Targeted Vectors

Abstract

This invention provides therapeutic and diagnostic agent delivery vehicles, including viral vectors, that are complexed to a targeting moiety by coordinate covalent linkages mediated by a transition metal ion. The complex is typically formed with a transition metal ion that is in a kinetically labile oxidation state; after the complex is formed, the oxidation state of the transition metal ion is changed to one that renders the complex kinetically stable. The use of a coordinate covalent linkage to attach the targeting moiety to the delivery vehicle provides advantages such as the ability to readily attach a different targeting moiety to a delivery vehicle without modifying the delivery vehicle itself. This flexibility is achieved without sacrificing stability of the complex.

1 . A targeted complex of the formula: 
       {(delivery vehicle-CM)-TMI-(CM-targeting ligand)}; wherein CM is a chelating moiety, TMI is a transition metal ion, and CM-targeting ligand is a chelating moiety (CM) covalently linked to a targeting ligand.    
   
   
       2 . The complex of  claim 1 , wherein the delivery vehicle is a virus and the chelating moiety is a chelating peptide.  
   
   
       3 . The complex of  claim 2 , wherein the virus lacks a native viral ligand that binds to a native cellular receptor for the virus.  
   
   
       4 . The complex of  claim 2 , wherein the virus is replication competent.  
   
   
       5 . The complex of  claim 2 , wherein the virus is replication deficient.  
   
   
       6 . The complex of  claim 2 , wherein the virus includes a polynucleotide that encodes a p53 tumor suppressor polypeptide and the targeting ligand is a antibody that binds to a tumor antigen.  
   
   
       7 . The complex of  claim 2 , wherein the virus is an adenovirus.  
   
   
       8 . The complex of  claim 7 , wherein the viral coat protein is selected from a fiber, a penton and a hexon.  
   
   
       9 . The complex of  claim 7 , wherein the adenovirus is replication competent.  
   
   
       10 . The complex of  claim 9 , wherein the adenovirus is a wild-type adenovirus.  
   
   
       11 . The complex of  claim 9 , wherein the adenovirus is a selectively replicating adenovirus.  
   
   
       12 . The complex of  claim 7 , wherein the adenovirus is replication deficient.  
   
   
       13 . The complex of  claim 12 , wherein the genome of the adenovirus comprises a partial or total deletion of the adenoviral E1 region.  
   
   
       14 . The complex of  claim 12 , wherein the genome of the adenovirus comprises a partial or total deletion of the protein IX-encoding region.  
   
   
       15 . The complex of  claim 2 , wherein the virus is selected from the group consisting of a retrovirus, a vaccinia virus, a herpes virus, an adeno-associated virus, a minute virus of mice (MVM), a human immunodeficiency virus, a sindbis virus, an MoMLV, and a hepatitis virus.  
   
   
       16 . The complex of  claim 1 , wherein the delivery vehicle is selected from the group consisting of a bacteriophage, a peptide vector, a peptide-DNA aggregate, a liposome, a gas-filled microsome, and an encapsulated macromolecule.  
   
   
       17 . The complex of  claim 1 , wherein the targeting ligand is an antibody.  
   
   
       18 . The complex of  claim 17 , wherein the antibody is reactive with a tumor antigen.  
   
   
       19 . The complex of  claim 17 , wherein the antibody is selected from the group consisting of Fab, Fab′, Fab 2 ′ and Fv fragments.  
   
   
       20 . The complex of  claim 17 , wherein the antibody is a human antibody.  
   
   
       21 . The complex of  claim 17 , wherein the antibody is a single chain antibody.  
   
   
       22 . The complex of  claim 21 , wherein the single chain antibody is reactive with carcinoembryonic antigen.  
   
   
       23 . The complex of  claim 1 , wherein the targeting ligand comprises a conformationally constrained peptide.  
   
   
       24 . The complex of  claim 23 , wherein the conformationally constrained peptide comprises a portion of an adenoviral fiber protein.  
   
   
       25 . The complex of  claim 1 , wherein the CM is a chelating peptide or an organic chelating agent.  
   
   
       26 . The complex of  claim 25 , wherein the organic chelating agent is selected from the group consisting of a bidentate, a tridentate, a quadridentate ligand and a tripod ligand.  
   
   
       27 . The complex of  claim 26 , wherein the organic chelating agent is selected from the group consisting of iminodiacetic acid, nitrilotriacetic acid, terpyridine, bipyridine, triethylenetetraamine, and biethylenetriamine.  
   
   
       28 . The complex of  claim 1 , wherein the delivery vehicle is a liposome.  
   
   
       29 . The complex of  claim 1 , wherein the delivery vehicle is a paramyxovirus.  
   
   
       30 . A viral vector complex that comprises a targeting ligand that is attached to a surface polypeptide of a viral vector by a coordinate covalent linkage mediated by a transition metal ion.  
   
   
       31 . A method of producing a kinetically inert targeted delivery vehicle complex, the method comprising: 
 a) preparing a kinetically labile transition metal complex by contacting a delivery vehicle-CM and a CM-targeting ligand with a transition metal ion that is in a kinetically labile oxidation state; and    b) changing the oxidation state of the metal ion to form the kinetically inert complex.    
   
   
       32 . The method of  claim 31 , wherein the kinetically labile transition metal complex is prepared by: 
 a) contacting the CM-targeting ligand with the transition metal ion in a reaction vessel and allowing the transition metal ion to bind to the CM to form a transition metal ion-CM-targeting ligand complex;    b) removing uncomplexed transition metal ion from the reaction vessel; and    c) contacting the transition metal ion-CM-targeting ligand complex with the delivery vehicle-CM and allowing the transition metal ion to bind to the CM to form the complex.    
   
   
       33 . The method of  claim 31 , wherein the kinetically labile transition metal complex is prepared by contacting the CM-targeting ligand and the delivery vehicle-CM with the transition metal ion simultaneously.  
   
   
       34 . A method of delivering a therapeutic or diagnostic agent to a target cell in an organism, the method comprising administering to an organism a targeted complex of the formula: 
       {(delivery vehicle-CM)-TMI-(CM-targeting ligand)}; wherein delivery vehicle-CM is a delivery vehicle that displays on its surface a polypeptide that comprises a chelating moiety (CM), TMI is a transition metal ion, and CM-targeting ligand is a chelating moiety (CM) covalently linked to a targeting ligand that binds to the target cell.    
   
   
       35 . The method of  claim 34 , wherein the delivery vehicle is a viral vector and the chelating moiety is a chelating peptide (CP).  
   
   
       36 . The viral vector of  claim 35 , wherein the viral vector is selected from the group consisting of an adenovirus, a retrovirus, a vaccinia virus, a herpes virus, an adeno-associated virus, a minute virus of mice (MVM), a human immunodeficiency virus, a sindbis virus, an MoMLV, and a hepatitis virus.  
   
   
       37 . The viral vector of  claim 35 , wherein the viral vector is an adenoviral vector and the surface polypeptide is a viral coat protein selected from the group consisting of a penton base, a hexon polypeptide, and a fiber polypeptide.  
   
   
       38 . The method of  claim 34 , wherein the therapeutic agent is a gene that encodes a therapeutic polypeptide.  
   
   
       39 . The method of  claim 38 , wherein the gene encodes a polypeptide selected from the group consisting of a tumor suppressor, an antigenic polypeptide, a cytotoxic polypeptide, a cytostatic polypeptide, a cytokine, a chemokine, a pharmaceutical protein, a proapoptotic polypeptide, a prodrug-activating polypeptide, an angiogenesis-inducing polypeptide, and an anti-angiogenic polypeptide.