Detection of CD28 in CD3+ Mouse Splenocytes by Flow Cytometry.
CD3+ mouse splenocytes were stained with Rat Anti-Mouse CD28 PE‑conjugated Monoclonal Antibody (Catalog # FAB4832P, filled histogram) or isotype control antibody (Catalog # IC005P, open histogram). View our protocol for Staining Membrane-associated Proteins.
Preparation and Storage
The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage
Protect from light. Do not freeze.
12 months from date of receipt, 2 to 8 °C as supplied.
CD28 and CTLA-4, together with their ligands B7-1 and B7-2, constitute one of the dominant costimulatory pathways that regulate T and B cell responses. CD28 and CTLA-4 are structurally homologous molecules that are members of the immunoglobulin (Ig) gene superfamily. Both CD28 and CTLA-4 are composed of a single Ig V‑like extracellular domain, a transmembrane domain and an intracellular domain. CD28 and CTLA-4 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 and mouse chromosome 1. Mouse CD28 is expressed constitutively on virtually 100% of mouse T cells and on developing thymocytes. Cell surface expression of mouse CD28 is down-regulated upon ligation of CD28 in the presence of PMA or PHA. In contrast, CTLA-4 is not expressed constitutively but is upregulated rapidly following T cell activation and CD28 ligation. Cell surface expression of CTLA-4 peaks approximately 48 hours after activation. 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. CD28/B7 interaction has been shown to prevent apoptosis of activated T cells via the up-regulation of Bcl‑xL. CD28 ligation has also been shown to regulate Th1/Th2 differentiation. Agonist activity has been reported using MAB4831 (4,5).
Lenschow, D.J. et al. (1996) Annu. Rev. Immunol. 14:233.
Hathcock, K.S. and R.J. Hodes (1996) Advances in Immunol. 62:131.
Submit a review and receive a $25US/€18/£15/$25CAN amazon gift card if you include an image - $10US/€7/£6/$10CAN Amazon card for reviews without an image. Limited to verified customers in USA, Canada and Europe.