Figure 4

Phenotypic characterization of MUC16-targeted Meso-TR3. A, OVCAR3 cells were challenged with a constant amount of Meso-TR3 (80% specific cell death) and increasing concentrations of soluble mesothelin to study the impact of the mesothelin/MUC16 interaction of Meso-TR3. B, OVCAR3 cells were challenged with a constant amount of Meso-TR3 (90% specific cell death) and increasing concentrations of DR5-Fc to verify involvement of the extrinsic death pathway as a mechanism of Meso-TR3 killing. C, OVCAR3 cells were treated with a constant amount of Meso-TR3 (75% specific cell death) in the presence of Z-VAD-FMK, a pan-caspase inhibitor, vital mediators of apoptosis. Cells treated with DMSO were used as a control. P < 0.001 (one-way ANOVA). D, MUC16-deficient Jurkat cells were treated with low dose Meso-TR3 (33% specific cell death) in the presence of anti-mesothelin mAb. Cells treated with anti-mesothelin Ab alone served as a control. P < 0.0019 (Student’s t-test). Error bars, mean ± SD. Results are representatives of at least 2 independent experiments done in triplicates.