Guanylate binding protein (GBP-1) as inhibitor of cell proliferation and molecular marker for the determination of the stage of cellular differentiation

Abstract

The present invention relates to a recombinant protein consisting of Guanylate Binding Protein-1 (GBP-1), or one or more functional parts thereof, linked to a shuttle protein. The present invention also relates to an expression vector comprising the Guanylate Binding Protein 1 (GBP-1) gene or parts thereof. The introduction of said vector comprising said gene or parts thereof in sense or antisense orientation into cells can be used to induce phenotypical changes of said cells and can, thus, be used for modulation of cell differentiation. Additionally, the present invention provides, inter alia, a method for determination of the stage of cellular differention by using GBP-1 gene expression as a marker.

1 . A recombinant protein consisting of Guanylate Binding Protein-1 (GBP-1) or one or more functional parts thereof linked to a shuttle protein.  
     
     
         2 . The recombinant protein according to  claim 1 , wherein the shuttle protein is specific for endothelial cells.  
     
     
         3 . The recombinant protein according to  claim 1 , wherein the shuttle protein is HIV-1-tat.  
     
     
         4 . A vector comprising a nucleic acid sequence encoding the recombinant protein according to  claim 1  and a regulatory element, wherein the recombinant protein is operably-linked to the regulatory element.  
     
     
         5 . The vector according to  claim 4 , wherein the vector is eukaryotic.  
     
     
         6 . The vector according to  claim 4 , wherein the nucleic acid sequence encoding the recombinant protein is under transcriptional control of a homologous regulatory element.  
     
     
         7 . The vector according to  claim 4 , wherein the nucleic acid sequence encoding the recombinant protein is under transcriptional control of a heterologous regulatory element.  
     
     
         8 . The vector according to  claim 4 , wherein the nucleic acid sequence encoding the recombinant protein is under transcriptional control of a heterologous promoter.  
     
     
         9 . The vector according to  claim 8 , wherein the heterologous promoter is selected from the group consisting of a constitutive, inducible, or cell-type-restricted promoter.  
     
     
         10 . The vector according to  claim 4  further comprising one or more genes coding for a substance which induces or enhances expression of the recombinant protein.  
     
     
         11 . The vector according to  claim 10 , wherein the one or more genes coding for a substance which induces or enhances expression of the recombinant protein is a cytokine gene.  
     
     
         12 . The vector according to  claim 4 , wherein the vector is a viral vector.  
     
     
         13 . The vector according to  claim 12 , wherein the viral vector is a retroviral vector.  
     
     
         14 . The vector according to  claim 13 , wherein the retroviral vector is a replication defective retroviral vector.  
     
     
         15 . A viral particle or a producer cell comprising the vector according to  claim 12 .  
     
     
         16 . A viral particle or a producer cell comprising the vector according to  claim 13 .  
     
     
         17 . A method for producing the recombinant protein according to  claim 1  comprising: 
 a) introducing a vector comprising a nucleic acid sequence the recombinant protein according to  claim 1  into a prokaryotic or eukaryotic producer cell;    b) culturing the producer cell under conditions suitable for expression of the recombinant protein; and    c) isolating and harvesting the recombinant protein expressed in b).    
     
     
         18 . A method for modulating GBP-1 gene expression or GBP-1 protein activity in a patient in need thereof, comprising: 
 a) administering to the patient a vector comprising a nucleic acid sequence encoding the recombinant protein according to  claim 1  under conditions suitable for expression of the recombinant protein in said patient; or    b) administering to a patient in need thereof the recombinant protein according to  claim 1  under conditions suitable for expression of the recombinant protein in said patient.    
     
     
         19 . The method according to  claim 18 , comprising the additional administration of a cytokine or a growth factor.