醋柴胡多糖靶向枯否细胞抑制肝移植免疫排斥作用基础及机制

移植排斥反应是肝移植术后影响患者预后和生存率的关键因素，免疫抑制是主要防治手段。目前临床上治疗方案存在特异性差和因长期应用致过度抑制引起严重不良反应的缺点，迫切需要寻找特异性好且能诱导机体免疫耐受的潜在药物。促使枯否细胞向M2免疫抑制型极化在肝移植术后诱导免疫耐受中起重要作用。前期我们研究发现醋柴胡多糖具有肝靶向性和免疫抑制作用，及类纳米粒的体内过程，推测其能靶向枯否细胞诱导免疫耐受从而抑制肝移植排斥。本课题通过色谱分离技术和动物模型结合筛选抑制肝移植排斥反应的醋柴胡活性多糖，利用流式、western blot和PCR等技术研究活性多糖靶向枯否细胞使其极化从而诱导免疫耐受的作用，并基于多糖受体效应信号网，利用磁珠分选、基因过表达/沉默动物等手段从细胞和动物层面探讨其作用机制。本课题的实施为醋柴胡多糖作为肝移植术后免疫抑制剂的开发提供科学依据，为寻找新的肝移植排斥治疗策略和靶点提供分子依据。

Transplant rejection is a key factor affecting the prognosis and survival rate of patients after liver transplantation, and immunosuppression is the main means of prevention and treatment. At present, the clinical treatments have the disadvantages of poor specificity and adverse reactions caused by excessive suppression. There is an urgent need to find potential drugs with good specificity and can induce immune tolerance. Promoting Kupffer cells to M2 immunosuppressive polarization plays an important role in inducing immune tolerance after liver transplantation. In the previous study, we found that polysccharides of vinegar-baked Radix Bupleuri have liver targeting and immunosuppressive effects, as well as the nanoparticles-like process in vivo, which speculated that it can target kupffer cells to induce immune tolerance and then inhibit liver transplantation rejection. In this study, the active polysccharides of vinegar-baked Radix Bupleuri inhibiting liver transplantation rejection will be screened by chromatographic separation technique and animal model. The effect of active polysaccharides on polarizing kupffer cells and then inducing immune tolerance will be studied by flow cytometry, western blot and PCR. Based on the effect signal network of polysaccharide receptor in kupffer cells, the mechanism will be discussed on the cellular and animal level of studies by means of magnetic bead sorting, gene overexpression / silencing animals. The implementation of this project will provide a scientific basis for the development of polysccharides of vinegar-baked Radix Bupleuri as immunosuppressants after liver transplantation, and also provide molecular basis for finding new strategies and targets for the treatment of liver transplantation rejection.