Groups of 5 BALB/c mice were orally immunized with 5x1010vp AdC68gag and i.m. immunized 2 months later with 1x109vp AdHu5gag, as shown in the timeline (A). Lymphocytes from spleen, MLN, and PP were isolated from sacrificed animals at day 10 and month 2 after the boost, and were stimulated for gag-specific IFN-γ ELISpot (B). Data for spleen represent mean + SD of five individual mice, whereas data for MLN and PP represent mean + SD of pooled cells in triplicate wells. Unstimulated cells from each sample were used as background control, and the numbers of background spots, which were similar for each tissue (<100 SFU/1E6), was subtracted from each sample before plotting the data. (C) Spleen and MLN cells were harvested at the Month 2 timepoint post boost and stained with a gag tetramer. Percentage of tetramer+ CD8+ cells are shown in the upper right corner of each dot plot. The plots for spleen are representative samples from individual mice, while the plots for MLN show pooled lymphocytes from 5 mice per group.