Expansion of EBV-specific T cells in patient 3 after T-cell transfer. (A) EBV DNA levels in peripheral blood cells (copies per 20 000 cells) and in throat lavage fluid (copies per milliliter). (B) Absolute numbers of CD8⁺ and CD4⁺ T-cell subsets in peripheral blood. (C) Frequencies of T cells specific for EBV epitopes in total PBLs were assessed by an ELISPOT assay for IFN-γ. Responses against CD8⁺ T-cell epitopes from latent antigens (epitopes VEI and KEH), a CD4⁺ T-cell epitope from an early antigen (PYYV), and a CD4⁺ T-cell epitope from a late antigen (TDAW) were included.