Capsid-modified recombinant adenovirus and methods of use
The present invention describes recombinant adenoviral vectors modified by incorporating targeting ligands or label into viral capsid or structural proteins. In one embodiment, single-chain antibody was introduced into the minor capsid proteins pIIIa or pIX so that the adenoviral vector can be targeted to a particular cell type. In another embodiment, there is provided a noninvasive imaging strategy useful for monitoring the replication and spread of conditionally replicative adenoviral vectors. Viral structural proteins such as pIX capsid protein, core proteins mu, V and VII were expressed as fusion protein with a fluorescent label. Once incorporated into the virions, detection of the structural fusion protein label would indicate the localization of the disseminated viral progeny. The detected fluorescent signals also closely correlate with the level of viral replication and progeny production.
1. A method of increasing the ability of an adenovirus to transduce a specific cell type relative to an unmodified adenovirus, comprising the step of: modifying a gene encoding an adenoviral capsid protein by introducing a DNA sequence encoding a single chain antibody into the 3′ end of the minor capsid protein pIX gene, wherein said modification increases the ability of said adenovirus to transduce a specific cell type relative to an unmodified adenovirus.
2. The method of claim 1 , wherein said single chain antibody is directed towards a protein, wherein said protein is specific to a cell type.
3. The method of claim 2 , wherein said cell type is a tumor cell.
4. The method of claim 2 , wherein said protein is a cell-surface protein.
5. The method of claim 1 , wherein said modified capsid protein retains its native display profile.
6. The method of claim 1 , wherein said adenovirus exhibits coxsackie adenovirus receptor CAR-independent gene transfer.
7. The method of claim 1 , wherein the adenoviral vector encoding said adenovirus further comprises a therapeutic gene.
8. A method of killing tumor cells in an individual, said method comprising the steps of: injecting directly to said tumor cells an effective amount of recombinant adenoviruses comprising a therapeutic gene encoding a protein that converts a non-toxic compound to a toxic compound and a gene encoding a pIIIa protein or a pIX protein modified by introducing a single chain antibody into the N-terminus of said pIIIa protein or the C-terminus of said pIX protein; and treating said individual with said non-toxic compound.
9. The method of claim 8 , wherein said therapeutic gene is herpes simplex virus-thymidine kinase gene and said non-toxic compound is ganciclovir.
10. The method of claim 8 , wherein said single chain antibody is directed towards a protein specific to a cell type.
11. The method of claim 10 , wherein said cell type is a tumor cell.
12. The method of claim 10 , wherein said protein is a cell-surface protein.
13. The method of claim 8 , wherein said modified capsid protein retains its native display profile.