Department of Neurology & Psychiatry, 1438 South Grand Boulevard, Saint Louis University School of Medicine, Saint Louis, MO, 63104, USA.
J Inflamm (Lond). 2012 May 29;9(1):20. doi: 10.1186/1476-9255-9-20.
Myasthenia gravis (MG) and animal model of experimental autoimmune myasthenia gravis (EAMG) is the most common autoimmune disorder of neuromuscular transmission. The disease is caused by the breakdown of the acetylcholine receptor (AChR) which is largely due to complement activation at the neuromuscular junction (NMJ). Limited knowledge exists to the extent that complement receptor 1-related gene/protein y deficiency (Crry -/-) modulates the adaptive immune response and EAMG outcome.
Mouse EAMG was induced by s.c. administrations of purified acetylcholine receptor (AChR) to Crry -/- and age- matched WT (C57BL/6) mice. Disease severity was assessed by clinical score assessment and muscle grip strength measurements. Serum complement activity was determined by hemolytic assay. ELISA was used to detect the level of AChR specific antibodies. Splenic cells were analyzed for T and B cells subsets distribution, release of cytokines and AChR specific recall responses. Deposition of complement components at the NMJ was assessed by immunofluorescence staining.
In comparison to WT EAMG, Crry -/- EAMG mice showed signs of augmented muscle weakness but differences, except for one time point, were not statistically significant. Serum complement activity was reduced in Crry -/- EAMG mice and no substantial changes in deposition of C3, C3b/iC3b and C5b-9 (MAC) at the NMJ between WT EAMG and Crry -/- EAMG mice were detected. Lack of Crry affected adaptive immune response. Crry -/- EAMG mice showed increases in the number of AChR specific splenic T-cells secreting IFN-γ and IL-4. Production of complement fixing antibodies (IgG2b, IgG2c) was also augmented. More Th1, Th2 and Th17 cytokines were released into the bloodstream of Crry -/- EAMG mice.
Data suggest that Crry deficiency modulates the adaptive immune response in EAMG, but its effect on disease outcome is limited. This was due to the generally lower serum complement level caused by increased C3 turnover. Modulation of complement activity with soluble or membrane bound regulators of complement activity represents a potentially effective approach to modify autoimmune processes in MG and EAMG.
重症肌无力（MG）和实验性自身免疫性重症肌无力（EAMG）的动物模型是最常见的神经肌肉传递自身免疫紊乱。这种疾病是由乙酰胆碱受体（AChR）的破坏引起的，而 AChR 的破坏在很大程度上是由于神经肌肉接头（NMJ）处补体的激活。目前对补体受体 1 相关基因/蛋白 y 缺乏（Crry -/-）调节适应性免疫反应和 EAMG 结果的了解有限。
通过皮下给予纯化的乙酰胆碱受体（AChR）将 EAMG 诱导至 Crry -/-和年龄匹配的 WT（C57BL/6）小鼠。通过临床评分评估和肌肉握力测量来评估疾病严重程度。通过溶血测定法测定血清补体活性。ELISA 用于检测 AChR 特异性抗体的水平。分析脾细胞中 T 和 B 细胞亚群分布、细胞因子释放和 AChR 特异性回忆反应。通过免疫荧光染色评估 NMJ 处补体成分的沉积。
与 WT EAMG 相比，Crry -/-EAMG 小鼠表现出肌肉无力加重的迹象，但除了一个时间点外，差异没有统计学意义。Crry -/-EAMG 小鼠的血清补体活性降低，在 WT EAMG 和 Crry -/-EAMG 小鼠之间未检测到 NMJ 处 C3、C3b/iC3b 和 C5b-9（MAC）的沉积有实质性变化。Crry 的缺乏影响适应性免疫反应。Crry -/-EAMG 小鼠中 AChR 特异性脾 T 细胞分泌 IFN-γ和 IL-4 的数量增加。补体结合抗体（IgG2b、IgG2c）的产生也增加。更多的 Th1、Th2 和 Th17 细胞因子释放到 Crry -/-EAMG 小鼠的血液中。
数据表明，Crry 缺乏症调节 EAMG 中的适应性免疫反应，但对疾病结果的影响有限。这是由于 C3 周转率增加导致血清补体水平普遍降低所致。用可溶性或膜结合的补体活性调节剂调节补体活性代表了一种有效修饰 MG 和 EAMG 中自身免疫过程的潜在方法。
