Antibody-Complement Complexes

Abstract

Soluble complexes containing the second and fourth compoezents of guinea pig complement, as well as hemolytic rabbit antibody, have been prepared by elution from sheep erythrocytes carrying these factors. These complexes render erythrocytes susceptible to lysis by the other factors of guinea pig complement, without the usual requirements for hemolytic antibody, Ca(++), and Mg(++).

Mechanism of Solubilization of Immune Aggregates by Complement. Implications for Immunopathology

“…122 TAKAHASHI, CZOP, FERREIRA & NUSSENZWEIG bound to the surface membrane of erythrocytes and to IgG in the fluid phase. Similar observations were made by Willoughby & Mayer (1965) who presented direct evidence that hemolytically active complexes containing Ab, C4 and C2 can be eluted from erythrocytes carrying these factors. While C2 decayed quickly, the Ab-C4 interaction was quite stable and the aggregates could be directly demonstrated by chromatography on a Sephadex column.…”

Requirements for the solubilization of immune aggregates by complement. The role of the classical pathway.

“…Miiller-Eberhard and Lepow (34) as well as Willoughby and Mayer (35) had already pointed out that activation of C4 in the presence of Ig leads to the formation of Ig-C4 complexes. When disaggregation occurred in EGTA-Mg++, most solubilized complexes still contained C3 and P in the absence of C4, providing additional evidence that a factor B-dependent C3-convertase can be assembled on the Ag-Ab lattice without participation of the classical pathway (5).…”

The Activation Mechanism of Human Complement System by Immune Precipitate Formed with Rabbit IgG Antibody

“…From these results, it was evident that activation of the classical pathway led to the binding of C4 to Ippt. Muller-Eberhard and Lepow (11) as well as Willoughby and Mayer (21) had already pointed out the formation of Ig-C4 complexes. In serum chelated with ethyleneglycol tetraacetic acid (EGTA), which permitted alternative pathway activation but inhibited classical pathway activation (Sandberg and Osler, 18), C3-and C5-cleaving enzymes were formed on Ippt (Fig.…”