Title

Studies on transplantation of human hepatocytes into genetically immunocompetent rodents

Date of Completion

January 2001

Keywords

Biology, Cell|Health Sciences, Immunology

Degree

Ph.D.

Abstract

The objective of this project is to study the feasibility of transplantation of human hepatocytes into immunocompetent rats and test the engraftment, survival and functioning of the transplanted cells. To avoid rejection of human hepatocytes by the rat immune system, tolerance was induced by injection of human hepatocytes into the peritoneal cavities of fetal rats during late gestation. Human hepatocytes were subsequently transplanted into tolerized rat livers via intrasplenic injection within 24 hrs after the birth. Engraftment of donor hepatocytes in the recipient livers was visualized by immunohistochemical staining for human albumin. PCR of genomic DNA and dot blotting results verified that transplanted human hepatocytes survived in rat liver for at least 16 weeks post-transplantation. Human hepatocytes sustained biological functions such as active transcription of human albumin mRNA and secretion of human albumin into the circulation. Transplanted human hepatocytes were found to be susceptible to HBV inoculation. HBV viremia was confirmed by detection of HBV cccDNA and HBsAg in the rat liver and serum. Elevated rat serum ALT levels and changes in liver histology following the HBV inoculation indicated possible hepatic inflammation in the host livers. In conclusion, we established a chimeric human-rodent liver model by prenatal tolerization and post-natal transplantation. This model could be used to study human hepatitis, liver biology, and transplantation immunology. ^