Method for introducing and expressing genes in animal cells, and live invasive bacterial vectors for use in the same

Abstract

A method for introducing and expressing genes in animal cells is disclosed comprising infecting the animal cells with live invasive bacteria, wherein the bacteria contain a eukaryotic expression cassette encoding the gene. The gene may encode, e.g., a vaccine antigen, a therapeutic agent, an immunoregulatory agent or an anti-sense RNA or a catalytic RNA.

1 - 20 . (canceled)  
   
   
       21 . A delivery vehicle for delivering a mammalian expression plasmid into a mammalian cell, said vehicle comprising a pure culture of attenuated  Shigella  cells into which said expression plasmid has been introduced, wherein said  Shigella  cells have at least one genetic mutation such that they lyse once inside said mammalian cell, thereby delivering said expression plasmid therein.  
   
   
       22 . The delivery vehicle according to  claim 21 , wherein said  Shigella  is  S. flexneri.    
   
   
       23 . The delivery vehicle according to  claim 21 , wherein said mammalian cell is a cell of an intestinal mucosal epithelium.  
   
   
       24 . The delivery vehicle according to  claim 23 , wherein said  Shigella  is  S. flexneri.    
   
   
       25 . The delivery vehicle according to  claim 21 , wherein said attenuated  Shigella  cells are inactivated.  
   
   
       26 . The delivery vehicle of  claim 21 , wherein said mutation is a mutation in the wild-type asd gene within said  Shigella  cells.  
   
   
       27 . A method for delivering a mammalian expression plasmid into a mammalian cell, said method comprising: 
 (i) introducing a mammalian expression plasmid into a pure culture of attenuated  Shigella  cells, wherein said  Shigella  cells have at least one genetic mutation such that they lyse once inside said mammalian cell; and    (ii) administering said  Shigella  cells to said mammalian cell, thereby delivering said expression plasmid therein.    
   
   
       28 . The method according to  claim 27 , wherein said  Shigella  is  S. flexneri.    
   
   
       29 . The method according to  claim 27 , wherein said mammalian cell is a cell of a mucosal epithelium.  
   
   
       30 . The method according to  claim 29 , wherein said mucosal epithelium is intestinal mucosal epithelium.  
   
   
       31 . The method according to  claim 27 , wherein said attenuated  Shigella  cells are inactivated.  
   
   
       32 . The method of  claim 27 , wherein said mutation is a mutation in the wild-type asd gene within said  Shigella  cells.