FIG. 4.

Effect of the N501S/A506V substitutions on restoring antibody-mediated neutralization. Neutralization with HCVpp bearing H77c, 02.E10, or N501S/A506V 02.E10 envelope proteins was performed as described in the legend to Fig. 1. HCVpp were preincubated with each HMAb, as indicated, at 37°C for 1 h at the specified concentrations, as shown on the y axis, prior to infection of Huh7.5 cells. Neutralization of the tested antibody is expressed on the z axis as percent reduction of luciferase activity relative to the level for a no-antibody control. On the x axis, the H77c, tested variants, and reverse-mutated variant are indicated. Variant 95.C8 is included as a binding reference in the top panels since the indicated antibodies failed to bind to H77c.