Anti-Human PD-L1 (CD274) (Clone 29E.2A3) - Dylight® 650 (P607-GRP)

Programmed cell death 1 ligand 1 (PD-L1; CD274; B7-H1) is a type I transmembrane glycoprotein widely expressed in many types of tissues that acts as a ligand for the immune inhibitory receptor programmed cell death 1 (PD-1; CD279)1, 2, 3. The PD-1 pathway is responsible for T cell activation, proliferation, and cytotoxic secretion, with PD-1/PD-L1 interaction triggering inhibitory signals that dampen T cell function. PD-L1 also plays a critical role in the differentiation of inducible regulatory T cells4. In normal tissues, PD-L1/PD-1 ligation is crucial to maintaining homeostasis of the immune system and preventing autoimmunity during infection and inflammation4. In the tumor microenvironment, their interaction provides an immune escape mechanism for tumor cells by turning off cytotoxic T cells. As such, blocking the PD-L1/PD-1 interaction is a target of many anti-cancer immunotherapies. 29E.2A3 was generated by immunizing female BALB/c mice with purified hPD-L1 cDNA5. Spleen cells were fused with SP2/0 myeloma cells, and the resulting hybridomas were screened by ELISA for reactivity against hPD-L1–Ig fusion protein followed by cell-surface staining of hPD-L1–transfected Chinese hamster ovary cells and 300.19 cells.