COMPLEMENT COATING OF ERYTHROCYTES IS REDUCED FOLLOWING THEIR INTERACTION WITH NEUTROPHILS IN-VITRO WITHOUT LOSS OF COMPLEMENT-RECEPTOR-1 (CR-1)

We have investigated the interaction of complement-coated erythrocytes (E) with neutrophils, in vitro, to determine the effects of erythrocy te CR1. Complement-coating in vitro, to mimic immune complex uptake, c aused a reduction in E-CR1, but subsequent interaction with neutrophil s effected a removal of E-C3b and a return of E-CR1 to levels approxim ating that of uncoated erythrocytes. These data indicate that C3b, ass ociated with immune complexes, may bind to E-CR1 in a reversible manne r and that subsequent interaction with phagocytes need not necessarily result in cleavage (and loss of) E-CR1. Further, we conclude that E-C R1 can apparently be reduced by epitope masking.