Our center will assess the impact of new and emerging tobacco products on the lung’s innate defense system. Project I and Project II are focused on determining the impact of on specific aspects of this system, namely, airway surface liquid homeostasis (Project I) and mucin/mucus (Project II). These projects will use an innovative in vitro smoke exposure system, in addition to samples obtained from smokers of NETPs, to measure specific biomarkers of innate lung defense. In Project III, researchers will develop a novel animal model of smoke exposure that more closely mimics the chronic bronchitis phenotype seen in human smokers with COPD. This model will then be used to validate tobacco exposure biomarkers seen in the first two projects as well as to determine epigenetic changes following in vivo exposure to NETPs. Project IV will use samples obtained from human volunteers to determine if genomic biomarkers are associated with exposure to these products. Additionally, Project IV will further test our hypothesis that NETPs impair the lung’s innate defense system by exposing volunteers to live attenuated influenza virus (the intranasal flu vaccine) to identify changes in antiviral host defense. Thus, using human and mouse in vivo and in vitro models, this project will identify novel biomarkers associated with tobacco-induced changes in the lung’s innate defenses, which will further our understanding of the toxicity of NETPs.