Project description:IL-18 plays a key role in the pathogenesis of pulmonary inflammatory diseases including pulmonary infection, pulmonary fibrosis, lung injury and chronic obstructive pulmonary disease (COPD). However, it is unknown whether IL-18 plays any role in the pathogenesis of asthma. We hypothesized that overexpression of mature IL-18 protein in the lungs may exacerbate disease activities of asthma. We established lung-specific IL-18 transgenic mice on a Balb/c genetic background. Female mice sensitized- and challenged- with antigen (ovalbumin) were used as a mouse asthma model. Pulmonary inflammation and emphysema were not observed in the lungs of naïve transgenic mice. However, airway hyperresponsiveness and airway inflammatory cells accompanied with CD4(+) T cells, CD8(+) T cells, eosinophils, neutrophils, and macrophages were significantly increased in ovalbumin-sensitized and challenged transgenic mice, as compared to wild type Balb/c mice. We also demonstrate that IL-18 induces IFN-γ, IL-13, and eotaxin in the lungs of ovalbumin-sensitized and challenged transgenic mice along with an increase in IL-13 producing CD4(+) T cells. Treatment with anti-CD4 monoclonal antibody or deletion of the IL-13 gene improves ovalbumin-induced airway hyperresponsiveness and reduces airway inflammatory cells in transgenic mice. Overexpressing the IL-18 protein in the lungs induces type 1 and type 2 cytokines and airway inflammation, and results in increasing airway hyperresponsiveness via CD4(+) T cells and IL-13 in asthma.
Project description:To gain insight into the promoting effect of ultrafine particle inhalation on development and progression of allergic asthma, we selected an experimental approach involving exposure to ultrafine carbon particles (UCP) and gene expression profiling of lungs from mice with experimental, ovalbumin induced allergy. Comparative gene expression analysis was performed by hybridizing pooled cDNA samples from lavaged lungs of different groups. These results suggest that allergic sensitization may represent a susceptibility factor for effects of UCP on gene expression in the lung. In sensitized individuals UCP exposure, such as found in polluted air, thus may contribute to the development and /or aggravation of allergic asthma. Keywords: Particle Inhalation, lung, ovalbumin sensitzed and challanged, experssion profiling Lungs of groups of six non-sensitized, ovalbumin sensitized, or sensitized and ovalbumin challenged BALB/cJ mice, either subjected to particle-free or UCP containing air; two replicates including one dye swap experiment have been performed for lungs: a) non-sensitized particle free air versus sensitized and ovalbumin challenged sensitized particle free air; b) non-sensitized UCP containing air versus sensitized and ovalbumin challenged sensitized UCP containing air
Project description:Mechanisms mediating the protective effects of molecular hydrogen (H2) are not well understood. This study explored the possibility that H2 exerts its anti-inflammatory effect by modulating energy metabolic pathway switch. Activities of glycolytic and mitochondrial oxidative phosphorylation systems were assessed in asthmatic patients and in mouse model of allergic airway inflammation. The effects of hydrogen treatment on airway inflammation and on changes in activities of these two pathways were evaluated. Monocytes from asthmatic patients and lungs from ovalbumin-sensitized and challenged mice had increased lactate production and glycolytic enzyme activities (enhanced glycolysis), accompanied by decreased ATP production and mitochondrial respiratory chain complex I and III activities (suppressed mitochondrial oxidative phosphorylation), indicating an energy metabolic pathway switch. Treatment of ovalbumin-sensitized and challenged mice with hydrogen reversed the energy metabolic pathway switch, and mitigated airway inflammation. Hydrogen abrogated ovalbumin sensitization and challenge-induced upregulation of glycolytic enzymes and hypoxia-inducible factor-1?, and downregulation of mitochondrial respiratory chain complexes and peroxisome proliferator activated receptor-? coactivator-1?. Hydrogen abrogated ovalbumin sensitization and challenge-induced sirtuins 1, 3, 5 and 6 downregulation. Our data demonstrates that allergic airway inflammation is associated with an energy metabolic pathway switch from oxidative phosphorylation to aerobic glycolysis. Hydrogen inhibits airway inflammation by reversing this switch. Hydrogen regulates energy metabolic reprogramming by acting at multiple levels in the energy metabolism regulation pathways.
Project description:IL-13 is known to affect many processes that contribute to an asthmatic phenotype, including inflammation, fibrosis, and mucus production. Members of the aquaporin (AQP) family of transmembrane water channels are targets of regulation in models of lung injury and inflammation. Therefore, we examined AQP mRNA and protein expression in allergen and IL-13-induced mouse models of asthma. Lungs from ovalbumin sensitized and ovalbumin challenged (OVA/OVA) and IL-13 treated mice showed airway thickening, increased mucus production, and pulmonary eosinophilia. Pulmonary function tests showed a significant increase in methacholine-induced airway hyperreactivity in OVA/OVA and IL-13-treated mice as compared with controls. Quantitative PCR analysis revealed differential regulation of AQPs in these two models. AQP1 and AQP4 mRNA expression was downregulated in the OVA/OVA model, but not in the IL-13 model. AQP5 mRNA was reduced in both models, whereas AQP3 was upregulated only in the IL-13 model. Western analysis showed that diminished expression of an apically localized aquaporin, (AQP5), and concomitant upregulation of a basolateral aquaporin (AQP3 or AQP4) are characteristic features of both inducible asthma models. These results demonstrate that aquaporins are common targets of gene expression in both allergen and IL-13 induced mouse models of asthma.
Project description:Dendritic cell (DC) subsets display different functional roles in regulating immune responses and lead to various outcomes, including T(H)1 versus T(H)2 or regulatory versus immunologic responses. Administration of Fms-like tyrosine kinase 3 (Flt3) ligand prevents and reverses allergic airway inflammation and airway hyperresponsiveness in a mouse model. However, the underlying mechanisms are unclear.We characterized and examined the role of lung DC subsets in the therapeutic effect of Flt3 ligand.DCs were isolated from the lungs of ovalbumin (OVA)-sensitized and OVA-challenged mice treated with recombinant human Flt3 ligand. Two populations of CD11c+ cells labeled with fluorochrome-conjugated antibodies were sorted. The ability of the purified cells to stimulate T-cell proliferation and cytokine secretion patterns by different DC subsets was examined. Also, DCs were adoptively transferred in mice to examine their effect on pulmonary function.Two DC populations, CD11c(high)CD11b(low) and CD11c(low)CD11b(high), were identified in the lungs of naive and OVA-sensitized and OVA-challenged mice with and without treatment with Flt3 ligand. The expression levels of CD8alpha, B220, CD19, F4/80, MHC II, CCR7, CD40, programmed death ligand 1, programmed death ligand 2, CD80, and CD86 were distinctly different between the 2 DC populations, which supports the notion that CD11c(high)CD11b(low) and CD11c(low)CD11b(high) DCs potentially have regulatory and immunogenic properties, respectively. Administration of Flt3 ligand increased the DCs with regulatory potential in the lungs of antigen-sensitized mice, and CD11c(high)CD11b(low) DCs acquired a maximum degree of regulatory capacity after Flt3 ligand treatment.These data suggest that Flt3 ligand reverses airway hyperresponsiveness by regulating the function of lung DCs in a mouse model of allergic airway inflammation.
Project description:Asthma is characterized by increases in airway resistance, pulmonary remodeling, and lung inflammation. The cytokine transforming growth factor (TGF)-beta has been shown to have a central role in asthma pathogenesis and in mouse models of allergic airway disease.To determine the contribution of TGF-beta to airway hyperresponsiveness (AHR), we examined the time course, source, and isoform specificity of TGF-beta production in an in vivo mouse asthma model. To then elucidate the function of TGF-beta in AHR, inflammation, and pulmonary fibrosis, we examined the effects of blocking TGF-beta signaling with neutralizing antibody.Mice were sensitized and challenged with ovalbumin (OVA) to establish allergic airway disease. TGF-beta activity was neutralized by intranasal administration of monoclonal antibody.TGF-beta1 protein levels were increased in OVA-challenged lungs versus naive controls, and airway epithelial cells were shown to be a likely source of TGF-beta1. In addition, TGF-beta1 levels were elevated in OVA-exposed IL-5-null mice, which fail to recruit eosinophils into the airways. Neutralization of TGF-beta1 with specific antibody had no significant effect on airway inflammation and eosinophilia, although anti-TGF-beta1 antibody enhanced OVA-induced AHR and suppressed pulmonary fibrosis.These data show that TGF-beta1 is the main TGF-beta isoform produced after OVA challenge, with a likely cellular source being the airway epithelium. The effects of blocking TGF-beta1 signaling had differential effects on AHR, fibrosis, and inflammation. While TGF-beta neutralization may be beneficial to abrogating airway remodeling, it may be detrimental to lung function by increasing AHR.