Inducement of rat liver transplantation tolerance by hFasL and hTGF-β1 gene modified dendritic cells

Abstract

Objective To improve immature dendritic cell ( imDC)' s tolerance capability which induces rat allogeneic orthotopic liver transplantation and prolong the survival time of allograft,this research co-modifying imDC with FasL and transforming growth factor-β1 ( TGF-[1 ) gene.Methods One hundred and forty cases of rat allogeneic orthotopic liver transplantation were accomplished in the strain combination of DA to Lewis rats,which were divided equally into 7 groups,including non- injection group ( control group),mDC group,imDC group,empty vector group,FasL group,TGF group and cotransfection group.Then 2 × 106 cells were respectively intraperitoneally injected to Lewis rats with distinct cells,such as mDC,imDC,empty vector-transfected imDC,hFasL-modified imDC,hTGF-β1-transformed imDC and comodified imDC with FasL and TGF-β1 gene.Four Lewis rats from each group were randomly sacrificed on days 3,7 and10 after transplantation.Hepatic function [ alanine aminotransferase (ALT) and total bilirubin (TBIL) ] and cytokines alteration were evaluated in peripheral blood.The pathological changes of the liver graft were observed.Survival analysis were performed for remnant rats,except rats dead for technical factor.Results At day 7,the difference was statistically significant ( P ＜ 0.01 ) between seven groups,and the AR in hepatic graft in cotransfection group were all lighter than those in TGF group and FasL group.At day 10,there was statistical significance between seven groups (P ＜0.01 ),the AR in hepatic graft in cotransfection group were all lighter than those in TGF group and FasL group,further more the AR in hepatic graft in TGF group was lighter than that in FasL group.At day 7,hepatic function of cotransfection group had reverted to normal and the hepatic function of FasL group took a turn for the better,but got worse at day 10;the concentration of ALT and TBIL of FasL group were obviously higher than those of cotransfection group at day 10 (P ＜0.01 and P ＜0.05).At day 10,Liver function of TGF group returned to normal,and ALT and TBIL concentrations of TGF group were significantly lower than those of FasL group ( P ＜ 0.01 and P ＜0.05 ).But compared to those of cotransfection group,the difference was not statistically significant ( P ＞0.05 ).The outcome of enzyme linked immunosorbent assay (ELISA) notified that at day 7,the serum levels of interleukin ( IL)-I,IL-10 and IL-12 in FasL group compared to those in cotransfection group and TGF group,the differences were all statistically significant ( P ＜ 0.05 ),on the contraty,the difference was not statistically significant ( P ＞ 0.05 ) between cotransfection group ane TGF group.The MST of rat recepients in FasL group was 20 days and compared to that in imDC group (23 d) with no statistically significance of difference (P ＞ 0.05),and the ability of TGF Group was limited in extending the rat receptors'survival time (48 d).There were rat recepients with long-term survival ( ＞ 90 d) only in cotransfection group,in which the survival of rat recepients was significantly prolonged than that in FasL group (P ＜0.01 ) and TGF group (P ＜0.01 ).Conclusion lmDC,hFasL or hTGF-β1 single gene-modified imDC all didn't induced long-term allograft survival of receptors in allogeneic rat liver transplantation.The ability of imDC with hFasL and hTGF-β1 co-transfection was significantly enhanced by hFasL and hTGF-β1 in inducing allogeneic rat liver transplantation immunology tolerance,which could significantly extended survival of recipients in allogeneic rat liver transplantation. Key words: Dendritic cells; Immune tolerance; FasL; TGF-β1 ; Liver transplantation