Inhibition of C3b and C3d Receptor Activity by Xenoantisera Prepared by Immunization with Cell-Bound C3 Receptor Protein

Abstract

Receptors for complement fragment 3b (C3b receptors) and/or 3d (C3d receptors) have been demonstrated on various human cell populations, namely, erythrocytes (E_hu), platelets, granulocytes, monocytes, renal glomerular cells, liver cells, and lymphocytes (8). There are several indications that C3 receptors play an important role in various biological processes, such as immunophagocytosis (5,6), clearance of immune complexes (4), antibody triggering (7), and the germinal center reaction (2,9,10); but the different functions of C3 receptors are far from clear. Antibodies capable of blocking C3 receptors would thus be useful tools for studying the biological functions of C3 receptors in various in-vivo and in-vitro systems.