scholarly journals The involvement of the complement system in the pressor response to the injection of Forssman antibody in the guinea-pig

1970 ◽  
Vol 206 (2) ◽  
pp. 481-493
Author(s):  
G. Darlow ◽  
G. F. Gough ◽  
R. Tanalp
Keyword(s):  
Guinea Pig ◽  
Complement System ◽  
Pressor Response ◽  
The Complement System ◽  
Forssman Antibody

The complement system enhances the clearance of phosphatidylserine (PS)-liposomes in rat and guinea pig

2001 ◽  
Vol 215 (1-2) ◽  
pp. 197-205 ◽  
Author(s):  
Tran Minh Huong ◽  
Tatsuhito Ishida ◽  
Hideyoshi Harashima ◽  
Hiroshi Kiwada
Keyword(s):  
Guinea Pig ◽  
Complement System ◽  
The Complement System

A Human Erythrocyte-based Haemolysis Assay for the Evaluation of Human Complement Activity

2020 ◽  
Vol 48 (3) ◽  
pp. 127-135
Author(s):  
Ruby Anne N. King ◽  
Fresthel Monica M. Climacosa ◽  
Bobbie Marie M. Santos ◽  
Salvador Eugenio C. Caoili
Keyword(s):  
Guinea Pig ◽  
Complement System ◽  
Clinical Setting ◽  
Human Erythrocyte ◽  
Human Erythrocytes ◽  
Human Complement ◽  
Complement Activity ◽  
Functional Assays ◽  
The Complement System ◽  
Complement Pathways

The complement system consists of at least 50 proteins that serve as one of the first lines of defence against foreign, or damaged, cells and invading microorganisms. Its dysregulation underlies the pathophysiology of many different diseases, which makes functional assays of complement activity crucial; they are, however, underutilised. Standard haemolysis assays for the analysis of complement function employ sensitised non-human erythrocytes (e.g. from the sheep, guinea-pig or rabbit), the use of which raises animal welfare concerns. To provide an alternative to the use of such animal-derived products for complement function assays, we developed a method that employs modified human erythrocytes to evaluate the activity of complement pathways. Human erythrocytes were subjected to various chemical and/or proteolytic treatments involving 2,4,6-trinitrobenzene sulphonate (TNBS) and pancreatin. Haemolysis assays demonstrated that sequential treatment with TNBS and pancreatin resulted in significantly greater complement-mediated haemolysis, as compared to TNBS or pancreatin treatment alone. Evidence that lysis of the modified erythrocytes was complement-mediated was provided by the chelation and subsequent restoration of calcium in the plasma. Thus, such modified human erythrocytes could be used as an alternative to animal-derived erythrocytes in haemolysis assays, in order to evaluate complement activity in human plasma during, for example, the screening of patients for complement deficiencies and other abnormalities in a clinical setting.

scholarly journals INTERACTIONS OF THE COMPLEMENT SYSTEM WITH THE SURFACE AND ENDOTOXIC LIPOPOLYSACCHARIDE OF VEILLONELLA ALCALESCENS

1967 ◽  
Vol 125 (5) ◽  
pp. 767-786 ◽  
Author(s):  
Howard A. Bladen ◽  
Henry Gewurz ◽  
Stephan E. Mergenhagen
Keyword(s):  
Cell Surface ◽  
Guinea Pig ◽  
Complement System ◽  
Biological Activities ◽  
Lesion Formation ◽  
Electron Microscopic ◽  
Reaction Conditions ◽  
Microscopic Studies ◽  
The Complement System ◽  
Pig Serum

Electron microscopic studies demonstrated that lesions were produced on the endotoxic lipopolysaccharide (LPS) as well as on the cell surface of V. alcalescens after reaction with fresh guinea pig serum. These lesions were approximately 90 A in diameter, and were seen on two characteristic structural entities derived from LPS preparations after incubation with serum. The use of numerous inhibitors, inactivators, and reaction conditions affecting hemolytic C' activity revealed that these lesions were mediated by the C' system. Concomitant with lesion formation, C' was fixed; the effect on classical C'3 activity was pronounced. It is concluded that endotoxic LPS, as contained in the outer three-layered membrane of the bacterial cell, is a substrate for the C' enzymes. It is suggested that certain biological activities of endotoxin may derive from its effects on the C' system.

Über die Wirkung von Heparin, Heparinoiden und Carrageenin auf die Komponenten des Meerschweinchen-Komplements in vitro

1965 ◽  
Vol 20 (6) ◽  
pp. 575-581 ◽  
Author(s):  
K. Lauenstein ◽  
H. G. Siedentopf ◽  
H. Fischer
Keyword(s):  
Guinea Pig ◽  
Complement System ◽  
Mode Of Action ◽  
Preceding Paper ◽  
Inhibitory Effect ◽  
The Complement System ◽  
Pig Serum

The mode of action of six inhibitors of the complement system of guinea pig serum was analysed by use of the method described in the preceding paper.Carrageenin is the most powerful inhibitor followed by polyvinylalcoholsulfate, polyethenesulfate, heparinoid “Bayer”, dextransulfate, and heparin. All six substances are directed against C′ 1 and C′ 2. Heparin and polyethenesulfate also inhibit C′ 3b,β, while an effect of heparinoid “Bayer”, dextransulfate, and polyvinylalcoholsulfate upon C′ 3b,β could not definitely be demonstrated. It is not clear whether these latter substances act upon C′ 3b,β, C′ 3c,d, or upon both components.All substances tested exert the strongest inhibitory effect upon C′ 1 which thus becomes the limiting component in guinea pig complement.

scholarly journals RELATION OF A ß1-GLYCOPROTEIN OF HUMAN SERUM TO THE COMPLEMENT SYSTEM

1960 ◽  
Vol 111 (2) ◽  
pp. 217-234 ◽  
Author(s):  
H. J. Müller-Eberhard ◽  
U. Nilsson
Keyword(s):  
Guinea Pig ◽  
Human Serum ◽  
Complement System ◽  
Hemolytic Activity ◽  
Initial Velocity ◽  
Rapid Decay ◽  
Fresh Serum ◽  
Serological Activity ◽  
The Complement System ◽  
Final Degree

The protein of human serum, tentatively designated ß1C-globulin, was shown to possess serological activity and to be related to the complement system. Another serum protein (ß1A-globulin) was identified as the inactivated form of ß1C-globulin. Incubation of fresh serum with various immune precipitates or with soluble γ-globulin aggregates at 37°C. resulted in the removal of ß1C-globulin. Treatment of fresh serum with zymosan at 17 and 37°C. had a similar effect. In both instances ß1C-globulin was removed from serum, apparently by conversion to ß1A-globulin. However, isolated ß1C-globulin did not react with immune precipitates or zymosan, nor did ß1C-globulin of serum previously heated at 56°C. Highly purified ß1C-globulin was tested for complement component activity by means of the usual reagents. All of the preparations examined were found to reconstitute the hemolytic activity of guinea pig R3. However, they failed to reconstitute R3 obtained from human serum. Isolated ß1A-globulin was found to be inactive in all systems. When isolated ß1C-globulin in either phosphate or in borate buffer was stored at 37°C., the activity detected by means of guinea pig R3 declined within 6 days to 20 to 30 per cent of its original value. As the activity decreased, ß1C-globulin was gradually converted to ß1A-globulin. Addition of ß1C-globulin to a limited complement system (human C') caused an increase of both initial velocity and final degree of hemolysis. Although ß1C-globulin did not cause lysis of EAC'1, 4, 2, it fully prevented the otherwise rapid decay of EAC'1, 4, 2 at 37°C., and so presumably interacted with this complex.

Protein S and C4b-Binding Protein: Components Involved in the Regulation of the Protein C Anticoagulant System

1991 ◽  
Vol 66 (01) ◽  
pp. 049-061 ◽  
Author(s):  
Björn Dahlbäck
Keyword(s):  
Vitamin K ◽  
Complement System ◽  
Protein C ◽  
Protein S ◽  
High Affinity ◽  
Anticoagulant System ◽  
Dependent Protein ◽  
The Complement System ◽  
Β Chain ◽  
Dependent Domain

SummaryThe protein C anticoagulant system provides important control of the blood coagulation cascade. The key protein is protein C, a vitamin K-dependent zymogen which is activated to a serine protease by the thrombin-thrombomodulin complex on endothelial cells. Activated protein C functions by degrading the phospholipid-bound coagulation factors Va and VIIIa. Protein S is a cofactor in these reactions. It is a vitamin K-dependent protein with multiple domains. From the N-terminal it contains a vitamin K-dependent domain, a thrombin-sensitive region, four EGF)epidermal growth factor (EGF)-like domains and a C-terminal region homologous to the androgen binding proteins. Three different types of post-translationally modified amino acid residues are found in protein S, 11 γ-carboxy glutamic acid residues in the vitamin K-dependent domain, a β-hydroxylated aspartic acid in the first EGF-like domain and a β-hydroxylated asparagine in each of the other three EGF-like domains. The EGF-like domains contain very high affinity calcium binding sites, and calcium plays a structural and stabilising role. The importance of the anticoagulant properties of protein S is illustrated by the high incidence of thrombo-embolic events in individuals with heterozygous deficiency. Anticoagulation may not be the sole function of protein S, since both in vivo and in vitro, it forms a high affinity non-covalent complex with one of the regulatory proteins in the complement system, the C4b-binding protein (C4BP). The complexed form of protein S has no APC cofactor function. C4BP is a high molecular weight multimeric protein with a unique octopus-like structure. It is composed of seven identical α-chains and one β-chain. The α-and β-chains are linked by disulphide bridges. The cDNA cloning of the β-chain showed the α- and β-chains to be homologous and of common evolutionary origin. Both subunits are composed of multiple 60 amino acid long repeats (short complement or consensus repeats, SCR) and their genes are located in close proximity on chromosome 1, band 1q32. Available experimental data suggest the β-chain to contain the single protein S binding site on C4BP, whereas each of the α-chains contains a binding site for the complement protein, C4b. As C4BP lacking the β-chain is unable to bind protein S, the β-chain is required for protein S binding, but not for the assembly of the α-chains during biosynthesis. Protein S has a high affinity for negatively charged phospholipid membranes, and is instrumental in binding C4BP to negatively charged phospholipid. This constitutes a novel mechanism for control of the complement system on phospholipid surfaces. Recent findings have shown circulating C4BP to be involved in yet another calcium-dependent protein-protein interaction with a protein known as the serum amyloid P-component (SAP). The binding sites on C4BP for protein S and SAP are independent. SAP, which is a normal constituent in plasma and in tissue, is a so-called pentraxin being composed of 5 non-covalently bound 25 kDa subunits. It is homologous to C reactive protein (CRP) but its function is not yet known. The specific high affinity interactions between protein S, C4BP and SAP suggest the regulation of blood coagulation and that of the complement system to be closely linked.

Stimulated Glanzmann’s Thrombasthenia Platelets Produce Microvesicles

1995 ◽  
Vol 74 (06) ◽  
pp. 1533-1540 ◽  
Author(s):  
Pål André Holme ◽  
Nils Olav Solum ◽  
Frank Brosstad ◽  
Nils Egberg ◽  
Tomas L Lindahl
Keyword(s):  
Complement System ◽  
Shape Change ◽  
Annexin V ◽  
Platelet Surface ◽  
Glanzmann’S Thrombasthenia ◽  
Large Numbers ◽  
Glanzmann's Thrombasthenia ◽  
Series Of Experiments ◽  
The Complement System ◽  
Number Of Particles

SummaryThe mechanism of formation of platelet-derived microvesicles remains controversial.The aim of the present work was to study the formation of microvesicles in view of a possible involvement of the GPIIb-IIIa complex, and of exposure of negatively charged phospholipids as procoagulant material on the platelet surface. This was studied in blood from three Glanzmann’s thrombasthenia patients lacking GPIIb-IIIa and healthy blood donors. MAb FN52 against CD9 which activates the complement system and produces microvesicles due to a membrane permeabilization, ADP (9.37 μM), and the thrombin receptor agonist peptide SFLLRN (100 μM) that activates platelets via G-proteins were used as inducers. In a series of experiments platelets were also preincubated with PGE1 (20 μM). The number of liberated microvesicles, as per cent of the total number of particles (including platelets), was measured using flow cytometry with FITC conjugated antibodies against GPIIIa or GPIb. Activation of GPIIb-IIIa was detected as binding of PAC-1, and exposure of aminophospholipids as binding of annexin V. With normal donors, activation of the complement system induced a reversible PAC-1 binding during shape change. A massive binding of annexin V was seen during shape change as an irreversible process, as well as formation of large numbers of microvesicles (60.6 ±2.7%) which continued after reversal of the PAC-1 binding. Preincubation with PGE1 did not prevent binding of annexin V, nor formation of microvesicles (49.5 ± 2.7%), but abolished shape change and PAC-1 binding after complement activation. Thrombasthenic platelets behaved like normal platelets after activation of complement except for lack of PAC-1 binding (also with regard to the effect of PGE1 and microvesicle formation). Stimulation of normal platelets with 100 μM SFLLRN gave 16.3 ± 1.2% microvesicles, and strong PAC-1 and annexin V binding. After preincubation with PGE1 neither PAC-1 nor annexin V binding, nor any significant amount of microvesicles could be detected. SFLLRN activation of the thrombasthenic platelets produced a small but significant number of microvesicles (6.4 ± 0.8%). Incubation of thrombasthenic platelets with SFLLRN after preincubation with PGE1, gave results identical to those of normal platelets. ADP activation of normal platelets gave PAC-1 binding, but no significant annexin V labelling, nor production of microvesicles. Thus, different inducers of the shedding of microvesicles seem to act by different mechanisms. For all inducers there was a strong correlation between the exposure of procoagulant surface and formation of microvesicles, suggesting that the mechanism of microvesicle formation is linked to the exposure of aminophospholipids. The results also show that the GPIIb-IIIa complex is not required for formation of microvesicles after activation of the complement system, but seems to be of importance, but not absolutely required, after stimulation with SFLLRN.

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