Immunization with Ad26 results in increased functional CD8 T cell responses compared to Ad5. (A) Representative FACS plots showing tetramer to cytokine ratio in Gag-specific CD8 T cells from the spleen. (B) Representative FACS plots showing tetramer to cytokine ratio in Gag-specific CD8 T cells from the liver. (C) MFI of IFN-γ, TNF-a, and IL-2 expression in Gag-specific CD8 T cells in spleen after peptide stimulation. (D) MFI of IFN-γ, TNF-a, and IL-2 expression in Gag-specific CD8 T cells in liver after peptide stimulation. (E) Representative FACS plots in spleen showing percentages of Gag-specific CD8 T cells co-expressing TNF-a and IL-2 in spleen and liver. Samples were gated on IFN-γ+ Gag-specific CD8 T cells. (F) Summary showing the proportion of functional CD8 T cells in spleen and liver coproducing IFN-γ, TNF-a, and IL-2 upon stimulation with peptide. Tissue data are from day 60 or day 380 post-immunization. Data are representative of two independent experiments, with n = 4 mice per group per experiment. *p < 0.05; **p < 0.01; ***p < 0.001. Error bars indicate SEM.