FIGURE 2.

Anti-4-1BB augments memory CD8 T cell responses to VACV-WR. WT mice were infected i.p. with VACV-WR (2 × 10⁴ PFU/mouse) and treated with 0, 25 or 100 μg anti-4-1BB on day 1 post-infection. Thirty-five days after infection, (A) Splenocytes were stimulated with B8R, A23R, or B2R peptide, and stained for intracellular IFN-γ and TNF. Total numbers of CD8⁺IFN-γ⁺ (top), CD8⁺TNF⁺ (middle), and CD8⁺IFN-γ⁺TNF⁺ cells (bottom) were calculated. (B) Total splenic CD8 T cell numbers were calculated. Data represent mean value ± SEM from n = 4 mice. Similar results were reproduced in two separate experiments. Statistical significance. *p < 0.05.