Transport proteins and their uses

Abstract

The present invention relates to transport proteins, in particular VP22 and homologues thereof, and to methods of delivering these proteins and any associated molecules to a target population of cells. This transport protein has applications in gene therapy and methods of targeting agents to cells where targeting at high efficiency is required.

1 . Use of VP22 or an active portion, fragment, or homologue thereof as a transport protein capable of being taken up by a target population of cells.  
     
     
         2 . Use according to  claim 1  wherein the transport protein comprises at least the C-terminal 34 amino acids of VP22.  
     
     
         3 . Use according to  claim 1  or  claim 2  wherein the transport protein is associated with one or more other molecules whose transport to the target population is desired.  
     
     
         4 . Use according to  claim 3  wherein the one or more associated molecules are non-peptidyl.  
     
     
         5 . Use according to any one of the preceding claims wherein the protein is further capable of being exported from a first part of the target population of cells in which it is expressed and taken up by a second part of the target population of cells not directly producing the protein.  
     
     
         6 . A transport protein comprising VP22 or an active portion, fragment, or homologue thereof, associated with one or more other molecules whose transport to a target population of cells is desired.  
     
     
         7 . A transport protein according to  claim 6  wherein the one or more associated molecules are non-peptidyl.  
     
     
         8 . A transport protein according to  claim 6  or  claim 7  wherein the protein is further capable of being exported from a first part of the target population of cells in which it is expressed and taken up by a second part of the target population of cells not directly producing the protein.  
     
     
         9 . A nucleic acid encoding a transport protein according to any one of claims  6 ,  7  and  8 .  
     
     
         10 . An expression vector comprising a nucleic acid according to  claim 9 .  
     
     
         11 . A mammalian or microbial host cell comprising a vector according to  claim 10  or a nucleic acid according to  claim 9 .  
     
     
         12 . A method of transporting a desired protein or peptide to a target population of cells, the method comprising: 
 i) introducing a nucleic acid or vector according to  claim 9  or  claim 10  into a first part of a target population of cells;    ii) expressing the nucleic acid to produce the protein(s), after which the transport protein is exported from the cells, together with any other proteins associated with it, to be taken up by a second part of the target population of cells not directly producing the protein(s).    
     
     
         13 . A method according to  claim 12  wherein introduction of the nucleic acid into the first part of the target population of cells is by a recombinant virus.  
     
     
         14 . A method according to  claim 12  wherein introduction of the nucleic acid into the first part of the target population of cells is by transfection.  
     
     
         15 . A method according to  claim 12  wherein introduction of the nucleic acid into the first part of the target population of cells is by microinjection.  
     
     
         16 . A method of transporting a desired molecule into a population of cells, the method comprising: 
 i) coupling the desired molecule to a transport protein comprising VP22 or an active portion, fragment, or homologue thereof to form a complex; and,    ii) exposing the cells to the complex so that cells can take up the complex.    
     
     
         17 . A method according to  claim 16  wherein the desired molecule is non-peptidyl.  
     
     
         18 . A method according to  claim 16  or  claim 17  wherein the desired molecule is coupled to the transport protein by incorporation into a lipid based vehicle.