19-CAR-ML NK cells display enhanced responses to primary lymphoma targets in vitro. (A) 19-CAR cNK and 19-CAR-ML NK cells were incubated with CD19⁺ B-cell lymphoma tumor cells for 6 hours at 5:1 total NK/T ratio. Summary data shown as scatter dot plot of percentage of IFN-γ and CD107a⁺ cells with line at mean ± SEM (n = 12; 3 independent experiments). (B) 19-CAR-ML and 33-CAR-ML NK cells were incubated with CD19⁺ B-cell lymphoma tumors for 6 hours at a 5:1 total NK/T ratio. Summary data show percentage of IFN-γ and CD107a⁺ cells (n = 8-13; 4-6 independent experiments). (C) Summary primary lymphoma killing assay showing mean ± SEM percentage of specific killing by 19-CAR-ML and 33-CAR-ML NK cells at the indicated effector/target ratios (n = 3-4; 2-3 independent experiments). (D) Experimental schema. Briefly, PB samples were obtained from patients with B-cell lymphoma at day 0. NK cells were isolated, activated with IL-12, IL-15, and IL-18, and transduced with 19-CAR lentivirus. On day 7, 19-CAR-ML NK cells were incubated with autologous B-cell lymphoma tumor for 6 hours at a 5:1 Total NK/T ratio. (E,G) Representative bivariate flow cytometry plots show percentage of NK cells positive for IFN-γ (E) and CD107a (G) in response to autologous tumor targets. (F,H) Summary data show percentage of IFN-γ (F) and CD107a⁺ cells (H) of autologous 19-CAR-ML NK cells and control ML NK cells (n = 3 patients; 2 independent experiments). Data were compared using 2-way analysis of variance with Bonferroni’s multiple comparisons test (A,C) or paired Student t test (B,F,H). *P < .05, **P < .01, ***P < .001, ****P < .0001. ns, no significance.