Suppression of protein expression of three avian reovirus S-class genome segments by RNA interference

RNA interference was used to suppress protein expression of three S-class genome segments of avian reovirus (ARV). Viral progeny titer was successfully down-regulated by RNA interference. Suppression of S1 genome segment, which has three open reading frames, not only decreased the expression level of the structural protein sigmaC but also reduced cell fusion and the level of Ser(15)-phosphorylated p53 protein caused by the nonstructural proteins p10 and p17, respectively. Suppression of S2 or S4 genome segment by RNA interference could also reduce the expression level of sigmaA or sigmaNS. Interestingly, suppression of sigmaNS resulted in down regulation of the expression of other viral products. In terms of variability of different genes among viral strains and of the impact after their suppression, it seems that the viral products involved in construction of viroplasm or core particles, like sigmaNS, are considerable choices to efficiently inhibit ARV multiplication by RNA interference. Using a GFP reporter system, it was discovered that ARV could not inhibit activated RNA interference, suggesting that RNA interference may be used in the suppression of ARV infection.