Key Product Details
Structure / Form
|Human CTLA-4 (Ala37-Phe162)
Accession # Q6GR94
N-terminal Sequence Analysis
Predicted Molecular Mass
The ED50 for this effect is 0.1-0.4 µg/mL when stimulated with 1 µg/mL Recombinant Human B7‑1/CD80 Fc Chimera (Catalog #
140-B1) in the presence of PHA.
Scientific Data Images for Recombinant Human CTLA-4 Fc Chimera His-tag Protein, CF
Recombinant Human CTLA-4 Fc Chimera His-tag Protein BioactivityRecombinant Human CTLA-4 Fc Chimera (Catalog # 325-CT/CF) inhibits IL-2 secretion by stimulated Jurkat human acute T cell leukemia cells. The ED50 for this effect is 0.1-0.4 µg/mL when stimulated with 1 µg/mL Recombinant Human B7-1 Fc Chimera (Catalog # 140-B1) in the presence of PHA.
Recombinant Human CTLA-4 Fc Chimera His-tag Protein SDS-PAGE1 μg/lane of Recombinant Human CTLA-4 Fc Chimera was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by silver staining, showing single bands at 51 kDa and 94 kDa, respectively .
Formulation, Preparation and Storage
|Formulation||Lyophilized from a 0.2 μm filtered solution in PBS.|
|Reconstitution||Reconstitute at 200 μg/mL in sterile PBS.|
|Shipping||The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.|
|Stability & Storage||Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
CTLA-4 (cytotoxic T-lymphocyte-4, designated CD152), is a type I transmembrane T cell inhibitory molecule that is a member of the Ig superfamily (1, 2). Human or mouse CTLA-4 cDNA encodes 223 amino acids (aa) including a 35 aa signal sequence, a 126 aa extracellular domain (ECD) with one Ig-like V-type domain, a 21 aa transmembrane (TM) sequence, and a 41 aa cytoplasmic sequence. It is found as a covalent homodimer of 41‑43 kDa (2). Within the ECD, human CTLA-4 shares 68%, 71% and 83‑86% aa sequence identity with mouse, rat and porcine/bovine/rabbit/feline/canine CTLA-4, respectively. A 174 aa form that lacks TM and cytoplasmic sequences (sCTLA-4) is possibly secreted (3‑5). Isoforms of 56‑79 aa that mainly contain parts of the cytoplasmic domain are reported. In mouse, an isoform lacking the Ig-like domain has ligand-independent inhibitory activity and is termed liCTLA-4 (6). CD28, which is structurally related to CTLA-4, is constitutively expressed on naïve T cells and promotes T cell activation when engaged by B7-2 on antigen-presenting cells (APC) within the immunological synapse (IS) (1, 7, 8). In contrast, CTLA-4 is recruited from intracellular vesicles to the IS beginning 1, 2 days after T cell activation (2, 7, 8). It forms a linear lattice with B7‑1 on APC, inducing negative regulatory signals and ending T cell activation (9). Abatacept, a therapeutic human CTLA-4-Ig fusion protein (trade name Orencia), competes with CD28 for B7-1 and B7-2 binding and has been used to antagonize T cell activation in autoimmune conditions and to enhance transplant survival (10). Mice deleted for CTLA-4 show no abnormalities until after birth, but then develop lethal autoimmune reactions due to continued T cell activation and poor control by regulatory T cells, which constitutively express CTLA-4 in wild-type mice and humans (11‑13).
- Harper, K. et al. (1991) J. Immunol. 147:1037.
- Teft, W.A. et al. (2006) Annu. Rev. Immunol. 24:65.
- Magistrelli, G. et al. (1999) Eur. J. Immunol. 29:3596.
- Tector, M. et al. (2009) BMC Immunol. 10:51.
- Oaks, M.K. and K.M. Hallett (2000) J. Immunol. 164:5015.
- Vijayakrishnan, L. et al. (2004) Immunity 20:563.
- Pentcheva-Hoang, T. et al. (2004) Immunity 21:401.
- Jansson, A. et al. (2005) J. Immunol 175:1575.
- Darlington, P.J. et al. (2005) J. Immunol. 175:996.
- Platt, A.M. et al. (2010) J. Immunol. 185:1558.
- Wing, K. et al. (2008) Science 322:271.
- Friedline, R.H. et al. (2009) J. Exp. Med. 206:421.
- Jain, N. et al. (2010) Proc. Natl. Acad. Sci. USA 107:1524.
Product Specific Notices for Recombinant Human CTLA-4 Fc Chimera His-tag Protein, CF
For research use only