FIG. 1.

p18-specific CD8⁺-T-cell responses elicited by DNA vaccination with delayed plasmid IL-12 administration. Groups of BALB/c mice were immunized with 50 μg of sham PMV plasmid, 50 μg of PMV-gp120 alone, or 50 μg of PMV-gp120 plus 200 μg of PMV-IL-12 given concurrently or on day (d.) 4, 7, 10, or 14 following vaccine administration. Peripheral blood was obtained from individual mice at the indicated times, and antigen-specific CD8⁺ T cells were detected with an H-2D^d/p18 tetramer. Data are presented as the percentage of gated CD8⁺ T cells that bound tetramer, as measured by flow cytometry, and are the means of six mice per group ± SEM.