title: Simple viral/minimal piggyBac hybrid vectors for stable production of self-inactivating gamma-retroviruses.
abstract: BACKGROUND
  Transient production of gamma-retroviruses, including self-inactivating (SIN) retroviruses, is a common method for rapidly generating virus capable of gene delivery. Stable (continuous) production of virus is preferable to transient production for clinical and biotechnology purposes, however, because it allows for significant quantities of a uniform virus to be generated over a prolonged period of time, thus allowing for longitudinal functional studies and quality analysis. Unfortunately, stable production of SIN retroviruses is difficult to achieve.
  
  
  RESULTS
  We describe a novel method to rapidly and cost-effectively create packaging cells capable of continuously producing self-inactivating gamma-retroviruses. We imbedded the SIN proviral construct into a minimal piggyBac transposon vector and then integrated the hybrid vector into packaging cells that already stably expressed the viral gag-pro-pol and envelope genes. Cells that stably produced self-inactivating gamma-retroviruses could be identified (and purified) as early as 3 weeks after initial transfection; these cells produced virus for at least 9 weeks without a decline in titer.
  
  
  CONCLUSIONS
  This viral-minimal piggyBac hybrid vector allowed for the rapid generation and purification of packaging cells capable of stably producing self-inactivated gamma-retroviruses. This method can be applied to the large-scale production of viruses for use in research, biotechnology, and potentially, clinical trials.
authors: Exscien Corporation, Mobile, AL, 36688, USA. btroyano@exsciencorp.com.
authors: Boris
authors: B
authors: Troyanovsky
authors: NanoBio Corporation, Ann Arbor, MI, 48105, USA. vira.bitko@nanobio.com.
authors: Vira
authors: V
authors: Bitko
authors: Center for Lung Biology, University of South Alabama School of Medicine, Mobile, AL, 36688, USA. bfouty@health.southalabama.edu.|Department of Pharmacology, University of South Alabama School of Medicine, Mobile, AL, 36688, USA. bfouty@health.southalabama.edu.|Internal Medicine, University of South Alabama School of Medicine, Mobile, AL, 36688, USA. bfouty@health.southalabama.edu.
authors: Brian
authors: B
authors: Fouty
authors: Center for Lung Biology, University of South Alabama School of Medicine, Mobile, AL, 36688, USA. vsolodushko@southalabama.edu.|Department of Pharmacology, University of South Alabama School of Medicine, Mobile, AL, 36688, USA. vsolodushko@southalabama.edu.
authors: Victor
authors: V
authors: Solodushko
mesh_terms: D004251:DNA Transposable Elements; D005822:Genetic Vectors; D057809:HEK293 Cells; D006801:Humans; D012190:Retroviridae / Q000235:genetics / Q000502:physiology*
chemical_list: D004251:DNA Transposable Elements