Source

Human B7-1, Fc Tag (H-B7-1-2) is expressed from human 293 cells (HEK293). It contains AA Val 35 - Asn 242 (Accession # NP_005182.1).

Predicted N-terminus: Val 35

Molecular Characterization

This protein carries a human IgG1 Fc 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 50 mM Tris, 100 mM Glycine, pH7.5. 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

B7\xad1 and B7\xad2, together with their receptors CD28 and CTLA\xad4, constitute one of the dominant co-stimulatory pathways that regulate T\xad and B\xadcell responses. Although both CTLA\xad4 and CD28 can bind to the same ligands, CTLA\xad4 binds to B7\xad1 and B7\xad2 with a 20 \xad 100 fold higher affinity than CD28 and is involved in the down\xadregulation of the immune response.\rB-lymphocyte activation antigen B7-1 (referred to as B7) also known as cluster of Differentiation 80 (CD80), is a member of cell surface immunoglobulin superfamily and is expressed on activated B cells, activated T cells, macrophages and dendritic cells. It is the ligand for two different proteins on the T cell surface: CD28 (for autoregulation and intercellular association) and CTLA-4 (for attenuation of regulation and cellular disassociation). CD80 works in tandem with CD86 to prime T cells. CD80 plays a role in induction of innate immune responses by activating NF-κB-signaling pathway in macrophages. CD80 is thus regarded as promising therapeutic targets for autoimmune diseases and various carcinomas.

Reference

(1) Peach RJ., et al., 1995, J. Biol. Chem. (UNITED STATES) 270 (36): 21181–7.

(2) Stamper CC., et al., 2001, Nature (England) 410 (6828): 608–11.

(3) Bhatia S., et al., 2005, Proc. Natl. Acad. Sci. 102: 15569-15574.

(4) Khan N., et al., 2007, Int. Immunol. 19:477-486.