Programmed death-1 (PD-1), also known as CD279, is another important negative costimulatory molecule. It is a protein in humans that is encoded by PDCD1 gene.
Ligands of PD-1
The ligands of PD-1 include: PD-L1 (B7-H1, CD274) and PD-L2 (B7-H2, CD273). The affinity between PD-L2 and PD-1 is 2-6 times that of PD-L1, but PD-L1 is the main ligand of PD-1, which is highly expressed in various malignant tumors. Both ligands are located on the human chromosome 9p24 and share similar extracellular domains. The homology of PD-L1 and PD-L2 is 40%.
PD-1 and its ligands belong to the CD28/B7 superfamily.
PD-L1/PD-1 Signaling Pathway
PD-1 binds with its main ligand PD-L1 to form the PD-1/PD-L1 signaling pathway. The process of the pathway is as follows: After PD-1 binds to its ligand PD-L1, tyrosine in the ITSM domain of PD-1 cytoplasmic region is phosphorylated, and SHP2 phosphatase molecules are recruited to cell membrane. These phosphatases dephosphorylate TCR receptor-associated signaling molecules ZAP70, PKCθ, and CD3ζ near the membrane, thereby inhibiting TCR/CD28 signaling. PD-1 signaling also inhibits CD28 - mediated PI3K activation, thereby reducing Akt phosphorylation and glucose metabolism.
The Function of PD-L1/PD-1 Signaling Pathway
PD-L1/PD-1 signaling pathway regulates T cell activation and inhibits the body's immune response. This makes it play an important protective role in regulating autoimmune tolerance and autoimmune diseases. However, its immunosuppressive effect is also an important factor causing chronic infection and tumor escape.
Research on PD-1 Targeting Drugs in Diseases
Current monoclonal antibodies for PD-1 include nivolumab and pembrolizumab. Targeting PD-1 has been applied in many diseases.
More Interesting read related PD-1-- An Important Immune Checkpoint
● Recombinant Human Programmed cell death protein 1(PDCD1),partial (Active) CSB-MP619964HU1
(Tris-Glycine gel) Discontinuous SDS-PAGE (reduced) with 5% enrichment gel and 15% separation gel.
Activity: ①Measured by its binding ability in a functional ELISA. Immobilized PD-1 at 2 μg/ml can bind Anti-PD-1 recombinant antibody, the EC50 of human PD-1 protein is 6.087-7.854 ng/ml.
Activity: ②Measured by its binding ability in a functional ELISA. Immobilized PD-1 at 2 μg/ml can bind Nivolumab, the EC50 of human PD-1 protein is 9.713-12.39 ng/ml.
● PDCD1 Recombinant Monoclonal Antibody CSB-RA240597A0HU
Positive WB detected in: MCF-7 whole cell lysate.
All lanes: PD1 antibody at 1:2000.
Goat polyclonal to rabbit IgG at 1/50000 dilution,
Predicted band size: 32 KDa,
Observed band size: 32 kDa.
IHC image of CSB-RA240597A0HU diluted at 1:100 and staining in paraffin-embedded human tonsil tissue performed on a Leica BondTM system. After dewaxing and hydration, antigen retrieval was mediated by high pressure in a citrate buffer (pH 6.0). Section was blocked with 10% normal goat serum 30min at RT. Then primary antibody (1% BSA) was incubated at 4°C overnight. The primary is detected by a Goat anti-rabbit IgG polymer labeled by HRP and visualized using 0.05% DAB.