Figure 5.

Intracellular staining for IL-2 and IFN-γ in CD8⁺ T cells. Groups of mice (n = 4 mice/group) with Treg cells depleted or non-depleted were first primed with plasmid gp120 DNA (A) or (B) boosted on day 42 with homologous gp120 DNA. On day 14 following priming or post boost, mice were sacrificed and splenocytes were harvested, isolated, and exposed for 6 h to the p18 peptides (2 μg/ml) or media alone. The percentage of intracellular IFN-γ⁺ CD8⁺ T cells, IL-2⁺CD8⁺ T cells, and IFN-γ⁺ IL-2⁺ dual function CD8⁺T cells was measured on a LSRII flow machine, we only see a statistically higher IFN-γ populations in both primary and memory phases (p < 0.05, one-way ANOVA test). Numbers indicate the percentages of these cell populations and representative of the means ± SE. (C) Representative flow plots are shown with percentages of IL-2-positive (upper panel), IFN-γ-positive (middle panel), and IL-2/IFN-γ double-positive populations in CD8 lymphocytes. Results shown are representative of three experiments performed.