Extended Data Fig. 5: CAR19-NK cell trogocytosis and reciprocal reduction in CD19 antigen expression on tumor cells in vivo.
From: KIR-based inhibitory CARs overcome CAR-NK cell trogocytosis-mediated fratricide and tumor escape
(a) Schematic illustration of timeline using a mouse model engrafted with Raji cells. Mice received three dose levels of Luc/GFP-expressing CD19+ Raji cells (0.2×105, 1×105, or 5×105), respectively, followed by a single infusion of CAR19-NK cells (1×107) or NT-NK cells alone (1×107) as control, (b) Graphs showing the intensity of bioluminescence imaging (BLI) over time; black: Raji cells only; blue: Raji cells with NT-NK cell infusion; green: Raji cells with CAR19-NK cell infusion. (c) tCD19 expression (indicated as TROG+/TROG− ratio) on singlet hCD45+GFP−CD56+CD3− on CAR-NK cell products gated on CAR19-expressing (green) vs. CAR-negative fractions (light blue) in peripheral blood samples collected at different time points after infusion (n = 15 mice). (d) CD19 expression on Raji cells, shown as the count of molecules per cell (grey) in peripheral blood (left, n = 15 mice), and organs [spleen, liver, bone marrow (BM), and blood] of mice at the end time point (right, n = 24 mice) after CAR19-NK cell infusion. (e) CD19 expression on Raji cells, shown as the count of molecules per cell in organs harvested at the end time point after NT-NK cell infusion (n = 10 mice). P values were determined by two-tailed Student’s t test for analyses, and two-tailed one-way ANOVA in panel d. Data were assessed by flow cytometry in samples with cell objects of interest >20 counts, and shown by mean + s.e.m, or medium (min/max) in boxplot. Each circle represents an individual mouse sample and outliers are indicated as dark dots.
