JEV感染过程中MDSCs对T细胞作用途径的研究

发布时间：2018-05-05 02:39

本文选题：日本乙型脑炎病毒 + MDSCs　；参考：《华中农业大学》2017年硕士论文

【摘要】：日本乙型脑炎(Japanese encephalitis,JE)是由日本乙型脑炎病毒(Japanese encephalitis virus,JEV)引起的一种人畜共患传染病,简称乙脑。JEV为嗜神经病毒,主要通过蚊虫传播。该病毒感染宿主后,经外周免疫逃逸,能穿越血脑屏障从而进入中枢神经系统(central nervous system,CNS),引起脑内炎症风暴,最终导致人和动物的发病、死亡。JEV经外周免疫逃逸进入CNS是引起乙脑发病的主要原因,但对于JEV外周免疫逃逸的机制仍不清楚。本研究以感染乙脑病毒强毒株JEV-P3的C57BL/6小鼠为模型,研究JEV外周免疫逃逸过程中,MDSCs发挥的功能。具体研究内容如下:首先建立合适的感染模型,以105 PFU感染剂量尾静脉注射C57BL/6小鼠,从感染后第1天到第5天,隔天采取小鼠血清及脾脏组织,用于MDSCs相关细胞因子m RNA水平检测及流式细胞术检测。结果发现在小鼠感染第3天,脾脏中MDSCs数量明显上升的同时,其发挥抑制功能相关的细胞因子表达也有所上调。用ELISA方法检测Arg-1,我们发现,在JEV刺激下,MDSCs所表达的Arg-1有明显的上升趋势,而Arg-1是MDSCs发挥抑制功能的一个重要的因子;相对荧光定量PCR方法检测与T细胞分化相关的细胞因子,发现MDSCs增殖的同时,T细胞的分化被抑制;流式细胞术检测MDSCs上ADAM17蛋白和T细胞上CD62L分子表达情况,结果显示:ADAM17上调的同时CD62L表达量下降。综上,本研究得出:乙脑病毒感染小鼠后能够在使得外周免疫器官脾脏中的免疫抑制性细胞群体MDSCs数量上升,且刺激其发挥免疫抑制功能,从而协助JEV逃脱外周免疫应答,最终进入CNS,感染神经元细胞。
[Abstract]:Japanese encephalitis Japanese encephalitis (JE) is a zoonotic infectious disease caused by Japanese encephalitis virus Japanese encephalitis virus. After infecting the host, the virus escapes through peripheral immunity and can cross the blood-brain barrier to enter the central nervous system central nervous system, causing inflammatory storms in the brain and eventually leading to the onset of human and animal disease. Death. JEV escape through peripheral immunity into CNS is the main cause of encephalitis B, but the mechanism of JEV peripheral immune escape is still unclear. In this study, C57BL/6 mice infected with Japanese encephalitis virus (JEV-P3) strain were used as models to study the function of JEV during peripheral immune escape. The specific contents of the study were as follows: firstly, a suitable infection model was established. C57BL/6 mice were injected by tail vein at a dose of 105 PFU. From the first day to the fifth day after infection, mice serum and spleen tissue were taken. It was used to detect the level of MDSCs related cytokine m RNA and flow cytometry. The results showed that the number of MDSCs in spleen increased significantly on the 3rd day of infection, and the expression of cytokines related to its inhibitory function was also up-regulated. ELISA assay was used to detect Arg-1. We found that the expression of Arg-1 in JEV stimulated by JEV showed an obvious upward trend, while Arg-1 was an important factor in the inhibition of MDSCs, and the relative fluorescence quantitative PCR method was used to detect the cytokines associated with T cell differentiation. The expression of ADAM17 protein on MDSCs and CD62L on T cell was detected by flow cytometry. In conclusion, this study concluded that the number of immunosuppressive cell population MDSCs in peripheral immune organs was increased in mice infected with Japanese encephalitis virus, and the immunosuppressive function was stimulated to assist JEV to escape the peripheral immune response. It eventually enters CNS and infects neuronal cells.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S852.65

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