Figure 6.

In vivo validation of CAT/9A8

(A) The Nalm-6 WT stress model was performed on NSG mice, where 10⁶ cells were intravenously injected on day −4 and 5 × 10⁶ CAR-expressing T cells were injected on day 0 intravenously. (B) The Nalm-6 tumor line was engineered to express HA-tag, as well as luciferase that was used to estimate tumor burden by BLI. (C) This graph illustrates the luciferase levels detected in (B). The presence of tumor cells in the bone marrow was evaluated by flow cytometry detecting the HA-tag on the tumor cells (D). (E) The CD19 antigen escape was simulated by knocking out CD19 in Nalm-6 cells. One million CD19^KO Nalm-6 cells were injected on day −8 and 5 × 10⁶ transduced T cells were injected on day 0. The tumor burden was measured by BLI to detect luciferase on mice over the course of 13 days. (H) The percentage of HA-expressing tumor cells was also enumerated in the bone marrow compartment by flow cytometry. (I) The expression of each CAR subpopulation in each condition was validated in vitro before the injection into mice, as well as in the bone marrow of mice sacrificed on day 14. The percentages shown for BM at day 14 in graph (I) are based on the cell number events shown in the graph in (J). Statistical analyses were performed by Student's t-test (n = 5 mice, T cells derived from 1 donor).