Fig. 5.

Selection and characterization of lycorine-resistant WNV. (A) Scheme for selection of lycorine-resistant WNV. Three independent selections were performed. P1 through P6 were selected at 0.8 μM lycorine; P7 through P12 were selected at 1.2 μM. (B) Resistance profile during selection. Viruses from each of the 12 passages were monitored for their resistance. Vero cells were infected with viruses at an MOI of 0.1 in the presence of 0.8 μM lycorine (P1-P6), 1.2 μM lycorine (P7-P12), or 1% DMSO (as a negative control). At 42 h p.i., viral titers in culture fluids were quantified by plaque assays. Resistance is quantified by comparison of the viral titers from the lycorine-treated infections with the viral titers from the mock-treated infections. Results for representative passages from the three selections are shown. (C) Plaque morphologies of WT and lycorine-resistant viruses. Plaque assays for WT and P12 viruses were performed on Vero cells in the absence of lycorine.