Human CD152 ( Cytotoxic T-lymphocyte protein 4: CTLA4 ) gene is a member of the immunoglobulin superfamily and encodes a protein which transmits an inhibitory signal to T cells. The affinity of CD152 for its natural B7 family ligands, CD80 and CD86, is considerably stronger than the affinity of their cognate stimulatory co-receptor CD28. CD152 protein contains a V domain, a transmembrane domain, and a cytoplasmic tail. Alternate transcriptional splice variants, encoding different isoforms, have been characterized. The membrane-bound isoform functions as a homo-dimer interconnected by a disulfide bond, while the soluble isoform functions as a monomer. Mutations in this gene have been associated with insulin-dependent diabetes mellitus, Graves disease, Hashimoto thyroiditis, celiac disease, systemic lupus erythematosus, thyroid-associated orbitopathy, and other autoimmune diseases. Engineered fusion proteins consisting of the extracellular domain of CTLA4 and the IgG Fc region (CTLA4-Ig), inhibit T-cell-dependent antibody responses, and are used as immunosuppressive agents. They are soluble, have an enhanced affinity for B7 ligands and act as a competitive inhibitor of CD28.

Full-length human CD152 extracellular domain cDNA (36 - 161 aa, derived from BC074893) was constructed with codon optimization and expressed with a small T7-His-TEV cleavage site Tag (29aa) fusion at its N-terminal and expressed in E.coli as inclusion bodies. The final product was refolded using our unique “temperature shift inclusion body refolding” technology and chromatographically purified.

1. May be used as coating or soluble factor for in vitro T cell activation pathway regulation study.

2. May be used for protein-protein interaction assay development.

3. As antigen for specific antibody production.