Figure 1.
4-1BB enhances CD8 T-cell activation and memory. BALB/c mice were primed with 100 µg of plasmid pTH.HM twice, 1 week apart. Two weeks later, mice were boosted with 1 × 106 pfu of MVA.HM and received 200 µg of either purified anti-4-1BB mAb or rat IgG i.p. with the boost. At the indicated number of days later, unfractionated spleen cells were cultured directly ex vivo for 6 hr with brefeldin A, in the presence or absence of 1 µg/ml RGPGRAFVTI peptide, then stained for CD8 and intracellular IFN-γ. One representative is shown from each group (a). Each point represents the average percentage (b) and number (c) of antigen-specific CD8 T cells ± SEM (day 6, n = 3 mice per group; day 22, n = 4 mice per group). A second experiment gave similar results.