Fig. 1.

Inhibitory effect of HS-058 on antigen synthesis and syncytium formation of RSV in HeLa cell monolayers.

HeLa cells grown on cover slips in culture plate wells were infected with 100 PFU/well of RSV. After virus adsorption to cells for 90 min at 37  C, infected cultures were treated with 3.1, 12.5 and 50 μM of HS-058 at 37 °C. At 48 hours after infection, cells on cover slips were fixed with acetone and stained with anti-RSV rabbit serum conjugated with fluorescein isothiocyanate. Cells were observed under a fluorescent microscope, and the number of antigen positive foci in 40 microscopic fields (●) and the number of infected cells in one syncytium (○) [average of 10 syncytia] were counted.