Interactions of C-reactive protein with the complement system. III. Complement-dependent passive hemolysis initiated by CRP.
Interactions of CRP with various substrates in the presence of human serum have been shown to result in efficient activation of C components C1-C5. We now report the ability of CRP to initiate C-dependent hemolysis. For this purpose CRP was isolated by affinity chromatography using pneumococcal CPS and gel filtration; its purity was established by several criteria. Erythrocytes were coated with CPS (E-CPS) and passively sensitized with CRP. C-dependent lysis of these cells was observed upon the addition of suitably absorbed human serum, and the efficiency of hemolysis compared favorably with that initiated by rabbit IgG anti-CPS antibody. CRP also sensitized E-CPS for lysis by guinea pig C; partial lysis was seen when C4-deficient guinea pig serum was used, suggesting that CRP also shares with antibody the ability of CRP to fully activate the C system and provide further evidence for a role for CRP similar to that of antibody in the initiation and modulation of inflammatory reactions via the complete system.
D000818:Animals; D000906:Antibodies; D001202:Ascitic Fluid / Q000032:analysis; D002097:C-Reactive Protein / Q000032:analysis / Q000302:isolation & purification / Q000502:physiology*; D002845:Chromatography; D002850:Chromatography, Gel; D003165:Complement System Proteins / Q000502:physiology*; D004912:Erythrocytes / Q000276:immunology; D006384:Hemagglutination; D006461:Hemolysis; D006801:Humans; D051379:Mice; D011817:Rabbits / Q000276:immunology
D000906:Antibodies; D003165:Complement System Proteins; D002097:C-Reactive Protein