Search results for "RESPIRATORY SYSTEM"
showing 10 items of 1829 documents
Effects of glycation of the model food allergen ovalbumin on antigen uptake and presentation by human dendritic cells.
2010
Advanced glycation endproducts (AGEs) of food proteins resulting from the Maillard reaction after cooking or heating may have particular importance in food allergy. The underlying immunological mechanisms are only poorly understood. The aim of the study was to examine the effects of AGE derived from the model food allergen ovalbumin (AGE-OVA) on dendritic cells (DCs), their immunostimulatory capacity and the T-cell response compared with regular OVA. For this purpose, human immature DCs were exposed to fluorescein isothiocyanate (FITC)-labelled AGE-OVA and FITC-labelled regular OVA and uptake was analysed by flow cytometry and fluorescence microscopy. Furthermore, autologous CD4(+) T-cell p…
MHC class II tetramer guided detection of Mycobacterium tuberculosis-specific CD4+ T cells in peripheral blood from patients with pulmonary tuberculo…
2007
Novel diagnostic tools are needed to diagnose latent infection and to provide biologically meaningful surrogate markers to define cellular immune responses against Mycobacterium tuberculosis (MTB). Interferon gamma-based assays have recently been developed in addition to the more than 100-year-old tuberculin skin test (TST) for the immune diagnosis of MTB in blood. The advent of soluble MHC/peptide tetramer molecules allows to objectively enumerate antigen-specific T cells. We identified novel MHC class II-restricted MTB epitopes and used HLA-DR4 tetrameric complexes to visualize ex vivo CD4(+) T cells directed against the antigens Ag85B and the 19-kDa lipoprotein, shared between MTB and ot…
Asthmatic changes in mice lacking T-bet are mediated by IL-13
2005
Mice with a targeted deletion of the T-bet gene exhibit spontaneous airway hyperresponsiveness (AHR), airway inflammation, enhanced recovery of T(h)2 cytokines from bronchoalveolar lavage fluid, sub-epithelial collagen deposition and myofibroblast transformation. Here we analyze the mechanisms responsible for the chronic airway remodeling observed in these mice. CD4+ T cells isolated from the lung of T-bet-deficient mice were spontaneously activated CD44(high)CD69(high) memory T cells, with a typical T(h)2 cytokine profile. Neutralization of IL-13 but not IL-4 resulted in amelioration of AHR in airways of mice lacking T-bet. IL-13 blockade also led to reduced eosinophilia and decreased vime…
Nitric oxide enhances Th9 cell differentiation and airway inflammation
2014
International audience; Th9 cells protect hosts against helminthic infection but also mediate allergic disease. Here we show that nitric oxide (NO) promotes Th9 cell polarization of murine and human CD4(+) T cells. NO de-represses the tumour suppressor gene p53 via nitrosylation of Mdm2. NO also increases p53-mediated IL-2 production, STAT5 phosphorylation and IRF4 expression, all essential for Th9 polarization. NO also increases the expression of TGFβR and IL-4R, pivotal to Th9 polarization. OVA-sensitized mice treated with an NO donor developed more severe airway inflammation. Transferred Th9 cells induced airway inflammation, which was exacerbated by NO and blocked by anti-IL-9 antibody.…
A method to enable the investigation of murine bronchial immune cells, their cytokines and mediators.
2007
Innovative therapies for severe lung diseases (such as allergic and chronic asthma, chronic obstructive pulmonary disease or any type of lung cancer) require a detailed understanding of the cellular and immune processes in the lung. This protocol details a method to obtain the immune cells of the bronchi as well as the cytokines and mediators produced by these cells for further investigation. The broncho-alveolar lavage fluid (BALF) is taken by injecting physiological solution through the tracheal tube into the murine airways and carefully regained by winding up the connected syringe. After centrifugation, the resulting BALF supernatant can be stored for detection of cytokines or other medi…
Local blockade of IL-6R signaling induces lung CD4+ T cell apoptosis in a murine model of asthma via regulatory T cells.
2007
We previously reported high levels of the soluble form of the IL-6R (sIL-6R) in the airways of asthmatic subjects. Here, we analyzed the IL-6R effects on Th2 cell survival in the lung by locally antagonizing sIL-6R-mediated trans-signaling with a designer fusion protein (gp130-Fc) as well as IL-6R signaling with an antibody against the gp80 unit of the IL-6R (alphaIL-6R) in a murine model of asthma after ovalbumin peptide (OVA) sensitization and challenge. Blockade of the sIL-6R led to a significant decrease in inflammatory cells by an apoptosis-independent mechanism. In contrast, local treatment with alphaIL-6R antibodies that also block signaling via the membrane-bound IL-6R (mIL-6R) led …
Efficient Targeting of Protein Antigen to the Dendritic Cell Receptor DEC-205 in the Steady State Leads to Antigen Presentation on Major Histocompati…
2002
To identify endocytic receptors that allow dendritic cells (DCs) to capture and present antigens on major histocompatibility complex (MHC) class I products in vivo, we evaluated DEC-205, which is abundant on DCs in lymphoid tissues. Ovalbumin (OVA) protein, when chemically coupled to monoclonal alphaDEC-205 antibody, was presented by CD11c+ lymph node DCs, but not by CD11c- cells, to OVA-specific, CD4+ and CD8+ T cells. Receptor-mediated presentation was at least 400 times more efficient than unconjugated OVA and, for MHC class I, the DCs had to express transporter of antigenic peptides (TAP) transporters. When alphaDEC-205:OVA was injected subcutaneously, OVA protein was identified over a …
Activation of nuclear factor erythroid 2-related (Nrf2) system as a novel therapeutic approach in COPD
2019
Background: Chronic Obstructive Pulmonary Disease (COPD) is an inflammatory lung disease caused by chronic exposure to cigarette smoke. Oxidative stress is one of the most important mechanisms involved in the physiopathology of COPD. Nuclear Factor Erythroid 2-related (Nrf2) is critical in protection against oxidative stress by inducing expression of antioxidant genes and a decrease in its expression has been observed in COPD patients. Objective: The aim of this study was to characterise the effects of Bardoxolone, Omavexolone and Obacunone as antioxidant drugs in COPD. Methods: Peripheral blood neutrophils from COPD and healthy volunteers and Primary Human Bronchial Epithelial cells were i…
TLR4 and NOD1 increase in stable COPD of increasing severity. Relationship with tissutal bacterial load
2016
Background: The immune host response related to bacterial and viral infections in the airways and lung of COPD patients is unclear. Objectives: To investigate the expression of anti-bacterial and anti-viral antigens in bronchial biopsies and lung parenchyma of stable COPD patients in relation to bacterial load. Methods: Immunohistochemical (IHC) and qRT-PCR-expression of TLR2-3-4-7-8-9, NOD1, NOD2, MYD88, TRIF, TIRAP, pIRAK1, IRAK4, IRF3, pIRF3, IRF7, pIRF7, RIG1, MDA5, LGP2, MAVS, STING, DAI, IFNα and IFNβ was measured in bronchial mucosa in patients with mild/moderate (n=16), severe/very severe (n=18) stable COPD, control smokers (n=12) and control non-smokers (n=12). Selected relevant an…
Cigarette smoke alters the EZH2/DAB2IP expression in bronchial epithelial cells. A risk factor for lung cancer in COPD patients
2016
Cigarette smoke is an environmental risk factor for COPD and Lung cancer, leading causes of morbidity and mortality worldwide. In cancer, enhancer of zeste homolog 2 (EZH2) silenced disabled homolog 2 interacting protein gene (DAB2IP) (tumor-suppressor gene) bytri-methylation of lysine 27 on histone H3 (H3K27me3). We studied EZH2 and DAB2IP expression in airway epithelial cells from COPD patients and their potential involvement in the progression of COPD toward lung cancer. We assessed EZH2 and DAB2IPimmunoreactivity in bronchial epithelial cells from surgical specimens of COPD patients and healthy control subjects (HC) by immunohistochemistry. Bronchial epithelial cell line (16HBE), primar…