ANTIVIRAL ACTION OF INTERFERON-BETA ON NEWCASTLE-DISEASE VIRUS - SELECTIVITY TO THE HEMAGGLUTININ-NEURAMINIDASE GENE-EXPRESSION

Interferon-beta (IFN-beta) strongly inhibited the expression of the hemaagglutinin-neuraminidase (HN) gene of Newcastle disease virus (NDV), a paramyxovirus, in HeLa cells under the conditions where it did not affect the expression of the four upstream genes encoding the nucleocapsid protein, phosphoprotein, membrane protein and fusion protein. Even the downstream gene, encoding the large protein as well as the genome replication, appeared to be less susceptible to IFN-beta than the HN gene. This selective action of IFN-beta did not appear to be attributable to its well characterized antiviral mechanisms such as acceleration of RNA decay and translation inhibition. No similar down-regulation of a particular gene expression was found with another paramyxovirus. Sendai virus, or with a rhabdovirus, vesicular stomatitis virus, or seems to have been reported previously with any negative-strand RNA viruses. This new effect of IFN-beta thus suggests gene expression mechanism unique to NDV and may further lead to the discovery of a novel biochemical effect of IFN-beta.