To improve liver-directed retroviral-mediated gene transfer, we injected C57/BL10 mice intravenously with three adenoviral vectors encoding retroviral vector genome and structural components: AdGagPol expressing the respective structural genes of Moloney murine leukaemia virus, Ad10A1Env expressing the 10A1 envelope protein of 10A1-MuLV, and AdLEIN, encoding the LEIN retrovirus genome, expressing green fluorescence protein (eGFP) and the neomycin resistance gene.
Materials and methods: The extent of eGFP expression was determined after 1 and 15 weeks by fluorescence microscopy and FACS analysis. Proviral integration was determined by a novel PCR-based technique.
Results: Hepatocytes infected with all three Ad vectors generated LEIN retrovirus after one week and in situ transduction of neighbouring cells resulted in stable proviral integration associated with eGFP expression ranging from 4.3% to 20.5% in different liver cell populations 15 weeks post-infection.
Conclusion: Hybrid adeno-retroviral vectors can be efficiently used to improve the efficiency of retroviral-mediated gene transfer to the liver.