title: Geogenic PM₁₀ exposure exacerbates responses to influenza infection.
abstract: Particulate matter (PM) exposure has been linked epidemiologically to exacerbations of lung disease, including respiratory infections. We investigated the effects of geogenic (earth-derived) PM10 (PM<10 μm diameter) on the response to a respiratory viral infection. Geogenic dust was sampled from four communities in arid environments in Western Australia. Adult female BALB/c mice were intranasally exposed to chronic doses of PM10 (10 μg/day for 10 days), and/or infected with influenza (A/Mem/1/71) virus. Inflammation (cells, IL-6, IFN-γ) was measured in bronchoalveolar lavage. Lung mechanics were measured using the forced oscillation technique. Geogenic PM10 induced lung inflammation (neutrophils, macrophages) with additive effects in mice also infected with influenza. PM10 also modified the influenza-induced IL-6 and IFN-γ responses. Geogenic PM10 increased airway resistance, and increased hysteresivity in those exposed to both insults. Viral titres were significantly higher after PM10 exposure. Iron concentration was inversely associated with IFN-γ and positively associated with viral titre and hysteresivity. Geogenic PM10 exposure increases inflammation, impairs lung function and increases viral load, exacerbating the response to respiratory viral infection. Iron in the particles may be a driver of these responses. This has important implications for respiratory health in communities exposed to high geogenic PM10, such as those in arid environments.
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia; Centre for Child Health Research, The University of Western Australia, Perth, Western Australia, Australia. Electronic address: holly.clifford@telethonkids.org.au.
authors.forename: Holly D
authors.initials: HD
authors.lastname: Clifford
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Kara L
authors.initials: KL
authors.lastname: Perks
authors.affiliation: Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia; Centre for Child Health Research, The University of Western Australia, Perth, Western Australia, Australia; School of Medicine, University of Tasmania, Hobart, Tasmania, Australia.
authors.forename: Graeme R
authors.initials: GR
authors.lastname: Zosky
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D000818:Animals; D005260:Female; D006801:Humans; D008168:Lung; D008171:Lung Diseases; D051379:Mice; D009976:Orthomyxoviridae Infections / Q000503:physiopathology*; D052638:Particulate Matter / Q000633:toxicity*; D011014:Pneumonia / Q000139:chemically induced*; D014904:Western Australia
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter
keywords: Geogenic; Inflammation; Influenza; Iron; Lung function; Particle; Viral titre