抑制胶质瘤EFEMP1联合STAT-3低表达的树突状细胞治疗大鼠胶质瘤的实验研究

发布时间：2018-05-23 10:06

本文选题：胶质瘤免疫治疗 + EFEMP1　；参考：《南方医科大学》2017年博士论文

【摘要】：神经胶质瘤也称为胶质瘤,为中枢神经系统常见的神经上皮性肿瘤,肿瘤多起源于神经间质细胞,包括神经胶质、室管膜、脉络丛上皮及神经元。对于神经胶质瘤的治疗方式也不是一成不变的,需要综合考虑肿瘤的起源部位、肿瘤体积大小及肿瘤性质等因素,才能选择并制定出最佳的治疗方案。研究证明,促使胶质瘤细胞生长、增殖的主要原因是胶质瘤细胞本身具有低免疫原性特点,这也是胶质瘤细胞能够逃避机体免疫细胞的监视及杀伤的主要原因;其次,神经胶质瘤细胞具有分泌免疫抑制因子的能力,这些免疫抑制因子可降低免疫细胞对肿瘤的杀伤效应。因此,如何提高胶质瘤细胞的免疫原性,促进抗原提呈细胞对胶质瘤抗原的识别,降低其发生“免疫逃逸”现象的几率;如何阻止胶质瘤细胞分泌免疫抑制因子,提高免疫细胞对胶质瘤细胞的杀伤效率,这些都是胶质瘤免疫治疗的研究重点。EFEMP1,即fibulin-3蛋白,其主要分布在细胞表面及细胞之间,主要功能是参与调节细胞与组织之间的生理活动,稳固细胞外基质结构完整。大量研究证明:EFEMP1参与并调节肿瘤细胞的生长及运动,在胶质瘤与EFEMP1的相关性研究中发现,通过对胶质瘤细胞内N ot c h信号通路和细胞内基质金属蛋白酶的控制,EFEMP1可以间接的控制胶质瘤细胞的生长、增殖及向周围组织侵袭的能力。因此我们提出了:可否通过抑制胶质瘤细胞EFEMP1的表达,从根本上降低胶质瘤细胞的活力,降低胶质瘤细胞对周围正常脑组织侵袭的实验设想,本课题也以此作为实验研究展开的关键切入点。树突状细胞(DCs)具有提呈胶质瘤抗原并辅助CTL杀伤胶质瘤细胞的重要功能。研究发现:STAT蛋白家族成员中的STAT-3与树突状细胞的分化成熟关系密切。STAT-3活化水平的增加,可以抑制树突状细胞的分化成熟。抑制树突状细胞的STAT-3活性后,可解除IL-10、TGF、VEGF等因子对树突状细胞的免疫抑制;并能够提高树突状细胞分泌细胞因子的水平。本课题拟将抑制胶质瘤细胞EFEMP1表达与降低树突状细胞STAT-3表达,两种治疗策略相结合。建立由EFEMP1低表达的胶质瘤细胞荷瘤的动物模型;利用慢病毒转染方式降低树突状细胞的STAT-3表达,制备出STAT3低水平表达的树突状细胞疫苗后,回输至荷瘤动物模型体内。通过与对照组比较动物模型的存活时间,荷瘤鼠胶质瘤组织内部淋巴细胞浸润、荷瘤鼠脾脏指数变化等实验指标,证实抑制胶质瘤EFEMP1联合低STAT-3表达的树突状细胞对于大鼠胶质瘤的治疗效果,为建立胶质瘤的新型免疫治疗策略提供理论支持。
[Abstract]:Glioma, also known as glioma, is a common neuroepithelial tumor in the central nervous system. Most of the tumors originate from nerve interstitial cells, including glia, ependyma, choroid plexus epithelium and neurons. The treatment of glioma is not inflexible. It is necessary to consider the origin of the tumor, tumor volume and tumor properties, in order to select and formulate the best treatment plan. It has been proved that the main reason for glioma cells to grow and proliferate is that glioma cells have low immunogenicity, which is the main reason that glioma cells can escape the surveillance and kill of immune cells. Glioma cells have the ability to secrete immunosuppressive factors which can reduce the killing effect of immune cells on tumor. Therefore, how to improve the immunogenicity of glioma cells, promote the recognition of glioma antigens by antigen-presenting cells, reduce the probability of "immune escape", and prevent glioma cells from secreting immunosuppressive factors, Increasing the killing efficiency of immune cells to glioma cells is the focus of immunotherapy of glioma. EFEMP1, or fibulin-3 protein, mainly distributes on the surface of glioma cells and between cells. The main function is to regulate the physiological activities between cells and tissues and to stabilize the structure of extracellular matrix. A large number of studies have shown that: EFEMP1 is involved in and regulates the growth and motility of tumor cells, and has been found in the study of the relationship between glioma and EFEMP1. Through the control of N ot c h signaling pathway and matrix metalloproteinases in glioma cells, EFEMP1 can indirectly control the growth, proliferation and invasion of glioma cells to surrounding tissues. Therefore, we propose a tentative idea of whether we can reduce the activity of glioma cells and the invasion of glioma cells to normal brain tissues by inhibiting the expression of EFEMP1 in glioma cells. This topic also takes this as the key breakthrough point of the experimental research. Dendritic cells (DCs) play an important role in presenting glioma antigens and assisting CTL in killing glioma cells. It was found that STAT-3 in the member of the protein family of 1: STAT was closely related to the differentiation and maturation of dendritic cells. The increase of activation level of STAT-3 could inhibit the differentiation and maturation of dendritic cells. Inhibiting the STAT-3 activity of dendritic cells could relieve the immunosuppressive effect of IL-10 TGF- STAT-3 on dendritic cells and increase the level of cytokines secreted by dendritic cells. The aim of this study is to combine the inhibition of EFEMP1 expression in glioma cells and the reduction of STAT-3 expression in dendritic cells. An animal model of glioma cells with low expression of EFEMP1 was established, the STAT-3 expression of dendritic cells was reduced by lentivirus transfection, and the dendritic cell vaccine with low expression of STAT3 was prepared, and then injected back into the tumor-bearing animal model. Compared with the control group, the survival time of the animal model, the infiltration of lymphocytes in glioma tissue and the change of spleen index in tumor-bearing mice were measured. It is confirmed that the inhibitory effect of EFEMP1 combined with low STAT-3 expression of dendritic cells on rat glioma provides theoretical support for the establishment of a new immunotherapy strategy for glioma.
【学位授予单位】：南方医科大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R739.41

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