title: Interleukin-9 as a T helper type 17 cytokine.
abstract: The production of interleukin-9 (IL-9) by CD4 T cells has gathered renewed interest as the result of the observation that its expression is broader than originally thought. This includes the production of IL-9 by a recently characterized subset of CD4 helper T (Th) cells that are termed Th9 as well as production by additional T-cell subsets including Th17 cells. There is an incomplete understanding as to which IL-9-producing T-cell subsets develop under physiological conditions. We describe the conditions used to generate IL-9 in Th17 cells in vitro. We also summarize conditions where both IL-9 and IL-17 are found in vivo and propose that Th17 cells producing IL-9 may co-exist and interact with Th9 cells during conditions of autoimmunity, allergy and infection.
authors.affiliation: Department of Microbiology and Immunology, Dartmouth Medical School and Norris Cotton Cancer Center, Lebanon, NH 03756, USA. Elizabeth.C.Nowak@Dartmouth.edu
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Nowak
authors.forename: Randolph J
authors.initials: RJ
authors.lastname: Noelle
mesh_terms: D000818:Animals; D006801:Humans; D016906:Interleukin-9 / Q000378:metabolism*; D018448:Models, Immunological; D058504:Th17 Cells / Q000276:immunology / Q000378:metabolism*
chemical_list: D016906:Interleukin-9