Lipoprotein-antibody immune complexes. Their catabolism and role in foam cell formation.
Immune complexes consisting of human [125I]LDL or [125I]VLDL and anti-apo B IgG were prepared in vitro. After intravenous administration of these complexes or free LDL to normal rabbits the elimination rate for complexes was 2-3-fold higher than for free lipoproteins. The liver/spleen radioactivity ratio after administration of immune complexes was 34% less than after administration of free lipoproteins. Investigations carried out on the cell cultures have shown that during 4-h incubation the uptake of [125I]LDL-anti-apo B IgG complex by human lung fibroblasts was lower than uptake of free [125I]LDL, whereas mouse peritoneal macrophages took up immune complex more actively than free LDL. During 3 days of incubation of macrophages with LDL-anti-apo B IgG the transformation of macrophages into foam cells was observed. This process was accompanied by almost a 60-fold increase of cholesteryl ester content in the cell. It is suggested that excessive uptake of lipoprotein-antibody complexes by macrophages leading to formation of foam cells may play an important role in atherogenesis.
D000818:Animals; D000936:Antigen-Antibody Complex / Q000378:metabolism*; D001055:Apolipoproteins B / Q000276:immunology / Q000378:metabolism; D001161:Arteriosclerosis / Q000209:etiology; D001693:Biological Transport, Active; D005487:Foam Cells / Q000276:immunology* / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D066298:In Vitro Techniques; D008074:Lipoproteins / Q000276:immunology* / Q000378:metabolism; D008077:Lipoproteins, LDL / Q000276:immunology / Q000378:metabolism; D008079:Lipoproteins, VLDL / Q000276:immunology / Q000378:metabolism; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism / Q000648:ultrastructure; D051379:Mice; D008854:Microscopy, Electron; D011817:Rabbits
D000936:Antigen-Antibody Complex; D001055:Apolipoproteins B; D007074:Immunoglobulin G; D008074:Lipoproteins; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL