FIG. 3.

Effect of hRBL2 knockdown on influenza virus replication. (A) Knockdown of hRBL2 in 293 cells. 293 cells were transfected with an siRNA specific to hRBL2 (siRBL2) or with a nonspecific control siRNA. Cells were also transfected with a plasmid expressing hRBL2 (pChRBL2) or a control vector. Two days later, hRBL2 expression levels were assessed by Western blot analysis. Beta-actin expression levels served as an internal control. (B) Viral polymerase activity in cells treated with an siRNA to hRBL2. 293 cells were transfected with hRBL2-specific or control siRNAs (si Control) and incubated at 37°C for 48 h. The transfected cells were then infected with strain WSN (MOI of 1). The amounts of vRNA, cRNA, and mRNA were determined at 5 h postinfection as described in the legend of Fig. 2b. (C) Viral M1 protein production in hRBL2 knockdown cells and control cells. Cells were transfected with siRNAs as described above and infected with WSN virus at an MOI of 3. M1 protein levels were assessed as described in the legend of Fig. 2c. (D) Influenza virus titers in hRBL2 knockdown cells and control cells. Cells were treated with siRNAs as described above, infected with WSN virus at an MOI of 0.05, and incubated at 37°C for the indicated time periods. Virus titers were determined in MDCK cells. The error bars represent standard deviations (n = 3). α, anti.