CD21 monoclonal antibody

Complement receptor type 2 (CD21/CR2) is a type 1 transmembrane glycoprotein whose expression is largely restricted to B lymphocytes and follicular dendritic cells. Research studies have shown that CD21/CR2 functions to bind the complement fragments iC3b, C3dg, and C3d, which function to activate the alternative complement pathway and MAC formation. In addition to its function as a complement receptor, CD21/CR2 also functions as the B lymphocyte receptor for Epstein-Barr virus and interferon alpha. Research studies have also shown that CD21/CR2 participates in B cell activation, proliferation, and protection from apoptosis through its association with components of the B cell coreceptor signaling complex such as CD19 and CD21.