74 Impact of Air Pollution on Lung Immune Responses in a Mouse Model of Influenza Infection

Abstract During air pollution peaks, influenza infections are more severe, and the number of hospitalizations associated to flu increases. This project aims to study if air pollution contributes to the severity of influenza infection. To this end, mice were intratracheally exposed once to well-characterized particulate matter collected from Paris atmosphere (PM2.5) and inflammation was determined in the broncho-alveolar lavages (BALs) of mice at different time points post-exposure. We observed that 2 mg/kg PM2.5 induced the recruitment of neutrophils in the BALs at 1-day post-exposure. Neutrophils recruitment decreased since the 3rd day post-exposure while the recruitment of eosinophils, monocytes, and lymphocytes appeared. CD4+ T lymphocyte recruitment was sustained at least until 5-7 days post-exposure. Concomitantly, the levels of proinflammatory cytokines and chemokines were evaluated in the BALs of PM-treated mice. Ongoing experiments of co-infection at different time points after PM2.5 exposure will elucidate if severity of influenza infection is exacerbated after PM exposure. This work is support by the la Fondation pour la Recherche Médicale (Foundation for Medical Research).