Clarithromycin Suppresses Human Respiratory Syncytial Virus Infection-Induced Streptococcus pneumoniae Adhesion and Cytokine Production in a Pulmonary Epithelial Cell Line

Figure 4

Suppression by CAM of RSV-induced adhesion of FITC-labeled S. pneumoniae to A549 cells, as observed by fluorescence microscopy. One hour before RSV infection, CAM (10 or 100 𝜇g/mL) or PDTC (50 𝜇M) was added to A549 cell monolayer. The cells were infected with RSV at MOI of 1. After 24 h of infection, FITC-labeled bacterial cells were added to the cell monolayer at MOI of 10, and incubation was continued at 37°C for 30 min. A PAF receptor antagonist (20 𝜇g/mL) was added to the cell monolayer 1 h before the addition of labeled bacterial cells. The bacteria adhering to the A549 cell monolayer were visualized by fluorescence microscopy.