高剂量gp96诱导调节性T细胞及治疗红斑狼疮等自身免疫疾病研究

Inadequent number of T regulatory cells (Tregs) and their impaired founction, as well as imbalance between Tregs and T effectors cells or T follicular helper cells (Tfh) have been implicated for development and progress of autoimmune diseases including systemic lupus erythematosus (SLE). Our previous studies indicated that high dose heat shock protein gp96 immunization induces Treg via its interaction with Toll like receptors and subsequent NF-κB activation. Treatment with high dose gp96 in mouse models showed highly efficiency for SLE, liver failure, type 1 diabetes. Importantly, our preliminary observation demonstrated that high dose gp96 was effective for treating patients with autoimmune diseases including SLE with no obvious side effects. In this project we will explore the mechanisms of high dose gp96-induce Treg response, and define the key receptors, targets and pathways. In addition, Treg-cell subsets and their function will be characterized. Then, gp96 function and usage will be optimized by designing its mutant form and formulation to increase its specificity for targeint Treg. The therapeutic effects of designed gp96 mutant or its modification forms will be evaluated in mouse models of SLE, liver failure, type 1 diabetes. The key inhibitory Treg subsets and pathways will also be defined. The results from this project will provide therapeutic potential for developing new generation of gp96-based drugs to treat autoimmine diseases.

调节性T细胞（Tregs）数量不足、功能失调以及与效应T细胞、Tfh之间失衡，是导致红斑狼疮（SLE）等自身免疫疾病致病的重要原因，我们前期研究提示高剂量热休克蛋白gp96免疫通过与TLRs作用活化NF-κB途径激活Treg，小鼠试验发现对SLE、肝衰竭、1型糖尿病等有明显疗效，更重要的是对SLE等自身免疫疾病患者志愿者的初步临床观察疗效明显，几乎没有毒副作用。本课题拟深入研究高剂量gp96活化Treg的免疫学机制，发现gp96作用的关键受体、靶点和通路，解析活化的Treg亚群和作用。进一步优化gp96免疫抑制功能(如突变体)和使用方式，增强活化Treg的特异性，通过小鼠模型，评价高剂量免疫gp96或修饰、突变体对SLE、1型糖尿病、肝衰竭治疗效果，查明活化免疫抑制应答的关键通路和Treg亚群，为研发以gp96为基础的新型治疗自身免疫疾病药物提供科学依据。

调节性T细胞（Tregs）数量不足、功能失调以及与效应T细胞、Tfh之间失衡，是导致红斑狼疮（SLE）等自身免疫疾病致病的重要原因。Treg中Foxp3表达的上调和稳定对于调节Treg功能和免疫稳态至关重要。在本研究中，gp96免疫在系统性红斑狼疮的Lyn-/小鼠模型中显示出明显的治疗效果。此外，gp96减轻了MOG诱导的实验性自身免疫性脑脊髓炎的发生和发展。gp96免疫可增加Treg频率、扩增和抑制功能。基因表达谱确定NF-kB家族成员p65和c-Rel是gp96增强Treg中Foxp3表达的关键转录因子。利用其Toll样受体（TLR）结合域内的突变gp96、TLR2敲除小鼠和MyD88细胞特异性缺失的小鼠，证明gp96通过TLR2-MyD88介导的NF-kB信号通路激活Treg并诱导Foxp3表达。综上所述，gp96免疫通过整合Treg扩增和激活，限制抗体诱导和Th诱导的自身免疫疾病。本研究为研发以gp96为基础的新型治疗自身免疫疾病药物提供科学依据。