<p>PRO0371155 was evaluated for its inhibitory activity against GT 1a/2a HCV over multiple weeks in culture. (A) Cell cultures were ∼90% infected with cell culture-derived GT 1a/2a HCV. Cultures were treated with 1 µM PRO0371155 or DMSO in the passage control. At 3–4 day intervals, cells were subjected to staining with anti-NS3 antibodies and analysis by flow cytometry as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035351#s2" target="_blank">Materials and Methods</a>. The percentage of HCV+ cells as a function of time was plotted for each experiment. (B) Results obtained in the protein expression analysis were confirmed and extended by qRT-PCR analysis of HCV RNA isolated from HCV infected cultures treated with PRO0371155 or DMSO control at various time points. HCV RNA was normalized to GAPDH mRNA and expressed in copies/cell. The limit of quantification of the qRT-PCR assay was found to be ∼0.5 copies/cell. (C) Cell cultures were ∼20% infected with cell culture-derived GT 1a/2a HCV. Cultures were treated with 1 µM PRO0371155, 10 IU/mL IFN-alpha (Sigma) or DMSO in the passage control. At 3–4 day intervals, cells were subjected to staining with anti-NS3 antibodies and analysis by flow cytometry as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035351#s2" target="_blank">Materials and Methods</a>. The percentage of HCV+ cells as a function of time was plotted for each experiment. (D) Data shown in panel C were re-plotted on a different scale to accentuate the differences between IFN-alpha and PRO0371155 treated HCV+ cultures.</p
