RNA interference targeting nucleocapsid protein (C) inhibits classical swine fever virus replication in SK-6 cells

The application of RNA interference (RNAi) strategy for controlling classical swine fever could become a promising alternative to the conventional eradication measures, as it was recently shown for foot-and-mouth disease (Chen et al., 2004), influenza (Ge et al., 2003), porcine reproductive and respiratory syndrome (He et al., 2007) and porcine transmissible gastroenteritis (Zhou et al., 2007). The use of synthetic siRNA which is corresponding to nucleotides 1130–1148 of the CSF virus strain Alfort, targeting the nucleocapsid protein (C) was investigated to show the inhibition of CSF virus replication. It could be shown that the virus titer of infected cells, which had been mock-transfected or transfected with control (non-silence) RNA were not affected. These data indicate that siRNA_253 is able to inhibit viral replication.