CTLs specific for pp65 from CMV are preserved in LV-transduced cells. T cells specific for the immunodominant HLA-A0201–restricted pp65_495-503 peptide derived from the matrix protein pp65 of CMV were detected by staining with CD8-QR, pp65 tetramer-PE, and LNGFr-FITC on IL-2–, IL-7–, IL-15–stimulated and transduced cells or CD3-FITC on PBMCs followed by flow cytometry analysis. The right panels show the percentage of CD8⁺/pp65-tetramer⁺ T cells analyzed on CD3⁺ cells on PBMCs and on LNGFr⁺ T cells and IL-2, IL-7, and IL-15 cells. Appropriate isotypic controls are shown in the left panels.