基于IgG糖基化修饰研究SLE发病机理、中医证分型及黄芪的治疗作用

Autoreactivity Immunoglobulin G (IgG) have long been recognized as an important pathogenic factor in systemic lupus erythematosus(SLE). For IgG, multiple glycoforms can be identified due to the presence of glycan chain attached . The glycan shows heterogeneity due to the presence or absence of fucose, galactose or sialic acid residues, contributing to different effects. Physiological pregnancy and some autoimmune diseases are associated with change of the IgG N-glycans. Dispite Integrated Chinese Traditioanal and Western therapy with Astragalus membranaceus widely applied in SLE therapy, the usage and mechanism are still debated. In the present study, we investigate the association between the alteration of IgG glycosylation and SLE pathogenesis, TCM syndrome types, Integrated Chinese Traditioanal and Western therapy with Astragalus membranaceus and the immune modulating mechanism regarding to IgG glycosylation..Our results may lead to improve diagnostic methods including TCM syndrome types, help to clarify the carbohydrate-related pathogenic mechanism of in?ammation in SLE. The results may also explain the synergistic effects mechanism of Astragalus membranaceus and glucocorticoid, define the indications in clinical practice, help to seek novel therapeutic targets in auto-IgG glycosylation process in SLE, and speed up the exploitation and utilization of Astragalus membranaceus.

自身反应性IgG是系统性红斑狼疮（SLE）发病的关键因素。近年来发现IgG糖基末端半乳糖、核心岩藻糖残基及末端唾液酸化的差异，表现为功能上的异质性。IgG糖型变化参与正常妊娠、某些自身免疫性疾病发病等过程。目前尚不明确SLE是否存在IgG糖基化修辞异常。包含黄芪的中西医结合法广泛用于治疗SLE，获得了肯定疗效，但黄芪免疫调节机制、临床用法（基于中医证分型）仍然存在争议。本项目通过以糖基化修辞为切入点，研究IgG糖型改变与SLE发病及中医证分型的关联，以及黄芪、糖皮质激素合用的方法及药理机制。.本研究结果将有望从抗自身IgG糖基化异常阐述SLE发病机制，改进诊断方法，用于中医证分型；有望从IgG糖基化调节角度解释黄芪、糖皮质激素合用的适应症(中医证分型)及协同效应，促进、推广其运用。

自身反应性IgG是系统性红斑狼疮（SLE）发病的关键因素。近年来发现IgG糖基修饰表现为功能上的异质性。目前尚不明确SLE是否存在IgG糖基化修辞异常。包含黄芪、雷公藤的中西医结合法广泛用于治疗SLE，获得了肯定疗效，但黄芪、雷公藤等免疫调节机制、临床用法（基于中医证分型）仍然存在争议。.临床部分.方法:(1)收集50例SLE患者临床特征资料，确定中医证型，保存血样本。3份静脉用丙种球蛋白，10例正常妊娠者血液。(2)基于SLEDAI按分层随机化法分为糖皮质激素组、糖皮质激素+黄芪组、糖皮质激素+雷公藤组，治疗后4、8、12周分别收集临床资料、血液样本。血清分离IgG，凝集素芯片法、液相色谱/质谱法分析IgG表面糖链的结构，免疫组化及直接免疫荧光法检测外周血单个核细胞α-1,2甘露糖苷酶。结果：1)SLE患者血清中IgG-Fc段G2型半乳糖、核心盐藻糖、唾液酸含量明显降低(P<0.05)，G0型半乳糖明显增高(P<0.05)；2）SLE患者辨证分为热毒炽盛、血瘀热蕴毒、阴虚内热、肝肾阴虚、脾肾阳虚5个证型，IgG表面的G0、G2型半乳糖、高甘露糖及唾液酸含量在各相关证型中差异明显，可作为辩证的参考指标；3）黄芪、雷公藤联合糖皮质激素治疗SLE，SLEDAI下降优于单用糖皮质激素；4）黄芪、雷公藤可提高SLE患者IgG-Fc段G2型半乳糖含量，对其他糖型影响不明显，对SLE患者外周血单个核细胞α-1,2甘露糖苷酶表达无明显影响。.动物实验部分.将28只MRL/lpr雌性小鼠随机分为糖皮质激素组、糖皮质激素+黄芪组、糖皮质激素+雷公藤组、无干预组四组，每组7支。雷公藤多苷10mg/kg/天， 黄芪2g/kg/天，强的松2mg/kg/天,用药时间为25天。实验开始前及结束后分别取血检测IgG糖型。然后全部处死，取出小鼠脾脏组织，使用免疫组化及实时定量荧光PCR技术检测α-1,2甘露糖苷酶表达的量。结果雷公藤联合糖皮质激素治疗组G0型半乳糖含量下降，黄芪组G2型半乳糖含量上升，糖皮质激素、糖皮质激素+黄芪、糖皮质激素+雷公藤均可增强MRL/lpr雌性小鼠脾脏α-1,2甘露糖苷酶表达，组间无显著差异。.结果提示SLE患者体内IgG表面存在异常的糖基化修饰，不同糖型含量可作为SLE中医辩证分型的参考指标，黄芪、雷公藤联合糖皮质激素治疗SLE疗效可能与修正IgG-Fc段糖基化修