Cigarette smoke-induced inflammation and respiratory host defense: Insights from animal models

While the devastating impact of tobacco on human health is well established, and efforts to reduce its prevalence are ongoing, over 1 billion people continue to smoke. Emerging evidence suggests that cigarette smoking distorts lung immune homeostasis, compromising respiratory host defense. Consequently, viral and bacterial agents are dealt with inefficiently and are associated with exaggerated immune inflammatory responses. In this article, we discuss mechanisms by which cigarette smoke elicits inflammatory processes and how smoking impacts respiratory host defense against viral and bacterial agents. Elucidating cigarette smoke's impacts on lung immune homeostasis will contribute to our understanding of the pathogenesis of chronic obstructive pulmonary disease COPD.