FIG. 5.

Transgene product-specific CD8⁺ T-cell responses to AdHu26 vector vaccination in mice. Groups of four BALB/c mice were immunized with varied doses of an AdHu26 vector expressing gag of HIV-1. Three weeks later the mice were bled and the frequencies of CD8⁺ cells and tetramer staining-positive CD8⁺ T cells from individual mice were determined. (A) Numbers of tetramer staining-positive (tet⁺) CD8⁺ cells/10⁷ PBMCs. In addition, PBMCs from individual mice were stimulated for 5 h with the immunodominant epitope of Gag and then stained for CD8 and intracellular IFN-γ. (B) Frequencies of gag-specific IFN-γ-positive CD8⁺ cells as a proportion of all circulating CD8⁺ cells. (C) Comparison of CD8⁺ T-cell responses to gag using different Ad vectors for immunization. Mice were immunized with 10¹⁰ vps of vector; the frequencies of tetramer staining-positive CD8⁺ T cells were determined 21 days later. (D) Frequencies of gag-specific CD8⁺ T cells tested 21 days after they were primed with different Ad vectors at 10⁸ vps or 21 days after booster immunization given 2 months after the cells were primed.