Kinetics of BMLF1- and pp65-specific CD8⁺ T-cell expansion over a 12-day ex vivo culture. PBMCs from an HLA-A2⁺ double seropositive donor were activated by CD3 mAb and 500 UI/mL IL-2 (1 representative experiment of 5). At the indicated time, cells were stained with CD8-PC5 mAb and PE-labeled BMLF1 or pp65 tetramers. (A) Expansion of BMLF1-specific (▴), pp65-specific (▪), CD8⁺ (⋄), and total cells (○) was calculated over the 12-day culture as described for Figure 3. (B) Data are expressed as the percentage of BMLF1 (▴) and pp65 (▪) tetramer⁺ cells within CD8⁺ cells. (C) Flow cytometry profiles of pp65 tetramer staining at day 0, 1, and 12 of culture. The percentage of tetramer⁺ cells among CD8⁺ cells is indicated above each profile.