In vivo functions of CD19 CAR T cells. (A) NSG mice were injected IV with 1 × 106 CD19 CAR T cells transduced either after IL-7 culture or CD3 activation (n = 6 per group). Flow cytometry analysis for CD3+ human T cells was performed on peripheral blood samples obtained every 14 days. Graph depicts the mean of 3 at each time point per group, with error bars representing standard deviation. (B) NSG mice were injected intraperitoneally with 1 × 105 luciferase expressing Raji cells. On day 7 after injection, mice were treated IV with 1 × 106 CD19 CAR T cells transduced either after IL-7 culture or CD3 activation (n > 8 per treatment group). Mice injected with Raji cells that received no treatment were used as controls. The graph depicts in vivo bioluminescence of tumors from 2 representative mice from each group at each time point. (C) Kaplan-Meier survival curve of Raji-injected mice. Statistically significant differences in survival were determined by log-rank test. CD3 activated compared to control ∗P = .0102; IL-7 cultured compared to control ∗∗P = .0013; IL-7 cultured compared with CD3 activated ∗P = .0211. The graph depicts 2 experiments with a total of 18 mice per group. (D) NSG mice were injected subcutaneously with 5 × 106 Raji cells. Mice with palpable tumors were treated IV on day 7 with 1 × 106 CD19 CAR T cells transduced either after IL-7 culture or CD3 activation. Tumor-bearing mice receiving no treatment were used as controls (n = 5 mice per each group). Data represent the mean at each time point with error bars indicating standard deviation. Statistically significant differences in tumor size were determined by 2-tailed Wilcoxon rank sum test. CD3 activated compared with control ∗P = .0317; IL-7 cultured compared with control ∗∗P = .0079; IL-7 cultured compared with CD3 activated ∗∗P = .0079.
