LAG-3调控HLA-DR基因参与帕金森病DA神经元变性的分子机制研究

帕金森病（PD）是遗传/环境介导的免疫紊乱的结果。淋巴细胞活化基因-3（LAG-3）与主要组织相容性复合体（MHC）结合，负向调节T淋巴细胞功能，参与DA神经元内α-synuclein（α-syn）介导的免疫应答。我们初步发现：①HLA-DRB*0301变异导致α-syn积聚，小胶质细胞活化，继发抗原呈递紊乱；②LAG-3基因rs951818 C/A增加女性的PD罹患风险，其体液sLAG-3水平异常，而rs870849变异频率不确定，需扩大样本进行全基因突变分析，以明确基因变异在PD免疫机制中的意义；③尚不清楚上述分子相互作用导致神经免疫紊乱的详细机制。因此，本项目拟在前期基础上，扩大PD病例-对照的分子免疫学研究，确定LAG-3基因变异与PD的关联性，分析模型细胞内α-syn积聚过程中，LAG-3调控HLA-DR介导的MHC抗原呈递的分子信号磷酸化规律，从而揭示DA神经元变性分子机制。

The immune-disorder resulted from gene-age-environment interaction is related to the landmark pathogenesis of Parkinson's disease (PD). As an immunological regulation, lymphocyte activation gene-3, called LAG-3, combines with the variation in HLA II genomics, may contribute to α-syneulein degradation as well as its chronic immune response in the process of MHC antigen presentation during dopaminergic (DA) neuron degeneration. We have preliminarily found that:① the allele frequency of HLA-DRB1*0301 was obviously increased in PD patients；②the C/A allele rs951818 of LAG-3 was difference to that reported Caucasians, with a high risk of PD in Chinese female following an elevated level of sLAG-3 in serum, but the alle of rs870849 varied among the population and need further to investigate; ③α-syneulein accumulation could induce immunoproteasome activation in DA neuron to maintain intracellular protein homeostasis. But it is still unclear about the molecular mechanism of inflammatory response and related immune disorder based on these gene mutations in substantia nigra. Based on our initial data, this study aims to expand case -control study, systematically confirm the related genes and their function in the pathogenesis and development of PD, explore the mechanism of immunoproteasome activation related to phosphorylated molecular signal pathways of MHC presentation conductedby LAG-3 as well as HLA-DRB in cell model or animal substantia nigra during α-synuclein accumulation in vivo under different conditions, so that to disclose the molecular mechanism of DA neuron degeneration involved chronic inflammatory immunological disorder.