title: Potential roles of IL-9 in the pathogenesis of systemic lupus erythematosus.
abstract: T helper (Th) cells and their cytokines play a pleiotropic role in the pathogenesis of systemic lupus erythematosus (SLE). Recently, a new effector T cell subset, Th9 cells, which preferentially secrete IL-9, has been identified. IL-9 is mainly produced by several T cell subsets including Th9 and Th17, and effective on the functions of Th cells and mast cell. However, there are no unambiguous conclusions that IL-9 contributes to the pathogenesis of SLE. Recently, IL-9 was reported to mediate profound anti-inflammatory effects in several cells or experimental autoimmune models. In particular, IL-9 production seemed to be important in mast cell recruitment. Defect in IL-9/IL-9R axis exhibited a more severe course of Experimental Autoimmune Encephalomyelitis (EAE) and enhanced activity of Tregs, phenotypes reminiscent of SLE. Consistently, IL-9 was implicated in the proliferation of several types of CD4+ T cells, indicating that IL-9 may be therapeutically relevant in SLE. In this article, we briefly discuss the biological features of IL-9 and summarize recent advances on the role of IL-9 in the pathogenesis and treatment of SLE.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University 81 Meishan Road, Hefei, Anhui, 230032, PR China ; Anhui provincial laboratory of population health & major disease screening and diagnosis, Anhui Medical University 81 Meishan Road, Hefei, Anhui 230032, PR China.
authors.forename: Rui-Xue
authors.initials: RX
authors.lastname: Leng
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Pan
authors.forename: Dong-Qing
authors.initials: DQ
authors.lastname: Ye
authors.forename: Yuekang
authors.initials: Y
authors.lastname: Xu
keywords: IL-9; T helper (Th) cells; Th17; Th9; systemic lupus erythematosus (SLE)