The effect of phlorizin on the multiplication of measles virus

Abstract

Phlorizin in a concentration of 5 × 105 M or higher prevented the syncytium-forming long-term cytopathic effect of measles virus both in a cell line, Lu 106 cells, and in primary dog kidney cells. The presence of phlorizin resulted in a retardation of extracellular accumulation of biologically active virus products. In Lu 106 cells the final yield of virus material was considerably increased and after equilibrium centrifugation in CsCl gradients, the products mainly accumulated at a density range of 1.23 to 1.25 g/cc. No increase in antigen quantities was obtained in primary dog kidney cells maintained on medium containing phlorizin, although there was an increase in hemagglutinin titers. Centrifugation in CsCl gradients demonstrated that the products obtained in the presence of phlorizin from this slow-growing virus-cell system still appeared markedly heterogeneous.