Lines, Bacteria, and Reagents. RSV strain Long, human type II pulmonary epithelial cell line A549 and S. pneumoniae strain R6 were obtained from the American Type Culture Collection (ATCC, Manassas, VA). RSV was grown in HEp-2 cells. The virus titer of RSV was determined using a plaque-forming assay with HEp-2 cells as the indicator cells [25] . RSV infection to A549 cells was performed at multiplicity of infection (MOI) of 1. CAM was donated by Abbott Japan (Tokyo, Japan). A PAF receptor antagonist, 1-O-hexadecyl-2-acetyl-sn-glycero-3-phospho(N,N,N,trimethyl)-hexanolamine, was purchased from Calbiochem-Merck (Darmstadt, Germany). An NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), was purchased from Sigma-Aldrich (St. Louis, MO).