title: Th9 cells in the pathogenesis of EAE and multiple sclerosis.
abstract: Interleukin (IL)-9 producing CD4+T helper cells (Th9) are the newest addition to the T helper cell subsets. IL-9 binds to a heterodimeric receptor consisting of the IL-9 receptor (IL-9R) and a common γ chain also presents in IL-2, IL-4, IL-7, and IL-15 receptor complexes. In addition to Th9 cells, Th17 cells secrete smaller amounts of IL-9. Many functional and regulatory roles associated with Th9 cells are currently not fully understood. IL-9 is a pleiotropic cytokine that affects the activity of multiple cell types in the immune compartment as well as in the central nervous system (CNS). Initially implicated in type 2 inflammation, IL-9 has been recently shown to be a key player in regulating autoimmune responses in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Here, we review the current understanding of the role of Th9/IL-9 signaling in EAE and MS. We summarize the source and regulation of Th9 cells in vivo, the influence of IL-9 signaling on peripheral and CNS-resident cells in EAE, and the association between IL-9 and MS disease activity.
authors.affiliation: Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA. welyaman@rics.bwh.harvard.edu.
authors.forename: Wassim
authors.initials: W
authors.lastname: Elyaman
authors.affiliation: Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA.|Abu Haidar Neuroscience Institute, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Samia J
authors.initials: SJ
authors.lastname: Khoury
mesh_terms: D056704:Adaptive Immunity; D000818:Animals; D015551:Autoimmunity; D002490:Central Nervous System / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D016207:Cytokines / Q000378:metabolism; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000209:etiology* / Q000378:metabolism*; D006801:Humans; D056747:Immunomodulation; D016906:Interleukin-9 / Q000378:metabolism*; D051379:Mice; D009103:Multiple Sclerosis / Q000209:etiology* / Q000378:metabolism*; D015398:Signal Transduction; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology* / Q000378:metabolism*
chemical_list: D016207:Cytokines; D016906:Interleukin-9
keywords: Autoimmunity; EAE; Immune regulation; Interleukin-9; Multiple sclerosis; T helper cells