Anti-Hu CD21 APC Mab (Clone : LT21)

Specificity: The antibody LT21 reacts with an extracellular epitope of CD21 (CR2), a 145 kDa transmembrane glycoprotein (complement C3d receptor - C3dR) expressed on B lymphocytes, follicular dendritic cells, some epithelial cells and a subsets of T lymphocytes. It is not expressed on immature B cells. 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.