FIG 3.

Removal of HVR1 in gpE1/gpE2 reduces neutralization activity against homologous HCVpp in vaccinated mice. Prevaccination or terminal-bleed antisera (diluted 1/100) from WT or ΔHVR1 gpE1/gpE2-vaccinated mice were examined for neutralization activity against HCVpp pseudotyped with H77C gpE1/gpE2. The amount of HCVpp entry was quantitated by measuring luciferase activity in cell extracts, as described in Materials and Methods. Neutralization activity was normalized to the luciferase activity observed in the absence of the addition of serum. Averages of data from three independent experiments performed in triplicate are shown. Statistical calculation was done by using GraphPad software. *, P < 0.05; NS, not significant (by one-way analysis of variance with a Tukey post hoc test).