Immune complexes bind preferentially to specific subpopulations of human erythrocytes

摘要: Abstract Primate erythrocytes have complement receptors (CR1) that, both in vivo and vitro, bind immune complexes (IC) opsonized with C3b. The present study was undertaken to determine whether the ability of human IC is a characteristic shared by all erythrocytes. Binding probably involves interaction several C3b molecules CR1 clustered small areas erythrocyte surface. To identify binding clusters, we first assessed fluorescein-labeled polystyrene beads coated monoclonal anti-CR1 antibodies (anti-CR1-beads) second, preformed IC. these ligands evaluated immunofluorescence microscopy flow cytometry. We found that only fraction from normal individuals bound anti-CR1-beads specifically percentage able increased increasing numbers per erythrocyte. However, number varied among cells same individual. demonstrated further sites for are also This shown demonstrating inhibited Incubation IC, followed FITC-labeled secondary antibodies, confirmed indeed capable occupy regions on membrane. By contrast, greater than 90% express CR1. In conclusion, some capacity Differences related differences clustering Anti-CR1-beads These should prove useful assess changes occur after exposure vivo.