Fig. 7

Single CAR19 construct strongly selects Raji tumor escape variants. a Diagram of the experimental design for tumor escape experiments. Raji and CAR T cells were co-cultured at E:T ratio of 1:1 either overnight or for 4 days. After overnight incubation and on day 4, cultures were harvested and viable Raji cells examined for CD19, CD20, and CD22 surface expression by flow cytometry. b Gating strategy for flow cytometric analysis used to analyze viable Raji cells (7AAD- and CD3-) from co-cultures is shown for representative treatment groups is shown in column 1. Columns 2, 3, and 4 show CD19, CD20, and CD22 expression levels, respectively, when Raji cells were co-cultured with no T cells (row 1), 19A CAR (row 2), or 2019 CAR (row 3). c Graphs of CD19, CD20 and CD22 surface expression (solid, open, gray, respectively) in surviving Raji and NALM-6 cells after overnight or 4 days of co-culture with CAR T cells, as listed on x-axis, as determined by flow cytometry. Bars represent group means + SD. Statistical analysis was performed by one-way ANOVA followed by Dunnett’s multiple comparisons test vs N.T. (non-transduced T cells) control from the same donor, *p < 0.05. T.A.- tumor alone control group