Updated project metadata. This project is based upon the fundamental observation that alveolar macrophage-derived extracellular vesicles (AM-EVs), when internalized by neighboring epithelial cells, inhibit their infection by influenza virus. This inhibitory activity of AM-EVs is abolished when AMs are treated with cigarette smoke extract (CSE). We chose to survey the AM-EV proteome in an effort to identify candidate proteins whose abundance within EVs was downregulated by CSE treatment of AMs, thus explaining the ability of CSE to abrogate the inhibitory activity against influenza.