Mechanism of interferon action. II. Induction and decay kinetics of the antiviral state and protein P54 in human amnion U cells treated with gamma interferon.

Abstract The kinetics of induction and decay of the antiviral state and polypeptide p54 expression induced by recombinant human interferon gamma (rIFN-gamma) were examined in human amnion U cells. The kinetics of induction of the antiviral state, as measured by the single-cycle yield reduction of vesicular stomatitis virus, were first order over the period of about 6-12 h following a lag of about 2-4 h. The induction of p54 synthesis by rIFN-gamma slightly preceded the induction of the antiviral state. The kinetics of p54 induction were first order over a period of about 2-8 h after a lag of about 1 h. The rate of polypeptide p54 synthesis induced by rIFN-gamma decayed significantly within 1 day after the removal of IFN. However, polypeptide p54 was comparatively stable, displaying a half-life of about 3 days. The antiviral state likewise decayed significantly within 3-4 days following removal of IFN-gamma, and by 5-8 days, the virus yields were comparable to those of untreated control cell cultures. These results suggest that polypeptide p54 may play an important role in the antiviral action of rIFN-gamma in human amnion U cells.