title: Innate immune processes are sufficient for driving cigarette smoke-induced inflammation in mice.
abstract: The objective of this study was to characterize the impact of cigarette smoke exposure on lung immune and inflammatory processes. BALB/c and C57BL/6 mice were exposed to cigarette smoke for 4 days (acute) or at least 5 weeks (prolonged). Both mouse strains manifested an inflammatory response after acute smoke exposure, characterized by an influx of neutrophils and mononuclear cells. Multiplex analysis revealed a greater than twofold increase of the cytokines IL-1alpha, -5, -6, and -18, as well as the chemokines monocyte chemotactic protein-1 and -3, macrophage inflammatory protein-1alpha, -beta, and -gamma, -2, -3beta, macrophage defined chemokine, granulocyte chemotactic protein-2, and interferon-gamma-inducible protein-10. In BALB/c mice, neutrophilia persisted after prolonged exposure, whereas C57BL/6 showed evidence of attenuated neutrophilia both in the bronchoalveolar lavage and the lungs. In both mouse strains, cigarette smoke exposure was associated with an expansion of mature (CD11c(hi)/major histocompatibility complex class II(hi)) myeloid dendritic cells; we observed no changes in plasmacytoid dendritic cells. Lymphocytes in the lungs displayed an activated phenotype that persisted for CD4 T cells only after prolonged exposure. In BALB/c mice, T cells acquired T helper (Th) 1 and Th2 effector function after 5 weeks of smoke exposure, whereas, in C57BL/6 mice, neither Th1 nor Th2 cells were detected. In both mouse strains, cigarette smoke exposure led to an accumulation of FoxP3+ T regulatory cells in the lungs. Studies in RAG1 knockout mice suggest that these regulatory cells may participate in controlling smoke-induced inflammation. Acute and prolonged cigarette smoke exposure was associated with inflammation, activation of the adaptive immune system, and expansion of T regulatory cells in the lungs.
authors.affiliation: Department of Pathology and Molecular Medicine, McMaster University, 1200 Main Street West Hamilton, ON L8N3Z5, Canada.
authors.forename: Fernando M
authors.initials: FM
authors.lastname: Botelho
authors.forename: Gordon J
authors.initials: GJ
authors.lastname: Gaschler
authors.forename: Sussan
authors.initials: S
authors.lastname: Kianpour
authors.forename: Cale C J
authors.initials: CC
authors.lastname: Zavitz
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Trimble
authors.forename: Jake K
authors.initials: JK
authors.lastname: Nikota
authors.forename: Carla M T
authors.initials: CM
authors.lastname: Bauer
authors.forename: Martin R
authors.initials: MR
authors.lastname: Stämpfli
mesh_terms: D056704:Adaptive Immunity / Q000235:genetics / Q000276:immunology; D000818:Animals; D018893:Bronchoalveolar Lavage; D039521:CD11c Antigen / Q000235:genetics / Q000276:immunology; D016207:Cytokines / Q000235:genetics / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology / Q000502:physiology; D005260:Female; D018398:Homeodomain Proteins / Q000235:genetics / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics / Q000276:immunology*; D008168:Lung / Q000276:immunology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D022423:Myeloid Cells / Q000276:immunology / Q000473:pathology; D020556:Neutrophil Infiltration / Q000235:genetics / Q000276:immunology; D009504:Neutrophils / Q000276:immunology / Q000473:pathology; D011014:Pneumonia / Q000209:etiology / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D012907:Smoking / Q000009:adverse effects* / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000473:pathology; D018417:Th1 Cells / Q000276:immunology / Q000473:pathology; D018418:Th2 Cells / Q000276:immunology / Q000473:pathology; D013997:Time Factors
chemical_list: D039521:CD11c Antigen; D016207:Cytokines; D018398:Homeodomain Proteins; C064658:RAG-1 protein