Lentiviral vector-derived shRNAs confer enhanced suppression of Semliki forest virus replication in BHK-21 cells compared to shRNAs expressed from plasmids

Semliki forest virus (SFV) is a pathogen causing lethal encephalitis in laboratory mice. In this study, we obtained three short hairpin RNAs (shRNAs) which could specifically target SFV sequence in GFP reporting systems and effectively suppress SFV replication in luciferase-containing reporter virus system. At a multiplicity of infection (MOI) of 0.001, the luciferase reporter activity was reduced by 78–92% by shRNA expression plasmids and virus yields reduced 2 to 10-fold at 20 h post-infection. When lentiviral vector-derived shRNAs were employed, the virus titers decreased 8 to 126-fold at 24 h post-infection and 6 to 19-fold at 48 h post-infection and the cell survival was prolonged. These data formed the basis for further in vivo studies of RNA interference in mouse models.