自身凋亡DNA诱导的SLE疾病动物模型的建立及其特性研究

Systemic lupus erythematosus (SLE) is a complex, multiple organs involved, potentially fatal disease and also the prototype of other autoimmune disease. The disease incidence is increased recently throughout the world and especially in China. However, the mechanisms involved in the pathogenesis of SLE disease remain unknown. Although the existing lupus models could partially imitate the disease course of SLE, the numerous and complicated mechanisms involved in the spontaneous lupus mouse models established on the susceptible genetic background and the induced lupus models triggered by the chemic components (for example: pristine) or xenogenic antigens, are hardly used for the pathogenesis mechanism exploration, preventive and therapeutic strategy development and pharmaceutical screening in SLE patients with general genetic background. In the present study, a SLE murine model was established and consummated on the general genetic background through immunizing with a self specific hypomethylated dsDNA. The characteristic spectrum of autoantibodies, proinflammatory cytokines, pathology and cytology, would be set up and the stability and controllability of this SLE murine model would be detected. Moreover, the analysis of cellular and molecular mechanisms involved in the pathogenesis of the SLE murine model would be performed. The classical Rx would be used to treat the lupus mice to explore the stability of this SLE murine model and validity of the classical Rx on the SLE murine model. Taken together, our established lupus murine model could fetch up the insufficiency of the existing lupus models, and the self specific antigen-induced stable SLE murine model which could be universally used, might push the progress of the basic and clinical study on SLE disease.

系统性红斑狼疮（SLE）是一种病因复杂、多器官受累、致死性严重自身免疫病和自身免疫病研究原型，其发病不断攀升而机制不明。现有的多种SLE动物模型虽一定程度模拟了SLE发病过程，但基于特殊遗传背景的自发性SLE模型和由化学物质及异体抗原诱导的SLE模型机制纷繁，差异巨大，难以用于常规遗传背景人群SLE发病机制、防治策略研究及相关的药物筛选。本研究拟以多年研究为基础，建立和完善一种基于常规遗传背景小鼠、以明确的自身低甲基化凋亡DNA（ALD-DNA）诱导的SLE动物模型，建立该模型自身抗体谱、炎症细胞因子谱、病理及细胞学特征全景，观测该模型的稳定性和可控性，深入探讨SLE发病的免疫学机制，并以临床一线治疗方案探讨和验证该模型的稳定性和药效评估价值。旨在弥补现有SLE动物模型不足，发展通用稳定、抗原明确的SLE模型，推动SLE基础和临床研究。

狼疮鼠模型在SLE疾病发生发展的机理研究以及治疗药物的筛选过程中扮演着重要的作用。我们借助循证分析的手段对B6/lpr小鼠进行了全面的系统的评价，分析了B6/lpr小鼠在模拟人类SLE疾病中的优势与局限性。B6/lpr小鼠可自发产生多种自身抗体，包括抗双链DNA自身抗体、抗单链DNA自身抗体、抗染色质自身抗体、类风湿因子、抗组蛋白抗体等；但B6/lpr小鼠无法自发产生抗Sm自身抗体， B6/lpr小鼠可自发生成肾小球肾炎但发病年龄较晚，炎症较轻缓。在本课题中我们应用自身凋亡DNA（ALD-DNA）免疫了自发性SLE模型鼠B6/lpr小鼠，对B6/lpr狼疮小鼠模型进行优化，进一步发挥其在模拟人类SLE疾病中的优势并弥补其局限性。我们发现：1）ALD-DNA可以加速B6/lpr小鼠自身抗体的生成，使其更早产生更高水平的致病性自身抗体并促进B6/lpr小鼠狼疮肾炎的发展；2）ALD-DNA免疫能够促进B6/lpr小鼠体内Th17细胞和Th2细胞的增生；3）ALD-DNA免疫能够促进B6/lpr小鼠脾脏和外周血中TCRαβ+CD4-CD8-双阴性T细胞的增生并促进DN αβ T细胞产生促炎细胞因子。此外，我们还对自身DNA诱导小鼠狼疮模型机制进行了探讨，发现：1）巨噬细胞自噬参与ALD-DNA诱导的SLE疾病进程，抑制自噬能够通过抑制促炎细胞因子的产生来缓解ALD-DNA诱导的SLE；2）ALD-DNA 刺激巨噬细胞极化的过程中microRNAs 的生物功能有很大差异; 3）胞外但非胞内HMGB1介导了ALD-DNA诱导的巨噬细胞活化并促进了ALD-DNA在巨噬细胞内体上的募集。本研究原创性的结果，弥补了现有SLE动物模型的不足并推动了SLE基础和临床研究。