Induction of hepatic allograft-infiltrating T lymphocyte apoptosis by pretransplant intraportal infusion of recipient blood into donor / 中国组织工程研究

ABSTRACT

BACKGROUND:When immunological rejection occurs following liver transplantation,liver cells are destroyed by infiltrated T lymphocytes,leading to progressive deterioration of hepatic function owing to reduction of liver cells.Induction of immunological tolerance of liver transplantation remains a challenge.OBJECTIVE:To observe the influences of pretransplant intraportal infusion of recipient blood into donor on the apoptosis of hepatic allograft-infiltrating T lymphocytes in rats.DESIGN,TIME AND SETTING:A randomized,controlled,animal experiment was performed at the Organ Transplant Unit,China University between May 2002 and May 2004.MATERIALSInbred rats were developed into models of orthotopic liver transplantation.Twenty-four female ACI rats(RT1a)served as donors,and an additional twenty-four male LEW rats(RT11)served as recipients.METHODS:A modification of cuff method was employed for orthotopic liver transplantation in rats.Twenty-four recipient rats recipient blood was infused into each donor rat via the portal vein.All blood infusions were performed 7 days prior to liver transplantation.MAIN OUTCOME MEASURES:Rat survival time,serum content of γ- interferon,histological changes of hepatic allograft,number of dendritic cells in the hepatic allograft,and T lymphocyte apoptosis following liver transplantation.RESULTS:Rat survival time was significantly longer in the intraportal infusion of non-recipient blood group than in the control group(P＜0.01).At 3 and 5 days after liver transplantation,the intraportal infusion of non-recipient blood group exhibited significantly higher serum content of y- interferon than the control group(P＜0.05).No significant differences in rat survival time and serum content of γ- interferon were found between intraportal infusion of non-recipient blood and intraportal infusion of non-recipient blood groups and control group(P＞0.05).In the intraportal infusion of non-recipient blood group,infiltrated T lymphocytes in the hepatic allograft were significantly reduced,and a large number of donor-sourced dendritic cells were detected.The number of apoptotic cells per square millimeter of hepatic tissue was significantly higher in the intraportal infusion of non-recipient blood group than in the control group(P＜0.01).CONCLUSION:Pretransplant intraportal infusion of recipient blood into donor can prolong the survival time of hepatic allograft and promote the apoptosis of hepatic allograft-infiltrating T lymphocytes.