TANNIN-MEDIATED ATTACHMENT OF AVIDIN TO ERYTHROCYTES DOES NOT CAUSE THEIR COMPLEMENT-MEDIATED LYSIS

Avidin, when attached to biotinylated erythrocytes, was previously sho wn to cause their lysis via homologous complement. We show here that a ttachment of avidin to erythrocytes with tannin does nor induce such l ysis. In this case the surface density of avidin on the erythrocyte me mbrane is comparable to its density obtained by immobilization mediate d by biotin ester Treatment with tannin alone slightly decreased the r esistance of erythrocytes to complement-mediated lysis in the presence of activators (hemolytic antibodies or activators of the alternative pathway). The avidin-induced complement-mediated lysis depends on the means of attachment of avidin to erythrocytes. Tannin-treated avidin-c oated erythrocytes bind biotinylated immunoglobulins, display high aff inity for antigen-coated surfaces, and therefore can be used as contai ners for directed transport. In addition, we show that these erythrocy tes can be lysed in the presence of hemolytic antibodies, a property t hat can be used for their opening at the target sites.