Retention of native antiviral activity of CAR.CD19-transduced PB-derived MV-CTLs. (A) IFNγ production by transduced and nontransduced MV-CTLs in response to CMV-pp65, AdV-hexon, and EBV antigens and irrelevant pepmix as measured by ELISPOT assay. Means and SDs from 3 CTL lines are shown. (B) Specific lysis of CMV-pp65, AdV-hexon, and irrelevant pepmix-pulsed autologous PHA blasts, and autologous EBV⁺ CD19⁺ LCLs by transduced and nontransduced MV-CTLs at E/T ratio of 40:1 measured by ⁵¹Cr-release assay. Means and SDs from 3 experiments are shown. (C) Surface expression of CAR.CD19 on both CD8⁺ (top plots) and CD4⁺ (bottom plots) MV-CTLs producing IFNγ in response to CMV-pp65, AdV-hexon, AdV-penton, and EBV-BZLF-1 pepmixes visualized by intracellular flow cytometry. Representative plots from 1 of 3 experiments are shown. TD CTLs indicates transduced cytotoxic T lymphocytes; NT CTLs, nontransduced cytotoxic T lymphocytes.