Anti-Human CD274 (PD-L1) (Clone CPTC-CD274-1) — Purified No Carrier Protein

Synthetic peptide NIIQFVHGEEDLK

This recombinant monoclonal antibody is aseptically packaged and formulated in 0.01 M phosphate buffered saline (150 mM NaCl) PBS pH 7.2 - 7.4 with no carrier protein, potassium, calcium or preservatives added. Due to inherent biochemical properties of antibodies, certain products may be prone to precipitation over time. Precipitation may be removed by aseptic centrifugation and/or filtration.

Liquid

Recombinant antibodies are manufactured in an animal free facility using only in vitro protein free cell culture techniques and are purified by a multi-step process including the use of protein A or G to assure extremely low levels of endotoxins, leachable protein A or aggregates.

This antibody may be stored sterile as received at 2-8°C for up to one month. For longer term storage, aseptically aliquot in working volumes without diluting and store at ≤ -70°C. Avoid Repeated Freeze Thaw Cycles.

Research Use Only

2 – 8° C Wet Ice

EB0103A-1H5-H3/K4 activity is directed against human CD274 (PD-L1).

CPTC-CD274-1

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.

EB0103A-1H5-H3/K4 was generated in rabbit for use in immuno-MRM assays using a synthetic peptide derived from residues 63-75 of human CD274, NIIQFVHGEEDLK⁵. EB0103A-1H5- H3/K4 detects CD274 by Western blotting as recombinant protein or in whole cell lysates of Jurkat or MCF7 cell lines⁶. EB0103A-1H5-H3/K4 does not detect CD274 by immunohistochemistry, immunofluorescence, or reverse phase protein array.

https://antibodies.cancer.gov/detail/CPTC-CD274-1#CPTC-CD274-1

PD-L1 is commonly expressed on the surface of antigen presenting cells (macrophages, activated B cells, dendritic cells), some epithelial cells under inflammatory conditions, some activated T cells, and several types of tumors as well as tumor infiltrating immune cells. PD-L1 can also exist in a soluble form (sPD-L1) in myeloid-derived cells (monocytes, macrophages, and dendritic cells) and several human cancer lines.

PD-1 (PDCD1; CD279), CMTM4, CMTM6, (phosphorylated) STAT3, CD80

1 Freeman GJ, Long AJ, Iwai Y, et al. J Exp Med. 2000192(7):1027-1034. 2000.
2 Tsai KK, Zarzoso I, Daud AI. Hum Vaccin Immunother. 10(11):3111-3116. 2014.
3 Han Y, Liu D, Li L. Am J Cancer Res. 10(3):727-742. 2020.
4 Dermani FK, Samadi P, Rahmani G, et al. J Cell Physiol. 234(2):1313-1325. 2019.
5 Whiteaker JR, Lundeen RA, Zhao L, et al. Front Immunol. 12:765898. 2021.
6 https://antibodies.cancer.gov/detail/CPTC-CD274-1