Search results for "Complement system"
showing 10 items of 157 documents
The Role of the Classical Pathway for the Bactericidal Effect of Normal Sera Against Gram-Negative Bacteria
1985
Many gram-negative bacteria are killed after treatment with normal serum. This phenomenon was already described in 1889 by Buchner. The serum-bactericidal effect is abolished when serum has been incubated for 30 min at 56° C. Gram-positive bacteria are less sensitive than gram-negative bacteria to direct killing, although gram-positive cocci are opsonized by the action of serum mediated by antibodies and complement (Inoue et al. 1968; Johnston et al. 1969). Normal sera exhibit bactericidal and bacteriolytic properties against some gramnegative strains; whereas, other gram-negative strains are serum resistant. It has been shown that serum from C4-deficient guinea pigs is able to kill some gr…
Interaction of Bacterial Endotoxin (LPS) with Fluid Phase and Macrophage Membrane Associated C1q, the FC-Recognizing Component of the Complement Syst…
1990
The bactericidal activity of normal serum was first described by Buchner in 1889 (10). This effect is abolished when serum has been incubated for 30 min at 56°C. Gram positives are less sensitive than Gram negative bacteria to direct killing, although gram positive cocci are opsonized by the action of serum mediated by antibodies and complement (22). It was found that most of the smooth strains of gram negative bacteria are serum resistant; whereas, the corresponding rough forms are extremely serum sensitive (32, 37). Thus evidence was provided that the composition of the bacterial surface may influence the reaction of the bacteria with the lytic system. The bacteriolytic properties of seru…
Complement activation and innate immunity
2007
Cloning and expression of the complement receptor glycoprotein C from Herpesvirus simiae (herpes B virus): protection from complement-mediated cell l…
2003
Simian herpes B virus (SHBV) is the herpes simplex virus (HSV) homologue for the species MACACA: Unlike in its natural host, and unlike other animal herpesviruses, SHBV causes high mortality in accidentally infected humans. SHBV-infected cells, like those infected with HSV-1 and equine herpesvirus types 1 and 4, express complement C3 receptor activity. To study immunoregulatory functions involved in susceptibility/resistance against interspecies transmission, the SHBV glycoprotein C (gC(SHBV)) gene (encoding 467 aa) was isolated. Sequence analysis revealed amino acid identity with gC proteins from HSV-2 (46.9 %), HSV-1 (44.5 %) and pseudorabies virus (21.2 %). Highly conserved cysteine resi…
Ultracentrifugation studies on the native form of the first component of human complement (C1)
1976
The modulation of immune complex aggregation by classical pathway-mediated reactions.
1985
Abstract Classical pathway (CP)-triggered reactions of complement-modulated immune complex(IC) aggregation (tetanus toxoid/human anti-tetanus toxoid-IgG; ICs of equivalence) were investigated turbidimetrically during the early stages of reaction. Monospecific Fab'- or Fab-fragments (rabbit) directed against certain complement components were used to block the complement function in normal human serum (NHS). Additionally, parts of the reactions were studied using purified complement components. C1q in serum generated by the addition of EDTA as well as purified C1q were found to increase the IC aggregation. In contrast to C1q, macromolecular C1 is able to inhibit IC aggregation, whereas addit…
Immunpathogenese der Atherosklerose
2002
Atherosclerosis is widely regarded as a chronic inflammatory disease that develops as a consequence of entrapment of low density lipoprotein (LDL) in the arterial intima. Native LDL lacks inflammatory properties, so the lipoprotein must undergo biochemical alterations in order to become atherogenic. Modification is commonly regarded as being dangerous because it bestows inflammatory properties onto the lipoprotein. Most current models regard oxidation to be the decisive modifying event. However, we have obtained experimental evidence in support of a different concept. We propose that modification of tissue-entrapped LDL is required because it enables the lipoprotein to signal to the immune …
ESR Spectra o f Normal Human Serum after Treatment with Complement Activating Agents*
1980
Abstract We describe the appearance of a free-radical signal in the ESR spectrum of normal human serum incubated with several complement activating agents. The intensity of this signal is dependent of dose of activating agents, time and temperature. Signals elicited by different complement activators differ in morphology and kinetics. Inhibition by treatment with EDTA and the presence of the signal in activated C 6-deficient rabbit serum suggest that the con-vertase forming steps of complement activation (C2 to 5) could be the source of free-radical containing molecules.
Cell-mediated lipoprotein transport: A novel anti-atherogenic concept
2010
Lipoprotein transport is thought to occur in the plasma compartment of the blood, where lipoproteins are modulated by various enzymatic reactions. Subsequently, lipoproteins can migrate through the endothelial barrier to the subendothelial space or are taken up by the liver. The interaction between pro-atherogenic (apoB-containing) lipoproteins and blood cells (especially monocytes and macrophages) in the subendothelial space is well known. This lipoprotein-inflammatory cell interplay is central in the development of the atherosclerotic plaque. In this review, a novel interaction is described between lipoproteins and both leukocytes and erythrocytes in the blood compartment. This lipoprotei…
Physicochemical characterization of the fifth (C5), sixth (C6), seventh (C7), eighth (C8) and ninth (C9) component of guinea pig complement.
1971
A physicochemical characterization of the purified guinea pig complement components C5 to C9 is given. For this purpose the sedimentation rate, the diffusion coefficient, the molecular weight and the isoelectric point were determined and compared with the values already known for the guinea pig and human complement system. For the determination of the physicochemical parameters gel filtration on Sephadex G-200, ultracentrifugation applying a sucrose density gradient and thin-layer isoelectric focusing were used. By comparing the values of the human and guinea pig complement a remarkable similarity is shown.