Figure 2.

Cigarette smoke condensate (CSC) exposure increases severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudovirus infection. (A) Primary tracheobronchial cells and (B) small airway cells were pretreated with 200 μg/ml CSC (middle) and 1.00% JUUL e-liquid (right) for 24 hours and challenged with SARS-CoV-2 pseudovirus. After incubation for 48 hours, live cells were imaged on a spinning-disc confocal microscopy system (UltraVIEW Vox; PerkinElmer). Cell nuclei were stained with Hoechst dye, and infected cells are shown in red. Flow cytometry quantification of relative SARS-CoV-2 pseudovirus infection reported as the fold change in (C) primary tracheobronchial cells and (D) small airway cells pretreated with different doses of CSC and JUUL e-liquid; n = 11–12 separate experiments. Bars represent the mean ± SEM. *P < 0.05, **P < 0.005, and ***P < 0.0005, unpaired t test. Scale bars, 170 μm.