Immune Checkpoint Bioassays to Characterize Immune-Modulating Antibodies
The human immune system is comprised of a complex network of co-inhibitory and co-stimulatory pathways that facilitate the elimination of cells expressing foreign antigens while maintaining tolerance to self antigen. Immune checkpoint pathways mediated by PD-1, CTLA-4, GITR, 4-IBB, OX4-O and TIGIT are promising immunotherapy targets for the treatment of cancer and autoimmunity. Immunotherapy agents that target combinations of these pathways (e.g., PD-1 and TIGIT) are particularly promising. Immune checkpoint reporter-based bioassays provide a simple, consistent and reliable cell-based assay to measure antibody function throughout the drug research and development pipeline.
Measure Antibody efficacy to block immune checkpoint inhibitory signals. Disruption of the receptor-ligand interaction induces luciferase activity.
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.
The performance characteristics of the PD-1/PD-L1 Blockade Bioassay are suitable for many applications of a bioassay used across antibody drug discovery research: It is specific, accurate over a relative potency range of 50-200%, and reproducible.
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.
Bioassay | Cell Components | Catalog or CS# | ||
---|---|---|---|---|
PD-1/PD-L1 Blockade Bioassay Kit¹ | PD-1 Effector Cells (Jurkat) PD-L1 aAPC Cells (CHO-K1)² |
J1250 | ||
PD-1/PD-L1 Blockade Bioassay Kit (5X) | PD-1 Effector Cells (Jurkat) PD-L1 aAPC Cells (CHO-K1) |
J1255 | ||
PD-L1 Negative Cells³ | PD-L1 Negative aAPC Cells (CHO-K1) | J1191 | ||
PD-L1 Negative Cells (5X)³ | PD-L1 Negative Cells (5X)³ | J1195 |
Bioassay | Cell Components | Catalog or CS# | ||
---|---|---|---|---|
PD-1/PD-L2 Blockade Bioassay Kit¹ | PD-1 Effector Cells (Jurkat) | CS187131-1 | ||
PD-1/PD-L2 Blockade Bioassay Kit¹, 5X | PD-L2 Cells (CHO-K1)² | CS187135-1 | ||
PD-1/PD-L2 Blockade Bioassay, Propagation Model |
NA | CS187127 |
Bioassay | Cell Components | Catalog or CS# | ||
---|---|---|---|---|
CTLA-4 Blockade Bioassay Kit¹ | CTLA-4 Effector Cells (Jurkat) aAPC Cells (Raji)² |
CS186920 | ||
CTLA-4 Blockade Bioassay Kit (5X) | CTLA-4 Effector Cells (Jurkat) aAPC Cells (Raji) |
CS186926 | ||
Control Ab, Anti-CTLA-4 | NA | CS186915 |
Bioassay | Cell Components | Catalog or CS# | ||
---|---|---|---|---|
TIGIT/CD155 Blockade Bioassays | TIGIT Effector Cells (Jurkat) CD155 aAPC Cells (CHO-K1)² |
CS198807 | ||
TIGIT/CD155 Blockade Bioassay Kit¹ | TIGIT Effector Cells (Jurkat) CD155 aAPC Cells (CHO-K1)² |
CS198811 |
Bioassay | Cell Components | Catalog or CS# | ||
---|---|---|---|---|
PD-1 + TIGIT Combination Bioassay Kit | PD-1 + TIGIT Effector Cells (Jurkat) PD-L1 + CD155 aAPC Cells (CHO-K1)² |
CS198813 | ||
PD-1 + TIGIT Combination Bioassay Kit | PD-1 + TIGIT Effector Cells (Jurkat) PD-L1 + CD155 aAPC Cells (CHO-K1)² |
CS198817 |
Bioassay | Cell Components | Catalog or CS# | ||
---|---|---|---|---|
GITR Bioassay | GITR Effector Cells (Jurkat) | CS184003 | ||
CD40 Bioassay | CD40 Effector Cells (Ramos) PD-L1 + CD155 aAPC Cells (CHO-K1)² |
CS193701 | ||
4-1BB Bioassay | 4-1BB Effector Cells (Jurkat) | CS196002 | ||
OX40 Bioassay | OX40 Effector Cells (Jurkat) | CS197701 |