Tetrafunctional bacteriophage

1. A recombinant targeted bacteriophage for expressing a transgene in a target cell transduced with the bacteriophage, the bacteriophage comprising:

(i) a first nucleic acid sequence encoding a pIII capsid minor coat protein fused to a cell-targeting ligand for enabling delivery of the bacteriophage to a mammalian target cell;

(ii) a second nucleic acid sequence encoding at least one wild type pVIII capsid major coat protein for supporting bacteriophage assembly, fused to a foreign peptide of less than ten amino acids;

(iii) a third nucleic acid sequence encoding a recombinant pVIII capsid major coat protein, which differs in nucleotide sequences from the nucleotide sequence encoding the wild-type pVIII capsid major coat protein, fused to a foreign peptide of more than ten amino acids, wherein the foreign peptide which is displayed on the pVIII capsid major coat protein comprises an endosome escape peptide (EEP), wherein the EEP is displayed on the recombinant pVIII capsid major coat protein; and wherein the endosome escape peptide is H5WYG peptide as set forth in SEQ ID NO: 9; and

(iv) a mammalian transgene cassette which encodes a protein which exerts a biological effect on the target cell.

2. The bacteriophage according to claim 1 , wherein the bacteriophage is F 1, Fd or M13.

3. The bacteriophage according to claim 1 , wherein the second nucleic acid sequence encoding a wild-type pVIII capsid major coat protein comprises a nucleotide sequence substantially as set out in SEQ ID No: 1, or wherein the wild-type pVIII capsid major coat protein comprises an amino acid sequence substantially as set out in SEQ ID No: 2.

4. The bacteriophage according to claim 1 , wherein the third nucleic acid sequence encoding a recombinant pVIII capsid major coat protein comprises a nucleic acid sequence substantially as set out in SEQ ID No:3, or the recombinant pVIII capsid major coat protein comprises an amino acid sequence substantially as set out in SEQ ID No:4.

5. The bacteriophage according to claim 1 , wherein the bacteriophage comprises a nucleic acid sequence substantially as set out in SEQ ID No: 1 and SEQ ID No: 3, or wherein the bacteriophage comprises a wild-type and a recombinant pVIII capsid major coat protein which comprise an amino acid sequence substantially as set out in SEQ ID No: 2 and SEQ ID No: 4.

6. The bacteriophage according to claim 1 , wherein the wild type pVIII capsid major coat protein displays a gold-binding peptide, wherein the amino acid sequence of the gold-binding peptide comprises VSGSSPDS as set forth by SEQ ID NO:6.

7. The bacteriophage according to claim 1 , wherein the cell-targeting ligand is a tumour-targeting ligand, and wherein the ligand comprises the RGD4C ligand.

8. The bacteriophage according to claim 1 , wherein the first nucleic acid sequence encoding the pIII capsid minor coat protein comprises a nucleic acid sequence substantially as set out in SEQ ID No: 7, or wherein the pIII capsid minor coat protein comprises an amino acid sequence substantially as set out in SEQ ID No: 8.

9. The bacteriophage according to claim 1 , wherein the foreign peptide which is displayed on the pVIII capsid major coat protein further comprises a nuclear localization signal (NLS) peptide, wherein the NLS peptide is selected from a group consisting of: the large tumour antigen of simian virus 40 (SV40 T antigen as set forth by SEQ ID NO:12); optimized SV40 NLS as set forth by SEQ ID NO:13; the optimized short M9 (osM9) as set forth by SEQ ID NO:14; and a heptamer NLS peptide as set for the by SEQ ID NO:15, wherein the NLS peptide is displayed on the recombinant pVIII capsid major coat protein.

10. The bacteriophage according to claim 1 , wherein the wild type pVIII major coat protein of the bacteriophage comprises an N-terminal modification which neutralises the negative charge of the surface of the phage, and results in a net positive charge at physiological pH.

11. The bacteriophage according to claim 10 , wherein the modification comprises a tetrapeptide comprising the amino acid sequence AKAS located in the N-terminal of the major coat wild type pVIII protein, and preferably between residues Gly3 and Asp4 of the protein.

12. A vaccine comprising the bacteriophage according to claim 1 .

13. A pharmaceutical composition comprising the bacteriophage according to claim 1 , and a pharmaceutically acceptable vehicle.