Elucidation of the Nature of the Murine Oncogenic Virus Inhibitor Isolated from JLS-V5 Cell Line

Abstract

Summary

An inhibitor (STAS) prepared from the supernatant of JLS-V5 cells blocked the replication of MLV in vitro when added to MEF cultures as late as 48 hr after but not prior to infection with MLV. Potent antiviral activity against MLV was also observed with inhibitor prepared from JLS—V9 tissue culture supernatant fluid, fetal calf serum (FCS), normal Balb/c mouse plasma, MEM + 10% FCS, saline, or silicotungstic acid (STA). Inhibitor prepared from JLS-V5 supernatant fluid, but substituting ZnSO₄ PCA, TCA, ethanol, or ammonium sulfate precipitants instead of STA, showed little or no activity against MLV in vitro. No viracidal activity was obtained when MLV was exposed directly to JLS-V5 STAS. These studies suggest that the active ingredient in JLS-V5 STAS may be silicotungstic acid.