Fig. 1.

Induction of GagL_85–93-specific CD8⁺ T cells by co-immunization with cytokine-encoding plasmids. CB6F1 mice were immunized once with a DNA plasmid encoding Leader-Gag, a mix of plasmids encoding Leader-Gag and Env (LG + Env), or a mix of plasmids encoding Leader-Gag, Env and cytokines as indicated; 25 µg of each plasmid were injected intramuscularly followed by in vivo electroporation. Two weeks after immunization, the frequency of GagL_85–93-specific CD8⁺ T cells in blood cells was analysed by MHC I tetramer staining (a), the production of IFNγ by GagL_85–93-specific CD8⁺ T cells was analysed by intracellular cytokine staining after peptide restimulation (b). Data were acquired in two to four independent experiments with three to four mice per group per experiment. Each dot indicates an individual mouse, the bars indicate the mean values. Data were analysed by Kruskall–Wallis One Way Analysis of Variance on Ranks and Dunn’s multiple comparison procedure, statistically significant differences (P < 0.05) compared to unvaccinated mice are indicated by *, significant differences compared to mice immunized with the combination of Leader-Gag and Env plasmids (LG + Env) are indicated by #