Changes in CD8⁺ T-cell populations, granularity, and degranulation. The percentage of CD8⁺ T cells (CD3⁺/CD8⁺) was assessed via flow cytometry in the blood, spleen, and mesenteric lymph nodes (A). Antigen-specific induction of perforin in CD8⁺ T cells was analyzed by flow cytometry via comparison of unstimulated cells (NP) with cells stimulated with HIV Gag peptides (Peptide). Results from a single experiment are shown (B) and averages for all experiments are graphed (C). Antigen-specific cytolytic degranulation was measured via stimulation with peptide in the presence of an antibody to CD107a, followed by analysis using flow cytometry (C). P values reflect comparisons between mice vaccinated with Gag4Y alone with mice vaccinated with Gag4Y plus IL-12 or IL-28B.