Potential Proallergenic Activity of Phytopathogenic Erysiphe palczewskii and Erysiphe convolvuli in in vitro Studies

Abstract

Purpose: Allergic diseases have reached epidemic proportions globally, affecting nearly 30% of the world’s population. One of the most prominent sources of allergens is fungi, causing up to 6% of respiratory diseases in the general population. However, the cause of respiratory allergies is not always identifiable. Therefore, we studied the ability of two representatives of common powdery mildew (Erysiphales), Erysiphe palczewskii and Erysiphe convolvuli, to induce a proinflammatory response in in vitro models of the upper and lower respiratory tract. Materials and Methods: Two cell lines, BEAS-2B and A549, were used to mimic upper and lower respiratory epithelial cells. The toxicity of fungal extracts was assessed with MTT and flow cytometry assay. The production of reactive oxygen species in the cells was measured with flow cytometry. ELISA tests were used to determine the production of proinflammatory cytokines. The presence of the cell integrity marker was assessed with the immunofluorescence method. Results: In both cell lines, the extract of E. palczewskii and E. convolvuli microfungi induced marked production of proinflammatory IL-1β, TNF-α, and GM-CSF cytokines involved in developing allergic reactions. The higher levels of these cytokines with higher reactive oxygen species synthesis positively correlated with the disruption of epithelial cell junctions. Conclusion: We conclude that E. palczewskii and E. convolvuli microfungi have strong proinflammatory and proallergenic potential, but this finding needs in vivo confirmation. Plain Language Summary: Phytopathogenic microfungi, commonly found in human environments, act as plant parasites. They harm plant yields, the quality of agricultural products, and the aesthetic appeal of ornamental plants. Additionally, these fungi pose a potential threat to human health due to their role as prominent allergen sources. Among the most significant allergenic fungi are Alternaria, Aspergillus, Cladosporium, Penicillium, and Fusarium. However, it is worth noting that even widely prevalent phytopathogenic microfungi, such as E. palczewskii and E. convolvuli, may also induce allergy symptoms. These fungi cause extensive plant infestations, releasing vast spores, particularly during spring, summer, and autumn. Consequently, the dispersion of plants and their parasitic fungi increases the risk of human exposure to potential allergens. Since the underlying causes of allergies are not always identified through conventional skin or blood tests, it is crucial to describe new fungal allergens for hypersensitivity diagnosis. Our study demonstrates that parasitic microfungi exhibit significant pro-inflammatory properties in in vitro upper and lower respiratory tract models.