Clinically applicable liver repopulation: the role of thymidine kinase and ganciclovir (GCV)

Background and Aims:

Due to the shortage of transplantable donor livers, hepatocyte transplantation is an alternative therapy for inherited liver diseases patients. Nevertheless, the transplantation efficiency and long-term benefits of hepatocytes transplantation have to be improved. Thus, we applied thymidine kinase recombinant adeno-associated virus (AAV-TK) and ganciclovir (GCV) in order to improve the repopulation of host liver by transplanted hepatocytes.

Methods:

We evaluated the transfection efficiency of AAV-GFP and apoptosis induction of AAV-TK and GCV in Hepa 1 – 6 cells and freshly isolated primary mouse hepatocytes in vitro. We transplanted mouse primary hepatocytes after AAV-TK recombinant virus injection in vivo, which was followed by gradually increased dosages of GCV administration. The in vivo long-term transplantation efficiency and functional analyses were performed at the end of the study.

Results:

We found robust transfection efficiency and rapid apoptosis induced by AAV-TK and GCV in Hepa 1 – 6 cells and primary mouse hepatocytes in vitro. High transduction efficiency and gradually induced liver injury was observed in vivo. The extensive repopulated livers (> 40%) revealed gradually recovered liver functions. Apoptosis of hepatocytes was restricted in recipient liver until month 6 after transplantation.

Conclusion:

Our findings reveal stable but non-fatal liver injury induced by AAV-TK and GCV system and increased repopulation of transplanted hepatocytes. Hence, AAV-TK/GCV may be suitable for increasing therapeutic efficiency of hepatocyte transplantation and may facilitate humanised mouse research.