Expansion and phenotype of PB-derived MV-CTLs genetically modified to express CAR.CD19. (A) Fold expansion of PB-derived CAR.CD19⁺ MV-CTLs compared with nontransduced control MV-CTLs. Fold expansion = total cell count at time point indicated divided by cell count at transduction. Means and SDs from 3 experiments are shown. (B) Phenotype of 3 CAR.CD19⁺ MV-CTLs at time of harvest. Percentage of total cells positive for each marker is shown. (C) CAR expression at completion of culture period in transduced MV-CTLs (top histogram) compared with nontransduced controls (bottom histogram). Representative plots from 1 of 3 experiments shown. (D) Coexpression of CAR.CD19 by CMV-pp65–, AdV-Hexon–, and EBV-BZLF1–specific CD8⁺ CTLs as detected by pentamer staining. Top 3 plots show CAR.CD19⁺ CTLs; bottom 3 plots show nontransduced CTLs for comparison. Sample plots from 1 of 3 experiments shown. TD CTLs indicates transduced cytotoxic T lymphocytes; and NT CTLs, nontransduced cytotoxic T lymphocytes.