PROLONGED SURVIVAL OF RAT LIVER ALLOGRAFTS TRANSFECTED WITH FAS-LIGAND EXPRESSING PLASMID

Abstract

524 The aim of this study is to evaluate the preventive effect of Fas-ligand transfected allogenic liver on graft rejection in rat. We constructed two expression vectors; pCAGGSFL to express rat Fas-ligand and pCAGGSLZ to express E. coli β-galactosidase (LacZ) under the control of chickenβ-actin promoter with CMV enhancer. These vectors were transfected into donor DA rat liver with an inactivated hemagglutinating virus of japan conjugated to liposome vesicles(HVJ-liposome). A couple of rats were sacrificed on 3,5,7 and 14 days after the HVJ-liposome injection, and analyzed the transduction efficiency with RT-PCR and X-gal staining. X-gal staining showed about 12% positive cells in liver sections obtained from the pCAGGSLZ transduced livers; Fas-ligand mRNA was detected by RT-PCR in pCAGGSFL transduced livers. These observations suggest that efficientin vivo gene transduction was achieved by using HVJ-liposome. Then, the genetic modified DA livers were transplanted into Lewis rats three days after HVJ-liposome injection, resulting in significant by (p<0.01) prolonged recipient survival time. Histological observation showed that pCAGGSFL-transfected liver allografts caused apoptotic cell death in infiltrating activated T cells. Based on these observations, we conclude that expression of Fas-ligand in donor liver probably acts to induce apoptotic cell death of recipient activated T cells, expressing a large amount of Fas antigens in response to donor graft antigens to reduce rejection induced in allogenic liver transplantation.