Extracellular\nVesicles\nAre Prevalent and Effective\nCarriers of Environmental Allergens in Indoor Dust

The global incidence\nof allergic diseases is rising and\nposes a\nsubstantial threat to human health. Allergenic proteins released by\nvarious allergenic species play a critical role in the pathogenesis\nof allergic diseases and have been widely detected in the environmental\nmatrix. However, the release, presence and interaction of environmental\nallergens with human body remain to be elucidated. In this study,\nwe reported the widespread of allergen-harboring extracellular vesicles\n(EVs) in indoor dust from 75 households across five provinces in China.\nParticle size and abundance of EVs were correlated with specific environmental\nfactors. EVs showed long persistence and high resistance to environmental\nstress. Metagenomics and metaproteomics data revealed that most indoor\nallergenic species released allergens within the EVs into dust. A\nhigher abundance of allergenic species and their derived EVs was observed\nin urban areas compared to rural areas. ELISA confirmed the allergenic\nactivity of the EV-associated allergens. Allergens are common components\nand even markers of EVs, as evidenced by the data compilation of various\nallergenic species. The proportion of EV-associated allergens varied\nacross species. EVs facilitated allergen entry into epithelial cells.\nIntranasally administered EVs can be rapidly transported to the lungs\nand gastrointestinal tract. EV-associated allergens exhibited higher\nallergenicity compared with non-EV allergens. Our findings elucidate\na vesicle pathway through which environmental allergens are released,\npersist, and trigger allergic responses within EVs.