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PubMed1981

Immunofluorescence studies on complement components in the hair follicles of normal scalp and of scalp affected by alopecia areata.

The deposition of complement components (Clq, C4 C3, C5 and C9) and properdin in scalp hair follicles was examined by the immunofluorescence method in patients with alopecia areata and in normal subjects. C3, C5 and C9 were found deposited there. The complement deposition was most frequent in the case of C3 and less frequent in C9 and C5. There was no difference regarding deposition between normal subjects and patients with alopecia areata. No deposition of Clq, C4 or properdin was observed in the hair follicles of the scalp. These findings suggest a relationship between the hair cycle and the activity of C3 and its late complement components in the scalp.

Adolescent↗
PubMed1976

[Properties and the protein composition of lymph and blood in burns].

Experiments conducted on 25 dogs demonstrated that burn was accompanied by a regular redistribution of plasma proteins between the fluid media of the organism and an intensification of lymphogenic resorption. Properdin, albumin, and alpha2-globulin retardation in tissues in case of burn was demonstrated indirectly. The degree of burn proved to depend on the initial properdin level.

Alpha-Globulins↗
PubMed1980

Hyaline arteriolar nephrosclerosis. Immunofluorescence findings in the vascular lesions.

Of 536 renal specimens examined by direct immunofluorescence in the past 2 years, 153 contained vascular deposits of C3 without associated immunoglobulin or fibrin deposition. Excluding vasculitides, renal transplants, and outside cases with inadequate clinical data, 110 were selected for further study. Light microscopy showed periodic acid-Schiff-positive hyaline vascular deposits in 83 cases, and large electron-dense deposits were identified by electron microscopy in 47 cases. Fifty-one patients had immunologic glomerular disease in addition to hyaline arteriolar nephrosclerosis. Albumin, transferrin, and alpha-2 macroglobulin were not detected in the vessel walls of several selected cases so tested, indicating that passive diffusion probably does not explain C3 deposition. However, properdin was present in 11 of 14, and C4 in two of 11. The mechanism for this association between C3 and properdin deposition and hyaline arteriolar nephrosclerosis is not clear at present, but our findings suggest possible involvement of the alternative pathway of the complement system.

Adolescent↗
PubMed1976

Immunofluorescence patterns in chronic membranoproliferative glomerulonephritis (MPGN).

90 patients, whose renal biopsies showed on light microscopy a pattern of MPGN, have been studied by immunofluorescence. 10 cases showed dense intramembranous deposits. Fluoresceinated antisera against IgG, IgA, IgM, C3, fibrinogen, IgD, IgE, C4, C1q, properdin and C3A were employed. Granular depostis of C3 were observed in all cases; IgG, IgM, properdin, C1q and C4 were found in 2/3 cases; IgA, IgE and C3A were rarely found. The localization of these deposits was parietal and often also mesangial. On the basis of glomerular deposition of C3 with or without immunoglobulins (Ig), we separated the cases into three groups: 1) C3 + Ig (59 cases), 2) predominant C3 (19 cases), 3) isolated C3 (12 cases). Most patients with dense deposits disease were classified in the third group. Deposits of C1q and C4 were found only in the first two groups. The localization of C3 deposits showed a more frequent mesangial extension in the second and third groups. Patients in these 3 groups also had different serum complement profiles. No significant differences in the major clinical features could be found in the 3 groups. Variable immunofluorescence patterns, in agreement with other serological parameters, confirm the heterogeneity of pathogenetic mechanisms in patients with MPGN.

Complement C1↗
PubMed1975

Phylogeny of complement components in non-human primates.

The antigenic properties and functional activities of complement components were analyzed in primates to determine their relative evolutionary development. The sera of eight different sub-human primate species were examined by double diffusion in agar and compared to a pool of human serum with rabbit and goat antisera to human complement components Clq, Cls, C4, C2 C3, C5, C6, C8, C9, properdin, factor B (B), and C1 inhibitor. There are no apparent antigenic differences in complement proteins between man and the apes except for C1q. Old world monkeys are antigenically deficient in Clq,C1s, C9, and variably deficient in C4, C3, and C8. New World monkeys are antigenically deficient in all components (measured) except C5, C6, and properdin factor B. Prosimians are antigenically deficient in all components. Functional analyses of complement components showed similar levels in man and primates, except in prosimians. There is a dissociation between hemolytic assays and antigenic analyses, suggesting that functional sites may be separate from antigenic sites.

Absorption↗
PubMed1975

Studies of the alternate pathway in chelated serum.

Activation of the alternate pathway in chelated serum by cobra venom factor (Co F), endotoxin of Escherichia coli, inulin, and zymosan was studied by immunoelectroprhoresis, radial immunodiffusion, and complement fixation tests. In serum chelated by 10 mM EGTA and 10 mM MgCl-2 (10 mM MgEGTA) activation by the classical pathway was blocked, but activation of C3PA and C3 occurred normally. By radial immunodiffusion assay, consumption of C3 and properdin was demonstrated to be similar to consumption in nonchelated sera. By immunoelectrophoresis, C3PA and C3 were shown to be activated by CoF in serum chelated with 6 mM but not with 10 mM EGTA without added Mg++. Inulin and endotoxin did not result in activation of either C3PA or C3, while C3PA but not C3 was activated by zymosan in the presence of 10 mM EGTA without Mg++ added. Consumption of properdin and C3, measured by radial immunodiffusion, was inhibited by 6 to 10 mM EGTA following activation by inulin, but not following activation by zymosan. The usefulness of 10 mM MgEGTA-chelated serum for the selective investigation of the alternate pathway in chemotaxis was demonstrated.

Blood Protein Electrophoresis↗
PubMed1977

Membranoproliferative glomerulonephritis with disruption of the glomerular basement membrane.

Seven patients with a form of membranoproliferative glomerulonephritis distinct in its glomerular ultrastructure from other forms are described. The use of silver impregnated electron micrographs revealed contiguous subepithelial and subendothelial deposits associated with basement membrane disruption, replication and layering of lamina densalike material. By light and fluorescence microscopy the appearance was distinctive but not diagnostic. Immunohistology consistently showed abundant C3 and properdin in a granular pattern while immunoglobulins and Clq were variably present. Low serum C3 concentrations were observed at some time in each patient, often accompanied by low levels of properdin, whereas the concentrations of Clq and C4 were normal. The patients were indistinguishable in their clinical course from those with other types of MPGN.

Basement Membrane↗
PubMed1977

[Non-specific immunity of persons exposed to contaminants emitted by nitrogen plants].

The examinations of methemoglobin and properdine levels as well as of the function of peripheral blood leukocytes in the tetranitrozolic blue reduction test (NBT) were performed in the exposed persons. The obtained results were compared with those of the control group, using statistical methods. It has been found that in persons exposed to the emitted contaminants occurs the increase of methemoglobin level, the decrease of peoperdine level and a disturbed phagocytes function. The recorded changes in the factors of nonspecific immunology, i.e. of properdine and phagocytes, can favour the development of inflammatory processes and of nonspecific diseases of the respiratory system.

Adult↗
PubMed1996

Inhibition of human complement by a C3-binding peptide isolated from a phage-displayed random peptide library.

We have screened a phage-displayed random peptide library for binding to C3b, the proteolytically activated form of complement component C3, and have identified a novel peptide that suppresses complement activation. This phage-displayed peptide bound to C3, C3b, and C3c, but not to C3d, indicating that it binds to the C3c region of C3. A synthetic 27-amino acid peptide corresponding to the phage-displayed peptide also bound to C3 and C3 fragments and inhibited both the classical and alternative pathways of complement activation. The inhibition of complement activation was reversible. Studies with overlapping peptides indicated that the functional activity was located in the cyclic 13-amino acid N-terminal region (ICVVQDWGHHRCT) of the parent peptide. Reduction and alkylation of this 13-residue synthetic peptide destroyed its inhibitory activity. Analysis of the mechanism of inhibition revealed that the peptide inhibited C3 cleavage in normal human serum as well as when the alternative pathway was reconstituted with purified complement components, and the observed inhibition was not due to sterically hindered access to the C3a/C3b cleavage site. Further, the peptide did not inhibit the cleavage of factor B, indicating that it did not affect the interaction of CA with factor B or the formation of C3b,Bb. The peptide also had no effect on the binding of properdin to C3, demonstrating that the observed inhibition of C3 cleavage in normal human serum was not due in part to its effect on the properdin-stabilized C3 convertase, C3b,Bb,P. These results indicate that the peptide we have identified interacts with C3 to inhibit its activation.

Amino Acid Sequence↗
PubMed1977

Complement activation in semisolid media: insolubilization of alternative pathway convertases in agar gels with C3 nephritic factor-containing sera.

It was previously shown that when normal human serum and purified properdin or serum containing nephritic factor were allowed to diffuse toward each other in agar, a stainable precipitin line formed only in the presence of an intact alternative pathway. In the present study we have shown that when guinea pig erythrocytes were incorporated in agar and normal human serum was allowed to diffuse toward C3 nephritic factor-containing serum, a line of hemolysis appeared that coincided with the stainable line. The line of hemolysis only formed in the presence of C3, factor B and Mg++, as does the properdin or C3 nephritic factor-induced stainable line. When C2-deficient serum was incorporated in agar with guinea pig erythrocytes and serum samples containing nephritic factor were applied in wells, rings of lysis developed, the areas of which correlated significantly with nephritic factor activity. When partially purified nephritic factor (contaminated only with IgG) or serum containing nephritic factor was subjected to electrophoresis in agar-guinea pig erythrocyte gels and overlaid with normal human serum, bands of lysis developed that required factor B and C3. Lysis of guinea pig erythrocytes in this system appears to be due to insolubilization of alternative pathway convertases with activation of the membrane attack unit C5-C9.

Complement C3↗
PubMed1977

[Alteration of the natural humoral immunity in experimental diphtheritic infection induced by different doses of the agent].

The authors carried out a complex study of natural humoral immunity factors in rabbits experimentally infected with various doses of diphtheria bacillus (500, 200, 100, 50 and 1 million, 10 000 and 1000 microorganisms). Natural protection factors--the complement, properdin, and lysozyme proved to undergo similar dynamic changes with each infection dose. The extent and direction of the changes depended on the infection dose. No significant natural immunity changes were caused by a low dose. A dose of 10 000 microbes caused stimulation of properdin and lysozyme activity. Dose of 1, 5, and 50 million suppressed the activity of all the components, the most pronounced with the later dose. Changes occurring with the doses of 200 and 100 million microbes were phasic in character.

Animals↗
PubMed1977

[Effect of several biologically active substances on the reactivity and immune response of the body].

Experiments were carried out with a total of 140 guinea pigs to study the effect of a tissue emulsion of swine embryos on some of the general defense reactions, the cell and humoral immunity of the organism in the treatment with an intact and a killed (with 3 per cent formalin) vaccine produced with two strains of Salmonella abortus ovis. Investigated were the phagocytic activity of the lung macrophages and the immobile cells of the reticulo-endothelial system in the spleen and the liver, the protein spectrum, the blood serum level of properdine, and the histologic changes in the parenchymal organs of the test animals. It was found that the application of a tissue emulsion simultaneously with the injection of the animals with an anti-Salmonella vaccine raised the unspecific reactivity of the organism. This was expressed with the rise of the gammaglobulin and properdine levels of the blood serum and the change in the immunologic pattern of the organism, an increase in the phagocytic activity of lung macrophages and RES immobile cells from 16 to 25 per cent, and the titer of agglutinins--from 10 to 32 times. Highest agglutinin titers of the blood and most active phagocytic defense were reached with the use of a vaccine having a whole antigen, combined with a tissue emulsion.

Adjuvants, Immunologic↗
PubMed1976

Activation of the alternative pathway of the complement system by radiographic contrast media.

Nine patients who underwent radiographic contrast media (RCM) infusion for diagnostic purposes were studied. Simultaneously, venous blood samples were collected and complement was measured. None of the patients had a clinical history of allergy to previous infusion of RCM. A significant drop in plasma complement (CH50) levels was detected in five of nine patients. The drop in CH50 was observed within the first 20 min after the initiation of RCM infusion. All five patients in whom a drop in complement was found showed a decrease in hemolytic C3, properdin, and factor B. In addition, by radial immunodiffusion low levels of C3, C6, properdin, and factor B were observed and split products of C3 and factor B were identified by immunoelectrophoresis. No significant changes in C1q and C4 were detected by radial immunodiffusion during the study of these five patients. This study strongly suggested that in some patients undergoing RCM infusion, activation of the complement system occurred and this activation appears to be through the alternative pathway.

Complement C1↗
PubMed1990

Cicatricial pemphigoid. Identification of two distinct sets of epidermal antigens by IgA and IgG class circulating autoantibodies.

A patient with severe cicatricial pemphigoid demonstrated both in vivo bound and circulating anti-basement membrane zone antibodies of the IgA and IgG classes. Complement component 3 (C3) was also deposited in the basement membrane zone of lesional skin as well as in normal-appearing buccal mucosa of the patient. However, C1q was absent, while granular deposits of two factors of the alternative complement activating pathway, properdin and properdin factor B, were present only in the basement membrane zone of lesional skin, but not in normal buccal mucosa. Deposition of alternative complement pathway reactants in the lesion suggests that complement activation by IgA was associated with lesion development. Western blot analysis of the patient's serum on electrophoresed cultured keratinocyte antigens identified two distinct sets of epidermal antigens. While IgG bound antigens of 230, 205, 140, and 90 kd, the patient's IgA antibodies bound a distinct set of antigens, 180 and 130 kd. The potential pathogenic role of IgA in cicatricial pemphigoid is discussed.

Aged↗
PubMed1977

Corneal rings with gram-negative bacteria.

Corneal rings have been described with corneal ulcerations caused by Gram-negative bacteria. Corneal rings were produced by intracorneal injections of viable Pseudomonas aeruginosa as well as heat-inactivated suspensions of Gram-negative bacteria (P aeruginosa and Escherichia coli) but not Gram-positive bacteria (Staphylococcus aureus) or Freund's adjuvant. It is suggested that endotoxin is the factor responsible for their production since purified endotoxin produced corneal rings after intracorneal injection. Histopathological examination of the areas corresponding to the corneal rings disclosed that the rings represented accumulations of polymorphonuclear leukocytes. Direct immunofluorescent studies of the corneal rings revealed staining for properdin and C3 complement but not for immunoglobulins. The present report suggests that endotoxin has the ability to stimulate the alternate pathway of complement through properdin activation with the production of chemotactic fragments that attract polymorphonuclear leukocytes into the cornea.

Animals↗
PubMed1983

Association studies between Type 1 (insulin-dependent) diabetes and 27 genetic markers: lack of association between Type 1 diabetes and Kidd blood group.

One hundred and three unrelated patients with Type 1 (insulin-dependent) diabetes were typed for HLA, properdin factor B (BF), glyoxalase 1 (GLO), Kidd blood group, and 24 other genetic markers. Observed distributions of marker phenotypes among these patients were compared with those expected according to population frequencies, in an attempt to detect associations between Type 1 diabetes and the markers. Strong associations between Type 1 diabetes and both HLA and properdin factor B were confirmed, as was a lack of association between Type 1 diabetes and glyoxalase (GLO). There was an apparent deviation from Hardy-Weinberg equilibrium at the GLO locus, and statistically significant distortions in the distributions of pancreatic amylase (AMY2), galactose-1-phosphate uridyl transferase (GALT), and group-specific component (GC) among Type 1 diabetes patients, but these results are not significant when corrected for performance of multiple tests. An increase in the Lewis-negative phenotype reported elsewhere was observed here but was not statistically significant. A distortion in the distribution of Kidd types reported elsewhere was not confirmed.

Blood Group Antigens↗
PubMed1994

Immunohistological studies of complement activation after xenogeneic perfusion of a working heart model.

Transplantation of organs from one species to another leads to immediate hyperacute rejection. Activation of complement is one important factor involved in this process. Whether complement activation is induced by preformed natural antibodies (PNAbs) via the classical pathway or by an "activator surface" via the alternative pathway is unclear. In order to simulate the relevant clinical situation of animal donor/human recipient we perfused working porcine hearts ex vivo with human blood. This also offered the possibility to study the process of complement activation in a precisely defined system with human complement proteins. PNAb titer and complement lytic activity of the plasma were measured. Immunohistological stainings for IgG, IgM, C1q, C4, C3d, C5-9, factor B, and properdin were performed on tissue sections of the left ventricle. PNAb titer almost totally disappeared within the first 5 min of perfusion. Complement lytic activity of the classical pathway decreased similarly within the first 3 h of xenogeneic and autologous perfusion from 70% to 40%. More detailed immunohistological studies revealed positive staining for C3d on endothelium and myocardium of ex vivo perfused xenogeneic hearts. Complement-induced cytotoxicity was proven by the presence of C5-9 (membrane attack complex). However, hardly any C1q and C4 could be found in the ex vivo xenogeneic perfused hearts. Staining for factor B was positive and proved activation via the alternative pathway. Beyond that, the presence of properdin binding even indicated an upregulation of the alternative pathway C3 convertase.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2006

Human monocyte-derived dendritic cells are a source of several complement proteins.

OBJECTIVE: Little is known about the role of local production of complement components by dendritic cells (DCs) during the generation of specific immune responses. In this study, we demonstrate that human DCs are an extrahepatic source of several soluble complement proteins. METHODS: Reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot were used to evaluate the expression and production of several complement proteins. RESULTS: We show that DCs produce C3, C5, C9, Factor (F)I, FH, FB, FD and properdin at levels similar to macrophages. Treatment of DCs with lipopolysaccharide (LPS) promoted an increase in the expression of C3 and FI mRNAs and a decrease in C5 mRNA, while C9, FH, FB, FD and properdin mRNA levels were not affected. Treatment with interleukin (IL) -1 or dexamethasone induced a modest increase in C3 mRNA levels and did not affect the expression of other complement components. CONCLUSION: DCs are a source of complement proteins whose synthesis may be regulated in response to different inflammatory stimuli.

Complement System Proteins↗