Conditional gene vectors regulated in cis.
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.
Department of Gene Vectors, Helmholtz Center Munich, German Research Center for Environmental Health, Marchioninistr. 25, 81377 Munich, Germany.
Dagmar
D
Pich
Sibille
S
Humme
Mark-Peter
MP
Spindler
Aloys
A
Schepers
Wolfgang
W
Hammerschmidt
D000494:Allosteric Regulation; D000818:Animals; D002460:Cell Line; D004261:DNA Replication; D019309:Epstein-Barr Virus Nuclear Antigens / Q000235:genetics / Q000378:metabolism; D005822:Genetic Vectors / Q000096:biosynthesis* / Q000737:chemistry; D025741:HMGA1a Protein / Q000235:genetics / Q000378:metabolism; D006801:Humans; D010957:Plasmids / Q000096:biosynthesis* / Q000737:chemistry; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism
D019309:Epstein-Barr Virus Nuclear Antigens; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; C034811:tetracycline resistance-encoding transposon repressor protein; D025741:HMGA1a Protein; C417029:EBV-encoded nuclear antigen 1