scholarly journals Mannan-Specific Immunoglobulin G Antibodies in Normal Human Serum Accelerate Binding of C3 to Candida albicans via the Alternative Complement Pathway

1998 ◽  
Vol 66 (10) ◽  
pp. 4845-4850 ◽  
Author(s):  
Mason X. Zhang ◽  
Thomas R. Kozel
Keyword(s):  
Candida Albicans ◽  
Human Serum ◽  
Immunoglobulin G ◽  
Alternative Pathway ◽  
Normal Human Serum ◽  
Yeast Cells ◽  
Classical Pathway ◽  
Intact Antibody ◽  
Alternative Complement ◽  
Normal Human

ABSTRACT Candida albicans activates the classical and alternative complement pathways, leading to deposition of opsonic complement fragments on the cell surface. Our previous studies found that antimannan immunoglobulin G (IgG) in normal human serum (NHS) allows C. albicans to initiate the classical pathway. The purpose of this study was to determine whether antimannan IgG also plays a role in initiation of the alternative pathway. Pooled NHS was rendered free of classical pathway activity by chelation of serum Ca2+ with EGTA alone or in combination with immunoaffinity removal of antimannan antibodies. Kinetic analysis revealed a 6-min lag in detection of C3 binding to C. albicans incubated in EGTA-chelated NHS, compared to a 12-min lag in NHS that was both EGTA chelated and mannan absorbed. The 12-min lag was shortened to 6 min by addition of affinity-purified antimannan IgG. The accelerating effect of antimannan IgG on alternative pathway initiation was dose dependent and was reproduced in a complement binding reaction consisting of six purified proteins of the alternative pathway. Both Fab and F(ab′)2 fragments of antimannan IgG facilitated alternative pathway initiation in a manner similar to that observed with intact antibody. Immunofluorescence analysis showed that addition of antimannan IgG to EGTA-chelated and mannan-absorbed serum promoted an early deposition of C3 molecules on the yeast cells but had little or no effect on distribution of the cellular sites for C3 activation. Thus, antimannan IgG antibodies play an important regulatory role in interactions between the host complement system and C. albicans.

scholarly journals Simple Method To Distinguish between Primary and Secondary C3 Deficiencies

2003 ◽  
Vol 10 (2) ◽  
pp. 216-220
Author(s):  
Marlene Pereira de Carvalho Florido ◽  
Patrícia Ferreira de Paula ◽  
Lourdes Isaac
Keyword(s):  
Human Serum ◽  
Complement System ◽  
Factor H ◽  
Normal Human Serum ◽  
Alternative Complement Pathway ◽  
Complement Pathway ◽  
Factor B ◽  
Alternative Complement ◽  
Normal Human ◽  
The Complement System

ABSTRACT Due to the increasing numbers of reported clinical cases of complement deficiency in medical centers, clinicians are now more aware of the role of the complement system in the protection against infections caused by microorganisms. Therefore, clinical laboratories are now prepared to perform a number of diagnostic tests of the complement system other than the standard 50% hemolytic component assay. Deficiencies of alternative complement pathway proteins are related to severe and recurrent infections; and the application of easy, reliable, and low-cost methods for their detection and distinction are always welcome, notably in developing countries. When activation of the alternative complement pathway is evaluated in hemolytic agarose plates, some but not all human sera cross-react to form a late linear lysis. Since the formation of this linear lysis is dependent on C3 and factor B, it is possible to use late linear lysis to routinely screen for the presence of deficiencies of alternative human complement pathway proteins such as factor B. Furthermore, since linear lysis is observed between normal human serum and primary C3-deficient serum but not between normal human serum and secondary C3-deficient serum caused by the lack of factor H or factor I, this assay may also be used to discriminate between primary and secondary C3 deficiencies.

A V region-connected autoreactive subfraction of normal human serum immunoglobulin G

1992 ◽  
Vol 22 (7) ◽  
pp. 1701-1706 ◽  
Author(s):  
Gilles Dietrich ◽  
Srinivas-Venkatesh Kaveri ◽  
Michel D. Kazatchkine
Keyword(s):  
Human Serum ◽  
Immunoglobulin G ◽  
Normal Human Serum ◽  
Serum Immunoglobulin ◽  
Normal Human ◽  
V Region

scholarly journals Complement Interaction with Trypanosomatid Promastigotes in Normal Human Serum

2002 ◽  
Vol 195 (4) ◽  
pp. 451-459 ◽  
Author(s):  
Mercedes Domínguez ◽  
Inmaculada Moreno ◽  
Margarita López-Trascasa ◽  
Alfredo Toraño
Keyword(s):  
Human Serum ◽  
Binding Capacity ◽  
Normal Human Serum ◽  
Leishmania Infection ◽  
Classical Pathway ◽  
Classical Complement Pathway ◽  
Ethylenediaminetetracetic Acid ◽  
Human Sera ◽  
Normal Human

In normal human serum (NHS), axenic promastigotes of Crithidia, Phytomonas, and Leishmania trigger complement activation, and from 1.2 to 1.8 × 105 C3 molecules are deposited per promastigote within 2.5 min. In Leishmania, promastigote C3 binding capacity remains constant during in vitro metacyclogenesis. C3 deposition on promastigotes activated through the classical complement pathway reaches a 50% maximum after ∼50 s, and represents >85% of total C3 bound. In C1q- and C2-deficient human sera, promastigotes cannot activate the classical pathway (CP) unless purified C1q or C2 factors, respectively, are supplemented, demonstrating a requirement for CP factor in promastigote C3 opsonization. NHS depleted of natural anti-Leishmania antibodies cannot trigger promastigote CP activation, but IgM addition restores C3 binding. Furthermore, Leishmania binds natural antibodies in ethylenediaminetetracetic acid (EDTA)-treated NHS; after EDTA removal, promastigote-bound IgM triggers C3 deposition in natural antibody-depleted NHS. Serum collectins and pentraxins thus do not participate significantly in NHS promastigote C3 opsonization. Real-time kinetic analysis of promastigote CP-mediated lysis indicates that between 85–95% of parasites are killed within 2.5 min of serum contact. These data indicate that successful Leishmania infection in man must immediately follow promastigote transmission, and that Leishmania evasion strategies are shaped by the selective pressure exerted by complement.

Factor J, an inhibitor of the complement classical pathway: The quantitation by an ELISA inhibition assay in normal human serum

1994 ◽  
Vol 27 (3) ◽  
pp. 169-176 ◽  
Author(s):  
Miguel Angel Jiménez-Clavero ◽  
Carolina González-Rubio ◽  
Gumersindo Fontán ◽  
Margarita López-Trascasa
Keyword(s):  
Human Serum ◽  
Normal Human Serum ◽  
Classical Pathway ◽  
Inhibition Assay ◽  
Normal Human ◽  
Elisa Inhibition

scholarly journals Novel C5-Dependent Mechanism of Neutrophil Stimulation by Bioincompatible Dialyzer Membranes

1999 ◽  
Vol 10 (1) ◽  
pp. 128-135
Author(s):  
ALEXANDER R. ROSENKRANZ ◽  
GÜNTHER F. KÖRMÖCZI ◽  
FLORIAN THALHAMMER ◽  
ERNST J. MENZEL ◽  
WALTER H. HÖRL ◽  
...  
Keyword(s):  
Human Serum ◽  
Alternative Pathway ◽  
Reactive Oxygen ◽  
Receptor Expression ◽  
Normal Human Serum ◽  
Reactive Oxygen Intermediate ◽  
Down Regulation ◽  
Receptor Modulation ◽  
Normal Human ◽  
Dependent Mechanism

Abstract. The objective of the study was to evaluate the contribution of reactive oxygen intermediate formation for receptor modulation on neutrophils by the cellulosic dialyzer membrane cuprophan (CU). In patients dialyzed with CU, CD11b and CD66b upregulation on neutrophils (by 104.3 ± 37.9% and 85.7 ± 31.1%, respectively), and a downregulation of L-selectin (by 44.9 ± 26.9%) was seen, whereas expression of CD11 a remained unaltered. Hemodialysis with polysulfone did not bring about major changes in surface receptor expression.In vitroincubation of isolated neutrophils in the presence of serum with hollow fibers of CU or polysulfone showed similar results: Only CU resulted in upregulation of CD11b and CD66b expression (by 65.5 ± 18.7% and 60.1 ± 24%) and a decrease in CD62L expression (by 60.6 ± 18.2%). In contrast to receptor alterations, generation of reactive oxygen intermediate by CU occurred in the absence of serum. Inhibition experiments with soluble complement receptor 1, which produced only partial inhibition of receptor up-/down-regulation, indicated the existence of also other than alternate complement-dependent mechanisms for neutrophil activation. By using C5-depleted serum instead of normal human serum, up-/down-regulation of CD11b, CD62L, and CD66b by CU was dramatically reduced, whereas C3-depleted serum did not produce that effect. C5-deficient serum repleted with purified C5, as well as purified C5 alone, was able to induce receptor modulation by CU comparable to normal human serum. L-Methionine, a specific inhibitor for the oxidative activation of C5, blocked the modulatory effect of CU in assays with purified C5 as well as with serum. As a result, in addition to the alternative pathway of complement, a C5-dependent mechanism probably activated by neutrophil-derived reactive oxygen intermediate leads to receptor modulation and subsequent generation of the well known side effects of bioincompatible dialyzer membranes.

scholarly journals Inactivation of classical and alternative pathway-activated bactericidal activity of human serum by sodium polyanetholsulfonate

1977 ◽  
Vol 5 (3) ◽  
pp. 278-284
Author(s):  
W H Traub ◽  
I Kleber
Keyword(s):  
Human Serum ◽  
Bactericidal Activity ◽  
Alternative Pathway ◽  
Inhibitory Effect ◽  
Final Concentration ◽  
Classical Pathway ◽  
Control Strain ◽  
E Coli ◽  
Alternative Complement ◽  
And Control

Sodium polyanetholsulfonate (SPS) at a final concentration of at least 250 microng/ml (0.025%) was required for inhibition of the bactericidal activity of 80% (vol/vol) of fresh human serum against "promptly serum-sensitive" strains of Serratia marcescens and control strain Escherichia coli C, i.e., for inhibition of the classical pathway of complement activation. In contrast, SPS at 125 microng/ml (0.0125%) was sufficient for neutralization of the bactericidal activity of 80% (vol/vol) fresh human serum against "delayed serum-sensitive" strains of S. marcescens known to activate the alternative pathway of human complement. Addition of up to 500 microng of SPS per ml to 80% (vol/vol) fresh human serum failed to neutralize transferrin-mediated, "late" bacteriostasis against control strain E. coli C, an effect that was demonstrable only after prolonged, i.e., overnight, incubation of the test strain. However, this late inhibitory effect against E. coli C was not observed in SPS-treated 20% (vol/vol) fresh human serum or in 10 or 20% (vol/vol) conventionally heat-inactivated human serum. Immunoelectrophoretic examination disclosed that SPS did not precipitate transferrin from either fresh or heat-inactivated human serum. Thus, SPS, at 250 microng/ml, was demonstrated to be sufficient for the inhibition of both classical and alternative complement pathway-activated bactericidal activity of 80% (vol/vol) human serum. However, SPS at a concentration of 500 microng/ml failed to antagonize one antimicrobial system of 80% (vol/vol) human serum, namely transferrin-mediated bacteriostasis.

scholarly journals Neutrophil attractant protein-1-immunoglobulin G immune complexes and free anti-NAP-1 antibody in normal human serum.

1992 ◽  
Vol 90 (2) ◽  
pp. 471-481 ◽  
Author(s):  
I Sylvester ◽  
T Yoshimura ◽  
M Sticherling ◽  
J M Schröder ◽  
M Ceska ◽  
...  
Keyword(s):  
Human Serum ◽  
Immunoglobulin G ◽  
Immune Complexes ◽  
Normal Human Serum ◽  
Normal Human
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