COMPLEMENT ACTIVATION BY INTERACTION OF POLYANIONS AND POLYCATIONS .3. COMPLEMENT ACTIVATION BY INTERACTION OF MULTIPLE POLYANIONS AND POLYCATIONS IN PRESENCE OF C-REACTIVE PROTEIN

Abstract

Interactions between heparin and protamine result in activation of the [human] complement (C'') system. This interaction resulted in the binding of purified C''.hivin.1 [activated C1], and this was markedly enhanced in the presence of C-reactive protein (CRP). CRP also enhanced C'' consumption during heparin-protamine interactions in whole serum, and in the presence of CRP, depletion of C'' components C'' 1-3 was observed. Similar C''1 binding and C'' consumption in the presence of CRP were seen upon the interaction of multiple additional polyanions including DNA, ENA [phosphate extractable nuclear antigen], hyaluronic acid, chondroitin sulfate and dextran sulfate with the polycations protamine sulfate and poly-L-lysine. These effects were observed with CRP concentrations well within the range found in normal human sera and considerably less than those found in most acute phase sera. C'' activation by polyanion-polycation interactions in the presence of CRP may be important to certain reactions of host defense and inflammation.