Developing a potentially immunologically inert tetracycline-regulatable viral vector for gene therapy in the peripheral nerve

Gene Ther. 2014 Jun;21(6):549-57. doi: 10.1038/gt.2014.22. Epub 2014 Apr 3.

Abstract

Viral vector-mediated gene transfer of neurotrophic factors is an emerging and promising strategy to promote the regeneration of injured peripheral nerves. Unfortunately, the chronic exposure to neurotrophic factors results in local trapping of regenerating axons or other unwanted side effects. Therefore, tight control of therapeutic gene expression is required. The tetracycline/doxycycline-inducible system is considered to be one of the most promising systems for regulating heterologous gene expression. However, an immune response directed against the transactivator protein rtTA hampers further translational studies. Immunogenic proteins fused with the Gly-Ala repeat of the Epstein-Barr virus Nuclear Antigen-1 protein have been shown to successfully evade the immune system. In this article, we used this strategy to demonstrate that a chimeric transactivator, created by fusing the Gly-Ala repeat with rtTA and embedded in a lentiviral vector (i) retained its transactivator function in vitro, in muscle explants, and in vivo following injection into the rat peripheral nerve, (ii) exhibited a reduced leaky expression, and (iii) had an immune-evasive advantage over rtTA as shown in a novel bioassay for human antigen presentation. The current findings are an important step toward creating a clinically applicable potentially immune-evasive tetracycline-regulatable viral vector system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Female
  • Gene Expression Regulation
  • Genetic Therapy / methods
  • Genetic Vectors / genetics
  • Genetic Vectors / immunology
  • Genetic Vectors / pharmacology*
  • HEK293 Cells
  • Humans
  • In Vitro Techniques
  • Lentivirus / genetics
  • Molecular Sequence Data
  • Muscle, Skeletal / physiology
  • Peripheral Nerves / drug effects*
  • Rats, Wistar
  • T-Lymphocytes, Cytotoxic / immunology
  • Tetracycline / pharmacology*
  • Trans-Activators / genetics
  • Trans-Activators / metabolism

Substances

  • Trans-Activators
  • Tetracycline