Invitrogen™ CD21/CD35 Monoclonal Antibody (eBio8D9 (8D9)), eBioscience™, Invitrogen™

Beschreibung

The MAb eBio8D9 reacts with an eptiope shared by mouse CD21 (CR2) and CD35 (CR1). CD21 and CD35 are alternatively spliced transcripts from the Cr2 gene, which produce cell-surface proteins of 145 and 190 kDa, respectively. CD21 and CD35 are expressed by mature B cells, but not on thymocytes, peripheral T cells, erythrocytes or platelets. Furthermore, there is some evidence which demonstrates their expression on macrophages. CD21 is a receptor for the complement component C3d and Epstein-Barr virus (EBV). In association with CD19 and CD81, CD21 also participates in B-cell activation through the B cell receptor. Cr2-deficient mice display impaired inflammatory and humoral immune responses in vivo. The anti-mouse CD21/35 MAb clones eBio4E3 and eBio8D9 do not cross-block each other, suggesting that they bind to different epitopes.

CD21 (complement receptor 2, CR2) binds C3 complement fragments, especially its breakdown fragments, which remain covalently attached to complement activating surfaces or antigen. CD21 has important roles in uptake and retention of immunocomplexes, survival of memory B cells and in development and maintenance of the humoral response to T-dependent antigens. CD21 also serves as a key receptor for Epstein-Barr virus binding and is involved in targeting prions to folicular dendritic cells and expediting neuroinvasion following peripheral exposure to prions. A soluble form of the CD21 (sCD21) is shed from the lymphocyte surface and retains its ability to bind respective ligands. CD35 encodes a membrane glycoprotein found on peripheral blood cells, glomerular podocytes, and follicular dendritic cells. The protein is a receptor for complement components C3b and C4b and regulates the activity of the complement cascade. Variation in this protein is the basis of the Knops blood group system. The two most common alleles, F and S, differ by 8 exons and are thought to be the result of an unequal crossover event. A secreted form of the protein present in plasma has been described, but its full length nature has not been determined.