Suppression of porcine arterivirus replication by baculovirus-delivered shRNA targeting nucleoprotein.

The ability to synthesize shRNAs from DNA templates driven by RNA polymerase III promoters has made it possible to apply virus-derived vectors as delivery vehicles for double-strand RNA-mediated interference. Baculovirus emerges as a promising vector for in vivo gene therapy most recently. To investigate its potential as a delivery vector for anti-virus shRNA targeting arterivirus porcine reproductive and respiratory syndrome virus (PRRSV), we constructed recombinant baculovirus vectors bearing a shRNA-synthesizing cassette driven by U6 promoter with enhanced transduction efficiency by displaying vesicular stomatitis virus glycoprotein on viral envelope. Transduction of Marc145 cells with a recombinant baculovirus delivering egfp gene-specific shRNA dramatically suppressed the expression of EGFP in this cell line; and transduction of Marc145 cells with a baculovirus delivering shRNA specific for the C-terminal nucleoprotein coding region of PRRSV genome resulted in inhibition of viral replication. Our data highlight the recombinant baculovirus as an alternative vehicle for anti-virus shRNA delivery.