• Species Reactivity

  Human

• Specificity

  Detects human CTLA-4 in direct ELISAs and Western blots. Shows approximately 10% cross-reactivity with recombinant mouse CTLA-4 and no cross-reactivity with recombinant human (rh) CD28 or rhICOS.

• Source

  Monoclonal Mouse IgG    _2B Clone # 48815

• Purification

  Protein A or G purified from hybridoma culture supernatant

• Immunogen

  S. frugiperda insect ovarian cell line     Sf 21-derived recombinant human CTLA-4    
  Ala37-Phe162 (Thr174Ala)    
  Accession # Q6GR94

• Formulation

  Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose. *Small pack size (SP) is supplied as a 0.2 µm filtered solution in PBS.

• Label

  Unconjugated

Applications

• Recommended    
  Concentration

  Sample

• Western Blot

  1 µg/mL

  Recombinant Human CTLA‑4 Fc Chimera (Catalog # )

• 
  

Please Note: Optimal dilutions should be determined by each laboratory for each application.  are available in the Technical Information section on our website.

Preparation and Storage

• Reconstitution

  Reconstitute at 0.5 mg/mL in sterile PBS.

• Shipping

  The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below. *Small pack size (SP) is shipped with polar packs. Upon receipt, store it immediately at -20 to -70 °C

• Stability & Storage

  Use a manual defrost freezer and avoid repeated freeze-thaw cycles.    

• 12 months from date of receipt, -20 to -70 °C as supplied.

• 1 month, 2 to 8 °C under sterile conditions after reconstitution.

• 6 months, -20 to -70 °C under sterile conditions after reconstitution.

Background: CTLA-4

CTLA-4 and CD28, together with their ligands B7-1 and B7-2, constitute one of the dominant costimulatory pathways that regulate T- and B-cell responses. CTLA-4 and CD28 are structurally homologous molecules that are members of the immunoglobulin (Ig) gene superfamily. Both CTLA-4 and CD28 are composed of a single Ig V‑like extracellular domain, a transmembrane domain and an intracellular domain. CTLA-4 and CD28 are both expressed on the cell surface as disulfide-linked homodimers or as monomers. The genes encoding these two molecules are closely linked on human chromosome 2. CTLA-4 was originally identified as a gene that was specifically expressed by cytotoxic T lymphocytes. However, CTLA-4 transcripts have since been found in both Th1 and Th2, and CD4⁺ and CD8⁺ T cell clones. Whereas CD28 expression is constitutive on the surfaces of 95% of CD4⁺ T cells and 50% of CD8⁺ T cells and is down regulated upon T cell activation, CTLA-4 expression is upregulated rapidly following T cell activation and peaks approximately 24 hours following activation. Although both CTLA-4 and CD28 can bind to the same ligands, CTLA-4 binds to B7-1 and B7-2 with 20-100-fold higher affinity than CD28. The physiological role of CTLA-4 in T cell costimulation is currently being studied. Recombinant human CTLA-4 Fc chimera preparations produced at R&D Systems have been shown to bind both B7-1 and B7-2 with high affinity and to inhibit CD 28 signalling competitively.

• References:

1. Lenschow, D.J. et al. (1996) Annu. Rev. Immunol. 14:233.

2. Hathcock, K.S. and R.J. Hodes (1996) Advances in Immunol. 62:131.

3. Ward, S.G. (1996) Biochem. J. 318:361.

• Long Name:

  Cytotoxic T-lymphocyte-associated Molecule 4

• Entrez Gene IDs:

  1493 (Human); 12477 (Mouse); 403696 (Canine); 102115124 (Cynomolgus Monkey)

• Alternate Names:

  CD; CD152 antigen; CD152; CD152IDDM12; CD28; celiac disease 3; CELIAC3; CTLA4; CTLA-4; cytotoxic T-lymphocyte antigen 4; cytotoxic T-lymphocyte protein 4; Cytotoxic T-lymphocyte-associated antigen 4; cytotoxic T-lymphocyte-associated protein 4; cytotoxic T-lymphocyte-associated serine esterase-4; GRD4; GSE; ICOS; ligand and transmembrane spliced cytotoxic T lymphocyte associated antigen 4