Background
The RNAi-based transient therapeutic approach has been well explored for its potential against the hepatitis V virus (HCV). However, to achieve a sustained virological response, a consistent presence of siRNA is needed and it can be achieved by constitutively expressing shRNAs. In this context, the lentiviral vector has emerged as an attractive tool for shRNA delivery against HCV.
Conclusion
A lentiviral vector-based delivery system is a "single-shot" therapeutic strategy. It can express duplex shRNA for long-term synergistic inhibition of HCV and qualify as a promising therapeutic approach for sustained inhibition of HCV replication.
Methods
We monitored HCV inhibition after single and multiple rounds of siRNA treatments against La autoantigen and HCV-NS5B in Huh-7.5 cells infected with the FL-J6/JFH chimeric HCV strain. A bicistronic self-inactivating third-generation lentiviral vector expressing shRNA under U6 and H1 promoters was constructed. To ascertain the long-term HCV inhibition, cells were transduced with lentiviral vectors and HCV inhibition was monitored by RT-PCR and Western blotting at regular intervals.
Results
We observed transient antiviral activity after a single round of siRNA treatment, and consecutive rounds of treatments with siRNA demonstrated a sustained HCV inhibition. Delivery of duplex shRNA expressing lentiviral vectors provided constant expression of shRNA leading to synergistic and sustained HCV inhibition.