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. 1987 Jun;61(2):105–110.

Formation of C3-IgG complexes in serum by aggregated IgG and by non-immunoglobulin activators of complement.

A P van Dam, C E Hack
PMCID: PMC1453373  PMID: 3596635

Abstract

We studied the generation of C3-IgG complexes during the activation of C3 in serum by aggregated human IgG (AHG), zymosan or cobra venom factor (CVF). C3-IgG complexes were detected by specific radioimmunoassays: samples to be tested were incubated with anti-IgG Sepharose, and complexes that had bound to the Sepharose were detected by incubation with either 125I-anti-C3c or 125I-anti-C3d, g. Incubation of serum with as little as 6 micrograms AHG per ml, for 30 min at 37 degrees, resulted in the generation of C3-IgG complexes. When serum was incubated with zymosan or CVF, C3-IgG complexes were also generated. AHG appeared to be more effective in the generation of C3-IgG complexes than CVF. We calculated that AHG (2 mg/ml) caused about 36% of the C3 to be fixed to IgG, CVF (400 micrograms/ml) about 14%. Finally, the presence of C3 fixed to IgG in serum incubated with CVF was demonstrated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), followed by immunoblotting. This study indicates that the formation of C3-IgG complexes in serum is not only induced by immune complexes but also by non-immunoglobulin activators. Therefore, C3-IgG complexes might be considered as complement activation products, and their detection in patients' samples should not be considered as conclusive evidence for the presence of immune complexes.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Alper C. A., Rosen F. S. Alper CA, Rosen FS: Studies of the in vivo behavior of human C'3 in normal subjects and patients. J Clin Invest. 1967 Dec;46(12):2021–2034. doi: 10.1172/JCI105691. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Ballow M., Cochrane C. G. Two anticomplementary factors in cobra venom: hemolysis of guinea pig erythrocytes by one of them. J Immunol. 1969 Nov;103(5):944–952. [PubMed] [Google Scholar]
  3. Capel P. J., Groeneboer O., Grosveld G., Pondman K. W. The binding of activated C3 to polysaccharides and immunoglobulins. J Immunol. 1978 Dec;121(6):2566–2572. [PubMed] [Google Scholar]
  4. Casali P., Bossus A., Carpentier N. A., Lambert P. H. Solid-phase enzyme immunoassay or radioimmunoassay for the detection of immune complexes based on their recognition by conglutinin: conglutinin-binding test. A comparative study with 125I-labelled Clq binding and Raji-cell RIA tests. Clin Exp Immunol. 1977 Aug;29(2):342–354. [PMC free article] [PubMed] [Google Scholar]
  5. Czop J., Nussenzweig V. Studies on the mechanism of solubilization of immune precipitates by serum. J Exp Med. 1976 Mar 1;143(3):615–630. doi: 10.1084/jem.143.3.615. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Eisenberg R. A., Theofilopoulos A. N., Dixon F. J. Use of bovine conglutinin for the assay of immune complexes. J Immunol. 1977 Apr;118(4):1428–1434. [PubMed] [Google Scholar]
  7. Fries L. F., Gaither T. A., Hammer C. H., Frank M. M. C3b covalently bound to IgG demonstrates a reduced rate of inactivation by factors H and I. J Exp Med. 1984 Dec 1;160(6):1640–1655. doi: 10.1084/jem.160.6.1640. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Gadd K. J., Reid K. B. The binding of complement component C3 to antibody-antigen aggregates after activation of the alternative pathway in human serum. Biochem J. 1981 May 1;195(2):471–480. doi: 10.1042/bj1950471. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Hack C. E., Belmer A. J. The IgG detected in the C1q solid-phase immune-complex assay is not always of immune-complex nature. Clin Immunol Immunopathol. 1986 Jan;38(1):120–128. doi: 10.1016/0090-1229(86)90129-7. [DOI] [PubMed] [Google Scholar]
  10. Hack C. E., Eerenberg-Belmer A. J., Hannema A. J., Out T. A., Aalberse R. C. Polyethylene glycol enhances the binding of C1q to circulating immune complexes. J Immunol Methods. 1981;44(2):211–221. doi: 10.1016/0022-1759(81)90349-5. [DOI] [PubMed] [Google Scholar]
  11. Hack C. E., Hannema A. J., Eerenberg-Belmer A. J., Out T. A., Aalberse R. C. A C1-inhibitor-complex assay (INCA): a method to detect C1 activation in vitro and in vivo. J Immunol. 1981 Oct;127(4):1450–1453. [PubMed] [Google Scholar]
  12. Hack C. E., Paardekooper J., Hannema A. J. Influence of C3 level on the determination of C3d in plasma and synovial fluid by radial immunodiffusion. J Immunol Methods. 1986 Feb 12;86(2):191–198. doi: 10.1016/0022-1759(86)90452-7. [DOI] [PubMed] [Google Scholar]
  13. Hoekzema R., Hannema A. J., Swaak T. J., Paardekooper J., Hack C. E. Low molecular weight C1q in systemic lupus erythematosus. J Immunol. 1985 Jul;135(1):265–271. [PubMed] [Google Scholar]
  14. Jacobs R. J., Reichlin M. Generation of low m.w., C3-bearing immunoglobulin in human serum. J Immunol. 1983 Jun;130(6):2775–2781. [PubMed] [Google Scholar]
  15. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  16. Miller G. W., Nussenzweig V. A new complement function: solubilization of antigen-antibody aggregates. Proc Natl Acad Sci U S A. 1975 Feb;72(2):418–422. doi: 10.1073/pnas.72.2.418. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Müller-Eberhard H. J., Schreiber R. D. Molecular biology and chemistry of the alternative pathway of complement. Adv Immunol. 1980;29:1–53. doi: 10.1016/s0065-2776(08)60042-5. [DOI] [PubMed] [Google Scholar]
  18. Nicol P. A., Lachmann P. J. The alternate pathway of complement activation. The role of C3 and its inactivator (KAF). Immunology. 1973 Feb;24(2):259–275. [PMC free article] [PubMed] [Google Scholar]
  19. Pangburn M. K., Müller-Eberhard H. J. Relation of putative thioester bond in C3 to activation of the alternative pathway and the binding of C3b to biological targets of complement. J Exp Med. 1980 Oct 1;152(4):1102–1114. doi: 10.1084/jem.152.4.1102. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Pangburn M. K., Schreiber R. D., Müller-Eberhard H. J. Formation of the initial C3 convertase of the alternative complement pathway. Acquisition of C3b-like activities by spontaneous hydrolysis of the putative thioester in native C3. J Exp Med. 1981 Sep 1;154(3):856–867. doi: 10.1084/jem.154.3.856. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Pereira A. B., Theofilopoulos A. N., Dixon F. J. Detection and partial characterization of circulating immune complexes with solid-phase anti-C3. J Immunol. 1980 Aug;125(2):763–770. [PubMed] [Google Scholar]
  22. Ross G. D., Medof M. E. Membrane complement receptors specific for bound fragments of C3. Adv Immunol. 1985;37:217–267. doi: 10.1016/s0065-2776(08)60341-7. [DOI] [PubMed] [Google Scholar]
  23. Sim R. B., Twose T. M., Paterson D. S., Sim E. The covalent-binding reaction of complement component C3. Biochem J. 1981 Jan 1;193(1):115–127. doi: 10.1042/bj1930115. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Tack B. F., Harrison R. A., Janatova J., Thomas M. L., Prahl J. W. Evidence for presence of an internal thiolester bond in third component of human complement. Proc Natl Acad Sci U S A. 1980 Oct;77(10):5764–5768. doi: 10.1073/pnas.77.10.5764. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Takata Y., Tamura N., Fujita T. Interaction of C3 with antigen-antibody complexes in the process of solubilization of immune precipitates. J Immunol. 1984 May;132(5):2531–2537. [PubMed] [Google Scholar]
  26. Theofilopoulos A. N., Wilson C. B., Dixon F. J. The Raji cell radioimmune assay for detecting immune complexes in human sera. J Clin Invest. 1976 Jan;57(1):169–182. doi: 10.1172/JCI108257. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Vogel C. W., Müller-Eberhard H. J. Cobra venom factor: improved method for purification and biochemical characterization. J Immunol Methods. 1984 Oct 12;73(1):203–220. doi: 10.1016/0022-1759(84)90045-0. [DOI] [PubMed] [Google Scholar]

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