Regulatable adenovector harboring the GFP and Yamanaka genes for implementing regenerative medicine in the brain

Gene Ther. 2019 Nov;26(10-11):432-440. doi: 10.1038/s41434-019-0063-x. Epub 2019 Feb 15.

Abstract

Biological rejuvenation by partial cell reprogramming is an emerging avenue of research. In this context, regulatable pluripotency gene expression systems are the most widely used at present. We have constructed a regulatable bidirectional adenovector expressing the humanized green fluorescent protein (GFP) and oct4, sox2, klf4, and c-myc genes (known as the Yamanaka genes or OSKM). The OSKM genes are arranged as a bicistronic tandem (hSTEMCCA tandem), which is under the control of a Tet-Off bidirectional promoter that also controls the expression of the gFP gene. Separately, a constitutive cassette expresses the regulatory protein tTA. Vector DNA was transfected in HEK293 Cre cells, which were additionally infected with the helper adenovector H14, unable to package its DNA due to the Cre recombinase produced by the HEK293 Cre cells. The newly generated vector was expanded by six iterated coinfections of the above cells which were lysed at the end of the process and the adenovector purified by ultracentrifugation in a CsCl gradient. The titer of the initial preparation was 1.2 × 1012 physical viral particles/ml. As expected, GFP fluorescence in vector-transduced rat fibroblast cultures declined with the dose of doxycycline (DOX) present in the medium. Immunocytochemical analysis of transduced cells confirmed the expression of the four Yamanaka genes. Additionally, 3 days after vector injection in the hypothalamus of rats, a significant level of fluorescence was observed in the region. Addition of 2 mg/ml DOX to the drinking water reduced the GFP expression. This adenovector constitutes a promising tool for implementing nonintegrative partial cell reprogramming.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae / genetics
  • Animals
  • Brain / physiology*
  • Cells, Cultured
  • Female
  • Gene Transfer Techniques
  • Genetic Therapy / methods*
  • Genetic Vectors / genetics
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • HEK293 Cells
  • Humans
  • Kruppel-Like Factor 4
  • Kruppel-Like Transcription Factors / genetics*
  • Kruppel-Like Transcription Factors / metabolism
  • Octamer Transcription Factor-3 / genetics*
  • Octamer Transcription Factor-3 / metabolism
  • Proto-Oncogene Proteins c-myc / genetics*
  • Proto-Oncogene Proteins c-myc / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Regeneration*
  • SOXB1 Transcription Factors / genetics*
  • SOXB1 Transcription Factors / metabolism

Substances

  • KLF4 protein, human
  • Klf4 protein, rat
  • Kruppel-Like Factor 4
  • Kruppel-Like Transcription Factors
  • Octamer Transcription Factor-3
  • POU5F1 protein, human
  • Proto-Oncogene Proteins c-myc
  • SOX2 protein, human
  • SOXB1 Transcription Factors
  • Green Fluorescent Proteins