Interaction of radiolabelled Na,K-ATPase-liposomes with human peripheral blood mononuclear cells

Artificial phospholipid vesicles (liposomes) containing in their membrane about eight Na,K-ATPase (sodium pump) molecules per vesicle were incubated in the presence of [110mAg]silver nitrate to label the membrane protein; silver binds specifically to the Na,K-ATPase protein. When such silver-labelled liposomes were incubated with freshly isolated human peripheral blood mononuclear cells, a large number of liposomes was found in cells as evidenced by their 110mAg content after washing them with powerful silver chelators. Thus, liposomes containing an integral membrane protein can be transferred to human peripheral blood mononuclear cells rapidly and without toxicity.