Although a relationship between inflammation and some cancers is well-established, the complex role of the complement system in cancer development remains incompletely understood. The studies that have investigated this relationship have primarily reported that the diverse components of the complement system support tumor growth. However, some studies have demonstrated that components of the co...

We have examined the role of macrophage (M phi plasma membrane receptors for the cleaved third complement component (iC3b; CR3) and mannosyl, fucosyl terminated glycoproteins (MFR) in uptake of unopsonized zymosan. Monoclonal antibodies against CR3, M1/70 (Mac-1) and MO1, each inhibited approximately 50% of uptake of 125I-zymosan by murine and human M phi, respectively. Yeast mannan inhibited 0...

Complement activation has long been associated with inflammation, primarily due to the elaboration of the complement anaphylotoxins C5a and C3a. In this work, we demonstrate that the phagocytosis of complement-opsonized particles promotes host inflammatory responses by a new mechanism that depends on the terminal complement components (C5b-C9). We demonstrate that during the phagocytosis of com...

As a model of IgM-induced hemolytic anemia in man, human erythrocytes were sensitized with IgM antibody and coated with complement components, including C3 and C4, using human serum as a source of complement. These coated red cells were then interacted with monolayers of human mononuclear phagocytic cells (monocytes). Complement-coated red cells so bound could be displaced from their monocyte a...

Despite considerable advances in the understanding of the pathogenesis of meningococcal disease, this infection remains a major cause of morbidity and mortality globally. The role of the complement system in innate immune defenses against invasive meningococcal disease is well established. Individuals deficient in components of the alternative and terminal complement pathways are highly predisp...

Vaccinia virus complement control protein (VCP) inhibits both pathways of complement activation through binding the third and fourth components. A homolog of mammalian regulators of complement activation, its ability to bind heparin endows VCP with additional activities of significance to viral infectivity. The structure of VCP reveals a highly extended molecule with a putative heparin recognit...

plement in the presence of Ca2+, but absenco of Mg2+, certain components (Cx') of complement combine with EA, while the other components (Cy') of complement are left in the fluid phase. In order to determine the complement components involved in EACx' and Cy', carp seru m was inactivated by carrageenin (Cn), ammonia (Am), hydrazine (Hd), zymosan (Z) and heat treatment (13), and each inactivated...

PURPOSE The complement system plays important roles in a variety of chronic ocular diseases such as age-related macular degeneration. Here we examined the deposition of complement components in mouse eyes damaged by various mechanisms. METHODS Mouse eyes were damaged by light or by three models of inflammation, i.e., local transgenic expression of cytokines, interleukin-1 or -7, or by inducti...

PURPOSE Aqueous humor inhibits activation of the classic complement pathway; however, the mechanism of this inhibition is unknown. We have examined at the molecular level potential factors responsible for the inhibition, and we have tried to determine where in the complement pathway the inhibition takes place. METHODS Fresh rabbit aqueous humor was size fractionated by centrifuge concentrator...

Complement activation occurs in atherosclerotic plaques. The capacity of arterial tissue to inhibit this activation through generation of the complement regulators C1 inhibitor, decay accelerating factor, membrane cofactor protein (CD46), C4 binding protein (C4BP), and protectin (CD59) was evaluated in pairs of aortic atherosclerotic plaques and nearby normal artery from 11 human postmortem spe...