and humans, T(H)17 cells differ in several ways. The differentiation of mouse T(H)17 cells requires transforming growth factor beta and IL-6, whereas human naive T cells can develop into T(H)17 cells in the presence of IL-1 beta and IL-23 alone, transforming growth factor beta having an indirect role in their development via the selective inhibition of T(H)1 cell expansion. in both mice and humans, a late developmental plasticity of T(H)17 cells towards the T(H)1 lineage has been shown. Mainly based on mouse gene knockout studies, T(H)17 lymphocytes have been found to have a pathogenic role in several autoimmune disorders; however, whether human autoimmune disorders, including rheumatoid arthritis (RA) and psoriasis, are prevalently T(H)1-mediated or T(H)17-mediated, is still unclear. research suggests that both T(H)1 and T(H)17 cells are involved in RA pathogenesis, raising the possibility that interventions that target both the IL-23-IL-17 (T(H)17) and the IL-12-interferon gamma(T(H)1) axes might be successful future therapeutic approaches for RA.