Figure 2. Repetitive challenge assay reveals differences in killing and proliferative potency between CD4⁺ and CD8⁺ CAR T cells.

(A) Degranulation and intracellular cytokine staining of CD4⁺ and CD8⁺ CAR T cells after 5 hours of co-culture with GBM cells (E:T=1:1). (B) CD4⁺, CD8⁺ or mixed (CD4:CD8=1:1) CAR T cells were applied to repetitive challenge assay, and viable tumor cells were quantified. *p<0.05, **p<0.01, ***p<0.001 compared with CD4⁺, using one-way ANOVA with Bonferroni’s Multiple Comparison Tests. (C) CD4⁺ and CD8⁺ CAR T cell expansion during repetitive tumor challenge assay. Comparison of (left to right): CD4⁺ vs CD8⁺, single subset; CD4⁺ vs CD8⁺, within the “mixed” group; CD4⁺, single vs mixed; CD8⁺, single vs mixed. *p<0.05, **p<0.01, ***p<0.001 using an unpaired Student’s t test. Error bars: ±SEM