FIG. 2.

Ad5-specific T-cell responses in SMLNs and spleens of C57BL/6 mice with or without preexisting Ad5 immunity. Naïve or Ad5-preimmune C57BL/6 mice (n = 6 for both s.l. and o.g. treatment groups) were immunized with 1 × 10¹⁰ vps of Ad5-HIV-Gag by either the s.l. or the o.g. route of delivery. Fourteen days postvaccination, IFN-γ (A) and IL-2 (B) ELISpot analyses were used to quantify Ad5-specific T-cell responses in both SMLN and splenocyte preparations. Cells were stimulated with heat-inactivated Ad5 particles. Spot-forming cells (SFCs) are reported per 1 × 10⁶ total cells plated per well. Each symbol represents one sample, and the horizontal line indicates the mean of the presented data. The induction of T-cell responses was considered significant if the average number of SFCs recalled with the indicated peptide was statistically higher than the number of SFCs derived from cells incubated in medium alone, as determined using a homoscedastic two-tailed t test (*, P < 0.05; **, P < 0.01). The average numbers of background SFCs are reported in the legend for Fig. 1.