• Purity

  >90%, by SDS-PAGE under reducing conditions and visualized by silver stain.

• Endotoxin Level

  <0.10 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its ability to induce IL-2 secretion by Jurkat human acute T cell leukemia cells. Freeman, G.J.     et al. (1993) Science     262:909. The ED    ₅₀ for this effect is 5‑30 ng/mL in the presence of PHA.

• Source

  Mouse myeloma cell line, NS0-derived

  Mouse B7-1 (Asp37-Lys245) Accession # Q00609	DIEGRMD	Human IgG1 (Pro100-Lys330)	6-His tag
  N-terminus			C-terminus

• Accession #

• N-terminal Sequence    
  Analysis

  Asp37

• Structure / Form

  Disulfide-linked homodimer

• Predicted Molecular Mass

  51.3 kDa (monomer)

• SDS-PAGE

  80-90 kDa, reducing conditions

Background: B7-1/CD80

B7-1/CD80 and B7-2/CD86, together with their receptors CD28 and CTLA-4, constitute one of the dominant co-stimulatory pathways that regulate T- and B-cell responses (1). Although both CTLA-4 and CD28 can bind to the same ligands, CTLA-4 binds to B7-1 and B7-2 with a 20-100 fold higher affinity than CD28 and is involved in the down-regulation of the immune response (2-6). Mature mouse B7-1 consists of a 209 amino acid (aa) extracellular domain (ECD) with two immunoglobulin-like domains, a 22 aa transmembrane segment, and a 38 aa cytoplasmic domain (7). Within the ECD, mouse B7-1 shares 50% and 68% aa sequence identity with human and rat B7-1, respectively. Alternative splicing generates a short isoform that lacks the second Ig-like domain but retains the ability to bind CD28 (8). Both human and mouse B7-1 and B7-2 can bind to either human or mouse CD28 and CTLA-4 (1). B7-1 is expressed on activated B cells, activated T cells, and macrophages. B7-2 is constitutively expressed on interdigitating dendritic cells, Langerhans cells, peripheral blood dendritic cells, memory B cells, and germinal center B cells (2).

• References:

1. Ville, S. et al. (2015) Front. Immunol. 6:411.

2. Azuma, M. et al. (1993) Nature 366:76.

3. Freeman, G.J. et al. (1993) Science 262:909.

4. Chen, C. et al. (1994) J. Immunol. 152:4929.

5. Freeman, G.J. et al. (1993) J. Exp. Med. 178:2185.

6. Lanier, L. et al. (1995) J. Immunol. 154:97.

7. Freeman, G. et al. (1991) J. Exp. Med. 174:625.

8. Inobe, M. et al. (1994) Biochem. Biophys. Res. Commun. 200:443.

• Entrez Gene IDs:

  941 (Human); 12519 (Mouse); 25408 (Rat); 102140078 (Cynomolgus Monkey)

• Alternate Names:

  Activation B7-1 antigen; B7; B71; B7-1; BB1; CD28LG1; CD28LGB7-1 antigen); CD80 antigen; CD80 molecule; CD80; costimulatory factor CD80; costimulatory molecule variant IgV-CD80; CTLA-4 counter-receptor B7.1; T-lymphocyte activation antigen CD80