- Anti-human CD28 mAb
- Product Number : CB-1118500
- Size : 500 µg
- Store at : see datasheet
- Sterile : Yes
- HS-Code : 29371900
- 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 mouse 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.
- Storage conditions and stability
+ Lyophilized CD28 is stable at 2 – 8 °C for 24 months from production date.
+ The lyophilized CD28 should be reconstituted in sterile distilled water to your desired concentration.
+ Should be stored in working aliquots at -20°C when reconstituted
