Fig. 2.
Cell viability and membrane integrity of 16HBE cells. Cell viability to cigarette smoke extract (CSE) at 1.5%, 2.5%, 3.5%, and 5% (A). Cell viability (B) and catalytic activity of LDH (C) in 16HBE cells exposed to Lr (1 × 106 CFU), CSE (2.5%), Lr + CSE or SARS-CoV-2 (MOI: 0.1), or CSE + SARS-CoV-2 (B). Cell viability was determined using the MTT assay with an absorbance of 570 nm, and the LDH activity was expressed as the extra-cellular LDH activity percentage of the total activity in the wells. Data are presented as means ± SE from triplicate samples for each treatment versus control. Ns, non-significant difference