FIG. 7.

Hepatoma cells constitutively expressing IRNA prevent PV and HCV-PV chimera infection. Huh-7 control cells or the IRNA expressing hepatoma cell line (pCDIR.Ribo.ΔT7) (∼10⁶ cells) were infected with 500 PFU of either PV (Polio) (A) or HCV-PV chimera (B and C). After 72 h, either cells were stained for the observation of cytopathic effects (C) or cell extracts were made to further infect HeLa monolayer cells for the plaque assay (A and B). Cells were stained by crystal violet. (D) Average virus titers obtained from three independent plaque assay experiments.