背景介绍 The binding of Programmed Cell Death Protein 1 (PD-1), a receptor expressed on activated T cells, to its ligands, PD-L1 and PD-L2, negatively regulates immune responses. The PD-1 ligands are found on most cancers, and PD-1:PD-L1/2 interaction inhibits T cell activity and allows cancer cells to escape immune surveillance. The PD-1:PD-L1/2 pathway is also involved in regulating autoimmune responses, making these proteins promising therapeutic targets for a number of cancers, as well as multiple sclerosis, arthritis, lupus, and type I diabetes. 产品介绍 The recombinant expression vectors are designed to express human engineered T cell receptor (TCR) activator and human PD-L2 (GenBank Accession #NM_025239) in mammalian cells. The transfected cells can be used in conjunction with PD-1/NFAT Reporter/Jurkat T cells (BPS #60535) to study the interactions of PD-1 with PD-L2 ligand in a cellular context and screen for modulators of this signaling pathway. In this assay, PD-1/NFAT Reporter/Jurkat T cells are used as effector cells; HEK293 cells overexpressing PD-L1 (or PD-L2) and an engineered T cell receptor (TCR) activator are used as target cells. When these two cells are co-cultivated, TCR complexes on effector cells are activated by TCR activator on target cells, resulting in expression of the NFAT luciferase reporter. However, PD1 and PD-L1 or PD-L2 ligation prevents TCR activation and suppresses the NFAT-responsive luciferase activity. This inhibition can be specifically reversed by anti-PD1 or anti-PD-L1 antibodies. PD1, PD-L1, or PD-L2 neutralizing antibodies block PD1:PD-L1 and/or PD1:PD-L2 interaction and promote T cell activation, resulting in reactivation of the NFAT responsive luciferase reporter.