Source

Human PD-L1, His Tag (H-PDL1-1) is expressed from human 293 cells (HEK293). It contains AA Phe 19 - Arg 238 (Accession # NP_054862.1 ).

Predicted N-terminus: Phe 19

Molecular Characterization

This protein carries a polyhistidine tag at the C-terminus.

Endotoxin

Less than 0.01 EU/mg by the LAL method.

Purity

>95% as determined by SDS-PAGE.

Bioactivity

ELISA ；

BIACORE (With our Research Grade Biosimilar Antibody products);

Formulation

Lyophilized from 0.22 μm filtered solution in PBS, pH7.4. Normally trehalose is added as protectant before lyophilization.

Reconstitution

Please see Certificate of Analysis for specific instructions.

For best performance, we strongly recommend you to follow the reconstitution protocol provided in the CoA.

Storage

For long term storage, the product should be stored at lyophilized state at -20°C or lower.

Please avoid repeated freeze-thaw cycles.

No activity loss was observed after storage at:

4-8°C for 12 months in lyophilized state;

-70°C for 3 months under sterile conditions after reconstitution.

Background

Programmed cell death 1 ligand 1 (PD-L1) is also known as cluster of differentiation (CD274) or B7 homolog 1 (B7-H1), is a member of the growing B7 family of immune molecules and is involved in the regulation of cellular and humoral immune responses. B7-H1 is a cell surface immunoglobulin superfamily with two Ig-like domains within the extracellular region and a short cytoplasmic domain. PD-L1 is highly expressed in the heart, skeletal muscle, placenta and lung and weakly expressed in the thymus, spleen, kidney and liver. PD-L1 is expressed on activated T-cells, B-cells, dendritic cells, keratinocytes and monocytes. PD-L1 is up-regulated on T- and B-cells, dendritic cells, keratinocytes and monocytes after LPS and IFNG activation and up-regulated in B-cells activated by surface Ig cross-linking. PD-L1 involve in the costimulatory signal, essential for T-cell proliferation and production of IL10 and IFNG, in an IL2-dependent and a PDCD1-independent manner.

Reference

(1) Dong H., et al., 1999, Nat. Med. 5:1365-1369.

(2) Freeman G.J., et al., 2000, J. Exp. Med. 192:1027-1034.

(3) Nishimura H., et al., 2001, Trends in Immunology 22:265.