P. aeruginosa is able to block IFN induction and signaling. (A) BEAS2B cells were pretreated with conditioned medium of P. aeruginosa (PAO1 and Boston) or control medium and subsequently infected with RSV. Induction of IFNL1 and IFNL2/3 mRNA were analyzed by qRT-PCR after 6, 10, and 14 h. (B) BEAS2B cells were treated as in (A) and IFNλ levels of cell culture supernatant (14 h) were analyzed by ELISA. (C) BEAS2B cells were treated as in (A) and p-STAT1 levels of cells (6 h) were analyzed in cell lysates by western blot. (D) BEAS2B cells were pretreated as in (A). Cells were then stimulated with recombinant IFNλ (5,000 pg/ml) and induction of MX1 and OAS1 were analyzed after 14 h by qRT-PCR. All experiments n = 3–4, ANOVA and Bonferroni post-test was used for statistical analysis. Significant differences were considered at *p < 0.05, **p < 0.01, and ***p < 0.001 as compared to the control condition. n.s., not significant.