Figure 9

Antiviral effect of IFN-α using stable cell lines replicating GFP labeled sub-genomic RNA of HCV 2a. S3-GFP and R4-GFP were treated with IFN-α from 10 to 1000 IU/ml. (A) Upper panel shows the antiviral effect of IFN-α against HCV 2a sub-genomic RNA replication in S3-GFP cells. There was a dose dependent decrease in the GFP expression in the S3-GFP cells with increasing concentration of IFN-α. Lower panel shows no effect of GFP expression in R4-GFP cells. (B) The GFP fluorescence was quantitatively measured by flow cytometry analysis after IFN-α treatment (1000 IU/ml) for 72 hours using S3-GFP and R4-GFP cells. A significant reduction in the number of GFP positive S3-GFP cells (53% to 2%) was seen after IFN treatment. The number of GFP-positive cells did not decrease when treated with interferon (58% to 55%) using R4-GFP cells. (C) RPA shows the intracellular HCV RNA level in the S3-GFP and R4-GFP after IFN-α treatment. Left panel shows HCV RNA levels in S3-GFP after IFN-α treatment at 72 hours. Right panel shows the HCV RNA level in R4-GFP after IFN-α treatment at 72 hours. There is a gradual reduction of HCV mRNA level in the S3-GFP replicon cells compared to the R4-GFP cells. (D) Shows the quantification of HCV RNA levels in the S3-GFP and R4-GFP after IFN-α treatment at 72 hours by real-time RT-PCR. In both the cells the HCV RNA level was detected up to a level of titer of log 7 GE/μg of total RNA. The HCV RNA levels reduced significantly after IFN-α treatment at 1000 IU/ml in the S3-GFP replicon cells. There was no decrease in the HCV RNA level in R4-GFP cells after IFN-α treatment.