HCV entry receptors as potential targets for siRNA-based inhibition of HCV.

Background: Hepatitis C virus (HCV) is a major health concern with almost 3% of the world's population (350 million individuals) and 10% of the Pakistani population chronically infected with this viral pathogen. The current therapy of interferon-α and ribavirin against HCV has limited efficiency, so alternative options are desperately needed. RNA interference (RNAi), which results in a sequence-specific degradation of HCV RNA has potential as a powerful alternative molecular therapeutic approach. Concerning viral entry, the HCV structural gene E2 is mainly involved in virus attachment to the host cell surface receptors i.e., CD81 tetraspanin, scavenger receptor class B type 1 (SR-B1), low density lipoprotein receptor (LDLR) and claudin1 (CLDN1).

Results: In this report, we studied the relationship of the HCV receptors CD81, LDL, CLDN1 and SR-B1to HCV infection. The potential of siRNAs to inhibit HCV-3a replication in serum-infected Huh-7 cells was demonstrated by treatment with siRNAs against HCV receptors, which resulted in a significant decrease in HCV viral copy number.

Conclusions: Our data clearly demonstrate that the RNAi-mediated silencing of HCV receptors is among the first of its type for the development of an effective siRNA-based therapeutic option against HCV-3a. These findings will shed further light on the possible role of receptors in inhibition of HCV-3a viral titre through siRNA mediated silencing.