PD-1:PD-L1 Cell-Based Inhibitor Screening Assay Kit

The PD-1:PD-L1 Cell-Based Inhibitor Screening Assay is a bioluminescent cell-based assay for screening and profiling inhibitors of the PD-1:PD-L1 interaction. The assay consists of two main components: effector cells and expression vectors encoding TCR activator and human PD-L1. Growth-Arrested PD-1 Effector Cells (PD-1/NFAT Reporter Jurkat cells) are Jurkat cells expressing   firefly luciferase, under the control of NFAT response elements, and human PD-1.  These cryopreserved cells are provided in a thaw-and-use format that does not require cell propagation. These cells cannot be expanded and are intended to be single use. The expression vectors for TCR Activator and human PD-L1 are transfection-ready vectors that can be used to transfect cells and create target cells that overexpress PD-L1 and an engineered cell surface T cell receptor (TCR) activator. The kit contains enough cells and plasmids for 100 assays if using a 96-well plate.Figure 1: Illustration of the principle ofthe PD-1:PD-L1 Cell-Based Inhibitor Screening Assay.Jurkat T cells expressing NFAT reporter with constitutive expression of PD-1 (PD-1/NFAT Reporter Jurkat Cells) act as effector cells. When co-cultivated, TCR complexes on PD-1/NFAT Reporter Jurkat cells are activated by the TCR activator expressed in the transfected cell line of interest, resulting in expression of the NFAT luciferase reporter. However, PD-1 and PD-L1 ligation prevents TCR activation and suppresses the NFAT-responsive luciferase activity. This inhibition can be specifically reversed by anti- PD-1 or anti-PD-L1 antibodies. Neutralizing antibodies block PD-1:PD-L1 interaction  and result in reactivation of the NFAT responsive luciferase reporter.