Interactions of Opsonized Immune Complexes with Whole Blood Cells: Binding to Erythrocytes Restricts Complex Uptake by Leucocyte Populations

摘要: The binding of opsonized, fluorescein-labelled bovine serum albumin (BSA)/rabbit anti-BSA complexes (IC) to washed human whole blood cells and isolated leucocytes in the presence autologous was investigated by flow cytometry. In erylhrocytes (E), IC-binding granulocytes (PMN), monocytes lymphocytes inhibited up 46%, 61% 48%, respectively, depending on incubation time IC-concentration tested. E-mediated inhibition PMN found correlate with average numbers CR1 per E during initial 15 min incubation. Thereafter, difference between IC absence E, decreased accordance decreasing E. IC-uptake induced a drop side-scatter characteristics, attributable degranulation, which could be prevented contrast findings for PMN, increased progressively over 90 observation period, suggesting that different mechanisms are involved late-phase uptake PMN. Lymphocytes were heterogeneous respect binding, main contributors being B cells. initially then later enhanced lymphocytes, promote cell C3d, g-covered via CR2. Our findings, can restrict circulating leucocytes, an IC-induced degranulation may indicate act as high capacity buffer limiting inappropriate activation phagocytes