The pp65 protein and the overlapping pentadecapeptides. (A) The sequence of the pp65 protein, consisting of 561 amino acids and the principle of 11 amino acids overlapping pentadecapeptides are illustrated. The sequence of the first 3 pentadecapeptides with 11aa overlap each is highlighted. A total of 138 pentadecapeptides are required for overspanning the entire pp65 protein. As a result of the 11aa overlap, HLA-A*0201-restricted peptide NLVPMVATV (aa 495-503) is contained within the pentadecapeptides 123 (AGILA RNLVP MVATV) and 124 (ARNLV PMVAT VQGQN). The HLA-A*2402-restricted peptide QYDPVAALF (aa 341-350) is represented by the pentadecapeptides 85 (VELRQ YDPVA ALFFF) and 86 (QYDPV AALFF FDIDL). (B) The principle of pp65-derived peptide pools of overlapping pentadecapeptides. A total of 12 pentadecapeptides are contained within one peptide-pool (eg, pentadecapeptides 3, 15, 27, 39, 51, 63, 75, 87, 99, 111, 123, and 135 forming peptide pool 3) requiring a total of 24 pools overspanning the pp65 protein. Pentadecapeptides 123 and 124, containing the A*0201-restricted nonamer sequence NLVP MVATV, are found in peptide pools 3, 4, and 23.