Figure 5.
BAdv significantly improves upon the already potent antigen-specific CD8+ T-cell response of Ad-LacZ. (a) β-gal-tetramer+ and CD8 staining of PBLs of mice (n = 13) treated with the indicated adenovectors (1 × 1010 vp/mouse). (b) IFN-γ ELISpot of splenocytes extracted from mice 9 days after treatment with indicated adenovectors. Results reflect the combining of two experiments with four mice per group. In one experiment, vp was held constant, and mice were injected with 1 × 1010 vp of Ad-Ctrl (Ad-Empty, 1.5 × 109 pfu), Ad-LacZ (1.6 × 109 pfu), and BAdv (1.2 × 109 pfu) per mouse. In the second experiment, pfu was held constant, and mice were injected with 1.6 × 108 pfu of Ad-Ctrl (Ad-Empty, 1.1 × 109 vp), Ad-LacZ (1 × 109 vp), and BAdv (1.4 × 109 vp) per mouse. The average number of ELISpots counted for a given treatment was comparable across the two experiments. (c) β-gal-tet+ and CD8 staining of intratumoral lymphocytes shows significantly more antigen-specific, CD8+ T-cells in tumors of mice treated with BAdv compared to Ad-LacZ. Mice (n = 4) were inoculated with 50,000 tumor cells and footpad-injected with the indicated adenovectors (1.6 × 108 pfu/mouse) 8 days later. Tumors were allowed to grow for 11 more days before they were removed and processed in single cell suspensions. Results are representative of two (b and d) or five (a) experiments. *P < 0.05. BAdv, bicistronic adenovirus; IFN-γ, interferon-γ N.S., not significant; PBL, peripheral blood lymphocytes; pfu, plaque-forming unit; vp, virus particle.