Air pollution-induced proteomic alterations increase the risk of child respiratory infections

Early life air pollution exposure may play a role in development of respiratory infections, but underlying mechanisms are still not understood. We utilized data from two independent prospective birth cohorts to investigate the influence of prenatal and postnatal ambient air pollution exposure of PM_2.5, PM₁₀ and NO₂ on maternal and child proteomic profiles and the risk of daily diary-registered common infections age 0-3 years in the Danish COPSAC₂₀₁₀ (n = 613) and pneumonia, croup and bronchitis age 1-2 years in the Swedish EMIL (n = 101). A supervised sparse partial least square model generated proteomic fingerprints of air pollution analyzed against infection outcomes using Quasi-Poisson and logistic regression models, respectively. Here we demonstrated that prenatal ambient air pollution exposure was associated with altered maternal proteomic profile with significant downregulation of the AXIN1 protein. The prenatal air pollution proteomic fingerprints related to a significantly higher risk of total number of infections, cold, pneumonia and fever episodes in COPSAC₂₀₁₀ and similar postnatal air pollution proteomic fingerprints related to a significantly higher risk of respiratory infections in EMIL. Higher AXIN1 protein levels associated with significantly decreased risks of total number of infections, cold, pneumonia, tonsillitis and fever episodes, and asthma risk in COPSAC₂₀₁₀ and a significantly decreased risk of respiratory infections in EMIL suggesting a protective effect of this specific protein in both cohorts. This study of two prospective birth cohorts demonstrates ambient air pollution alterations in the maternal and child’s proteomic profiles that associates with respiratory infection risk suggesting the AXIN1 protein as a potential target for respiratory infection and asthma prevention in childhood.