Intrasplenic Transplantation of Cytotoxic T-Lymphocyte Associated Protein 4-Fas Ligand--Modified Hepatic Oval Cells for Acute Liver Injury in Rats.

BACKGROUND

Intrasplenic transplantation of xenogeneic hepatic oval cells (HOCs) may provide metabolic support for acute liver injury. However, xenoreactive lymphocyte-mediated immune response hinders HOCs' survival in the xeno-spleen parenchyma. Cytotoxic T-lymphocyte associated protein 4-Fas ligand (CTLA4.FasL), a fusion product integrating 2 inhibitory elements against lymphocytes into 1 molecule, effectively inhibited the proliferation of allogeneic and autoimmune lymphocytes. The purpose of this study was to explore the effect of CTLA4.FasL on the proliferation of xenoreactive lymphocytes and evaluate the therapeutic efficacy of CTLA4.FasL-modified HOC transplantation on acute liver injury in rats.

METHODS

The effect of CTLA4.FasL-modified mouse liver epithelial progenitor cells (CTLA4.FasL-LEPCs) on the proliferation of rat lymphocytes in xeno-mixed lymphocyte reaction was investigated. Furthermore, CTLA4.FasL-LEPCs were intrasplenically transplanted in carbon tetrachloride- and partial hepatectomy-treated rats, and the therapeutic effect was evaluated using hematoxylin and eosin staining and alanine aminotransferase and aspartate aminotransferase assays. The hepatocytic differentiation of CTLA4.FasL-LEPCs in xenogeneic spleen was monitored by immunohistochemical staining for albumin.

RESULTS

In xeno-mixed lymphocyte reaction, CTLA4.FasL-LEPCs substantially inhibited the rat lymphocytes proliferation. CTLA4.FasL-LEPC transplantation significantly ameliorated liver injury compared with mCherry-modified LEPC and LEPC transplantation, as assessed by hematoxylin and eosin staining, alanine aminotransferase, and aspartate aminotransferase assays. Albumin positive cells appeared only in CTLA4.FasL-LEPCs group, but not in the mCherry-modified LEPCs group and LEPCs group.

CONCLUSIONS

Our results indicate CTLA4.FasL-LEPCs substantially improved liver function and structure in carbon tetrachloride- and partial hepatectomy-induced acute liver injury rats through long-term hepatocytic differentiation.