Figure 4.

Comparisons of CARRGO model parameters with cell line and CAR T-cell dose. CARRGO model parameters: (top row) killing rate (κ₁), (middle row) proliferation/exhaustion rate (κ₂), (bottom row) and persistence/death rate (θ), for cell lines PBT138-H, PBT030 and HT1080-H treated with three different effector to target (ET) ratios (1 : 5, 1 : 10 and 1 : 20). CAR T-cell killing rate is observed to decrease with increasing ET ratio for all cell lines. This suggests CAR T-cells kill more cancer cells per unit time at a lower concentration when compared with higher ET ratio. By contrast, the CAR T-cell proliferation/exhaustion rate increases with ET ratio. This suggests that the CAR T-cells are stimulated to proliferate and are less exhausted with higher ET ratio when compared with lower. For reference, CAR T-cells are hypoactivated in mock (κ₂ < 0). The CAR T-cell death rate, or persistence, is observed to be independent of target cell line and ET ratio.