Inhibition of primary transcription of vesicular stomatitis virus by prostaglandin A1.

Prostaglandin A (PGA) exhibits antiviral activity against RNA and DNA viruses. The effect of PGA1 on vesicular stomatitis virus (VSV) was investigated. When VSV-infected L-1210 cells were kept in the presence of PGA1 the amount of all five viral proteins and their respective mRNAs was dose-dependently decreased. To determine whether the effect was on viral transcription or translation, the temperature-sensitive VSV mutant tsG 41 was employed. This is a good model system for the investigation of primary transcription; at the restrictive temperature of 39 degrees C, tsG 41 is unable to replicate but can transcribe viral mRNA. Mutant mRNA synthesis was strongly inhibited by PGA1 at this temperature, indicating that the major effect is on primary transcription. This conclusion is supported by data demonstrating that in vitro transcription of viral genomic RNA was also inhibited by PGA1.