Direct exposure to SARS-CoV-2 and cigarette smoke increases infection severity and alters the stem cell-derived airway repair response

To study the effect of cigarette smoke exposure on Sars-Cov2 infection, we directly exposed mucociliary air-liquid interface (ALI) cultures derived from primary human nonsmoker airway basal stem cells (ABSCs) to short term cigarette smoke and infected them with live SARS-CoV-2. We set out to examine the underlying mechanisms governing the increased susceptibility of cigarette smoke exposed ALI cultures to SARS-CoV-2 infection by usingle cell profiling of the cultures, which showed that interferon response genes were induced in SARS-CoV-2 infected airway epithelial cells in ALI cultures but smoking exposure together with SARS-CoV-2 infection reduced the interferon response.