PTHs can be infected by HCVpp. (A) HCVpp of diverse genotypes and control (no E1E2) were used to infect PTHs; Huh7.5 cells were used as a positive control. Three days after infection, the cells were lysed and assayed for luciferase activity. The values are the means ± standard deviations of three independent experiments. (B) Inhibition of HCV infection by anti-CD81 antibodies. PTHs and Huh7.5 cells were incubated with the human anti-CD81 MAbs 5A6, JS81, and 1.3.3.22, mouse IgG1 at 5 μg/ml, polyclonal antibodies at 50 μg/ml, human or tupaia SR-BI immune serum, or preimmune control serum at 1:50 dilution for 1 h prior to the addition of HCVpp. The values are the means ± standard deviations of three independent experiments.