title: Interleukin-9 stimulates the production of interleukin-5 in CD4+ T cells.
abstract: We recently showed that interleukin-9 (IL-9), a Th2 cytokine, promotes IL-5-mediated rejection of allografts in mice. This observation led us to investigate the functional link between IL-9 and IL-5 production during alloreactive T cell responses in vitro and in vivo. Firstly, we found that IL-9 was produced by alloreactive Th2 cells, and IL-9 mRNA was detected in skin allograft during Th2-type rejection. We then established that IL-5 production was impaired in alloreactive Th2 cells isolated from IL-9-deficient mice and that optimal IL-5 production after allogeneic stimulation requires a functional IL-9 receptor (IL-9R) on the responding cells. Finally, the production of IL-5 by anti-CD3-stimulated CD4+ T cells was abolished by neutralization of IL-9. Despite the fact that IL-9 promotes IL-5 production by alloreactive T cells, IL-9-deficient recipients of skin allografts still developed eosinophilic graft infiltrates and neither IL-9 nor IL-9R deficiency modified Th2-type allograft rejection.
authors.affiliation: The Institute for Medical Immunology, Université Libre de Bruxelles, 8 rue Adrienne Bolland, 6041 Gosselies, Belgium.
authors.forename: Lionel F
authors.initials: LF
authors.lastname: Poulin
authors.forename: Claude
authors.initials: C
authors.lastname: Habran
authors.forename: Patrick
authors.initials: P
authors.lastname: Stordeur
authors.forename: Michel
authors.initials: M
authors.lastname: Goldman
authors.forename: Andrew
authors.initials: A
authors.lastname: McKenzie
authors.forename: Jacques
authors.initials: J
authors.lastname: Van Snick
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Renauld
authors.forename: Michel Y
authors.initials: MY
authors.lastname: Braun
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004804:Eosinophils / Q000276:immunology; D006084:Graft Rejection / Q000276:immunology*; D015848:Interleukin-5 / Q000096:biosynthesis*; D016906:Interleukin-9 / Q000096:biosynthesis / Q000494:pharmacology / Q000502:physiology*; D007519:Isoantigens / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D018123:Receptors, Interleukin / Q000378:metabolism; D053651:Receptors, Interleukin-9; D016038:Skin Transplantation / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology; D018418:Th2 Cells / Q000187:drug effects / Q000276:immunology*
chemical_list: D015848:Interleukin-5; D016906:Interleukin-9; D007519:Isoantigens; D018123:Receptors, Interleukin; D053651:Receptors, Interleukin-9