α-突触核蛋白特异性B细胞在PD中作用机制的研究

Parkinson’s disease (PD) is the second most common neurodegenerative disease, and the most cardinal mechanism is misfolding and abnormal aggregation of a-synuclein. At present, there’s no effective methods to control PD. More and more researchs show that immunotherapy is promising in PD. After stimulating by specific antigen, B cells are clonally expanded and secreting antigen-related antibodies, which could inhibit the aggregation and accumulation of neuron-toxic proteins, and this could become a new therapy target of neurodegenerative disease. In the first most common neurodegenerative disease, Alzheimer's disease, immunotherapy has already entered the clinical trials. Similarly, there’s aggregation of toxic proteins in PD. Previous reports indicate that the anti- a-synuclein antibodies have already been purified from the peripheral blood of PD patients. Besides, adding single-chain antibody fragment to culturing cells could inhibit the aggregation of a-synuclein and reduce its toxicity. We will first make fluorescent a-synuclein tetramers to isolate a-synuclein specific B cells by FACS, and characterize the variable region gene of immunoglobulin. We will next express the recombinant immunoglobulin specific to a-synuclein. We will further investigate the protective effect on dopaminergic neurons of anti- a-synuclein antibodies.

帕金森病(PD)是第二大神经系统退行性疾病，严重影响人类身心健康，目前尚无有效防治方法。α-突触核蛋白(α-syn)的变性聚集以及在邻近神经元之间的传播与PD发病密切相关，特异性抗体可以通过中和变性聚集的α-syn而发挥多巴胺能神经元的保护作用，成为PD免疫治疗的新兴靶点。本课题拟在前期工作基础上体外表达α-syn单体，纯化后制备成荧光标记的α-syn四聚体，通过流式细胞学方法分离α-syn特异性B细胞，对B细胞免疫球蛋白可变区基因进行测序，分析其突变、同型转换、克隆变异等特性；将上述基因克隆至表达质粒，体外表达α-syn特异性重组抗体，在细胞水平和动物体内水平探讨抗α-syn抗体通过阻止α-syn在邻近神经元之间的传播而发挥潜在的多巴胺能神经元保护作用，为以PD为主的共核蛋白病的被动免疫治疗提供科学依据。

帕金森病（Parkinson’s disease, PD）是第二大神经系统退行性疾病，严重威胁人类的身心健康，其发病机制不明，研究认为其和遗传、环境和老龄化关系密切。近年来，越来越多的研究表明其和免疫炎症密切相关。调节性T细胞（Regulatory T cells, Tregs）是一种特殊的T细胞亚群，在生理状态下维持免疫耐受，而在神经退行性疾病中其作用效应与机制尚存在争议。本研究利用全反式维甲酸（ATRA）与抗CD25抗体处理MPTP诱导帕金森病小鼠模型，调节小鼠免疫状态，探究不同免疫状态下小鼠对MPTP的耐受性以研究Tregs在帕金森病中可能的作用机制。研究结果发现ATRA处理组小鼠较抗CD25抗体处理小鼠运动受损更轻，脑内炎症瀑布反应较少，多巴胺能神经元存活更多，说明外周Tregs功能增强能够减少中枢神经炎症反应，对多巴胺能神经元起保护作用。该研究显示Tregs在帕金森病的发病机制中发挥重要作用，并提示ATRA可能通过增强Tregs抑炎效应，间接发挥多巴胺能神经元的保护作用，有望成为延缓PD进展甚至治疗PD的潜在药物之一。