Project description:While the pathogenesis of asthma is mainly orchestrated by antigen-specific Th2 cells and their cytokines, recent findings indicate the involvement of other subsets of helper T cells including Th17 cells. Previous studies have shown that IL-22, one of Th17 cell-related cytokines, plays multiple roles in regulating allergic airway inflammation; however, the mechanism underlying the Il-22-mediated regulation remains unclear. Here, we show that allergic airway inflammation upon intratracheal administration of house dust mite extract (HDM), a representative allergen, were exacerbated in IL-22-deficient mice. To address the molecular mechanisms by which IL-22 inhibits the development of HDM-induced allergic airway inflammation, we next performed an unbiased comprehensive screening of genes induced by IL-22 administration in the lung by RNA-seq analysis.
Project description:Levels of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, are increased in lung, sputum, exhaled breath condensate and plasma samples from asthma patients. ADMA is metabolized primarily by dimethylarginine dimethylaminohydrolase 1 (DDAH1) and DDAH2. We determined the effect of DDAH1 overexpression on development of allergic inflammation in mouse models of asthma. Wild type and DDAH1-transgenic mice were challenged with PBS or house dust mite (HDM). Airway inflammation was assessed by bronchoalveolar lavage (BAL) total and differential cell counts. Gene expression in lungs was determined by RNA-Seq and RT-quantitative PCR (qPCR). The expression of DDAH1 and DDAH2 was decreased in the lungs of mice following HDM exposure. Transgenic overexpression of DDAH1 resulted in decreased BAL total cell and eosinophil numbers following HDM exposure. Total IgE levels in serum and BAL fluid were decreased in HDM-exposed DDAH1-transgenic mice compared to HDM-exposed wild type mice. RNA-Seq results showed downregulation of genes in inducible nitric oxide synthase (iNOS) signaling pathway in PBS-treated DDAH1 transgenic mice versus PBS-treated wild type mice and downregulation of genes in IL-13/FOXA2 signaling pathway in HDM-treated DDAH1 transgenic mice versus HDM-treated wild type mice. Our findings suggest that decreased expression of DDAH1 in airway epithelial cells may contribute to allergic asthma and overexpression of DDAH1 attenuates allergen-induced airway inflammation through modulation of Th2 responses. mRNA profiles of WT and DDAH1-transgenic mice treated with PBS or house dust mite (HDM).
Project description:Obesity is associated with severe, difficult to control asthma, and increased airway oxidative stress. Mitochondrial reactive oxygen species (mROS) are an important source of oxidative stress leading us to hypothesize that targeting mROS in obese allergic asthma might be an effective treatment strategy. Using a mouse model of house dust mite (HDM) induced allergic airway disease in mice fed a low- (LFD) or high-fat diet (HFD), and the mitochondrial antioxidant MitoQuinone (MitoQ); we investigated the effects of obesity and mROS on airway inflammation, remodelling and airway hyperreactivity (AHR). HDM induces airway inflammation, remodelling and hyperreactivity in both lean and obese mice. Obese allergic mice showed increased lung tissue eotaxin levels, airway tissue eosinophilia and AHR when compared to lean allergic mice. MitoQ reduced markers of airway inflammation, remodelling and hyperreactivity in both lean and obese allergic mice, and tissue eosinophilia in obeseHDM mice. mROS regulates cell signalling by protein oxidation of multiple downstream targets: MitoQ reduced HDM-induced cysteine-sulfenylation of several proteins including those involved in the unfolded protein response (UPR). In summary, mROS mediates the development of allergic airway disease and hence MitoQ might be effective for the treatment for asthma, and specific features of obese asthma.
Project description:Background: A specific subset of regulatory IL-10 producing B cells has been extensively studied in autoimmune and inflammatory pathologies. These cells are able to constrain exacerbated inflammation by inhibiting T cell mediated responses and maturation of antigen presenting cells. In allergic diseases, observations that increase of regulatory B cells is necessary for allergen tolerance suggest that development of allergic asthma would be associated with a defect in the regulatory B cells compartment. Objective: We sought to (i) characterize regulatory IL-10+ regulatory B cell subset in Balb/c mice by microarray and flow cytometry and (ii) investigate their regulatory capacity in vivo in a house dust mite model of allergic asthma. Results: We identified an IL-10 producing B cells subset able to control T cell proliferation in vitro in both control and asthmatic mice. This subset is decreased in allergic mice. IL-10+ Breg cells express high levels of CD9 and upregulate CD70 and CD73 after activation. Expression of CD9 allows identifying more than 50% of Bregs. Interestingly CD9+ B cells inhibit TH2-TH17 allergic airway inflammation in vivo after adoptive transfer in an IL-10 dependent manner. Conclusions: Herein, we demonstrate that induction of allergic asthma dampens the generation of Bregs contributing to exacerbated airway inflammation. We identified a distinct CD9+ Breg-cell population decreased in lung of HDM mice and able to control asthma and allergic airway inflammation by producing IL-10 after adoptive transfer. This study points B cells as an interesting therapeutic target in allergic asthma. IL-10+ B cells (n=3) and 3 IL-10- B cells (n=3) in control mice + IL-10+ B cells (n=3) and 3 IL-10- B cells (n=3) from asthmatic allergic (HDM) mice
Project description:Allergic asthmatic, allergy only, asthma only (no allergy), and non-allergic non-asthmatic (control) subjects underwent bronchoscopy with instillation of saline, lipopolysaccharide (LPS), and house dust mite antigen in separate subsegmental bronchi. Airway epithelial cells were collected four hours later (three samples per subject). RNA was extracted from these cells for microarray analysis. Experiment Overall Design: There are four main phenotypic groups: Experiment Overall Design: 1. control (no allergy or asthma) Experiment Overall Design: 2. allergy only (no asthma) Experiment Overall Design: 3. asthma only (no allergy) Experiment Overall Design: 4. allergy and asthma Experiment Overall Design: and three exposures: saline, house dust mite antigen (HDM), and LPS. Samples from the different exposures were all collected at the same time: four hours after instillation. The hybridizations were carried out in two main "batches": samples in batch 1 were processed in mid 2004, samples in batch 2 about a year later in 2005. There is a clear "batch effect": differences between expression profiles from the two batches (likely caused by technical differences between hybridization and scanning methods). This should be considered when analyzing the data.
Project description:Allergic asthmatic, allergy only, asthma only (no allergy), and non-allergic non-asthmatic (control) subjects underwent bronchoscopy with instillation of saline, lipopolysaccharide (LPS), and house dust mite antigen in separate subsegmental bronchi. Airway epithelial cells were collected four hours later (three samples per subject). RNA was extracted from these cells for microarray analysis. Keywords: gene expression arrays (two-dye: sample against common "universal" reference RNA)
Project description:Alteration in the gene expression level in the lungs are thought to play a crucial role during the development of asthma and airway hyperresponsiveness. House dust mite induced allergic asthma is a Th2-lymphocyte driven inflammation characterized by airway hyperresponsiveness and eosinophilia while c-di-GMP, which is a potent mucosal adjuvant, induces a Th1-Th17 response accompanied by neutrophilia along with a low Th2 response. We aimed to identify changes in the expression of genes important in asthma pathology via targeted gene expression arrays.
Project description:Background: In asthma, airway epithelium remodeling can already be detected during childhood, and epithelial cells are more susceptible to virus and oxidative stress. Their exact role in natural history and severity of children allergic respiratory disease remains however surprisingly unexplored. Aim: To analyze dysfunctions of epithelium in dust mite allergic respiratory disease (rhinitis ± asthma) in children. Methods: Expression profilings of nasal epithelial cells collected by brushing were performed on Affymetrix Hugene 1.0 ST arrays. All allergic patients were sensitized to dust mite. 19 patients had an isolated allergic rhinitis (AR). 14 patients had AR associated with asthma. Patients were compared to 12 controls, their severity and control being assessed according to NAEPP and ARIA criteria. Infections by respiratory viruses were excluded by real-time PCR measurements. Results: 61 probes were able to distinguish allergic rhinitis children from healthy controls. A majority of these probes was under the control of Th2 cytokines, as evidenced by parallel experiments performed on primary cultures of nasal epithelial cells. In uncontrolled asthmatic patients, we observed not only an enhanced expression of these Th2-responsive transcripts, but also a down-regulation of interferon-responsive genes. Conclusion: Our study identifies a Th2 driven epithelial phenotype common to all dust mite allergic children. Besides, it suggests that epithelium is involved in the severity of the disease. Expression profiles observed in uncontrolled asthmatic patients suggest that severity of asthma is linked at the same time to atopy and to impaired viral response. Nasal epithelium gene expression profiling of dust mite allergic children with isolated rhinitis, rhinitis associated with asthma and controls. 38 samples classified in 4 categories : 14 isolated rhinitis (R), 6 rhinitis with uncontrolled asthma (UA), 7 rhinitis with controlled asthma (CA) and 11 healthy subjects (C )
Project description:Using mouse lung resident conventional CD11b+ dendritic cells (CD11b+ cDCs) in the context of house-dust mite (HDM)-driven allergic airway sensitization as a model, we aimed here to identify transcriptional events regulating the pro-Th2 activity of cDCs. We used microarray analyses to identify genes differentially expressed by lung CD11b+ conventional dendritic cells in response to house dust mite allergens in wild-type and Irf3-deficient mice
Project description:Background: A specific subset of regulatory IL-10 producing B cells has been extensively studied in autoimmune and inflammatory pathologies. These cells are able to constrain exacerbated inflammation by inhibiting T cell mediated responses and maturation of antigen presenting cells. In allergic diseases, observations that increase of regulatory B cells is necessary for allergen tolerance suggest that development of allergic asthma would be associated with a defect in the regulatory B cells compartment. Objective: We sought to (i) characterize regulatory IL-10+ regulatory B cell subset in Balb/c mice by microarray and flow cytometry and (ii) investigate their regulatory capacity in vivo in a house dust mite model of allergic asthma. Results: We identified an IL-10 producing B cells subset able to control T cell proliferation in vitro in both control and asthmatic mice. This subset is decreased in allergic mice. IL-10+ Breg cells express high levels of CD9 and upregulate CD70 and CD73 after activation. Expression of CD9 allows identifying more than 50% of Bregs. Interestingly CD9+ B cells inhibit TH2-TH17 allergic airway inflammation in vivo after adoptive transfer in an IL-10 dependent manner. Conclusions: Herein, we demonstrate that induction of allergic asthma dampens the generation of Bregs contributing to exacerbated airway inflammation. We identified a distinct CD9+ Breg-cell population decreased in lung of HDM mice and able to control asthma and allergic airway inflammation by producing IL-10 after adoptive transfer. This study points B cells as an interesting therapeutic target in allergic asthma.