Regulation of MuIFN-alpha/beta and MuIFN-gamma-induced antiviral states: differential effects with different challenge viruses and lack of correlation with 2'5' oligoadenylate synthetase levels

The MuIFN-alpha/beta and MuIFN-gamma induced antiviral states which are directed against mengovirus have been shown previously to be differentially regulated. Following interferon removal, the MuIFN-alpha/beta-induced antiviral state decays rapidly, while the MuIFN-gamma-induced antiviral state increases dramatically. To determine whether these observations with mengovirus represent part of a general phenomenon, these studies have been extended using vesicular stomatitis virus and vaccinia virus, which represent two distinctly different groups of viruses. The antiviral states induced by MuIFN-gamma against all three viruses increased dramatically following interferon removal. The antiviral state induced by MuIFN-alpha/beta against vesicular stomatitis virus was stable following interferon removal, while the antiviral states induced by MuIFN-alpha/beta against mengovirus and vaccinia virus decayed rapidly. Also, levels of 2'5' oligoadenylate synthetase were determined at various times following interferon removal. MuIFN-alpha/beta was found to be a relatively strong inducer of 2'5' oligoadenylate synthetase, while MuIFN-gamma was a relatively weak inducer. Further, while the changes in 2'5' oligoadenylate synthetase levels paralleled the changes in the levels of the antiviral states induced by MuIFN-alpha/beta and MuIFN-gamma against mengovirus and vaccinia virus, the changes in 2'5' oligoadenylate synthetase levels did not parallel the changes in the antiviral state induced by MuIFN-alpha/beta against vesicular stomatitis virus. The results suggested that the 2'5' oligoadenylate synthetase levels did not correlate with the level of antiviral state.