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| Product Name | Human CD28 Protein (Recombinant) |
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| Description | Purity >95% by SDS-PAGE gel and HPLC analyses., MW: 82.4 kDa or 60-70 kDa or 150-160 kDa. CTLA-4 and CD28 are receptors of the immunoglobulin superfamily that are expressed, along with the transmembrane glycoproteins B7-1 and B7-2, by antigen-presenting cells, and with these ligands constitute crucial co-stimulatory pathways for T and B cell regulatory responses. It is through engagement with CD28 and CTLA-4 that the B7 family ligands B7-1 and B7-2 play principal roles in immunity by activating immune response and maintaining immune tolerance. Co-stimulatory signals generated by B7-1 and B7-2 interactions with CD28 serve to stimulate T cell activation and prevent anergy through the amplification of T cell receptor (TCR) signaling. In contrast, interactions of the ligands with CTLA-4 serves to maintain T cell homeostasis and self-tolerance through the disruption of stimulatory signaling from B7 isoform-bound CD28 complexes, and by inducing powerful inhibitory signals in T cells. CTLA-4, like B7-1, is only poorly expressed on resting dendritic cells; therefore, up-regulation of their interaction and resultant amplification and regulation of T cell activity at peripheral inflammation sites is considerably delayed upon immune activation. Conversely, B7-2 and CD28 are constitutively expressed by resting hematopoietic and T cells, respectively, and as a result are able to rapidly induce up-regulation upon immune activation, making them critical to the early co-stimulatory signaling of immune response. Unlike B7-1 and B7-2, the ligands PD-L1 (or B7-H1) and B7-H2, which also belong to the B7 family, have not been shown to influence immunity through interaction with CTLA-4. B7-H2 has been shown to have restricted interaction with CD28. The difference in expression of B7-1, B7-2 and B7-H2 may enable temporally and spatially-specific regulation of T cell response through non-competitive CD28 interaction. PeproTech's CHO cell-derived Recombinant Human sCD28 Fc is a glycosylated, disulfide-linked homodimer of 734 amino acid residues whose monomer consists of the 134-amino-acid length extracellular portion of CD28 fused to the 231-amino-acid length Fc portion of human IgG1 by two glycines. The calculated molecular weight of Recombinant Human sCD28 Fc dimer is 82.4 kDa; however, due to glycosylation, the monomer and dimer migrate at apparent molecular weights of approximately 60-70 kDa and 150-160 kDa by SDS-PAGE analysis under reducing conditions. |
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| Size | n/a |
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| Concentration | n/a |
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| Applications | n/a |
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| Other Names | CD28, CD28 antigen, CD28 antigen (Tp44), Tp44, CD28 molecule |
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| Gene, Accession, CAS # | CD28, Gene ID: 940 |
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| Catalog # | LS-G133813 |
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| Order / More Info | Human CD28 Protein (Recombinant) from LIFESPAN BIOSCIENCES INC. |
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| Product Specific References | n/a |
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