Episomal vector systems and related methods

DETAILED DESCRIPTION The present invention provides papilloma virus episomal vector systems and methods for papilloma virus episomal vector replication in a variety of human and animal cells not normally permissive for replication of a particular papilloma virus or for maintenance of a particular papilloma virus sequence.
There are provided episomal vector systems containing papilloma virus E1 and E2 genes and a papilloma virus origin of replication.
These vectors are capable of episomal replication and due to their small size allow for insertion of a therapeutic nucleic acid sequence, which may be efficiently expressed in a human or other animal cell.
In a first aspect the invention features an episomal vector system for gene therapy in humans or animals which contains a polyfunctional nucleic acid sequence from a papilloma virus, the polyfunctional nucleic acid sequence including an origin of replication, a vector maintenance sequence, a first promoter and a unique restriction site for insertion of one or more therapeutic nucleic acid sequences; a first expression cassette containing a papilloma E1 gene sequence and a second promoter to drive transcription of the E1 gene; a second expression cassette containing a papilloma E2 gene sequence and a third promoter to drive transcription of the E2 gene; the first and second expression cassettes cloned into an episomal vector; and the episomal vector system includes one or more episomal vectors, each capable of episomal replication in a human or other animal cell.
In a preferred embodiment this invention features an episomal vector system for gene therapy in humans or animals which contains a polyfunctional nucleic acid sequence from BPV-1 (nucleotides 4780 to 471 from the BPV-1 genome, (e.
g.
, 3636 bp in length)) in a vector, SEQ.
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1, the polyfunctional nucleic acid sequence including an origin of replication, a vector maintenance sequence, a first promoter and a unique restriction site for insertion of one or more therapeutic nucleic acid sequences; a first expression cassette containing a BPV-1 E1 gene sequence, SEQ