Figure 8

N-acetylcysteine and GSH monoethyl ester inhibit cigarette smoke effects on antiviral defense. RSV and β-actin protein levels were assessed using immunoblot analysis of extracts from hTBE cells that were first treated in media without (A) or with NAC for 1 hour (B) or GSH monoethyl ester for 2 hours (C). Cells were then incubated in media containing the same antioxidant without or with CSE at the indicated concentration for 4 hours, followed by incubation for 8 hours with the same compounds without or with IFN-γ. Cells were then infected with RSV for 24 hours. D: Protein levels were quantified using band densitometry of immunoblot analyses from separate experiments performed as outlined for A-C. The band intensities of RSV G/β-actin were compared between conditions by calculating ratios for each comparable condition in which cells were versus were not exposed to IFN-γ. Values are expressed as mean ± S.D. (n = 3 experiments), and a significant difference (p < 0.05) in levels between comparable antioxidant incubation conditions for cells without versus with CSE treatment is indicated by one asterisk, and in CSE-treated levels between cells not incubated versus incubated with NAC or GSH-MEE is indicated by two asterisks.