FIG. 5.

Annexin V staining of p18-specific CD8⁺ T cells elicited by DNA vaccination with or without delayed administration of plasmid IL-12. Groups of BALB/c mice were immunized with 50 μg of PMV-gp120 alone (closed circles) or with 50 μg of PMV-gp120 plus 200 μg of PMV-IL-12 on day 10 following vaccine administration (open circles). Spleen cells from individual mice were harvested at the indicated times and stained with anti-CD8 MAb, H-2D^d/p18 tetramer, and annexin V. Data are presented as the percentage of gated CD8⁺ T cells that bound tetramer (A) and the percentage of gated tetramer-positive CD8⁺ T cells that bound high levels of annexin V (B), as measured by flow cytometry. The background level of annexin V binding to gated CD8⁺ T cells from naive animals is also indicated. Data are the mean of four mice per group ± SEM.