INTERACTION OF AVIDIN-CARRYING ERYTHROCYT ES WITH HOMOLOGOUS NUCLEATED CELLS

Modification of erythrocytes by avidin-biotin complex has been suggest ed recently for their multipurpose usage, including application. Howev er, this modification might lead to alteration of biocompatibility of avidin-coated erythrocytes. Earlier it was found that attachment of av idin induces lysis of avidin- and streptavidin-coated biotinylated ery throcytes by homologous complement. In the present work we found that avidin-coated, but not streptavidin-coated erythrocytes bind to homolo gous nucleated cells. Fibroblasts, Kupfer cells and hepatocytes posses s maximal adhesiveness, human vascular smooth muscle cells and endothe lial cells demonstrate moderate adhesivennes, while rat liver endothel ium is virtually unadhesive for avidin-coated homologous erythrocytes. In contrast with avidin-induced lysis by complement, avidin-induced a dhesion does not depend on temperature, method of avidin attachment to erythrocytes and the presence of divalent cations. Polyelectrolytes b lock adhesion to fibroblasts interacting with membrane-bound avidin an d, at less efficiency block lysis by complement, interacting with comp lement. The results obtained demonstrate that attachment of avidin to erythrocytes alters their biocompatibility due to high positive charge of avidin.