Hepatocyte transplantation techniques: large animal models.

The poor hepatocyte engraftment efficiency and the low level of their expansion in the host liver are a major limitation to cell therapy for the treatment of life-threatening liver diseases. Many rodent models have shown that liver repopulation via transplanted hepatocytes occurs only when liver growth capacity is impaired for an extended period of time. However, these models are not transposable to the clinics and to date there is no safe method to achieve this result in a clinical setting.Therefore, it is necessary to define on large animal models strategies that provide to transplanted hepatocytes sufficient proliferation stimuli to induce their division and that could permit a direct extrapolation to humans. Such procedures should be transposable to patients. We have defined a protocol of liver partial portal branch embolisation and shown that it induces the proliferation of transplanted hepatocytes in non-human primates (Macaca mulatta). This animal model is also appropriate to evaluate the lentiviral-mediated ex vivo gene therapy approach, since simian hepatocytes are efficiently transduced by HIV-1-derived lentivirus vectors.