Stability of Borna disease virus-based episomal vector under physical and chemical stimulation

Borna disease virus (BoDV), a nonsegmented, negative-sense RNA virus, establishes persistent infection and replicates in the cell nucleus. Since BoDV genomic RNA exists as episomal RNA, the host genome is not invaded by BoDV infection. These unique features make BoDV a promising gene delivery system as an RNA virus-based episomal vector (REVec). Previously, the stable expression of genes of interest in vitro and in vivo using a REVec was reported. For the clinical application of a REVec, the fundamental properties under various physical and chemical conditions must be determined to develop purification processes, supply chains, and biosafety management. This study investigated the effects of the following conditions on the inducibility of transmission-defective Delta G-REVec: freeze-thaw cycles, dehydration, UV, temperature, pH, and reagents for virucides and laboratory experiments. Although the titer of Delta G-REVec was not influenced by the freeze-thaw process or 5 minute incubation at <= 50 degrees C, Delta G-REVec was significantly inactivated by incubation at >= 70 degrees C for 5 minutes. The induction titer of Delta G-REVec was decreased by long-term incubation, dehydration, and UV irradiation in a temperature- and time-dependent manner. Delta G-REVec was sensitive to lower pH and inactivated by chemical reagents under general conditions. These results provide important knowledge for developing the clinical use of REVec and biosafety management.

Automated summary

This study investigated the effects of various physical and chemical conditions on the inducibility of transmission-defective Delta G-REVec. Results showed that Delta G-REVec was not influenced by freeze-thaw cycles or brief incubation at lower temperatures, but was significantly inactivated at higher temperatures. Long-term incubation, dehydration, and UV irradiation also decreased the induction titer of Delta G-REVec. Additionally, Delta G-REVec was sensitive to lower pH and chemical reagents, providing important information for the development of clinical use and biosafety management of REVec.