Inhibition of hepatitis C virus genotype 4 replication using siRNA targeted to the viral core region and the CD81 cellular receptor.

Hepatitis C virus (HCV) is one of the most important causative agents of hepatitis worldwide. The current study aimed to evaluate the silencing effect of the small interference RNA (siRNA) molecules designed against the core region of HCV genotype 4 (HCV-4) and the CD81 gene, which is the cellular receptor for HCV in the human hepatocytes. RT-PCR was used to measure the changes in both the viral HCV core and the cellular CD81 genes induced by the specific siRNA molecules. Additionally, the fluctuations in either the viral or the cellular proteins of the target regions were tested by flow cytometry and immunofluorescence. The results showed the effectiveness of the used siRNA molecules against the target genes in either RNA or protein levels. The effect of 100 nM of siCD81 and 40 nM of siCore was more evident at 24 and 48 h post-transfection. The combination of the two siRNA molecules resulted in an extra inhibitory effect of the HCV core at both the RNA (85.6%) and protein (98.5%) levels. The current study suggested that targeting of the CD81 cellular receptor and/or the viral HCV core region by the small interference molecules might be a suitable choice in the suppression of HCV-4 replication. This might assist the development of new antiviral medications and provides a new alternative strategy for the targeting and treatment of HCV genotype 4.