FIG 10.

The analog RIDK34 has increased antiviral activity relative to that of digoxin. (A) Structure of RIDK34. (B) Yield reduction assay. Cells were infected with HAdV-C5, treated with RIDK34 or digoxin, and harvested at 24 h p.i. for assay of total virus by endpoint dilution. Data represent the results of three experiments. Error bars show the standard error of the mean. (C) E1A and hexon expression in HAdV-C5 infected cells incubated with DMSO or 12.5 nM RIDK34 and harvested at 8 h p.i. (E1A) or 24 h p.i. (hexon). Data are representative of results from three experiments. (D) Effect of RIDK34 on cell metabolism and viability. Following infection with HAdV-C5, cells were treated with the indicated concentrations of RIDK34. After 24 h, metabolic activity was assessed using alamarBlue and cell viability by counts with trypan blue. More than 99% of the cells excluded trypan blue. The results shown are the averages from three independent assays. (E) qPCR analysis of adenovirus genome amplification in cells incubated with DMSO or 12.5 nM RIDK34 and harvested at 0, 10, 16, and 22 h p.i. The relative amount of viral DNA at each time point is plotted as the ratio of viral DNA to cellular TBP DNA (E3/TBP). Results represent two independent experiments, with each sample analyzed in duplicate. Error bars represent the standard error of the mean.