Investigations in Asthma Heterogeneity: The Roles of Aspergillus Fumigatus-Derived Eicosanoid Synthases and Occupational Exposures to Grain Dusts on the Development of Fungal Allergic Asthma
Abstract
Allergic asthma is an inflammatory syndrome of the respiratory system which changes the airway wall architecture. Using an aeroallergen, murine model of A. fumigatus-mediated asthma, the two studies herein examine the development of asthma in the contexts of host-allergen interactions via A. fumigatus knock-outs of eicosanoid synthases and occupational exposures to corn and soybean dusts. The lack of difference between control and treatment groups seen in post-methacholine airway responses, goblet cell metaplasia, peribronchial inflammation, and fibrosis in the first study show that fungus-derived eicosanoid synthases are dispensable in the development of fungal allergic asthma. However, the same set of respiratory parameters in the grain dust study reveals an increase in BAL neutrophilia and serum IgE titer. The study also underscores a need for modifications of dust exposure times and of time-points of data analysis. These two studies represent unique perspectives on asthma pathogenesis and emphasize the heterogeneity of the syndrome.