Effects Of CTLA4-Ig On T Lymphocyte Subsets In Rat Allograft Hepatocyte Transplantation Model

Objective:To master the way of isolating and purifying hepatocytes through an in-situ collagenase cycle perfusion.To investigate the immunosuppressive effect of cytotoxic T lymphocyte associated antigen 4 immunoglobulin fusion protein(CTLA4-Ig) on T lymphocyte subsets in rat allograft hepatocyte transplantation model and the rejection mechanisms. Methods:Preparation of ALF model:10% D-gal solution was prepared and injected to rates via abdominal cavity with dosage of 1.0g/kg respectively.Cell seperation and purification:Collagenase perfusion was performed on SD rats to separate liver cells and suspension was counted.SD rats with ALF induced by D-gal was performed intrasplenic hepatocyte transplantation(approximately 2 ×10~7 cells ) and were randomly divided into two groups:Group I and II.Group I received CTLA4-Ig 100μg by intraperitoneal injection.Liver function, the splenic pathohistological examination in the recipients were performed.The T lymphocyte subsets were detected by using immunohisto-chemistry technique. Results: The hepatocytes isolated and purified yielded amount to 2.0-2.5×10~8 per rat.More than 95% of hepatocytes identified with trypan blue were viable.The comparison between group I and II shows that signficant differences were found in ALT and TBil after injection CTLA4-Ig ( p< 0.01 ).The splenic pathohistological: There still were some hepatocytes in the group I , but not in group II.T lymphocyte subsets,mainly CD4~+,in CTLA4-Ig treated group was significantly decreased compared with control group(p﹤0.05), so did the CD4~+ /CD8~+. Conclusion:The viability of hepatocytes isolated by the method mentioned above was high.CTLA4-Ig has significant immunosuppressive effects on rat hepatocyte allograft transplantation.CTLA4-Ig can decrease T lymphocyte subsets, mainly CD4~+.