Figure 3
From: Inhibition of IFN-γ-dependent antiviral airway epithelial defense by cigarette smoke
Cigarette smoke extract inhibits type II interferon-induced Stat1 activation. A: Tyrosine-701 and serine-727 phosphorylated and total Stat1, and β-actin levels were assessed using immunoblot analysis of extracts from hTBE cells that were first treated with media without or with CSE at the indicated concentrations for 4 hours, followed by incubation for 30 minutes in media containing the same CSE concentration without or with IFN-γ. B: Tyrosine-701 and serine-727 phosphorylated and total Stat1, ICAM-1, and β-actin levels were assessed using immunoblot analysis of extracts from hTBE cells that were first treated with media without or with CSE at the indicated concentrations for 4 hours, followed by incubation for 20 hours in media containing the same CSE concentration without or with IFN-γ. In A and B, protein levels were quantified using band densitometry of immunoblot analyses from separate experiments with the value for cells not exposed to CSE but treated with IFN-γ set at 1 in each experiment. Values are expressed as mean ± S.D. (n = 3 experiments) in the bar graph adjacent to a representative immunoblot analysis, and a significant difference (p < 0.05) in IFN-γ-induced levels between cells treated versus not treated with CSE is indicated by an asterisk.