Immunoglobulin G receptor-mediated phagocytosis by the pigmented epithelium of the ciliary processes.
The current ultrastructural study of cultured explants of bovine and rabbit posterior ciliary processes using immunoglobulin (Ig) G-opsonized red blood cells (E-IgG) showed specific IgG Fc receptor-mediated attachment, ingestion, and digestion of IgG-coated erythrocytes by the pigmented epithelium (PE). Nonpigmented epithelial cells (NPE) in the cultured explants and a transformed cell line of bovine NPE, with and without lymphokine stimulation, did not have IgG-receptor activity. The interaction between PE and E-IgG involved the extension of micropseudopods toward adherent E-IgG, the formation of a linear uniform cap of roughly 200 A between opposing cell membranes, the ingestion of E-IgG by PE into a membrane-lined compartment, and the disintegration of the ingested ligand into membranous debris. Disintegration of some surface-associated E-IgG was also observed and was consistent with the release of a lytic substance by the receptor-activated PE.
Peress
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NS
Research & Development Service, Department of Veterans Affairs Medical Center, Northport, New York.
Perillo
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E
D000818:Animals; D000943:Antigens, Differentiation / Q000276:immunology*; D002417:Cattle; D002448:Cell Adhesion; D002478:Cells, Cultured; D002924:Ciliary Body / Q000276:immunology* / Q000648:ultrastructure; D004912:Erythrocytes / Q000276:immunology / Q000648:ultrastructure; D007074:Immunoglobulin G / Q000276:immunology*; D008024:Ligands; D009895:Opsonin Proteins / Q000276:immunology; D010587:Phagocytosis / Q000276:immunology*; D010857:Pigment Epithelium of Eye / Q000276:immunology* / Q000648:ultrastructure; D011817:Rabbits; D011961:Receptors, Fc / Q000276:immunology*; D017452:Receptors, IgG; D012397:Rosette Formation; D012756:Sheep
D000943:Antigens, Differentiation; D007074:Immunoglobulin G; D008024:Ligands; D009895:Opsonin Proteins; D011961:Receptors, Fc; D017452:Receptors, IgG