Patients with severe Th2 type asthma often have a steroid resistant phenotype and are prone to acute exacerbations. Current novel therapies have only marginal therapeutic effects. One of the hypotheses for lack of major efficacy in most patients is targeting only one redundant pathway leaving others active.
View Article and Find Full Text PDFInt Arch Allergy Immunol
September 2017
The past 20 years have seen a proliferation of scientific data on the pathophysiology of asthma. Most of these data were generated in mice using tool reagents, gene-deficient or transgenic animals. In contrast, studies on disease pathogenesis in patients are scarce.
View Article and Find Full Text PDFSmoking is an important risk factor for the development of chronic obstructive pulmonary disease (COPD) and viral infections are believed to be major triggers of exacerbations, which periodically lead to a worsening of symptoms. The pro-inflammatory IL-1 family members IL-1α and IL-1β are increased in COPD patients and might contribute to disease pathology. We investigated whether individual or combined inhibition of these cytokines reduced lung inflammation in cigarette smoke (CS)-exposed and H1N1-infected BALB/c mice.
View Article and Find Full Text PDFBI 1002494 [(R)-4-{(R)-1-[7-(3,4,5-trimethoxy-phenyl)-[1,6]napthyridin-5-yloxy]-ethyl}pyrrolidin-2-one] is a novel, potent, and selective spleen tyrosine kinase (SYK) inhibitor with sustained plasma exposure after oral administration in rats, which qualifies this molecule as a good in vitro and in vivo tool compound. BI 1002494 exhibits higher potency in inhibiting high-affinity IgE receptor-mediated mast cell and basophil degranulation (IC50 = 115 nM) compared with B-cell receptor-mediated activation of B cells (IC50 = 810 nM). This may be explained by lower kinase potency when the physiologic ligand B-cell linker was used, suggesting that SYK inhibitors may exhibit differential potency depending on the cell type and the respective signal transduction ligand.
View Article and Find Full Text PDFViral infections trigger exacerbations in chronic obstructive pulmonary disease (COPD), and tiotropium, a M3 receptor antagonist, reduces exacerbations in patients by unknown mechanisms. In this report, we investigated whether tiotropium has anti-inflammatory effects in mice exposed to cigarette smoke (CS) and infected with influenza virus A/PR/8/34 (H1N1) or respiratory syncytial virus (RSV) and compared these effects with those of steroid fluticasone and PDE4-inhibitor roflumilast. Mice were exposed to CS; infected with H1N1 or RSV; and treated with tiotropium, fluticasone, or roflumilast.
View Article and Find Full Text PDFAm J Respir Cell Mol Biol
September 2015
Viral vectors have been applied successfully to generate disease-related animal models and to functionally characterize target genes in vivo. However, broader application is still limited by complex vector production, biosafety requirements, and vector-mediated immunogenic responses, possibly interfering with disease-relevant pathways. Here, we describe adeno-associated virus (AAV) variant 6.
View Article and Find Full Text PDFSevere asthma is characterised by persistent inflammation, hyperreactivity and remodeling of the airways. No efficient treatment is available, this is particularly the case for steroid resistant phenotypes. Our aim therefore was to develop a preclinical model showing characteristics of severe human asthma including steroid insensitivity.
View Article and Find Full Text PDFPulm Pharmacol Ther
February 2014
Recurrent relapses of allergic lung inflammation in asthmatics may lead to airway remodeling and lung damage. We tested the efficacy of tiotropium bromide, a selective long-acting, muscarinic receptor antagonist as an adjunct therapy in relapses of allergic asthma in mice. We compared the effectiveness of local intranasal administration of tiotropium and dexamethasone in acute and relapsing allergic asthma in BALB/c mice.
View Article and Find Full Text PDFDuring the past 10 years, immunologists, epidemiologists and parasitologists have made many new exciting discoveries in the field of helminth-mediated immune regulation. In addition, many animal experiments have shown that certain helminths or products derived from helminths can protect mice from developing allergic or autoimmune disease. Some clinical trials utilising Trichuris suis or Necator americanus for the treatment of allergic disorders and inflammatory bowel disease have been conducted.
View Article and Find Full Text PDFAtopic asthma is a chronic inflammatory pulmonary disease characterised by recurrent episodes of wheezy, laboured breathing with an underlying Th2 cell-mediated inflammatory response in the airways. It is currently treated and, more or less, controlled depending on severity, with bronchodilators e.g.
View Article and Find Full Text PDFThe spleen tyrosine kinase (Syk) is a key mediator of immunoreceptor signaling in immune cells. Thus, interfering with the function of Syk by genetic deletion or pharmacological inhibition might influence a variety of allergic and autoimmune processes. Since conventional Syk knockout mice are not viable, studies addressing the effect of Syk deletion in adult animals have been limited.
View Article and Find Full Text PDFToll-like receptor (TLR) mediated signaling induces pro-inflammatory responses and can both suppress and exacerbate allergic responses in the airways. The aim of our study was to directly compare the efficacy of different TLR agonists in inhibiting or exacerbating the development of Th2-mediated responses in the airways and investigate if the suppressive effects were associated with increased pro-inflammatory responses. Mice were immunized on day 0, 14 and 21 by intraperitoneal injection of ovalbumin/alum and exposed to ovalbumin aerosol on day 26 and 27.
View Article and Find Full Text PDFBackground: Recent clinical trials, epidemiological studies and animal experiments have suggested that probiotics may help suppress the development of allergic responses.
Objective: To investigate whether the application of the probiotic Escherichia coli strain Nissle 1917 (EcN) protects mice from developing ovalbumin (OVA)-specific T helper-2 responses in the airways.
Methods: OVA-specific Th2 responses were induced by 2 intraperitoneal (i.
Trends Immunol
February 2009
Recent epidemiological and experimental data indicate that infection with helminths can protect humans from the development of allergic disorders by immunosuppressive mechanisms that involve the induction of IL-10 and/or regulatory T cells. Furthermore, helminth-derived immune modulators suppress allergic responses in mice. Trichuris suis therapy has been shown to be safe and efficacious in treating inflammatory bowel disease in humans.
View Article and Find Full Text PDFIdentifying and developing novel chemical entities (NCE) for the treatment of asthma is a time-consuming process and liabilities that endanger the successful progression of a compound from research into the patient are found throughout all phases of drug discovery. In particular the failure of advanced compounds in clinical studies due to lack of efficacy and/or safety concerns is tremendously costly. Therefore, in order to try and reduce the failure rate in clinical trials various in vitro and in vivo tests are performed during preclinical development, to rapidly identify liabilities, eliminate high risk compounds and promote promising potential drug candidates.
View Article and Find Full Text PDFEosinophils play a major role in the development and severity of asthma. Robust and rapid preclinical animal models are desirable to profile novel therapeutics inhibiting the influx of eosinophils into the airways. To develop a rapid, airway eosinophil recruitment model in the rat, Brown-Norway (BN) rats were immunised with ovalbumin (OVA)/alum on day 0, 1 and 2 and challenged with OVA aerosol on day 5 and 6.
View Article and Find Full Text PDFTh2 responses induced by allergens or helminths share many common features. However, allergen-specific IgE can almost always be detected in atopic patients, whereas helminth-specific IgE is often not detectable and anaphylaxis often occurs in atopy but not helminth infections. This may be due to T regulatory responses induced by the helminths or the lack of helminth-specific IgE.
View Article and Find Full Text PDFAm J Respir Crit Care Med
February 2007
Rationale: Epidemiological studies suggest that infections with helminths protect from the development of asthma. Supporting this view is our published finding that infection with Nippostrongylus brasiliensis decreased ovalbumin-induced Th2 responses in the lung of mice.
Objectives: To evaluate if N.
T effector cells require selectin ligands to migrate into inflamed regions. In vitro, IL-12 promotes induction of these ligands as well as differentiation of CD4+ T cells into IFN-gamma-producing Th1 but not Th2 cells. STAT4 is strongly involved in these processes.
View Article and Find Full Text PDFBackground: Successful allergen-specific immunotherapy (SIT) is associated with reduced Th2 cytokine production and the induction of IL-10-producing regulatory T cells. To improve treatment efficacy, we investigated the impact of an IL-4/IL-13 inhibitor during SIT.
Methods: BALB/c mice were sensitized intranasally with ovalbumin (OVA) for 4 weeks.
The only disease-modifying treatment that is available for allergic patients is allergen-specific immunotherapy. Two competing application forms are used: subcutaneous immunotherapy, which has been used for > 90 years, and a relatively new immunotherapy where the allergen is applied sublingually. Numerous studies have shown efficacy for subcutaneous immunotherapy and have identified possible mechanisms that are responsible for the observed reduction in allergic responses.
View Article and Find Full Text PDFWe analysed the effects of murine polyomavirus-like particles (PLPs) on bone marrow-derived dendritic cells (BMDCs) and T cells in vitro. BMDCs activated with PLPs up-regulated CD40, CD80, CD86 and major histocompatibility complex (MHC) class II surface markers and produced proinflammatory cytokines. Chimeric PLPs [expressing the ovalbumin (OVA)-peptides OVA(257-264) or OVA(323-339)], but not wildtype PLPs, activated OVA-specific CD8 T cells and OVA-specific CD4 T cells, respectively, indicating both MHC class I and II presentation of the peptides by antigen-presenting cells.
View Article and Find Full Text PDFAm J Respir Cell Mol Biol
January 2007
Eosinophils represent one of the main effector cell populations of allergic airway inflammation and allergic bronchial asthma. Their infiltration correlates with many characteristics of the disease, including airway hyperresponsiveness (AHR) and increased mucus production. CCR-3 is the principle chemokine receptor involved in eosinophil attraction into inflamed tissue.
View Article and Find Full Text PDFTh1- and Th2-polarized immune responses are crucial in the defense against pathogens but can also promote autoimmunity and allergy. The chemokine receptors CXCR3 and CCR4 have been implicated in differential trafficking of IFN-gamma- and IL-4-producing T cells, respectively, but also in tissue and inflammation-specific homing independent of cytokine responses. Here, we tested whether CD4+ T cells isolated from murine tissues under homeostatic or inflammatory conditions exhibit restricted patterns of chemotactic responses that correlate with their production of IFN-gamma, IL-4, or IL-10.
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