Various P. aeruginosa strains (Table 1) were cultured in lysogeny broth (LB) broth overnight at 37°C, shaking at 200 rpm. The culture was then diluted 1:50 in RPMI-1640 medium and grown for 5 days at 37°C, shaking at 200 rpm, in order to activate quorum-sensing and virulence factor secretion. On day 5, the medium was centrifuged for 10 min at 4,200 rcf and passed through a 0.2 μm filter. This medium was used as conditioned medium (CM). For each experiment at least two different CM were used. A RPMI-1640 control was cultured and filtered alongside the cultured P. aeruginosa strains. 100,000 BEAS2B or primary cells were seeded in 24-well-plates in BEAS2B medium. The following day, the cell medium was changed to infection medium, which was RPMI-1640 supplemented with 2% FCS, 1% P/S, 25 mM HEPES, and 0.075% NaHCO3. Twenty-four hours later, BEAS2B were pretreated with CM (20% v/v) for 1 h at 37°C, 5% CO2. Cell medium was then removed, and respiratory syncytial virus (RSV) or rhinovirus (RV1B) at a multiplicity of infection of 1 (MOI 1) (stocks prepared in house) in combination with fresh CM was added to BEAS2B cells. After 1 h at room temperature, shaking at 30 rpm, medium was removed, cells washed twice with warm 1X PBS, and infection medium added to the cells. Fresh CM was once again added to the cells as indicated above. Cell culture supernatant was collected at the indicated times and cells were lysed in RNA lysis buffer.