ENHANCED DEGRADATION OF SOLUBLE IMMUNE-COMPLEXES BY GUINEA-PIG PERITONEAL-MACROPHAGES IN THE PRESENCE OF COMPLEMENT

  • 1 January 1981
    • journal article
    • research article
    • Vol. 43  (2) , 345-352
Abstract
The role of complement [c] in the processing of soluble immune complexes [IC] by guinea pig peritoneal macrophages was studied in an homologous system in vitro by using IC prepared with bovine thyroglobulin as the antigen and guinea pig IgG2 antibodies. The simplest complexes showing complement activation and which were degradable by macrophages had a composition of Ag1 Ab2-3. C had an enhancing effect on the degradation of IC which had an antibody:antigen ratio in the complexes which was at least 4 (Ag1 Ab4). The effect of size on C activation and degradation of the IC by macrophages was studied by employing the observation that IC increase in size during their preparation. In the presence of serum as a C source, degradation of small IC by macrophages was inhibited but the degradation of large IC was enhanced. The enhanced IC degradation in the presence of fresh serum did not occur in C4-deficient serum or in EDTA-serum; the observed effect apparently is C-mediated. Evidently C may play an important role in IC elimination in vivo.