The interferon antagonistic activities of the V proteins of NDV correlated with their virulence.

Abstract

Protein V of Newcastle disease virus (NDV) serves as interferon (IFN) antagonist, and NDV stains with different pathogenicity show different abilities in inhibition IFN expression. To further reveal the relationship between viral virulence and their IFN-antagonistic activity derived from protein V, six NDV strains with three different pathotypes were used in this study and their V gene were cloned into eukaryotic expression vector. The V gene derived from different NDV strains were expressed in same level in cells after transfection according to the results from Western blotting. And these proteins showed different interferon-antagonistic activities based on interferon expression using Luciferase Reporter Assay and ELISA. The expression of IFN and viral virulence index, mean death time, have a good linear relationship indicating a good correlation between viral virulence and IFN antagonism of their V Protein.