摘要目的 探讨腺相关病毒介导血红素加氧酶-1(AAV-HO-1)诱导大鼠肝移植免疫耐受的有效性及其分子机制.方法 按Kamada二套管法建立大鼠原位肝移植模型.在供肝冷保存阶段分别经门脉灌注磷酸盐缓冲液(PBS)、Empty AAV或AAV-HO-1,孵育2h后行DA→Lewis大鼠原位肝移植,检测移植术后大鼠的中位存活时间(MST);血清中白细胞介素(IL)-2、肿瘤坏死因子(TNF)-α的表达;移植肝中CD4+、CD8+,调节性T细胞(Treg细胞、CD4+ CD25+ Foxp3+)的表达;耐受组脾脏中Treg细胞百分率并对耐受组脾脏行混合淋巴细胞培养(MLC)观察免疫耐受.结果 AAV-HO-1组MST为30 d,显著长于PBS组(11 d)或Empty AAV(12 d)(P＜0.01),其中20％存活超过90 d;血清中IL-2、TNF-α的表达明显降低,CD4+和CD8+T细胞的浸润减少,Treg细胞在移植肝中的浸润增加.耐受组脾脏中Treg细胞为6.7％,显著提高,行MLC后几乎无淋巴细胞反应.结论 AAV-HO-1可通过增加Treg细胞,延长大鼠的存活期,证实AAV-HO-1可诱导肝移植免疫耐受.

abstractsObjective To investigate the efficacy and molecular mechanisms of AAV-HO-1 inducing immuno-telorance in rats.Methods An orthotopic liver transplantation model by DA to Lewis was set up using Kamada' s two cuff technique.PBS,empty AAV or purified AAV-HO-1 was injected into the portal vein and incubated for 2 h at the donor liver cold preserved stage,and then OLT was done.The media survival time (MST),serum levels of interleukin (IL)-2 and tumor necrosis factor (TNF)-α,infiltration of CD4 +,CD8 + and Treg (CD4 + CD25 + Foxp3 +) cells into donor livers and percent of Treg in the spleen were examined.A mixed lymphocyte reaction (MLR) was performed.Results Recipients transplanted with AAV-HO-1-perfused liver allografts had a median survival time of 30 days,which was significantly longer than that in the PBS group (11 days) and empty AAV group (12 days) (both P ＜0.01).Overexpression of HO-1 reduced the production of IL-2 and TNF-α,inhibited infiltration of CD4+ and CD8 + cells,and increased infiltration of Treg ceils into donor livers.Splenocytes from the tolerant recipients had higher percentages of Treg cells,and responded poorly to the allogeneic donor splenocytes.Conclusion Persistent expression of HO-1 in the donor livers by intraportal delivery of AAV-HO-1 can prolong the survival by expanding Treg cells,suggesting that AAV-HO-1 can induce immuno-tolerance in liver allograft in rats.