Figure 3.

IFN-λ stimulates airway epithelial cells and compromises barrier integrity. (A) Immunoblot and densitometry of confluent human airway epithelial cells (16HBEs) stimulated with their respective cytokine for 24 hours (n = 3). (B and C) qRT-PCR of EZR and OCLN after stimulation of 16HBE cells with IFN-λ (B) or IL-22 (C) for 24 hours (n = 4). (D) qRT-PCR of IFN-λ (IFNL2/3) and IL-22 (IL22) (n = 5) levels in 16HBE cells after 24 hours of KP35 infection. (E and F) Dextran permeability with or without basolateral pretreatment of IFN-λ (E) or IL-22 (F) for 24 hours (n = 8, 2 compiled experiments). (G) The percent change in transepithelial electrical resistance (TEER) before and after treatment with IFN-λ or IL-22 for 24 hours (n = 4). (H) Neutrophil transmigration across polarized 16HBE cells after 4 hours of apical KP35 infection. (I) KP35 cfu (n = 6) recovered from the basolateral side of polarized 16HBE cells after 4 hours of apical infection with or without basolateral pretreatment of IFN-λ or IL-22 for 24 hours (n = 3). EDTA served as a positive control for transmigration assays. For column graphs, the bar is the mean value ± SEM. Representative data from at least two independent experiments are shown, unless otherwise indicated. For all graphs, each column is the mean value ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001, by Student’s t test (B–D) or one-way ANOVA, Dunnett’s post hoc test for multiple comparisons compared with media (MED) control (E, F, H, and I) or between the means of every other mean in other columns in the data set. Veh = vehicle.