Reduction of Cry j 1 allergenicity by nano-sized electrostatic atomized water particles (NEAWPs) in human bronchial epithelium and dendritic cells

Japanese cedar pollen (Cryptomeria japonica) is a major cause of seasonal allergic rhinitis in Japan, and Cry j 1 has been identified as its principal allergen. Although current treatments provide symptomatic relief, they do not prevent sensitization, highlighting the need for novel preventive strategies. Nanosized electrostatically atomized water particles (NEAWPs) are nanometer-scale water droplets containing reactive oxygen species (ROS) that have demonstrated antimicrobial activity; however, their effects on airborne allergens remain unclear. Therefore, this study investigated whether NEAWPs could reduce the allergenicity of Cry j 1 in human bronchial epithelial cells (BEAS-2B) and monocytic antigen-presenting cells (THP-1). Briefly, Cry j 1 was exposed to NEAWPs for 24–48 h, and allergenicity was assessed by ELISA, calcium imaging, flow cytometry, and cytokine analyses. NEAWPs treatment markedly reduced Cry j 1 antigenicity in a time-dependent manner, achieving 98.6% reduction after 48 h. In BEAS-2B cells, untreated Cry j 1 induced significant Ca²⁺ influx and upregulated IL-8, TNF-α, and IL-6 expression, whereas NEAWP-treated Cry j 1 failed to elicit these responses. Similarly, in THP-1 cells, NEAWP-treated Cry j 1 decreased CD11c+CD86+ cells and inflammatory cytokine production. These results indicate that NEAWPs denature Cry j 1, preventing epithelial activation and antigen presentation, thereby attenuating downstream immune responses. This study provides the first evidence that NEAWPs can effectively reduce the allergenicity of Japanese cedar pollen, suggesting a potentially non-invasive, environmentally friendly approach for allergy prevention. Therefore, future studies are required to explore the molecular mechanisms, in vivo efficacy, and safety of NEAWPs exposure to establish its translational potential in managing pollinosis and other airborne allergies.