TAT Peptides Mediated Small Interfering RNA Delivery to Huh-7 Cells and Efficiently Inhibited Hepatitis C Virus RNA Replication

Objective: To observe whether or not the small-interfering RNA (siRNA) that conjugated with human immunodeficiency virus type 1 (HIV-1) TAT(47-57) peptides can enter Huh-7 cells and efficiently silence hepatitis C virus (HCV) infection in cell culture.

Methods: siRNA targeting the highly conserved stem loop IV of the HCV 5' untranslated region (5'UTR) was conjugated to TAT(47-57) peptides via the crosslinker sulfosuccinimidyl-4-(p-maleimidophenyl)-butyrate, and then the conjugates were added to the Huh-7 cell culture. Firefly luciferase activity and HCV RNA were assessed using a luciferase assay reagent and real-time reverse transcript polymerase chain reaction, respectively.

Results: The expression of firefly luciferase in HCV replicons and the concentration of HCV RNA were downregulated by siRNA-TAT(47-57), and siRNA-TAT(47-57) mediated RNA interfering activity which was directly correlated with increasing concentrations of the siRNA-TAT(47-57) conjugate used.

Conclusion: Cell-penetrating peptides such as HIV-1 TAT are an effective method for the delivery of siRNA targeted at 5'UTR of HCV in mammalian cells.