An ex vivo human model system to evaluate specificity of replicating and non-replicating gene therapy agents

✍ Scribed by M. G. Rots; M. G. L. Elferink; W. M. Gommans; D. Oosterhuis; J. A. C. Schalk; D. T. Curiel; P. Olinga; H. J. Haisma; G. M. M. Groothuis

• Book ID: 102339549
• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 176 KB
• Volume: 8
• Category: Article
• ISSN: 1099-498X
• DOI: 10.1002/jgm.815

✦ Synopsis

Background:

Inefficiency, aspecificity and toxicity of gene transfer vectors hamper gene therapy from showing its full potential. on this basis significant research currently focuses on developing vectors with improved infection and/or expression profiles. screening assays with validity to the clinical context to determine improved characteristics of such agents are not readily available since this requires a close relationship to the human situation. we present a clinically relevant tissue slice technology to preclinically test improved vector characteristics.

Methods:

Slices were prepared from rat, mouse and human liver samples and from tumor tissue. specificity of gene expression and replication was determined by infecting target and non-target tissue slices with transcriptionally retargeted adenoviruses and oncolytic viruses.

Results:

Using rat liver slices, we demonstrate efficient knob-mediated adenoviral infectivity. a favorable tumor-on/liver-off profile, resembling in vitro and mouse in vivo data, was shown for a tumor-specific transcriptionally retargeted adenovirus by infecting slices prepared from tumor or liver tissue. similar liver-off data were found for mouse, rat and human samples (over 3-log lower activity of the tumor-specific promoter compared to cytomegalovirus (cmv)). more importantly, we show that this technology when applied to human livers is a powerful tool to determine aspecific replication of oncolytic viruses in liver tissue. a 2- to 6-log reduction in viral replication was observed for a tumor-specific oncolytic virus compared to the wild-type adenovirus.

Conclusions:

The precision-cut tissue slice technology is a powerful method to test specificity and efficiency of gene transfer as well as of viral replication using human tissue.