半乳凝集素-9在诱导大鼠肝移植免疫耐受中的作用

目的通过观察半乳凝集素-9(Galectin-9)在大鼠肝移植急性排斥模型中的作用,探讨其在诱导肝移植免疫耐受中的机制。方法建立Lewis到BN大鼠肝移植急性排斥反应模型(n=30),受体分为3组,每组10只。转染组于肝移植冷缺血期经门静脉转染重组galectin-9腺病毒质粒2 ml,空质粒组灌注2 ml空腺病毒载体,对照组灌注2 ml生理盐水。术后7 d各组处死5只大鼠,余观察生存率,采用Banff分级观察移植物排斥程度;实时荧光定量PCR检查肝组织Galectin-9、T-bet、RORγt mRNA表达水平;Western blot检测肝组织IFN-γ及IL-17蛋白表达水平。结果术后7 d转染组Banff评分Ⅰ～Ⅱ级,空质粒组及对照组为Ⅲ级;转染组、空质粒组及对照组Galectin-9 mRNA水平依次为(1.14±0.05)、(0.46±0.03)、(0.49±0.07),转染组Galectin-9 mRNA水平较其余2组明显增加(P<0.05)。转染组、空质粒组及对照组T-bet及RORγt mRNA表达水平分别为(0.27±0.07)、(1.26±0.12)、(1.31±0.08)和(0.57±0.13)、(1.57±0.09)、(1.58±0.07),转染组T-bet及RORγt mRNA表达水平明显低于其余2组(P<0.05);转染组、空质粒组及对照组IFN-γ及IL-17蛋白表达水平分别为(0.39±0.06)、(1.28±0.11)、(1.47±0.05)和(0.64±0.07)、(1.52±0.05)、(1.67±0.04),转染组IFN-γ及IL-17蛋白表达水平低于空质粒组及对照组(P<0.05)。结论 Galectin-9通过清除Th1/Th17细胞诱导肝移植免疫耐受形成。

Role of galectin-9 in inducing immune tolerance of rats after liver transplantation

Objective To study the mechanism of galectin-9 in inducing immune tolerance of rats after liver transplantation by observing its role in an acute rejection model of rats.Methods An acute rejection model of Lewis-BN rats after liver transplantation was established.Thirty rats were randomly divided into transfection group,blank plasmid group,and control group(10 in each group).Rats in transfection group were injected with 2 ml recombinant Ad-galectin-9 through the portal vein,those in blank plasmid group were injected with 2 ml adenoviral vector,and those in control group were injected with 2 ml normal saline during the cold ischemia period.Five rats in each group were sacrificed on day 7 after operation.Survival time of the remaining rats was observed.Degree of acute graft rejection was assayed according to the Banff scale.Expression levels of galectin-9,T-bet and RORγt mRNA,and IFN-γ and IL-17 protein in liver tissue were measured by RT-PCR and Western blot,respectively.Results Seven days after operation,the Banff scale wasⅠ to Ⅱin transfection group and Ⅲ in blank plasmid group and control group,the expression level of galectin-9 mRNA was significantly higher in transfection group than in blank plasmid group and control group(1.14±0.05 vs 0.46±0.03 and 0.49±0.07,P<0.05),while the expression level of T-bet and RORγt mRNA,and IFN-γ and IL-17 protein was significantly lower in transfection group than in blank plasmid group and control group(0.27±0.07 vs 1.26±0.12 and 1.31±0.08,0.57±0.13 vs 1.57±0.09 and 1.58±0.07;0.39±0.06 vs 1.28±0.11 and 1.47±0.05,0.64±0.07 vs 1.52±0.05 and 1.67±0.04,P<0.05).Conclusion Galectin-9 can induce immune tolerance of rats after liver transplantation by clearing Th1 and Th17 cells.