Allergic inflammation induced by a Penicillium chrysogenum conidia-associated allergen extract in a murine model

Background: Recent evidence has shown that viable conidia from the fungus Penicillium chrysogenum induce allergic effects in mice. The present study was conducted to determine the specific allergic dose response of C57BL/6 mice to the protease extract, Pen ch, isolated from viable P. chrysogenum conidia. Methods: Mice were treated with primary intraperitoneal (IP) injections of 10 or 100 mug of Pen ch adsorbed to alum, followed by weekly IP injections of 0.1, 1.0, or 10.0 mug Pen ch with alum for 4 weeks, and with 10.0 mug of Pen ch by intranasal (IN) inoculations the final 2 weeks before killing. Results: Intraperitoneal injections of 10 and 100 mug of Pen ch for 5 weeks followed by 2 weeks of IN instillation of 10 mug induced significant increases of total serum immunoglobulin (Ig)E and IgG(1). Bronchoalveolar lavage cell counts revealed increased numbers of eosinophils and neutrophils. Histopathological examination of lungs detected perivascular inflammation by eosinophils and neutrophils and increased mucous production. Conclusions: The data presented in this study indicate that sensitization to protease allergens released by viable P. chrysogenum conidia in vivo induce a strong allergic inflammatory response in a murine model, which could have implications for people exposed to high levels of conidia of this organism.