Search results for "bronchial hyperreactivity"
showing 10 items of 53 documents
CD4-mediated regulatory T-cell activation inhibits the development of disease in a humanized mouse model of allergic airway disease
2012
Background Based on their potency to control allergic diseases, regulatory T (Treg) cells represent a promising target for novel strategies to interfere with allergic airway inflammation. We have previously demonstrated that stimulation of the CD4 molecule on human Treg cells activates their suppressive activity in vitro and in vivo . Objective We sought to determine the effect of CD4-mediated Treg-cell activation on pulmonary inflammation in a humanized mouse model of allergic airway inflammation. Methods PBMCs obtained from donors allergic to birch pollen or from healthy donors were injected into NOD-severe combined immunodeficiency γc −/− mice, followed by allergen airway challenges and …
Determinants of bronchial hyperresponsiveness in subjects with rhinitis.
2005
Subjects with rhinitis but without asthma may have coexisting bronchial hyperresponsiveness, although the reasons for this are uncertain. To evaluate the factors that determine BHR in rhinitis we examined 410 patients with symptomatic rhinitis with forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) ≥ 80% of the predicted value. In all subjects a skin prick test (SPT) was performed, a determination of total serum IgE and an eosinophils count in the blood. Of the 410 subjects we found that 161 (39.3%) exhibited a methacholine PD20 of 800 mg or less (Group A), whereas 249 (60.7%) had a methacholine PD20 more of 800 mg (Group B). Despite the matched mean values for FEV…
Mast Cells Induce Migration of Dendritic Cells in a Murine Model of Acute Allergic Airway Disease
2009
<i>Background: </i>The migration of dendritic cells (DCs) from the lungs to the regional lymph nodes is necessary for the development of allergic airway disease. Following activation, mast cells release a variety of stored or de novo-produced inflammatory mediators, several of them being capable of activating DCs. In this study, the role of mast cells on DC migration from the lungs to the thoracic lymph nodes was investigated in sensitized mice. <i>Methods:</i> Mast cell-deficient mice (Kit<sup>W-sh/W-sh</sup>) and their wild-type counterparts were sensitized intraperitoneally with ovalbumine (OVA) in saline and challenged by a single intranasal administr…
Airways Hyperresponsiveness and the Effects of Lung Inflation
2001
Lung inflation has a beneficial effect on the airways of healthy subjects. It acts as a bronchoprotector, that is to prevent bronchoconstriction, and as a bronchodilator, in that it reverses bronchial obstruction. The bronchoprotective effect of deep inspiration is more potent than the bronchodilatory one, and the two phenomena appear to advocte different mechanisms. Asthmatics and rhinitics with airways hyperresponsiveness show an impairment in bronchoprotection induced by deep breaths, whereas the bronchodilatory effect, although reduced, is still effective. The lack of the bronchoprotective effect of deep inspiration may contribute to the development of airways hyperresponsiveness. The m…
Iperreattività bronchiale aspecifica in pazienti monosensibili con rinite allergica: variazioni stagionali in rapporto alle IgE sieriche totali ed ag…
2005
Introduction: The significance of the association between allergic rhinitis and abnormal airway responsiveness is unclear. For this reason, we have studied, in patients with seasonal allergic rhinitis, non specific bronchial hyperreactivity, total serum IgE and blood eosinophils, with reference to the responsible allergen, during and out of the pollen season. Materials and methods: Fourty-nine, non-smoking patients, living in Palermo, with clinical diagnosis of allergic rhinitis, skin prick tests and specific serum IgE mono-sensitive to pollen allergens, were enrolled in the study. Twenty patients suffered from seasonal rhinitis to Parietaria pollen, 15 patients to Graminacee pollen and 14 …
Docosahexaenoic acid modulates the expression of T-bet and GATA-3 transcription factors, independently of PPARα, through suppression of MAP kinase ac…
2009
The present study was conducted on CD4(+) T cells, isolated from wild type (WT) and PPARalpha(null) mice, in order to assess the mechanism of action of docosahexaenoic acid (DHA), an n-3 fatty acid, in the modulation of two transcription factors, i.e., T-bet and GATA-3, implicated in T-cell differentiation towards, respectively, T(H)1 and T(H)2 phenotype. The T-cells from PPARalpha(null) mice secreted higher IFN-gamma and lower IL-4 concentrations than WT T-cells. Furthermore, the deletion of PPARalpha gene in T-cells resulted in the upregulation of T-bet and downregulation of GATA-3 both at mRNA and protein levels. DHA exerted not only an inhibitory effect on T-cell proliferation, but also…
Influenza A virus infection inhibits the efficient recruitment of Th2 cells into the airways and the development of airway eosinophilia.
2003
Abstract Most infections with respiratory viruses induce Th1 responses characterized by the generation of Th1 and CD8+ T cells secreting IFN-γ, which in turn have been shown to inhibit the development of Th2 cells. Therefore, it could be expected that respiratory viral infections mediate protection against asthma. However, the opposite seems to be true, because viral infections are often associated with the exacerbation of asthma. For this reason, we investigated what effect an influenza A (flu) virus infection has on the development of asthma. We found that flu infection 1, 3, 6, or 9 wk before allergen airway challenge resulted in a strong suppression of allergen-induced airway eosinophil…
Non-specific bronchial hyper-responsiveness in children with allergic rhinitis: relationship with the atopic status
2003
An increased prevalence of bronchial hyper-responsiveness (BHR) has been demonstrated in children from a general population, and in non-asthmatic adults with allergic rhinitis. Thus, also children with allergic rhinitis are expected to be at higher risk of BHR. We evaluated the prevalence of BHR in a sample of non-asthmatic children with allergic rhinitis by means of the methacholine (Mch) bronchial challenge, and by monitorizing the airway patency using the daily peak expiratory flow variability (PEFv). Fifty-one children (ranged 6-15 years of age) with allergic rhinitis, ascertained by skin prick test to inhalant allergens, underwent a 14-day peak expiratory flow monitoring, and a Mch bro…
TGF-beta regulates airway responses via T cells.
2003
Abstract Allergic asthma is characterized by airway hyperreactivity, inflammation, and a Th2-type cytokine profile favoring IgE production. Beneficial effects of TGF-β and conflicting results regarding the role of Th1 cytokines have been reported from murine asthma models. In this study, we examined the T cell as a target cell of TGF-β-mediated immune regulation in a mouse model of asthma. We demonstrate that impairment of TGF-β signaling in T cells of transgenic mice expressing a dominant-negative TGF-β type II receptor leads to a decrease in airway reactivity in a non-Ag-dependent model. Increased serum levels of IFN-γ can be detected in these animals. In contrast, after injection of OVA …
Treatment of allergic airway inflammation and hyperresponsiveness by antisense-induced local blockade of GATA-3 expression.
2001
Recent studies in transgenic mice have revealed that expression of a dominant negative form of the transcription factor GATA-3 in T cells can prevent T helper cell type 2 (Th2)-mediated allergic airway inflammation in mice. However, it remains unclear whether GATA-3 plays a role in the effector phase of allergic airway inflammation and whether antagonizing the expression and/or function of GATA-3 can be used for the therapy of allergic airway inflammation and hyperresponsiveness. Here, we analyzed the effects of locally antagonizing GATA-3 function in a murine model of asthma. We could suppress GATA-3 expression in interleukin (IL)-4–producing T cells in vitro and in vivo by an antisense ph…