Circulating and tissue-bound immune complex formation in murine malaria.
Immune complex formation during Plasmodium berghei infection of OF1 mice was investigated. Circulating immune complexes (CIC) were detected by the Clg-binding assay and the conglutinin-binding solid-phase assay in lethal or drug-limited infections. CIC appeared on day 9 of infection, peaked on day 11, and disappeared only after complete cure of the infection. Analysis of the immune complexes detected by the Clq-binding assay revealed the following characteristics: sedimentation coefficients of 13S to 21S, resistance to DNAse, and selective removal by filtration through protein A bound to Sepharose. Glomerular deposits of IgM preceded the appearance of CIC, whereas deposits of IgG and C3 were concomitant with the appearance of CIC. Tissue-bound immunoglobulins were also found in the choroid plexus. The appearance of anti-malarial antibodies and malarial antigens in the serum was closely associated with a depression of C3 levels and the presence of CIC. Drug treatment was followed by normalization of C3 levels, and clearance of both CIC and malarial antigens.
D000818:Animals; D000906:Antibodies; D000936:Antigen-Antibody Complex; D000941:Antigens; D001665:Binding Sites; D003172:Complement C1; D003176:Complement C3; D003168:Complement Fixation Tests; D005260:Female; D007668:Kidney / Q000276:immunology; D008288:Malaria / Q000276:immunology* / Q000469:parasitology; D051379:Mice; D010962:Plasmodium berghei / Q000276:immunology; D010965:Plasmodium malariae / Q000276:immunology
D000906:Antibodies; D000936:Antigen-Antibody Complex; D000941:Antigens; D003172:Complement C1; D003176:Complement C3