AAV-plasmid DNA simplifies liver-directed in vivo gene therapy: Comparison of expression levels after plasmid DNA-, adeno-associated virus- and adenovirus-mediated liver transfection

摘要

Background:udSuccessful liver gene therapy depends on efficient gene transfer techniques and long-lasting gene expression after successful transfer. Over the last decades important progress has been made with the introduction of viral vectors using animal models, but their use is hampered by a complex and costly preparation when compared to the simple and cost-effective preparation of plasmid DNA. These problems become even more critical when considering application of viral vectors in human gene therapy and gene therapy trials. In a recent report we were able to show that the hydrodynamics-based gene transfer of plasmid-DNA, containing the adeno-associated-virus specific inverted terminal repeats (AAV-ITR), prolong gene expression in the liver, but it remained unclear if plasmid gene transfer could achieve similar expression levels compared to viral-vector gene transfer.udMethods:udRat livers were transfected in-vivo with AAV-ITR-containing plasmid-DNA using a modified hydrodynamics-based procedure. Expression levels were monitored thereafter and compared with expression levels after viral-vector gene transfer.udResults:udA high and stable long-term expression was achieved after in vivo transfection of rat livers with AAV-ITR-containing plasmids. The expression course resembled that after AAV-mediated gene transfer, and expression was at least as high, and lasted as long, as with rAAV-mediated gene transfer.udConclusion:udWe consider AAV-ITR-containing plasmids as a simple and cost-effective alternative to recombinant viral vectors, especially for liver-directed gene therapy in rodents. With ongoing progress in gene transfer methods for naked DNA, these plasmids may also become a successful alternative to recombinant viral vectors in human gene therapy.