FIGURE 2.

rAd5-HIV/Gag and rAd5-EAT-2 covaccination enhances the Gag-specific CD8⁺ T lymphocyte responses despite Ad5 pre-existing immunity. Ad5 preimmune BALB/c mice (n = 12) were coimmunized i.m. in the tibialis anterior with equivalent viral particles of rAd5-HIV/Gag mixed with either rAd5-EAT-2 or rAd5-GFP (total of 1 × 10⁸ vps mixed prior to injection). PBMCs were collected from the immunized mice and stained with a PE-conjugated H2-Kd-AMQMLKETI tetramer complex together with an allophycocyanin-conjugated anti-CD3 and Pacific Blue-conjugated anti-CD8 Abs. The percentage of Gag-specific CD8⁺ T cells (%Tet⁺) is depicted. (A) Representative figures of Gag-specific tetramer⁺CD8⁺ T cells at the indicated time points are shown. (B) Gag-specific CD8⁺ T cell responses after prime vaccination at 11 dpi in PBMCs (pool of three mice in each group). (C) Gag-specific CD8⁺ T cell responses after prime vaccination at 17 dpi in PBMCs. (D) Gag-specific CD8⁺ T cell responses after prime-boost vaccination at week 24 in PBMCs. The bars represent means ± SD for 12 mice per group. Data were collected in an LSRII and analyzed by FlowJo software. Statistical analysis was completed using one-way ANOVA with a Student–Newman–Keuls post hoc test. A p value < 0.05 was deemed statistically significant. *p < 0.05, ***p < 0.001 versus naive animals.