Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology
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Short ragweed (Ambrosia artemisiifolia) allergies affect more than 36 million people annually. Ragweed pollen grains release subpollen particles (SPP) of respirable size upon hydration or a change in air electrical conditions. The aim of this study was to characterize the proteomes and allergomes of short ragweed SPP and total pollen protein extract (TOT), and compare their effects with those of standard aqueous pollen protein extract (APE) using sera from short ragweed pollen-sensitized patients. ⋯ We demonstrated that the complete major (Amb a 1 and 11) and almost all minor (Amb a 3, 4, 5, 6, 8 and 9) short ragweed pollen allergen repertoire as well as NADH oxidases are present in SPP, highlighting an important role for SPP in allergic sensitization to short ragweed.
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Chronic exposure to environmental triggers, such as house dust mite (HDM), drives T helper 2 (Th2) cell-mediated asthma. Recent evidence has shown that B-T cell interaction, and in particular germinal centre reactions and follicular T helper (Tfh) cells are required for the development of eosinophilic airway inflammation in HDM-driven models containing a sensitization and challenge phase. Whether B-T cell interactions are essential for pulmonary eosinophilic inflammation following chronic allergen provocation remains unknown. ⋯ From these findings, we conclude that B-T cell interaction is required for robust Tfh and Th2 cell induction, but not essential for eosinophilic airway inflammation during a chronic HDM-driven asthma model.
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Interferons play an important role in innate immunity. Previous studies report deficiency in virus induction of interferon (IFN)-α, IFN-β and IFN-λ in bronchial epithelial and bronchial lavage cells in atopic asthmatics. It is now recognized that asthma is a heterogeneous disease comprising different inflammatory phenotypes, some of which may involve innate immune activation in the absence of overt infection. ⋯ Neutrophilic, but not eosinophilic, asthmatics display overexpression of IFN-β, IFN-λ1/IL-29 and ISGs in their sputum cells that may reflect ongoing innate immune activation.
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Children with risk alleles at the 17q21 genetic locus who wheeze during rhinovirus illnesses have a greatly increased likelihood of developing childhood asthma. In mice, overexpression of the 17q21 gene ORMDL3 leads to airway remodelling and hyperresponsiveness. However, the mechanisms by which ORMDL3 predisposes to asthma are unclear. Previous studies have suggested that ORMDL3 induces endoplasmic reticulum (ER) stress and production of the type I interferon (IFN)-regulated chemokine CXCL10. ⋯ Multiple lines of evidence support an association between higher ORMDL3 and increased rhinovirus-induced HSPA5 and type I IFN gene expression. These associations with ORMDL3 are cell type specific, with the most significant 17q21 genotype effects on ORMDL3 expression and HSPA5 induction evident in B cells. Together, these findings have implications for how the interaction of increased ORMDL3 and rhinovirus may predispose to asthma.
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Review Meta Analysis
Comparison of anti-interleukin-5 therapies in patients with severe asthma: global and indirect meta-analyses of randomized placebo-controlled trials.
Inconsistent results have been reported regarding IL-5 blockade treatment in asthma. There were no direct between-treatment comparisons. Only differences between each drug and placebo were studied. ⋯ The data interpretations were not affected by the sensitivity analysis. IL-5 blockade appears to be a relevant treatment strategy to improve severe asthma management, particularly for eosinophilic patients. No clear superiority appeared between the drugs when appropriate doses were compared.