预输注RelB shRNA慢病毒修饰树突细胞诱导大鼠肝移植免疫耐受

背景：肝移植后的排斥反应是威胁患者和移植物长期存活的主要原因。诱导受者产生特异性免疫耐受是解决排斥反应的理想措施。 目的：探讨RNAi RelB树突状细胞预输注诱导大鼠肝移植特异性免疫耐受的可能性。 方法：将近交系雄性清洁级DA(RT1a)大鼠和近交系雄性SPF级Lewis(RT11)大鼠分别作为供、受体，行原位肝移植手术。术前随机配对分为4组：①对照组，受体鼠移植前不做预输注。②治疗组：受体鼠移植前7 d静脉输注供体大鼠RNAi RelB树突状细胞(5×106)。③未成熟树突状细胞组：受体鼠移植前7 d静脉输注供体大鼠未成熟树突状细胞(5×106)。④成熟树突状细胞组：受体鼠移植前7 d静脉输注供体大鼠成熟树突状细胞(5×106)。 结果与结论：与对照组、未成熟树突状细胞组以及成熟树突状细胞组相比，治疗组移植肝的平均生存时间显著延长。移植后第7天，治疗组天冬氨酸转氨酶，总胆红素水平低于对照组、成熟树突状细胞组、未成熟树突状细胞组(P < 0.01)，移植后第14天治疗组、未成熟树突状细胞组天冬氨酸转氨酶，总胆红素均有轻微下降，两组比较差异仍有显著性意义(P < 0.01)。移植后第7天，与治疗组比较，对照组、成熟树突状细胞组、未成熟树突状细胞组γ-干扰素、白细胞介素2水平升高(P < 0.01)，而白细胞介素4、白细胞介素10下降(P < 0.01)；移植后第14天治疗组、未成熟树突状细胞组γ-干扰素、白细胞介素2水平均有下降，白细胞介素4、白细胞介素10水平均有升高，两组比较差异仍有显著性意义(P < 0.01)。对照组、成熟树突状细胞组、未成熟树突状细胞组移植后第7天排斥活动指数为8.0-9.0。未成熟树突状细胞组第14天肝细胞、内皮细胞坏死及汇管区炎性细胞浸润进一步增多。治疗组移植后第7天排斥活动指数为6.0-8.0，第14天时排斥活动指数为4.0-5.0。结果提示RNAi RelB树突状细胞预输注可以减轻移植肝排斥程度，延长移植肝生存时间，这是通过间接途径实现的，其机制可能与T细胞的调节和无能有关。

Immune tolerance of rat liver transplantation induced by pre-infusion of RNA interference RelB short hairpin RNA lentiviral modified dendritic cells

BACKGROUND:Homograft rejection is the most important factor that limits the survival of recipients and donor organs fter liver transplantation. Induced specific immune tolerance is a most satisfactory method to release rejection after transplantation. OBJECTIVE:To explore the possibility of the specific immune tolerance induced by RNA interference RelB dendritic cells pre-infusion after liver transplantation in rats. METHODS:A stable rat model of acute rejection was established by allograft liver transplantation from DA (RT1a) rats to Lewis (RT11) rats. Before transplantation, the donor and recipient rats were paired and randomly divided into four groups: (1)Control group: the recipient rats were not injected before liver transplantation. (2)RNA interference RelB treatment group: the recipient rats were pre-injected with RNA interference RelB dendritic cells from donor (5×106) via veins at the 7 days before transplantation. (3)Immature dendritic cells group: the recipient rats were pre-injected with immature dendritic cells (5×106) from donor via veins at the 7 days before transplantation. (4)Mature dendritic cells group: the recipient rats were pre-injected with mature dendritic cells (5×106) from donor via veins at the 7 days before transplantation. RESULTS AND CONCLUSION:Compared with control group, immature dendritic cells group and mature dendritic cells group, the average survival time of graft renal in RNA interference RelB treatment group prolonged significantly (P < 0.01). The content of aspartate aminotransferase and total bilirubin in RNA interference RelB treatment group at 7 days after transplantation were significantly lower that those in the control group, immature dendritic cells group and mature dendritic cells group (P < 0.01), while the content of aspartate aminotransferase and total bilirubin at 14 days after transplantation in RNA interference RelB treatment group and immature dendritic cells group were slightly decreased, and there was significant difference between two groups (P < 0.01). At 7 days after transplantation, compared with RNA interference RelB treatment group, the contents of interferon-γ and interleukin-2 were increased in the control group, immature dendritic cells group and mature dendritic cells group (P < 0.01), while the contents of interleukin-4 and interleukin-10 were decreased (P < 0.01); at 14 days after transplantation, the contents of interferon-γ and interleukin-2 were decreased and the contents of interleukin-4 and interleukin-10 were increased in RNA interference RelB treatment group and immature dendritic cells group, and there was significant difference between two groups (P < 0.01). At 7 days after transplantation, the rejection active index in the control group, immature dendritic cells group and mature dendritic cells group was 8.0-9.0. At 14 days after transplantation, more necrosis of hepatocytes and endotheliocyte and inflammatory cells imbibition in header zone were observed in immature dendritic cells group. The rejection active index in RNA interference RelB treatment group at 7 days after transplantation was 6.0-8.0, and rejection active index was 4.0-5.0 at 14 days after transplantation. Pre-injection of RNA interference RelB dendritic cells may contribute to reduce the degree of graft rejection and prolong the survival time of grafted liver, which related to the regulation and immune-incompetent of T cells.