Fig. 1: CAR T cells are less effective at killing myeloid leukemia than B-lineage leukemia.

A Representative histograms showing CD33 expression. B Cytolytic activity of CD33 CAR T cells in vitro. n = 3 biological replicates with T cells from different donors per point. C Cytolytic activity of CLL1 and CD123 CAR T cells in vitro, n = 3. D Percentage of CD25 and CD69, IFN-γ, Granzyme B (GZMB), and IL-2 in CAR T cells, n = 3. E Cytolytic activity of CD33 CAR T cells against different cell lines in vitro, n = 3. F Representative histograms showing CD38 expression on sorted primary samples and CD38 CAR T cytolytic activity in vitro, n = 4 in ALL group, n = 5 in AML group. G Schematic of mouse model. NSG mice were intravenously injected with tumor cells, followed by 1 × 10⁶ CAR or PCDH T cells 5 days later. Peripheral blood (PB), spleen (SP), and bone marrow (BM) cells were collected from mice euthanized on days 3–5. H CAR T-cell counts in SP, BM, and PB from (G), n = 4 in SP and BM, n = 5 in PB. I Percentage of Annexin V⁺ of CAR T cells in spleen from (G), n = 3. J Percentage of CD25, GZMB, IFN-γ, and IL-2 of CAR T cells in spleen from (G), n = 3 in IL-2 expression, n = 4 otherwise. K Total Naïve (N, CD45RA⁺CD62L⁺), central memory (CM, CD45RA⁻CD62L⁺), effector memory (EM, CD45RA⁻CD62L⁻) and effector (E, CD45RA⁺CD62L⁻) CAR T cells were assigned to CD4⁺ and CD8⁺ CAR T cells in spleen, n = 3. L Percentage of PD-1, TIM-3, and TOX in CAR T cells in spleen, n = 5 in TOX, n = 3 otherwise. For all bar plots, data are shown as mean ± SD. Assays were performed on day 10 after T-cell initial activation. Two-sided unpaired t-tests or multiple two-sided unpaired t tests were used to assess significance in (B, C, D, F, H–L). One-way ANOVA was used in (E). All numbers defined by “n” indicate the number of biological replicates with different human donors or mice. Data are representative of two independent experiments. NS not significant. Source data are provided in the Source Data file.