Patent ID: 7259014

Claim:
A viral vector system comprising: a) a first nucleic acid segment comprising a nucleotide sequence encoding at least a first Gag polypeptide or a functional variant of the first gag polypeptide and a protease polypeptide or a functional variant of the protease polypeptide, and said first nucleic acid segment does not encode at least one of a functional Reverse Transcriptase polypeptide and a functional Integrase polypeptide; and, b) a second nucleic acid segment comprising at least one nucleotide sequence encoding a fusion protein selected from the group consisting of: i) a second Gag polypeptide, wherein said second Gag polypeptide is truncated and fused in frame to a second Reverse Transcriptase polypeptide or a functional variant of the second Reverse Transcriptase polypeptide; and, ii) the second truncated Gag polypeptide fused in frame to a second Integrase polypeptide or a functional variant of the second Integrase polypeptide; wherein said second truncated Gag polypeptide of i) and ii) lacks the P6 domain and is capable of providing for the incorporation of said fusion protein into a viral particle; and, wherein said viral vector system produces the viral particle capable of infecting a target cell; and wherein the first Gag polypeptide, the protease polypeptide, the second Gag polypeptide, the second Reverse Transcriptase polypeptide, and the second Integrase polypeptide are from a retrovirus.