RNA silencing in animals as an antiviral defense

Abstract

The present invention provides recombinant DNA constructs for inactivation of viral or endogenous genes in a cell, wherein the construct comprises viral sequence sufficient to activate RNA silencing. In another aspect, the invention provides methods for identifying RNA silencing suppressors by sequence analysis and functional tests. In yet another aspect, the invention provides a method for identifying inhibitors of RNA silencing suppressors. In still other aspects, the invention comprises methods for identifying genes in the antiviral RNA silencing pathway, enhancers of the antiviral pathway, and methods of treating or preventing viral infections using enhancers of the pathway.

1 - 25 . (canceled)  
     
     
         26 . A method for identifying a candidate inhibitor of an RNA silencing suppressor, said method comprising: 
 (a) infecting a cell in vitro with a viral polynucleotide sequence which induces RNA silencing in the cell and an RNA silencing suppressor gene from an animal virus;    (b) contacting said cell with a candidate inhibitor of the RNA silencing suppressor; and    (c) testing for a rate or extent of virus RNA accumulation less than that for a cell not contacted with said candidate inhibitor of the RNA silencing suppressor.    
     
     
         27 . The method of  claim 26 , wherein said candidate inhibitor is a small molecule.  
     
     
         28 . The method of  claim 26 , wherein said testing for accumulation of virus RNA comprises a method selected from the group consisting of: visual assays for expressed reporter molecules and Northern blots.  
     
     
         29 . The method of  claim 26 , wherein said cell is a  Drosophila  cell.  
     
     
         30 . The method of  claim 26 , wherein the viral polynucleotide sequence which induces RNA silencing in said cell is a polynucleotide encoding FHV-ΔB2.  
     
     
         31 . The method of  claim 26 , wherein the RNA silencing suppressor gene is NS1.  
     
     
         32 . The method of  claim 26 , wherein the RNA silencing suppressor gene is B2.