Examining the Interaction between Allergic Asthma and Air Pollution: a Potential Role for Trained Immunity

Asthma represents a major global health burden, with incidence increasing substantially over the past 50 years. Epidemiologic studies have linked this rise in asthma to escalating air pollution; however, the biological mechanisms remain undefined. Recent evidence has highlighted a role for innate immune memory, or trained immunity, in asthma pathogenesis; however, the contribution of air pollution remains unclear. This review synthesizes emerging findings on how air pollution shapes trained immunity in asthma and related inflammatory lung diseases.

Air pollutants increase gene acetylation and methylation and disrupt innate immune cell metabolism. These immune mediated changes are consistent with features of trained immunity, a process that remains largely underexplored. Collectively, these data support the concept that air pollution imprints long-lasting epigenomic and immunometabolic changes on innate immune cells, thereby contributing to asthma susceptibility and severity. Future studies will focus on mechanistic investigations to further elucidate how pollutants dysregulate innate immune memory.