Negative regulation of immediate-early gene expression of pseudorabies virus by interferon-α

Pseudorabies rabies (PrV) replication in Vero cells was suppressed by treatment with human natural interferon-alpha (IFN-alpha). Messenger RNA transcribed from the PrV immediate-early (IE) gene was reduced in the IFN-alpha-treated cells. Transient expression assays showed that transcription from the PrV IE promoter was selectively inhibited in the IFN-alpha-treated cells. Analysis of deletion mutants of the PrV IE promoter sequence suggested that at least one element between the transcription initiation site (+1) and -90 in the PrV IE promoter was concerned with the negative regulation.