LFA-1调控T细胞活化及分化在实验性自身免疫性脑脊髓炎中的作用

发布时间：2018-04-14 16:39

本文选题：淋巴细胞功能相关抗原1 + 实验性自身免疫性脑脊髓炎　；参考：《吉林大学》2014年硕士论文

【摘要】：多发性硬化（multiple sclerosis，MS）是典型的自身免疫性疾病，以中枢神经系统脱髓鞘为特征，多在青壮年中发病，其临床症状重，具有反复发病、迁延不愈的特点，具有较高的病情恶化及致残的发生率。MS的发病是多因素综合作用的结果，其中T淋巴细胞在MS的病理发生以及疾病进程的生物学过程中各自发挥着重要的作用。淋巴细胞功能相关抗原1（lymphocytefunction-associated antigen-1，LFA-1）参与免疫细胞的发育和分化，参与免疫应答和免疫调节，其在辅助性T细胞增殖和分化中的作用受到关注。本研究通过观察LFA-1基因敲除对实验性自身免疫性脑脊髓炎（experimental autoimmuneencephalomyelitis, EAE）小鼠关节局部引流淋巴结T细胞活性的影响，并检测CD4+T细胞产生细胞因子的情况，探讨LFA-1调控T细胞活性在EAE发病中的作用。目的：观察LFA-1基因敲除鼠的EAE发病情况，并探讨LFA-1基因缺失对EAE发病时的T细胞影响。方法：采用MOG35-55多肽免疫法诱导野生型小鼠及LFA-1基因敲除小鼠EAE模型，观察两组EAE模型小鼠的发病情况、体重、临床症状及神经损害情况，BrdU法检测LFA-1基因敲除小鼠及野生型小鼠引流淋巴结T细胞增殖，流式细胞术检测CD4+T细胞产生细胞因子情况。结果：研究显示MOG诱导后，与野生型小鼠相比，LFA-1基因敲除组小鼠的EAE发病率降低、潜伏期延长，差异具有统计学意义（P0.01）。且发病症状较轻，发病时间较晚，神经功能损害评分较低，在发病初期，，二者的评分差异有显著性（P0.01）。与LFA-1基因敲除鼠相比，野生型小鼠的体重下降出现的时间较早，下降的幅度更大。组织学检查发现，野生型小鼠脊髓出现明显的脱髓鞘病理变化，而LFA-1基因敲除小鼠脊髓无明显脱髓鞘改变；进一步研究表明在疾病早期7天时LFA-1基因敲除可以减少淋巴细胞向引流淋巴结聚集，降低MOG体外刺激T细胞增殖能力，产生IFN-γ及IL-17的T细胞比例也较野生型小鼠组明显降低。而在疾病缓解期21天时LFA-1基因敲除鼠淋巴细胞聚集及T细胞增殖能力与对照组几乎没有差别。结论：1、LFA-1基因敲除鼠的EAE发病率低、潜伏期长、临床症状及神经损害较野生型小鼠轻；2、LFA-1基因敲除可通过减少淋巴细胞向引流淋巴结聚集，降低T淋巴细胞增殖能力，并通过调节Th1细胞分泌IFN-γ及Th17细胞分泌IL-17等机制影响EAE的发生发展；3、在EAE疾病发生早期，LFA-1可能起到了关键性的作用，因此LFA-1有可能成为EAE治疗的重要分子靶点。
[Abstract]:Multiple sclerosis (MS) is a typical autoimmune disease characterized by demyelination of the central nervous system.High incidence of disease deterioration and disability. The incidence of MS is the result of multiple factors, in which T lymphocytes play an important role in the pathogenesis of MS and the biological process of disease progression.Lymphocyte function-associated antigen (1(lymphocytefunction-associated antigen-1) is involved in the development and differentiation of immune cells, immune response and immune regulation, and its role in the proliferation and differentiation of helper T cells has attracted much attention.To investigate the role of LFA-1 in the regulation of T cell activity in the pathogenesis of EAE.Objective:Methods:The EAE model of wild-type mice and LFA-1 knockout mice was induced by MOG35-55 polypeptide immunization. The incidence and body weight of the two groups of EAE model mice were observed.LFA-1 gene knockout mice and wild-type mice were detected for T cell proliferation in draining lymph nodes by BrdU method and cytokines produced by CD4 T cells were detected by flow cytometry.Results:The results showed that compared with wild type mice, the incidence of EAE was decreased and the latent period was prolonged after induction of MOG, and the difference was statistically significant (P 0.01).The symptoms were mild, the onset time was late, and the neurological impairment score was lower. At the beginning of the disease, there was a significant difference between the two groups (P 0.01).Compared with LFA-1 knockout mice, the body weight loss of wild type mice appeared earlier and the decline was larger than that of LFA-1 knockout mice.Histological examination showed that there were obvious demyelinating pathological changes in the spinal cord of wild type mice, but there was no obvious demyelinating change in the spinal cord of LFA-1 gene knockout mice.Further studies showed that LFA-1 gene knockout could reduce the aggregation of lymphocytes to drainage lymph nodes, reduce the proliferation of T cells stimulated by MOG in vitro, and reduce the proportion of T cells producing IFN- 纬 and IL-17 in wild type mice.The ability of lymphocyte aggregation and T cell proliferation of LFA-1 knockout mice was almost the same as that of the control group at 21 days after remission.Conclusion the incidence of EAE was lower, the incubation period was longer, and the clinical symptoms and nerve damage were higher in the knockout mice with the LFA-1 gene knockout.LFA-1 knockout of wild-type mice can reduce lymphocyte aggregation to draining lymph nodes, reduce T lymphocyte proliferation, and regulate the secretion of IFN- 纬 by Th1 cells and IL-17 secretion by Th17 cells.The pathogenesis and development of EAE may play a key role in the early stage of EAE disease, so LFA-1 may be an important molecular target for EAE therapy.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R744

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