Lactic Acid-Based Chemical Air Interventions Disrupt Aeroallergen Structure and Immunodetection
TESS EIDEM, Kristin Rugh, Mark Hernandez, University of Colorado at Boulder
Abstract Number: 371
Working Group: Reducing Aerosol Exposure with Control Technologies and Interventions
Abstract
Airborne allergens are a major driver of allergic respiratory disease and asthma. Most airborne allergens (aeroallergens) are exogenous proteins with three-dimensional structures recognized by the human immune system, triggering allergic responses. Therefore, air interventions that alter aeroallergen protein structure may reduce immune recognition and allergic response.
We evaluated a lactic acid (LA)-based aerosol spray for its ability to alter airborne allergen structure using the commercial Multiplex Array for Indoor Allergens (MARIA) immunoassay, which requires intact protein structure for antibody-based immunodetection. Dust containing cat, dog, pollen, and dust mite allergens was aerosolized into respirable particles within a 1 m3 environmentally controlled chamber, and condensation capture was used to collect allergen-containing aerosols over time. Following baseline collection, airborne allergens were exposed to no treatment (control), LA aerosol spray, or aerosol spray without LA (placebo). All aeroallergens showed significant reductions after 5 minutes of LA aerosol spray treatment compared to control and placebo, ranging from 14–71% LA-dependent aeroallergen reduction, with the most pronounced effect observed in the dust mite group 1 allergen Der p1.
To investigate the mechanism of reduced MARIA immunodetection of airborne Der p1, we assessed Der p1 structure via circular dichroism spectroscopy. In vitro Der p1 LA treatment converted 18% of α-helical structure to unordered structure, increasing overall Der p1 disorder from 23% to 41%. Native polyacrylamide gel electrophoresis also confirmed protein conformational changes, showing altered migration of Der p1 after LA exposure. Importantly, these structural changes were irreversible upon LA removal by dialysis.
Ongoing studies continue to investigate whether Der p1 structural changes reduce human IgE immunodetection using sera from dust mite-sensitized patients. Overall, these findings support the potential of LA-based aerosol sprays as a novel air intervention strategy to mitigate allergic disease by altering the structure, and therefore immunodetection, of airborne protein allergens.