FIG 7.

Monensin blocks cell-to-cell transmission. (A) Huh-7 cells were seeded on coverslips and infected with HCVcc for 2 h at 37°C. Cells were then washed and cultured for 72 h at 37°C in culture medium containing the 3/11 neutralizing MAb (50 μg/ml), in the presence or absence of monensin (Mon; 0.1 μM) or chloroquine (CQ; 1.75 μM), as indicated. Foci of infected cells were detected using an A4 anti-E1 indirect immunofluorescence assay. (B) The number of infected cells per focus was determined in the presence of no drug (CTL), 0.1 μM monensin, or 1.75 μM chloroquine. (C) HCVcc-infected donor cells were labeled with CMFDA, mixed with naive Huh-7 cells (ratios of 1:4 and 1:6), and cultured in the presence of a saturating concentration of the 3/11 MAb (50 μg/ml) and with monensin at the indicated concentrations. Cocultures were incubated for 24 h at 37°C and then stained for HCV NS5. Cell-to-cell transmission levels were quantified by flow cytometry. ***, P < 0.001.