Recombinant Human CD274 protein(Met1-Thr239), His-tagged

• Cat.No.: CD274-592H
• Product Overview: Recombinant Human B7-H1 (NP_054862.1)(Met 1-Thr 239) was expressed in HEK293 with a C-terminal polyhistidine tag.

Specification

• Species: Human
• Source: HEK293
• Tag: His
• Protein Length: 1-239 a.a.
• Form: Lyophilized from sterile PBS, pH 7.4. Normally 5 % - 8 % trehalose, mannitol and 0.01% Tween80 are added as protectants before lyophilization.
• Bio-activity: 1. Measured by its binding ability in a functional ELISA. Immobilized human B7-H1 at 20 μg/ml (100 μl/well) can bind human PD1 with a linear range of 0.032-0.8 μg/ml. 2. Using the Octet RED System, the affinity constant (Kd) of PD-1 Protein, Human, Recombinant (Fc Tag) bound PD-L1 Protein, Human, Recombinant (His Tag) was 19.2nM.
• Molecular Mass: The recombinant mature human B7-H1 comprises 232 amino acids and predicts a molecular mass of 26.8 kDa. As a result of glycosylation, the human B7-H1 migrates as an approximately 35-38 kDa protein in SDS-PAGE under reducing conditions.
• Endotoxin: < 1.0 EU per μg of the protein as determined by the LAL method
• Purity: > 95 % as determined by SDS-PAGE
• Storage: Samples are stable for up to twelve months from date of receipt at -20°C to -80°C. Store it under sterile conditions at -20°C to -80°C. It is recommended that the protein be aliquoted for optimal storage. Avoid repeated freeze-thaw cycles.
• Reconstitution: It is recommended that sterile water be added to the vial to prepare a stock solution of 0.2 ug/ul. Centrifuge the vial at 4°C before opening to recover the entire contents.

Gene Information

• Gene Name: CD274 CD274 molecule [ Homo sapiens ]
• Official Symbol: CD274
• Synonyms: CD274; CD274 molecule; CD274 antigen , PDCD1LG1, programmed cell death 1 ligand 1; programmed cell death 1 ligand 1; B7 homolog 1; B7 H; B7 H1; B7H1; PD L1; PDL1; CD274 antigen; PDCD1 ligand 1; programmed death ligand 1; B7-H; PD-L1; PDCD1L1; PDCD1LG1; MGC142294; MGC142296
• Gene ID: 29126
• mRNA Refseq: NM_014143
• Protein Refseq: NP_054862
• MIM: 605402
• UniProt ID: Q9NZQ7

Case Study

Case 1: Li H, et al. J Transl Med. 2024

In gastric cancer, myeloid-derived suppressor cells (MDSCs) significantly assist tumors in dodging the immune system. A study involving 90 patients found that those with higher levels of exosomal PD-L1 had worse survival rates, as these levels boost the number of MDSCs. This increase happens because exosomal PD-L1 activates the IL-6/STAT3 pathway, leading to more MDSC proliferation. Tests confirmed that these exosomes support tumor growth and immune evasion by boosting MDSCs.

Fig1. Western blotting analysis of the PD-L1 content in GC cells and exosome from the culture supernatant of GC cells.

Fig2. Percentages of MDSCs (CD45 + CD11b + Gr1+) and PD-L1 + MDSCs in tumors determined via flow cytometry.

Case 2: Agborbesong E, et al. Cells. 2024

The primary cilium, a sensory structure on most cells, is linked to diseases if defective. While related to immune synapses, the role of immune components in cilia formation isn't well-known. This study reveals that PD-L1, a protein usually involved in immune function, also affects ciliogenesis. It's present in crucial cell areas and, when depleted, enhances cilia growth and the presence of essential cilia proteins. PD-L1 interacts with proteins like BBS5 and PC-2, playing a role in sensory signaling.

Fig1. Western blot analysis indicating the differential expression of PD-L1 in fibroblast and epithelial cells.

Fig2. Quantitative data of PC-2-positive cilia in PD-L1 siRNA knockdown NIH3T3 cells compared to control siRNA cells.

Application

CD274, or PD-L1, is an important player in the immune system. It works by binding to PD-1, which helps regulate T cell activity, maintaining immune balance. This interaction not only supports immune tolerance but also lets tumors hide from immune attacks. In research, scientists use recombinant CD274 protein to study how it partners with PD-1 to influence immune responses and to understand its involvement in autoimmune diseases. Blocking the CD274/PD-1 pathway can help restore immune balance, making it a significant focus in tumor immunology where CD274 is often highly expressed on cancer cells, helping them escape immune attacks. This pathway is a target in cancer treatments to reactivate T cell responses. Recombinant CD274 also plays a role in cell culture and functional studies, providing insights into how it affects T and B cell activation and differentiation. Its involvement in infectious diseases, like being a biomarker in HIV progression, is another area of study. Furthermore, CD274 is crucial in developing antibodies for various experimental techniques, allowing scientists to detect its levels in cells and tissues. Industrially, recombinant CD274 is produced in mammalian cells to ensure high purity, aiding in diagnostic test development, such as ELISA standards for measuring CD274 in tumors or infections. It's instrumental in drug development too, with its immune-regulating ability via the CD274/PD-1 pathway forming the basis for creating checkpoint inhibitors, such as PD-1/PD-L1 antibodies, which are effective in treating several cancers. Overall, recombinant CD274 is a valuable tool in research and industry, especially in immune regulation, cancer immunotherapy, and drug development.

Fig1. Schematic diagram of the effect of exosomal PD-L1 on tumor microenvironment. (Lingxiao Ye, 2021)