Description
The cluster of differentiation (CD) system is commonly used as cell markers in Immunophenotyping. Different kinds of cells in the immune system can be identified through the surface CD molecules associating with the immune function of the cell. There are more than 320 CD unique clusters and subclusters have been identified. Some of the CD molecules serve as receptors or ligands important to the cell through initiating a signal cascade which then alter the behavior of the cell. Some CD proteins do not take part in cell signal process but have other functions such as cell adhesion. CD21, also known as Complement component (3d / Epstein Barr virus) receptor 2 and CR2, is a member of the CD system and is a protein involved in complement system. CD21 is present on all mature B-cells and some T-cells and follicular dendritic cells. CD21 on mature B-cells form a complex called the B cell receptor complex with two other membrane proteins, CD19 and CD81. CD21 has a function in the complement system through serving as the cellular receptor specific for ligands such as C3 and C4 which can be attached to foreign macromolecules in order to remove or uptake them. This results in B-cells having enhanced response to the antigen.
Target
CR2
Target Alias Names
C3DR, CD21, CR, CVID7, SLEB9
Isotype/Mimetic
Rabbit IgG
Animal-Derived Biomaterials Used
No
Sequence Available
No
Original Discovery Method
Phage display technology
Antibody/Binder Origins
Animal-dependent discovery (in vitro display, OR immunisation pre-2020), In vitro recombinant expression