Fig. 4

Antiviral cytokine and pattern recognition receptor induction by influenza virus infection was inhibited in CSE-treated HBEC isolated from nonsmokers. HBEC were cultured in growth media with 2 % CSE for 24 h. After infection of the cells with IAV at an MOI of 1 for 24 h, total RNA was extracted, and cell cytokine, (a-c), and PRR, (d, e), mRNA expression was assessed by qRT-PCR. Transcript levels were normalized relative to the constitutively expressed β-actin gene. Data were expressed as the means ± SEM from three separate experiments from different donors. * denotes significant difference between the indicated groups, P < 0.05