Structure and functions of gp 140, the C3d/EBV receptor (CR2) of human B lymphocytes.

Analysis of the interaction of human C3 fragments with human B lymphoma cell line, led us to isolate gp 140, the C3 receptor of Raji cells. Rabbit anti-gp 140 was prepared against this highly purified receptor. Using these polyclonal antibodies, it was found that: gp 140 is the C3d receptor (CR2) which reacts with the C3d site expressed on C3d, C3dg, C3bi and at a less extent on C3b. Gp 140 is a specific marker of human B lymphocytes; gp 140 is also the Epstein-Barr virus receptor (EBVR); CR2 is a membrane site involved in B-cell regulation; and the C3d/C3dg receptor (CR2) of human B lymphocytes is distinct to the C3dg receptor (CR4) of human neutrophils.