Virosome preparation: differences between influenza and rubella hemagglutinin adsorption

Rubella and influenza virosomes were prepared from preformed liposomes or dried lipid films with or without nonionic detergent beta-D-octylglucoside. The preformed liposomes and lipid films were prepared from lecithin and dicetyl phosphate (3.5:1). Viral hemagglutinin rosettes were prepared from purified viruses after solubilization with Triton X-100 (1%), centrifugation through a continuous sucrose gradient containing 30 mM octylglucoside, and dialysis. Analysis of virosomes by sucrose density gradient centrifugation, hemagglutination assay, and electron microscopy revealed that rubella hemagglutinin did not require the presence of detergent to form virosomes, whereas influenza hemagglutinin could absorb efficiently to liposomes only in the presence of detergent.