title: The absence of interleukin 9 does not affect the development of allergen-induced pulmonary inflammation nor airway hyperreactivity.
abstract: Interleukin (IL)-9 is a pleiotropic cytokine secreted by T helper (Th)2 cells and has been proposed as a candidate gene for asthma and allergy. We have used mice genetically deficient in IL-9 to determine the role of this cytokine in the pathophysiologic features of the allergic pulmonary response-airway hyperreactivity (AHR) and eosinophilia. We have demonstrated that IL-9 is not required for the development of a robust Th2 response to allergen in sensitized mice. IL-9 knockout mice developed a similar degree of eosinophilic inflammation and AHR to their wild-type littermates. Goblet cell hyperplasia and immunoglobulin (Ig) E production were also unaffected by the lack of IL-9. Moreover, levels of bronchoalveolar lavage (BAL) IL-4, IL-5, and IL-13 were comparable between wild-type and knockout mice. These findings indicate that IL-9 is not obligatory for the development of eosinophilia and AHR, and imply that other Th2 cytokines can act in a compensatory fashion.
authors.affiliation: Leukocyte Biology Section, Division of Biomedical Sciences, Faculty of Medicine, Imperial College of Science, Technology, and Medicine, London SW7 2AZ, England.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: McMillan
authors.forename: Benjamin
authors.initials: B
authors.lastname: Bishop
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Townsend
authors.forename: Andrew N
authors.initials: AN
authors.lastname: McKenzie
authors.forename: Clare M
authors.initials: CM
authors.lastname: Lloyd
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002452:Cell Count; D054413:Chemokine CCL11; D019742:Chemokines, CC / Q000378:metabolism; D004802:Eosinophilia / Q000209:etiology*; D020397:Goblet Cells / Q000473:pathology; D006965:Hyperplasia; D007073:Immunoglobulin E / Q000096:biosynthesis; D016906:Interleukin-9 / Q000172:deficiency* / Q000235:genetics; D007378:Interleukins / Q000378:metabolism; D051379:Mice; D008817:Mice, Mutant Strains; D009093:Mucus / Q000378:metabolism; D011014:Pneumonia / Q000209:etiology*; D012130:Respiratory Hypersensitivity / Q000209:etiology*; D018418:Th2 Cells / Q000276:immunology
chemical_list: C515457:Ccl11 protein, mouse; D054413:Chemokine CCL11; D019742:Chemokines, CC; D016906:Interleukin-9; D007378:Interleukins; D007073:Immunoglobulin E