Graduate School, Nanchang University, Nanchang, China.
Department of Neurology, Jiangxi People's Hospital, 153 Aiguo road, Nanchang, China.
BMC Immunol. 2019 Jul 8;20(1):24. doi: 10.1186/s12865-019-0301-4.
Multiple sclerosis is a demyelinating and autoimmune disease and its immune response is not fully elucidated. This study was conducted to examine the pathological changes and B cell subsets in experimental autoimmune encephalomyelitis (EAE) mice, and analyze the expression of triosephosphate isomerase (TPI) and GADPH to define the role of B cell subsets in the disease.
Female C57BL/6 mice were randomly divided into EAE group (n = 18) and control (n = 18). During the experiments, the weight and nerve function scores were determined. The proportions of B cell subsets in the peripheral blood were measured by flow cytometry. Seven, 18 and 30 days after immunization, the brain and spinal cord tissues were examined for the infiltration of inflammatory cells using hematoxylin-eosin (HE) HE staining and the demyelination using Luxol fast blue staining. The expression of B cell-related proteins was detected immunohistochemistrially and the expression of antigenic TPI and GADPH was analyzed using enzyme-linked immunosorbent assay (ELISA). HE staining showed that mice had more severe EAE 18 d than 7 d after modelling, while the symptoms were significantly relieved at 30 d. The results were consistent with the weight measurements and neural function scores. Immunohistochemistry studies showed that B cells aggregated in the spinal cord, but not much in the brain. Flow cytometry studies showed that there were more B cells in control than in EAE models from day 7 and the difference was narrowed at day 30. The level of plasma cells increased continuously, reached the top at day 21 and obviously declined at day 30. On other hand, the numbers of memory B cells increased gradually over the experimental period. The numbers of plasma and memory B cells were similar between the control and EAE mice. ELISA data revealed that the brain contents of TPI and GAPDH were higher in EAE mice than in control at day 7, while at day 18, the levels were reversed.
In the central pathological process of EAE mice, B cells exert role through the mechanism other than producing antibodies and the levels of brain TPI and GADPH are related to the severity of autoimmune induced-damage.
多发性硬化症是一种脱髓鞘和自身免疫性疾病，其免疫反应尚未完全阐明。本研究旨在观察实验性自身免疫性脑脊髓炎（EAE）小鼠的病理变化和 B 细胞亚群，并分析三磷酸甘油醛异构酶（TPI）和 GAPDH 的表达，以明确 B 细胞亚群在疾病中的作用。
将雌性 C57BL/6 小鼠随机分为 EAE 组（n=18）和对照组（n=18）。在实验过程中，测定体重和神经功能评分。采用流式细胞术测定外周血 B 细胞亚群比例。免疫后 7、18 和 30 天，采用苏木精-伊红（HE）染色观察脑和脊髓组织炎症细胞浸润，卢索快速蓝染色观察脱髓鞘。免疫组化法检测 B 细胞相关蛋白的表达，酶联免疫吸附试验（ELISA）检测抗原 TPI 和 GADPH 的表达。HE 染色显示，造模后 18 天小鼠 EAE 较 7 天严重，30 天症状明显缓解。结果与体重测量和神经功能评分一致。免疫组化研究显示，B 细胞在脊髓聚集，但在脑内聚集较少。流式细胞术研究显示，从第 7 天开始，对照组的 B 细胞多于 EAE 模型，第 30 天差异缩小。浆细胞水平持续升高，第 21 天达到高峰，第 30 天明显下降。另一方面，记忆 B 细胞的数量在实验期间逐渐增加。对照组和 EAE 组的浆细胞和记忆 B 细胞数量相似。ELISA 数据显示，EAE 小鼠脑内 TPI 和 GAPDH 含量在第 7 天高于对照组，而在第 18 天则相反。
在 EAE 小鼠中枢病理过程中，B 细胞通过非产生抗体的机制发挥作用，脑内 TPI 和 GADPH 水平与自身免疫诱导损伤的严重程度有关。
