FIG. 5.

Down-expression of cyr61 reduces viral growth in HeLa cells infected with CVB3. (A) cyr61 was down-expressed in HeLa cells (si-cyr61-HeLa) performed with silencing RNA. Cells were transfected with two siRNA plasmids (1 and 2) for cyr61 genes (see details in Materials and Methods). After 48 h of transfection with siRNA plasmids, cyr61 expression was assayed. Controls were HeLa cells transfected with pCA as a vehicle. Tubulin was used as an internal control. (B) HeLa cells transiently down-expressing cyr61 were infected with CVB3 (MOI = 10) for 1 h after 48 h of transfection with siRNA-1 plasmids (indicated by si-cyr61 HeLa/1), washed twice with PBS, and then cell lysates were harvested at the indicated times postinfection (pi). VP1 protein production indicated CVB3 replication and growth. Tubulin was used as an internal control. (C) Each bar represents the mean VP1 expression (after normalization to tubulin) at 6 h postinfection in HeLa cells infected with CVB3 (MOI = 10). VP1 production in controls is expressed as 100% and compared with the percentage converted by the VP1 production from si-cyr61-HeLa/1 cells. (D) The viral titers in cell medium from control and si-cyr61-HeLa/1 cells after CVB3 infection (MOI = 10) were compared. Viral titration in the extracellular space was performed by plaque assay (see details in Materials and Methods). The results shown are the averages of three independent assays, with error bars representing the standard deviations.