Nucleic Acids Research Advance Access originally published online on June 19, 2008
Nucleic Acids Research 2008 36(13):e83; doi:10.1093/nar/gkn273
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Nucleic Acids Research, 2008, Vol. 36, No. 13 e83
© 2008 The Author(s)
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Methods Online |
Conditional gene vectors regulated in cis
Department of Gene Vectors, Helmholtz Center Munich, German Research Center for Environmental Health, Marchioninistr. 25, 81377 Munich, Germany
*To whom correspondence should be addressed. Tel: +49 89 3187 1506; Fax: +49 89 3187 19 1506; Email: hammerschmidt{at}helmholtz-muenchen.de
Received March 13, 2008. Revised April 23, 2008. Accepted April 25, 2008.
Non-integrating gene vectors, which are stably and extrachromosomally maintained in transduced cells would be perfect tools to support long-term expression of therapeutic genes but preserve the genomic integrity of the cellular host. Small extrachromosomal plasmids share some of these ideal characteristics but are primarily based on virus blueprints. These plasmids are dependent on viral trans-acting factors but they can replicate their DNA molecules in synchrony with the chromosome of the cellular host and segregate to daughter cells in an autonomous fashion. On the basis of the concept of the latent origin of DNA replication of Epstein-Barr virus, oriP, we devised novel derivatives, which exclusively rely on an artificial replication factor for both nuclear retention and replication of plasmid DNA. In addition, an allosteric switch regulates the fate of the plasmid molecules, which are rapidly lost upon addition of doxycycline. Conditional maintenance of these novel plasmid vectors allows the reversible transfer of genetic information into target cells for the first time.