Inhibition of IFN-gamma-dependent antiviral airway epithelial defense by cigarette smoke.

Background: Although individuals exposed to cigarette smoke are more susceptible to respiratory infection, the effects of cigarette smoke on lung defense are incompletely understood. Because airway epithelial cell responses to type II interferon (IFN) are critical in regulation of defense against many respiratory viral infections, we hypothesized that cigarette smoke has inhibitory effects on IFN-gamma-dependent antiviral mechanisms in epithelial cells in the airway.

Methods: Primary human tracheobronchial epithelial cells were first treated with cigarette smoke extract (CSE) followed by exposure to both CSE and IFN-gamma.