Frequency of HLA-A2–restricted BMLF1, EBNA-3C, pp65, or IE1 peptide–specific cells among CD8⁺ Co cells. The frequency of tetramer⁺ cells or IFN-γ⁺ cells, evaluated by ELISPOT assay, within CD8⁺ PBMCs was set as the 100% reference (dotted line). Data are expressed as the variation of the percentage of tetramer⁺ (□) or IFN-γ⁺ (▦) cells in CD8⁺ Co cells, as compared with the CD8⁺ PBMC reference (mean ± SE of 13 experiments for BMLF1 and pp65 and 7 experiments for EBNA-3C and IE1).