This non-therapeutic biosimilar antibody uses the same variable regions from the therapeutic antibody Pembrolizuma making it ideal for research use.This Pembrolizumab biosimilar reats with human PD-1（programmed death-1）also known as CD 279。PD-1is a50-55kDa cell surface receptor encoded by the Pdcdcd1gene that belongs to the CD28family of the Ig superfamily.PD-1is transiently expressed on CD4and CD8thymocytes as well as activated T and velymphocytes and myeloid cells.PD-1expression declines after successfuinal in in in in in in of Addigations cd1mRNA is expressed in developing B lymphocytes during the pro-B-cell stage.PD-1’s structure includes a ITIM（immunoreceptor tyrosine-based inhibitory motif）suggesting that PD-1negatively regulates TCR signals。PD-1signals via binding its two ligands，PD-L1and PD-L2both members of the B7family.Upon ligand binding，PD-1signaling inhibits T-cell activation，leading to reduced proliferation，cytokine production，and T-cell death.Additionally，PD-1is know to play proliferation，cytokine production production，T-cel death.Additionaly to plance of opertivance immune disease.Induced PD-L1expression is common in many tumors including squamous cell carcinoma，colon adenocarcinoma，and breast adenocarcinoma.PD-L1overexpression ression ressults in inincreased resistance of tumor cells to CD8T cell mediated lysis.PD-L1overexpression ression ressults in ininincreased ressistance of tumor cells in increds in incells eds in in increds extis in increds in in in increased excells exted extis in in in in in in in in in in in eds in in in in in in in in in in in imental models of melanoma单击功能区上，tumor growth can be transiently arrested via treatment with antibodies which block the interaction between PD-L1and its receptor PD-1.For these reasons anti-PD-1mediated immunotherapies are currently being used ascancer treatments.Pembrolizumab binds to PD-1onactived immucelly-1 with its ligands。
Yu W，He J，Wang F，He Q，Shi Y，Tao X，Sun B.（2023）。“NR4A1mediates NK-cell dysfunction in hepatocellular carcinoma via the IFN-γ/p-STAT1/IRF1pathway”Immunology169（1）：69-82。PubMed
Hepatocellular carcinoma（HCC）is one of the most fatal tumours worldwide and has a high recurrence rate。Nevertheless，the mechanism of HCC genesis remains partly unexplored，while the efficiency of HCC treatments remains limited.The present study analysed the expression of nuclear receptor subfamily4 group A member1 bearing mouse models，as well as the features of NR4A1high and NR4A1low NK cells.In addition，knockout of NR4A1by CRISPR/Cas9and adoptive transfer experiments were applied to verify the function of NR4A1in both tumour-infiltrating NK cells and anti-PD-1therapy.The present study fouth tumour-infiltrating NK cells and antifilify expressed in tumour-infiltrating NK cells，which mediated the dysfunction of tumour-infiltrating NK cells by regulating the IFN-γ/p-STAT1/IRF1signalling pathway.Knockout of NR4A1in NK cells not only restored the antitumour function of NK cells but also enhanced the efficicacy of anti-PD-1therapy.The repgront fings NR4A1in the immune progress of NK cells against HCC，which may provide a new direction for immunotherapies of HCC。
