Inhibition of Rejection Reaction by Modulating Actions of Adhesion Molecules on Sinusoidal Endothelial Cells in Rat Liver Allograft.

在本研究中，我们探讨了粘附分子和趋化因子在排斥反应中的作用。从治疗的角度来看，有两个重要的阶段；再灌注后中性粒细胞与内皮细胞的粘附，以及急性排斥反应中T细胞的粘附。体外大鼠肝脏缺血再灌注后，血清IL-8水平立即升高，并在再灌注后6小时达到峰值。Kupffer细胞的失活完全抑制了升高。在大鼠肝脏再灌注后分离的Kupffer细胞中，Northern blot检测到IL-8 mRNA，对照组未检测到IL-8 mRNA。这些发现提示IL-8来源于活化的Kupffer细胞。体外研究表明，血小板在肝再灌注损伤中起重要作用。因此，在体外研究中，血小板在中性粒细胞粘附中的可能作用进行了研究。结果表明，在炎症早期，凝血酶刺激的血小板通过Gp IIb/IIIa粘附在未刺激的内皮细胞（HUVEC）上，此后中性粒细胞被p选择素拴在血小板上。ii .肝细胞生长因子（HGF）在大鼠同种异体肝移植排斥反应中的可能作用我们已经在体外研究中证明了HGF促进CD4记忆T细胞的粘附和迁移，并提出它可能有助于诱导T细胞在肝脏中的浸润。因此，我们评价了大鼠同种异体肝移植（ACI-Lewis）排斥反应过程中血清和肝脏中的HGF水平，并与供体特异性耐受（DST）组进行比较。与拒绝组相比，DST组血清HGF水平显著升高。DST组肝脏门静脉区单核细胞强烈表达HGF，肝小叶内CD4 t细胞浸润。另一方面，排斥组肝脏HGF表达分散在肝小叶和胆管周围的门静脉区。这些结果提示HGF在排斥反应中的可能作用如下：(1)促进肝细胞再生(2)诱导肝内CD4 t细胞迁移(3)刺激胆管细胞增殖。少

In this study we have investigated into roles of adhesion molecules and chemokines in rejection reaction. It is thought from a therapeutic point of view that there are two important phases ; neutrophil-adhesion to the endothelial cells immediately after reperfusion, and T cell-adhesion in acute rejection.I.Hepatic Injury after Ischemia-Reperfusion1.in vitroWhen rat liver was exposed to ischemia-reperfusion, serum IL-8 levels were immediately elevated and peaked at 6 hr after the reperfusion. The elevation was completely inhibited by inactivation of Kupffer cells.IL-8 mRNA was detected by Northern blot in the Kupffer cells isolated from the rat liver after the reperfusion, but was not detected in the control. These findings imply that IL-8 was derived from the activated Kupffer cells.2.in vitroIt has been reported that platelet plays an important role in hepatic injury after reperfusion. Thus in an in vitro study a possible role of platelet in neutrophil-adhesion was investigated. It wa … More s demonstrated that in an early phase of inflammation platelet stimulated by thrombin adhered to unstimulated endothelial cells (HUVEC) via Gp IIb/IIIa, and thereafter neutrophils were tethered by P-selectin on the platelet. The similar experiment using sinusoidal endothelial cells is under consideration.II.Possible roles of hepatocyte growth factor (HGF) in rejection reaction of rat liver allograftWe have demonstrated in an in vitro study that HGF promotes adhesion and migration of CD4 memory T-cells, and have proposed that it may contribute to induction of T cell-infiltration in the liver. Thus, we evaluated HGF level in the serum and the liver during the process of rejection reaction of rat liver allograft (ACI-Lewis), as comparing with those of donor specific tolerant (DST) group as the control. Serum HGF levels were significantly increased in DST as compared with those of the rejected group.In the liver of DST group, HGF was strongly expressed in the mononuclear cells in the portal areas, and there was infiltation of CD4 T-cells in the hepatic lobule. On the other hand, the liver of the rejected group showed HGF expression scattering in the hepatic lobules and the portal area surrounding the bile ductule. These results suggested possible roles of HGF in rejection reaction as follows : (1) it promotes hepatocyte regeneration (2) it induces CD4 T-cell migration in the liver (3) it stimulates proliferation of bile ductule cells. Less