Figure 4.

Sera from mice immunized with GPΔmucin antigens neutralize GP-pseudotyped lentiviruses. (A) Lentiviruses pseudotyped with GPΔmucin were produced by transfecting a lentiviral packaging vector as well as plasmids expressing lentiviral helper proteins and GPs into HEK239T cells. Viruses were harvested from HEK293T supernatant and used to assess viral entry inhibition via expression of a luciferase reporter gene. (B) Viral neuralization of both GPΔmucin and FL GP pseudotyped viruses was assessed at a single dilution point (1:300) with serum collected at weeks 2, 4, 6, 18, and 20 post prime immunization. Each point represents the mean % infectivity in the presence of 1:300 serum dilution for each group at each time point and error bars represent the standard deviation. (C) Final bleeds were assessed for neuralization of both GPΔmucin and FL GP pseudotyped viruses using a 6-point dilution series. Dilution curves were fit to obtain NT₅₀ values; each point represents the average NT₅₀ for a single mouse, the line represents the geometric mean per group, and error bars represent the geometric standard deviation. Statistical analysis was performed using ordinary one-way ANOVA with Tukey’s multiple comparisons test and no statistically significant differences were found between the three antigen groups.