Co-exposure to microplastics enhances the allergenic potentials of house dust mite allergen Der p 1

Air pollution is believed to exacerbate the prevalence of allergic diseases. But the underlying processes and mechanisms are not fully understood. In this study, the effects of polystyrene microplastics (PS-MPs) with a diameter of 0.1 μm, 1 μm, and 5 μm were investigated on the allergenic potentials of house dust mite allergen Der p 1. The results reveal that co-exposure to PS-MPs promoted the IgE-binding capacity of Der p 1 by altering the conformation, elevating the ligand-binding activity, and strengthening the aggregation of Der p 1. PS-MPs also exacerbated the damage to airway epithelial barrier by increasing the permeability of bronchial epithelial cells. Ultimately, co-exposure to PS-MPs aggravated the Th2-mediated immune responses and allergic sensitization induced by Der p 1. These evidences indicate that co-exposure to PS-MPs enhanced the allergenic potentials of Der p 1. Moreover, the PS-MPs-induced enhancement of the allergenic potential of Der p 1 is size-dependent, with smaller PS-MPs exhibiting greater promotion on the allergenic potential of Der p 1. Given the ubiquitous occurrence of PS-MPs in the environment, the co-exposure of allergens and PS-MPs should be seriously considered when assessing the allergenic risk of allergens in the real environment, especially for the PS-MPs with smaller size.