Liu Gang, He Xianghui, Lu Ning, Qiu Yujie, Wang Hao
Department of General Surgery, Tianjin Medical University General Hospital, Tianjin General Surgery Institute, Tianjin, People's Republic of China.
Microsurgery. 2015 Jan;35(1):52-9. doi: 10.1002/micr.22265. Epub 2014 Apr 25.
Major histocompatibility complex-II (MHC-II) plays an important role in graft rejection and class II transactivator (CIITA) is the key regulator for MHC-II expression. The aim of this study was to determine the efficacy of intragraft inhibition of CIITA in attenuating liver transplant rejection. Three plasmids containing small hairpin RNA (shRNA) against rat CIITA (pCIITA-shRNA) and one control plasmid of pHK-shRNA were constructed. In vitro dendritic cell (DC) transfection and liver transfection via portal vein in donor rats (n = 8) by shRNA plasmids were performed to confirm the inhibitory effect of pCIITA-shRNA on CIITA expression. It showed that expressions of CIITA and MHC-II were significantly inhibited by pCIITA-shRNA in both DC in vitro and liver of donor rats in vivo (p < 0.05 vs. control pHK-shRNA treatment). pCIITA1-shRNA was proved to be the best inhibitor among three pCIITA-shRNAs and then used in high-responder rat liver transplantation model (DA donors-to-Lewis recipients). Transplant groups (n = 16/group) include untreated recipients transplanted with donor liver graft pretreated with either saline, or pHK-shRNA, or pCIITA1-shRNA. Cyclosporine-treated (10 mg/kg, im, day 0-7) recipients transplanted with unmodified liver grafts were used as no rejection control. The results showed that the recipient rats survived significantly longer in pCIITA1-shRNA-treated group with markedly attenuated liver graft rejection (p < 0.05 vs. saline and pHK-shRNA-treated groups). Furthermore, significantly decreased intragraft expressions of CIITA, MHC-II, IL-2, and IFN-γ were found in pCIITA1-shRNA-treated group (p < 0.05 vs. saline and pHK-shRNA-treated groups). This study suggests that intragraft inhibition of CIITA could be a novel strategy for attenuating graft rejection in liver transplantation.
主要组织相容性复合体II（MHC-II）在移植排斥反应中起重要作用，而II类反式激活因子（CIITA）是MHC-II表达的关键调节因子。本研究的目的是确定移植内抑制CIITA在减轻肝移植排斥反应中的疗效。构建了三种针对大鼠CIITA的含小发夹RNA（shRNA）的质粒（pCIITA-shRNA）和一种pHK-shRNA对照质粒。通过shRNA质粒对供体大鼠（n = 8）进行体外树突状细胞（DC）转染和经门静脉的肝转染，以证实pCIITA-shRNA对CIITA表达的抑制作用。结果表明，pCIITA-shRNA在体外DC和体内供体大鼠肝脏中均显著抑制了CIITA和MHC-II的表达（与对照pHK-shRNA处理相比，p < 0.05）。pCIITA1-shRNA被证明是三种pCIITA-shRNA中最佳的抑制剂，随后用于高反应性大鼠肝移植模型（DA供体至Lewis受体）。移植组（每组n = 16）包括未处理的受体，其移植的供体肝移植物分别用生理盐水、pHK-shRNA或pCIITA1-shRNA预处理。用环孢素处理（10 mg/kg，肌肉注射，第0 - 7天）并移植未修饰肝移植物的受体作为无排斥对照。结果显示，pCIITA1-shRNA处理组的受体大鼠存活时间显著延长，肝移植排斥反应明显减轻（与生理盐水和pHK-shRNA处理组相比，p < 0.05）。此外，在pCIITA1-shRNA处理组中，移植内CIITA、MHC-II、IL-2和IFN-γ的表达显著降低（与生理盐水和pHK-shRNA处理组相比，p < 0.05）。本研究表明，移植内抑制CIITA可能是减轻肝移植排斥反应的一种新策略。
