Lipids of plasma membranes of monkey and hamster kidney cells and of parainfluenza virions grown in these cells

Abstract

Plasma membranes have been isolated from primary rhesus monkey kidney (MK), baby hamster kidney (BHK21-F), and adult hamster kidney (HaK) cells, and detailed lipid analyses of the membranes, the whole cells, and parainfluenza virus SV5 grown in MK and BHK21-F cells have been carried out. The lipid compositions of the plasma membranes differ from those of the respective whole cells, and show characteristic features, including a high cholesterol and sphingomyelin content, and a cholesterol to phospholipid ratio which is higher than that of the whole cell. The lipid patterns of the membranes of the various cell types are significantly different from each other, especially with regard to phospholipids. In MK membranes, e.g., phos-phatidylethanolamine is the major phospholipid, and there is a relatively high content of phosphatidylserine, whereas in BHK21-F membranes, phosphatidylcholine is present in highest amount, and there is relatively little phosphatidylethanolamine and phosphatidylserine. Previous studies have shown that the plasma membranes of these cells exhibit significant biological differences, particularly in their interactions with SV5. SV5 virions grown in MK or BHK21-F cells have a lipid composition that is closely similar to that of the plasma membrane of the particular cell type in which the virus was grown. The data support the hypothesis that during the maturation of the virion by budding from the cell surface, the lipids of the plasma membrane are incorporated quantitatively into the viral envelope.