C6, Human, mAb WU 6-4

The monoclonal antibody WU 6-4 recognizes C6, one of the components of the terminal complement complex (TCC), also know as the membrane attack complex (MAC). Proteolytic cleavage of C5 by C5 convertase generates C5b which initiates assembly of the C5b-9 MAC. This complex is assembled from five precursor molecules in the serum, finalized with the polymerization of C9 which accompanies insertion of the complex into the cell membrane causing cellular lysis. Polymorphonuclear leukocytes represent a major source of C6. The monoclonal antibody WU 6-4 recognizes native C6 but not C6 after incorporation into the TCC. Furthermore, WU 6-4 is capable of inhibiting C5b6 and TCC formation in the fluid phase and to a lesser extent, haemolysis. Haemolytic activity could be inhibited only when WU 6-4 was introduced before C5b6 formation.