C‐reactive Protein Reactivity With Complement and Effects on Phagocytosis*

Abstract

In the studies described here we have attempted to evaluate the hypothesis that CRP may function in host defense using two systems in which CRP in the presence of C appears to have opsonic properties. In the first, CRP and C were found to stimulate ingestion of erythrocytes by human monocyte or mouse macrophages in vitro, and to alter clearance patterns in vivo. In the second, we have studied opsonization of S. pneumoniae by CRP and C. Experiments with human neutrophils indicate that although CRP and C can enhance opsonization of S. pneumoniae, this effect is more pronounced in the absence of antibody. In vivo CRP was found to protect mice against intravenous infection with S. pneumoniae.

Inflammatory mediators in dengue virus infection in children: interleukin-6 and its relation to C-reactive protein and secretory phospholipase A2.

“…30 Among the IL-6-induced acute phase proteins are CRP and sPLA2. [30][31][32] We found, however, no difference in CRP concentrations between patients with increased IL-6 and those with normal IL-6 levels, whereas levels of sPLA2 were higher in the former than in the latter group. It is possible that the generation of IL-6 was not abundant enough to generate high levels of CRP, which were elevated in only about one-third of the dengue patients and not different between DSS and non-shock patients.…”

Application of acute phase protein measurements in veterinary clinical chemistry

“…The presence of CRP has also been described in human patients during acute infections caused by acute lobar pneumonia, active rheumatic fever and bacteremia caused by "colon bacillus" [1]. Among the biological functions described in the literature are complement activation [49,182] and opsonisation [116,182] (Tab. III).…”

“…CRP binds released bacterial or host DNA [57,147]. For other prominent acute phase proteins like SAA, Bacteriostatic effect [30,36] Stimulation of angiogenesis [26] Role in lipid metabolism/development of fatty liver in cattle [87,180] Immunomodulatory effect [42,120] Inhibition of neutrophil respiratory burst activity [129] C-reactive protein Complement activation and opsonisation [49,116,182] Modulation of monocytes and macrophages, cytokine production [13,25,143] Binding of chromatin [147] Prevention of tissue migration of neutrophiles [196] Serum amyloid A Transport of cholesterol from dying cells to hepatocytes [102] Inhibitory effect on fever [159] Inhibitory effect on the oxidative burst of neutrophilic granulocytes [103] Inhibitory effect on in vitro immune response [4,16] Chemotaxic effect on monocytes, polymorphonuclear leucocytes and T cells [9,189] Induction of calcium mobilisation by monocytes [10] Inhibition of platelet activation [195] no biological function has yet been firmly established. Some of the common APP have recently been shown to share the ability to down-regulate pro-inflammatory cytokine production and activity in monocytic cells, potentially providing a feedback mechanism by which they affect their own induction as well as other cytokinedriven aspects of the acute phase response in vivo (reviewed by [176]).…”

Mucosal Immunization with an Unadjuvanted Vaccine That Targets Streptococcus pneumoniae PspA to Human Fcγ Receptor Type I Protects against Pneumococcal Infection through Complement- and Lactoferrin-Mediated Bactericidal Activity

“…It has been previously demonstrated that PspA-specific antibody can enhance complement activation in the presence of S. pneumoniae, further enhancing complement-mediated opsonophagocytosis (20,44,45,46,50,54,55,62,63,71). Thus, we examined whether the enhanced antibody production to S. pneumoniae following immunization with anti-hFc␥RI-PspA enhanced complement C3 deposition on S. pneumoniae.…”