title: ICOS/ICOSL interaction is required for CD4+ invariant NKT cell function and homeostatic survival.
abstract: The development of airway hyperreactivity (AHR), a cardinal feature of asthma, requires the presence of invariant NKT (iNKT) cells. In a mouse model of asthma, we demonstrated that the induction of AHR required ICOS costimulation of iNKT cells. ICOS was highly expressed on both naive and activated iNKT cells, and expression of ICOS was greater on the CD4(+) iNKT than on CD4(-) iNKT cells. Furthermore, the number of CD4(+) iNKT cells was significantly lower in spleens and livers of ICOS(-/-) and ICOSL(-/-) mice, and the remaining iNKT cells in ICOS(-/-) mice were dysfunctional and failed to reconstitute AHR when adoptively transferred into iNKT cell-deficient Jalpha18(-/-) mice. In addition, direct activation of iNKT cells with alpha-GalCer, which induced AHR in wild-type mice, failed to induce AHR in ICOS(-/-) mice. The failure of ICOS(-/-) iNKT cells to induce AHR was due in part to an inability of the ICOS(-/-) iNKT cells to produce IL-4 and IL-13 on activation. Moreover, survival of wild-type iNKT cells transferred into ICOSL(-/-) mice was greatly reduced due to the induction of apoptosis. These results indicate that ICOS costimulation plays a major role in induction of AHR by iNKT cells and is required for CD4(+) iNKT cell function, homeostasis, and survival in the periphery.
authors.affiliation: Division of Immunology, Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA. omid.akbari@childrens.harvard.edu
authors.forename: Omid
authors.initials: O
authors.lastname: Akbari
authors.forename: Philippe
authors.initials: P
authors.lastname: Stock
authors.forename: Everett H
authors.initials: EH
authors.lastname: Meyer
authors.forename: Gordon J
authors.initials: GJ
authors.lastname: Freeman
authors.forename: Arlene H
authors.initials: AH
authors.lastname: Sharpe
authors.forename: Dale T
authors.initials: DT
authors.lastname: Umetsu
authors.forename: Rosemarie H
authors.initials: RH
authors.lastname: DeKruyff
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology / Q000378:metabolism*; D017209:Apoptosis; D001249:Asthma / Q000276:immunology*; D016535:Bronchial Hyperreactivity / Q000276:immunology / Q000378:metabolism; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D060945:Inducible T-Cell Co-Stimulator Ligand; D060889:Inducible T-Cell Co-Stimulator Protein; D008024:Ligands; D051379:Mice; D008807:Mice, Inbred BALB C; D008817:Mice, Mutant Strains; D011506:Proteins / Q000276:immunology / Q000378:metabolism*; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D016207:Cytokines; C556694:Icos protein, mouse; C400230:Icosl protein, mouse; D060945:Inducible T-Cell Co-Stimulator Ligand; D060889:Inducible T-Cell Co-Stimulator Protein; D008024:Ligands; D011506:Proteins