Antiviral effects of xanthate D609 on the human respiratory syncytial virus growth cycle.

The antiviral compound tricyclo-decan-9-yl-xanthogenate (D609) inhibits respiratory syncytial (RS) virus growth in human epithelial (Hep 2) cells. D609 treatment resulted in a decrease in the accumulation of viral proteins, in the phosphorylation of the viral phosphoprotein, and in the amount of extracellular antigens and infectious particles. The relative accumulation of viral proteins was also unbalanced, however no differences were found in the amount of viral RNA with plus or minus polarity. In addition nucleocapsids formation was not inhibited. These observations suggested that this antiviral compound affects the relative proportion of viral proteins and the phosphorylation of P protein. Both features appear to be important in RS virus morphogenesis.