IMMUNE-COMPLEX ALTERATIONS OCCUR ON THE HUMAN RED-BLOOD-CELL MEMBRANE

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  • 1 January 1983
    • journal article
    • research article
    • Vol. 50  (1) , 11-18
Abstract
Experimental antigen-antibody complexes (Ag-Ab) were incubated at 37.degree. C with human red blood cells (RBC) suspended in autologous normal serum and the reaction stopped after progressively increasing times. Bound antigen-antibody-complement complexes (Ag-Ab-C) were eluted from C3b [complement component 3b] receptors and the eluted Ag-Ab-C reincubated with different blood cell types suspended in serum or centrifuged (along with unbound Ag-Ab-C found in the serum) through 20-50% sucrose gradients. Ag-Ab-C recovered from C3b receptors shortly after initial binding to RBC bound efficiently to other RBC, polymorphonuclear and mononuclear cells and sedimented rapidly. Ag-Ab-C simultaneously present in the serum sedimented with a similar velocity. Ag-Ab-C recovered at a subsequent time during RBC interaction bound less well to each blood cell type and sedimented less rapidly. Decreased amounts of rapidly sedimenting Ag-Ab-C were present in the serum. Ag-Ab-C recovered from C3b receptors at a still later time in the course of RBC interaction bound poorly to each cell type and sedimented slowly. Increased amounts of slowly sedimenting Ag-Ab-C were found in the serum. Apparently, alterations in properties of immune complexes can occur while they are associated with C3b receptor on RBC membrane in solid phase.