Identification of an autophagy defect in smokers' alveolar macrophages

MM Monick, LS Powers, K Walters, N Lovan… - The Journal of …, 2010 - journals.aai.org
MM Monick, LS Powers, K Walters, N Lovan, M Zhang, A Gerke, S Hansdottir
The Journal of Immunology, 2010journals.aai.org
Alveolar macrophages are essential for clearing bacteria from the alveolar surface and
preventing microbe-induced infections. It is well documented that smokers have an
increased incidence of infections, in particular lung infections. Alveolar macrophages
accumulate in smokers' lungs, but they have a functional immune deficit. In this study, we
identify an autophagy defect in smokers' alveolar macrophages. Smokers' alveolar
macrophages accumulate both autophagosomes and p62, a marker of autophagic flux. The …
Abstract
Alveolar macrophages are essential for clearing bacteria from the alveolar surface and preventing microbe-induced infections. It is well documented that smokers have an increased incidence of infections, in particular lung infections. Alveolar macrophages accumulate in smokers’ lungs, but they have a functional immune deficit. In this study, we identify an autophagy defect in smokers’ alveolar macrophages. Smokers’ alveolar macrophages accumulate both autophagosomes and p62, a marker of autophagic flux. The decrease in the process of autophagy leads to impaired protein aggregate clearance, dysfunctional mitochondria, and defective delivery of bacteria to lysosomes. This study identifies the autophagy pathway as a potential target for interventions designed to decrease infection rates in smokers and possibly in individuals with high environmental particulate exposure.
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