| ObjectiveTo study the tolerance capability which induces rat allogeneic orthotopic liver transplantation and prolong the survival time of allograft that combines with imDCs and Tregs.MethodsOne hundred cases of rat allogeneic orthotopic liver transplantation were accomplished in the strain combination of DA to Lewis rats, which were divided into 5 groups, including acute rejection group, mDC group, imDC group , Treg group, co-infusion group (imDC-Treg group). Then 2×10~6 imDC , 2×10~6 mDC and 1×10~7 Treg cells were respectively injected to Lewis rats in every group via caudal vein before transplantation, Four Lewis rats from each group were randomly sacrificed on days 3, 7 and 10 after transplantation. Hepatic function (ALT and TBIL) and cytokines alteration (IL-10,IL-2 and TGF-β)were evaluated in peripheral blood. The pathological changes of the liver graft were observed. And the DNA fragmentaion characteristic of apoptosis in liver were detected by carrying out TUNEL staining. Survival analysis were performed for remnant rats, except rats dead for technical factor.ResultsAt day 7, hepatic function of imDC-Treg group had reverted to normal and the hepatic function of Treg group took a turn for the better, but got worse at day 10.At day 10, Liver function of imDC group returned to normal, But compared to that of imDC-Treg group, the difference was not statistically significant ( P>0.05 ). The outcome of ELISA notified that at day 7, the serum levels of IL-10 in imDC-Treg group compared to those in acute rejection group,mDC group and Treg group,on the contraty, the difference was not statistically significant( P=0.275) between imDC-Treg group and imDC group. The serum levels of TGF-βin imDC-Treg group compared to those in acute rejection group,mDC group and imDC group, the differences were all statistically significant,on the contraty, the difference was also not statistically significant( P>0.05 ) between imDC-Treg group and Treg group. The serum levels of IL-2 in imDC-Treg group was lower than that in acute rejection group,mDC group , and althogh IL-2 in imDC-Treg group was lower than that in imDC and Treg group ,the differences were not statistically significant(P>0.05).Liver pathology showed that there was only a slight number of mononuclear cell infiltration in hepatic graft after orthotopic liver transplantation in co-infusion group (imDC-Treg group), which belonged to a"non-identified"or"slight"type of AR with RAI score 1 to 5; and the liver graft showed up regeneration of hepatocyte along with a small number of neutrophile granulocyte infiltration at day 10. At day 3, although the rejection in liver graft of each group was rated as"slight"type of AR, the AR in liver graft in imDC-Treg group was lighter than that in mDC group,Treg group and imDC group;At day 7, the AR in hepatic graft in imDC-Treg group was lighter than that in Treg group and imDC group,imDC group was also lighter than that in Treg group ;At day 10, the AR in hepatic graft in imDC-Treg group was lighter than that in other groups ,further more the AR in hepatic graft in Treg group was severer than that in imDC group.Apoptosis of T cells in recipient liver were analyzed by TUNEL staining.We found that apoptosis of T cells were much less in control groups than in imDC-Treg groups.The MST of rat recepients in Treg group was 15 days and compared to that in imDC group ( 23 d ) with statistically significance of difference ( P = 0.003). There were rat recepients with long-term survival only in imDC-Treg group, in which the survival of rat recepients was significantly prolonged than that in imDC group and Treg group. |
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