Schematic representation of the blockade bioassays for PD-1/PD-L1, TIGIT/CD155 and PD-1 + TIGIT. Each bioassay consists of a T effector cell (expressing PD-1, TIGIT or PD-1 + TIGIT) and an aAPC cell (expressing PD-L1, CD155 or PD-L1 + CD155), respectively. Co-culture of a T effector cell with its corresponding aAPC cell leads to three events as noted in the cell image.

PD-1 Effector Cells and PD-L1 aAPC Cells were incubated for 6 hr at 37°C with increasing concentrations of either an anti-PD-1, PD-L1, or CTLA-4 antibody. The anti-PD-1 and PD-L1 antibodies, but not the anti-CTLA-4 antibody, blocked the immune checkpoint inhibitory signal resulting in luciferase activity. Data were analyzed using a 4PL model and GraphPad® Prism software.

PD-1 Effector Cells and PD-L1 aAPC Cells were incubated with increasing concentrations anti-PD-L1 antibody preparations representing a 50-200% potency range. The PD-1/PD-L1 Blockade Bioassay demonstrated appropriate rank ordering of antibody potency.

PD-1 Effector Cells and PD-L1 aAPC Cells were incubated with increasing concentrations of anti-PD-L1 antibody preparations representing 100% potency. The PD-1/PD-L1 Blockade Bioassay was reproducible across four independent 96-well plates.