Effect of Interferon on Synthesis of Eastern Equine Encephalitis Virus RNA 1

Abstract

Summary

Rabbit cell cultures were treated with interferon and then infected with EEE in the presence of actinomycin D. Concentrations of interferon that inhibited virus replication by 99%, inhibited accumulation of viral RNA, as measured by continuous labeling, by about 70%. On the other hand, the rate of synthesis of viral RNA, as measured by short-pulse labeling, was not significantly inhibited by large doses of interferon. Sucrose density gradient analysis of viral RNA from interferon-treated and untreated cells showed that ³H-uridine was rapidly incorporated into a ribonuclease-resistant structure sedimenting at 20S. This incorporation was unaffected by interferon; but interferon reduced accumulation of 40S virion RNA and ribonuclease sensitive RNA sedimenting at 23S. We conclude that the observed inhibition of accumulation might be due to an increased rate of turnover which may be associated with the well-known ability of interferon to inhibit viral protein synthesis.