Microfungus Podosphaera fusca and the Fungus-like Organism Peronospora ficariae as Potential Inhalant Allergens in a Mouse Model of Asthma

Allergic conditions have surged to unprecedented levels globally, affecting approximately 30% of the population. Fungi are among the major sources of allergens, accounting for about 6% of respiratory issues. Identifying the causes of respiratory allergies is not always possible. Our study assessed the capacity of two plant parasites, <i>Podosphaera fusca</i> and <i>Peronospora ficariae</i>, which infect <i>Cucurbita pepo</i> and <i>Ficaria verna</i>, to provoke inflammatory and asthmatic reactions in mouse models of acute and chronic asthma. We performed experiments by sensitizing mice through intranasal challenges with extracts from <i>P. fusca</i> and <i>P. ficariae</i>. Subsequently, we used ELISA tests to measure pro-inflammatory cytokines, including IL-4, IL-5, IL-13, TNF-α, and TGF-β. We evaluated specific IgE production through ELISA and examined histological changes in mouse lungs using hematoxylin-eosin staining. Our research revealed that <i>P. fusca</i> and <i>P. ficariae</i> induced significant production of all tested cytokines, increased specific IgE levels, and caused histological changes characteristic of acute and chronic asthma progression. Although weaker than the reference allergen ovalbumin, <i>P. fusca</i> and <i>P. ficariae</i> possess proinflammatory and asthma-inducing capabilities, indicating the potential to expand the current list of fungal allergens.