Analyses of T cells of an HLA-A*0201⁺- and A*2402⁺-expressing seropositive donor after sensitization with peptide pools of pentadecapeptides or with the complete pool. T-cell cultures were generated simultaneously by stimulation with either peptide pool 23 (CD3 + pool 23), containing HLA-A*0201–restricted peptide NLVPMVATV, or with peptide pool 20 (CD3 + pool 20), containing HLA-A*2402–restricted peptide QYDPVAALF. A third T-cell line was generated with DCs pulsed with the complete pool (CD3 + all pools). (A) Staining with A*0201-restricted MHC tetramers, complexed with NLVPMVATV peptide. (B-D) Intracellular IFN-γ responses to A*0201-restricted NLVPMVATV, A*2402-restricted QYDPVAALF, or to the complete pool. (E) T cells sensitized with the complete pool effectively lysed targets pulsed with either NLVPMVATV or QYDPVAALF peptide. T cells sensitized with peptide pool 23 or peptide pool 20 selectively lysed the targets after pulsing with the corresponding A*0201 or A*2402-restricted peptide. All 3 T-cell lines recognized autologous CMV-infected fibroblasts but failed to lyse nonpulsed, noninfected target cells. All target cells were plated in triplicates. Results represent percentage of lysis ± standard deviation.