Figure 5.

Killing kinetics of CAR T-cells when compared with antigen expression level. IL13Rα2 antigen expression measured with flow cytometry (mean fluorescence intensity (MFI), % of cells positive) for cell lines HT1080, PBT138 (mock, low, medium, high) (a) and CAR T-cell killing dynamics measured by xCELLigence (b). κ₁ shows a decreasing trend from medium to high antigen levels (c) suggesting that high levels of antigen expression may not result in faster rates of CAR T-cell killing. κ₂ increases from low to medium antigen expression and plateaus with high antigen levels (d). This suggests limited activation of CAR T-cells at lower antigen expression and that exhaustion rates from medium to high antigen may not change significantly. (Online version in colour.)