Multiple inducible gene regulation system

Abstract

The present invention relates to the field of biotechnology or genetic engineering. More specifically, the present invention relates to a multiple inducible gene regulation system that functions within cells to simultaneously control the quantitative expression of multiple genes.

1 - 20 . (canceled) 
     
     
         21 . An inducible gene expression modulation system comprising at least two orthogonal gene switches that control expression of at least two genes of interest, the system comprising:
 at least two gene switches, wherein each gene switch comprises a fusion protein; and   at least two ligands, wherein at least one of the ligands is a diacylhydrazine.   
     
     
         22 . The inducible gene expression modulation system of  claim 21 , wherein the system is used in mammalian gene therapy applications. 
     
     
         23 . The inducible gene expression modulation system of  claim 21 , wherein expression of at least one gene switch is driven by a tissue-specific promoter. 
     
     
         24 . An inducible gene expression modulation system comprising at least two orthogonal gene switches that control expression of at least two genes of interest, wherein each gene switch is activated by a different ligand, and wherein each gene switch comprises:
 a gene expression cassette comprising a promoter operably linked to a polynucleotide that encodes a fusion protein, wherein the fusion protein comprises a DNA-binding domain that recognizes a response element associated with a gene of interest, a ligand binding domain comprising at least a portion of a Group H nuclear receptor ligand binding domain;   
       wherein the DNA-binding domain is from a nuclear receptor other than a Group H nuclear receptor. 
     
     
         25 . The inducible gene expression modulation system according to  claim 24 , wherein the Group H nuclear receptor is an ecdysone receptor. 
     
     
         26 . The inducible gene expression modulation system of  claim 24 , wherein expression of at least one gene switch is driven by a tissue-specific promoter. 
     
     
         27 . The inducible gene expression modulation system of  claim 24 , wherein the system is used in mammalian gene therapy applications. 
     
     
         28 . A vector comprising the inducible gene expression modulation system according to  claim 24 . 
     
     
         29 . An isolated host cell into which the inducible gene expression modulation system according to  claim 24  has been introduced. 
     
     
         30 . The isolated host cell according to  claim 29 , wherein the host cell is selected from the group consisting of a bacterial cell, a fungal cell, a yeast cell, a plant cell, an animal cell, a mammalian cell, a mouse cell, and a human cell. 
     
     
         31 . A non-human organism comprising a host cell into which the inducible gene expression modulation system according to  claim 24  has been introduced. 
     
     
         32 . The non-human organism according to  claim 31 , wherein the non-human organism is selected from the group consisting of a bacterium, a fungus, a yeast, a plant, an animal, and a mammal. 
     
     
         33 . An inducible gene expression modulation system comprising at least two orthogonal gene switches that control tissue-specific expression of at least two genes of interest, wherein each gene switch is activated by a different ligand, and wherein each gene switch comprises the elements of I or II:
 I)   a) a first gene expression cassette comprising a tissue-specific promoter operably linked to a polynucleotide sequence that encodes a first polypeptide comprising:
 a DNA-binding domain that recognizes a response element associated with a gene of interest; a ligand binding domain comprising at least a portion of a ligand binding domain from a Group H nuclear receptor polypeptide; 
   b) a second gene expression cassette comprising a tissue-specific promoter operably linked to a polynucleotide sequence that encodes a second polypeptide comprising:
 a transactivation domain; and 
 a ligand binding domain comprising at least a portion of a ligand binding domain from a truncated retinoid X receptor; 
   
       wherein the transactivation domain is from a nuclear receptor other than an ecdysone receptor, a retinoid X receptor, or an ultraspiracle receptor, and wherein the first and second polypeptides dimerize and bind to a ligand;
 II) 
 a) a first gene expression cassette comprising a tissue-specific promoter operably linked to a polynucleotide sequence that encodes a first polypeptide comprising:
 a DNA-binding domain that recognizes a response element associated with a gene of interest; a ligand binding domain comprising at least a portion of a ligand binding domain from a truncated retinoid X receptor; 
 
 b) a second gene expression cassette comprising a tissue-specific promoter operably linked to a polynucleotide sequence that encodes a second polypeptide comprising:
 a transactivation domain; and 
 a ligand binding domain comprising at least a portion of a ligand binding domain from a Group H nuclear receptor polypeptide; 
 
 
       wherein the transactivation domain is from a nuclear receptor other than an ecdysone receptor, a retinoid X receptor, or an ultraspiracle receptor, and wherein the first and second polypeptides dimerize and bind to a ligand. 
     
     
         34 . The inducible gene expression modulation system according to  claim 33 , wherein each gene switch is associated with an expression cassette comprising:
 a response element to which the DNA-binding domain of the first polypeptide binds;   a promoter that is activated by the transactivation domain of the second polypeptide; and a gene of interest.   
     
     
         35 . The inducible gene expression modulation system according to  claim 33 , wherein the Group H nuclear receptor is an ecdysone receptor. 
     
     
         36 . The inducible gene expression modulation system according to  claim 33 , wherein the tissue-specific promoters are developmentally-specific promoters. 
     
     
         37 . A vector comprising the inducible gene expression modulation system according to  claim 33 . 
     
     
         38 . An isolated host cell into which the inducible gene expression modulation system according to  claim 33  has been introduced. 
     
     
         39 . The isolated host cell according to  claim 38 , wherein the host cell is selected from the group consisting of a bacterial cell, a fungal cell, a yeast cell, a plant cell, an animal cell, a mammalian cell, a mouse cell, and a human cell. 
     
     
         40 . A non-human organism comprising a host cell into which the inducible gene expression modulation system according to  claim 33  has been introduced.