HUMAN-IGG IN IMMUNE-COMPLEXES BOUND TO HUMAN ERYTHROCYTE CR-1 IS RECOGNIZED DIFFERENTLY THAN HUMAN-IGG BOUND TO AN ERYTHROCYTE SURFACE-ANTIGEN

We have developed several methods, including a new use of magnetic cel l separation techniques, to examine how human IgG bound to human eryth rocytes can be recognized. We find that human IgG in complement-opsoni zed immune complexes bound to erythrocyte CR1 is less accessible to se veral probes than human IgG bound to the rhesus antigen on erythrocyte s. These findings suggest that the mechanism by which immune complexes are removed and cleared from erythrocyte CR1 in the circulation is di fferent from the mechanisms which lead to splenic clearance of IgG sen sitized erythrocytes.