Use of interfering RNAs targeted against feline herpesvirus 1 glycoprotein D for inhibition of feline herpesvirus 1 infection of feline kidney cells

To evaluate the use of RNA interference targeted against feline herpesvirus 1 (FHV-1) glycoprotein D for inhibition of FHV-1 infection of feline kidney cells. Crandell-Rees feline kidney cells. Crandell-Rees feline kidney cells were transfected with small interfering RNAs (siRNAs) that were designed to inhibit expression of FHV-1 glycoprotein D. The effectiveness of the treatment was determined via measurement of amounts of glycoprotein D mRNA, intracellular glycoprotein D, and glycoprotein D expressed on the surface of infected cells and comparison with appropriate control sample data. 2 of 6 siRNAs tested were highly effective in reducing expression (ie, knockdown) of glycoprotein D mRNA; there were 77% and 85% reductions in mRNA in treated samples, compared with findings in the control samples. The knockdown of glycoprotein D mRNA resulted in reduced glycoprotein D protein production, as evidenced by 27% and 43% decreases in expression of glycoprotein D on the surface of siRNA-treated, FHV-1-infected cells and decreased expression of the protein within infected cells, compared with control samples. Treatment with these siRNAs also resulted in inhibition of FHV-1 replication, with reductions of 84% and 77% in amounts of virus released into cell culture supernatant, compared with findings in control samples. 2 chemically produced siRNAs that targeted the glycoprotein D gene significantly reduced FHV-1 titers in treated cells, suggesting that glycoprotein D is necessary for production of infective virions. This gene is a potential target for RNA interference as a means of inhibition of FHV-1 infection of feline cells.