Glycosphingolipid synthesis in human fibroblasts infected by cytomegalovirus.

Infection of serum-deprived human foreskin fibroblasts (HFF-cells) by cytomegalovirus (HCMV) resulted in enhanced precursor incorporation into glycosphingolipids (GSL). Analysis of the component patterns revealed a unique biphasic effect on the rate labeling of neutral GSL. Early during infection or in the presence of phosphonoacetic acid, radiolabel was found predominantly in ceramide tri- and tetrahexoside, whereas late after infection label in ceramide monohexoside exceeded that in the other components. Determination of the chemical amounts of neutral GSL components from infected cultures supported the view of increased biosynthesis of ceramide tri- and tetrahexoside early, and of ceramide monohexoside late postinfection. Changes, comparable to those observed under the influence of "early" viral functions were observed also during S-phase of serum-stimulated HFF cells. With respect to acidic GSL a decrease of metabolic labeling occurred late during infection. Relatively little alteration was found in the component pattern.