Effects of Airborne Fungal Diversity in Urban forest on Allergic Inflammation

초록

Rationale The environmental microbiota plays a role in the activation of immunologic inflammation and development of allergic diseases as well. We hypothesized that diversity of airborne microorganisms in urban forest, especially airborne molds, could affect the allergic inflammation and prevalence of asthmatics in a metropolitan city, Seoul, South Korea. Methods Fungi were isolated from air samples collected from 17 different urban forests and 3 urban centers in Seoul. The mycobiome strains were identified and analyzed and compared to their allergic inflammation through both in human mast cells (HMC-1) and experimental asthma animal models. Results Forest fungal species were at least 3 times more diverse than those in the urban centers. Among them, Alternaria (68%), Porostereum (55%), and Cladosporium (50%) were the most common fungal species in the forest samples. There was a significant negative correlation between the number of urban forest and the asthmatics in a district. When asthma animal model was exposed to mold, airway hyperresponsiveness was lower on mold from the urban forest than from the urban centers. Asthma animal model exposed to mold from the urban forest also demonstrated lower inflammatory reactions than those in models exposed to mold from the urban centers. Conclusions There is a wide diversity in the species of mold in the urban forest and shows a statistically significant negative correlation with the number of asthmatics. Furthermore, the fungi in the urban forest shows less inflammation and airway hyperresponsiveness in the asthma animal model.