FIG 5.

Anti-hRSV activity of selected hit compounds in air-liquid interface cultures of immortalized BCi-NS1.1 cells and RSV-strain dependence of antiviral activity. (a) Anti-hRSV activity of selected hit compounds was assessed in differentiated BCi-NS1.1 cells (23) cultured in an air-liquid interface configuration. Cells were treated from the basolateral side with compounds (concentrations used are summarized in Table S1; 2 and 0.2 μM for BMS-433771) and simultaneously infected with the recombinant rHRSV-A-GFP reporter virus. Basolateral treatment was repeated once daily. Apical washes were collected, and cells were lysed for determination of viral genome copies by reverse-transcription quantitative PCR (qRT-PCR). Genome copies in the mucus after 8 and 96 h and in cell lysate (96 hpi) are shown. Mean values and SD from a single experiment with duplicate measurements are depicted. (b) RSV strain-dependence of the antiviral activity of selected hit compounds. Clinical isolates of RSV-A and RSV-B were used to infect HEp-2 cells (multiplicity of infection [MOI] of 1 or 0.5; dots and triangles, respectively) in the presence of compounds (concentrations as in panel a). After 24 h, infection efficiency was determined by intracellular hRSV phosphoprotein staining and flow cytometry. Bars represent the mean values. Means and SDs are given. Four to seven independent replicates are shown.