The present invention concerns a production bacterial cell for producing phage particles or phage-derived delivery vehicles, said production bacterial cell stably comprising at least one phage structural gene(s) and at least one phage DNA packaging gene(s), said phage structural gene(s) and phage DNA packaging gene(s) being derived from a first type of bacteriophage, wherein the expression of at least one of said phage structural gene(s) and/or at least one of said phage DNA packaging gene(s) in said production bacterial cell is controlled by at least one induction mechanism, and wherein said production bacterial cell is from a bacterial species or strain different from the bacterial species or strain from which said first type of bacteriophage comes and/or that said first type of bacteriophage targets.

The present invention concerns a production bacterial cell for producing lytic phage particles or lytic phage-derived delivery vehicles, said production bacterial cell stably comprising at least one phage structural genes and at least one phage DNA packaging genes, said phage structural gene(s) and phage DNA packaging gene(s) being derived from a lytic bacteriophage, wherein the expression of at least one of said phage structural genes and/or at least one of said phage DNA packaging gene(s) in said production bacterial cell is controlled by an induction mechanism.

The invention provides hybrid and recombinant phagemid vectors for expressing a transgene in a target cell transduced with the vector. A recombinant phagemid particle comprises at least one transgene expression cassette which encodes an agent which exerts a biological effect on the target cell, characterised in that the phagemid particle comprises a genome which lacks at least 50% of its bacteriophage genome. The invention extends to the use of such phagemid expression systems as a research tool, and for the delivery of transgenes in a variety of gene therapy applications, DNA and/or peptide vaccine delivery and imaging techniques. The invention extends to in vitro, in vivo or in situ methods for producing viral vectors, such as recombinant adeno-associated viruses (rAAV) or lentivirus vectors (rLV), and to genetic constructs used in such methods.

The invention provides hybrid and recombinant phagemid vectors for expressing a transgene in a target cell transduced with the vector. A recombinant phagemid particle comprises at least one transgene expression cassette which encodes an agent which exerts a biological effect on the target cell, characterised in that the phagemid particle comprises a genome which lacks at least 50% of its bacteriophage genome. The invention extends to the use of such phagemid expression systems as a research tool, and for the delivery of transgenes in a variety of gene therapy applications, DNA and/or peptide vaccine delivery and imaging techniques. The invention extends to in vitro, in vivo or in situ methods for producing viral vectors, such as recombinant adeno-associated viruses (rAAV) or lentivirus vectors (rLV), and to genetic constructs used in such methods.