NOVEL, HIGH EXPRESSING AND ANTIBIOTIC-CONTROLLED PLASMID VECTORS DESIGNED FOR USE IN GENE-THERAPY

The promise of effective gene therapy can only be accomplished by high -level expression and regulatable delivery of gene products. To achiev e this end, a eukaryotic expression plasmid was modified to make trans cription dependent on a tetracycline(Tc)-regulated chimeric transactiv ator. Mouse muscle injected with this two plasmid cis/trans control sy stem expressed reporter proteins at levels five- to 10-fold greater th an the cytomegalovirus immediate-early promoter-controlled parental pl asmid. Tetracycline could be used to either repress or activate transa ctivator-controlled expression based on the position of the tetO contr ol sequences within the reporter plasmid. Finally, a prototype single plasmid construct was made and shown to express a self-regulating bici stronic transcript containing both the reporter and the transactivator . These Tc-controlled plasmids, termed maximum expression and regulate d vectors (MERVs), have the potential to target a variety of gene ther apy applications.