Objective: Hepatic progenitor cell transplantation has shed light on the treatment of liver failure. The present study was designed to evaluate whether xenogeneic liver epithelial progenitor cells（LEPCs） transplantation could promote liver recovery in a rat model of acute liver failure. The engraftment and hepatocytic differentiation of transplanted hepatic progenitor cells in the rat spleen was also investigated. Methods: LEPCs were propagated in vitro for long and transduced with lentiviral vector carrying mCherry gene. Intraperitoneal injection of CCl4 followed by 2/3 partial hepatectomy three days later were used to establish rat models of acute liver failure. Rats were intrasplenically injected with mCherry modified LEPCs（n=20

1×107cells/0.5 mL） or the same volume of medium（n=20）. Serum liver enzymes（ALT

AST） and liver histology were evaluated for 21 days after transplantation. The engraftment of transplanted LEPCs in the spleens was tested by polymerase chain reaction（PCR） amplification targeting mCherry gene. The differentiation into hepatocytic lineage of transplanted LEPCs was investigated using immunohistochemistry staining against Alb. Results: LEPCs were effectively transduced with lentiviral vector showing a transduction efficiency of 90%. Compared with control

cell-injected group displayed significantly lower levels of ALT and AST（P<0.05） and better histological features including less swelling change and hepatocyte death. PCR amplification of mCherry sequences confirmed the engraftment of LEPCs in the spleens. Alb-positive cells first appeared 5 days after cell transplantation and the number of Alb-positive cells increased substantially（P<0.05）

which revealed the hepatocytic differentiation process. Conclusion: Xenogeneic hepatic progenitor cells can engraft and differentiate into hepatocytes in the splenic parenchyma. Intrasplenic delivery of hepatic progenitor cells ameliorates CCl4 /partial hepatectomy-induced liver injury in rats.