Aggravation of bronchial eosinophilia in mice by nasal and bronchial exposure to Staphylococcus aureus enterotoxin B |
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Authors: | P W Hellings G Hens I Meyts D Bullens J Vanoirbeek P Gevaert M Jorissen J L Ceuppens C Bachert |
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Institution: | Laboratory of Experimental Immunology, Department of Otorhinolaryngology, University Hospitals, Faculty of Medicine, University of Leuven, Belgium. Peter.Hellings@med.kuleuven.be |
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Abstract: | BACKGROUND: The role of bacterial enterotoxins like Staphylococcus aureus enterotoxin B (SEB) in allergic asthma remains unknown. We used a mouse model of airway allergy to study the effects of nasal or bronchial contact with SEB on bronchial allergic inflammation. METHODS: The features of allergic asthma were induced in ovalbumin (OVA)-sensitized mice (days 1-13) by repeated exposures to nebulized OVA (days 33-37). Nasal or bronchial application of SEB was performed on three occasions (days 33-35-37), and the effects on bronchial inflammation, IgE titres and expression levels of mRNA for T helper type 2 cytokines and other inflammatory mediators were evaluated. RESULTS: Both nasal and bronchial SEB enhanced the allergen-induced bronchial inflammation, as reflected by more eosinophilic inflammation in the airway lumen and in bronchial tissue. Aggravation of experimental asthma correlated with higher expression of mRNA for IL-5, IL-4, IFN-gamma, IL-12 p40, eotaxin-1 and TGF-beta in bronchi. In addition, nasal SEB elevated concentrations of IL-4, IL-5 and IFN-gamma in serum and bronchial SEB increased titres of OVA-specific and total IgE in serum. CONCLUSION: Our data illustrate the potential of both nasal as well as bronchial SEB to aggravate several features of allergic asthma in a mouse model. |
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Keywords: | allergic asthma allergic rhinitis animal model Staphylococcus aureus enterotoxin B superantigen |
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