Objective

•      The blockade of immune checkpoints is a promising approach to activate therapeutic antitumor immunity. It is now clear that tumors co-opt certain immune-checkpoint pathways as a major mechanism of immune resistance, particularly against T cells that are specific for tumor antigens. Because many of the immune checkpoints are initiated by ligand–receptor interactions, they can be readily blocked by antibodies or modulated by recombinant forms of ligands or receptors.

•      It is the soluble and membrane-bound receptor–ligand immune checkpoints that are the most druggable targets using agonist (for co-stimulatory pathways) or antagonist (for inhibitory pathways). Antibodies or small molecules that block immune checkpoints target lymphocyte receptors or their ligands to regulate T cell activation.

•      This poster illustrates the binding and blocking assays using Cisbio HTRF® platform on a panel of immune checkpoints (PD1/PDL1, CTLA4/CD80, CTLA4/CD86, LAG3/MHCII, TIM3/GAL9, CD47/SIRPa, OX40/OX40L and A2aR/Adenosine). Using a simple mix-and- read protocol, these assays are a rapid alternative to traditional methods such as ELISA and SPR.