【作者】 朱杰；

【导师】 赵鲁杭；

【作者基本信息】 浙江大学 ， 生物化学与分子生物学， 2006， 硕士

【摘要】 枸杞(lycium barbarum)是我国传统的名贵中药材,尤其以宁夏枸杞最为著名。现代医学临床研究认为,从枸杞中提取的枸杞多糖(lycium barbarum polysaccharides,LBPs)是枸杞生物学作用的主要有效成份之一,它由阿拉伯糖、葡萄糖、半乳糖、甘露糖、鼠李糖和木糖等6种单糖组成。其具有延缓衰老,抗氧化;抗肿瘤,促进肿瘤细胞凋亡;降血糖,降血脂;免疫调节和抗辐射等生物学功能。 树突状细胞(dendritic cell,DC)因其表面具有星状多形性或树枝状突起而得名。它是一种专职的抗原递呈细胞(antigen presenting cell,APC),在启动T细胞对病原微生物或肿瘤的免疫应答中发挥着关键的作用。不成熟DC通过俘获和处理外周组织中的外源性抗原而变成成熟DC。成熟DC迁移至淋巴器官,在这里主要通过主要组织相容性复合物(MHC)分子递呈抗原多肽。成熟DC通过DC-SIGN受体和静止T细胞上的黏附分子ICAM-3互相经过短暂、高亲和力接触。其它黏附分子和它们对应的配体(ICAM-1/LFA-1,LFA-3/CD2)互相接触起到辅助作用。然后T细胞受体作为免疫学的突触参与进来,成熟DC上的多个刺激分子和它们在T细胞上相应配体互相作用,从而激活T细胞启动免疫应答。 本实验主要探讨枸杞多糖对小鼠骨髓来源的树突状细胞(bone marrow derived dendritic cell,BMDCs)表型及成熟功能的影响。小鼠骨髓细胞自C57BL/6小鼠的股骨骨髓中分离并在含有GM-CSF和IL-4的完全培养基中培养5天。然后用免疫磁珠法纯化获得DC,实验组加入枸杞多糖(100μg/ml),空白对照组更多还原

【Abstract】 Lycium barbarum is well-known Chinese traditional medicine and also a kind of food. Lycium barbarum polysaccharides (LBPs) are its important bioactive component. Lycium barbarum polysaccharides are known to palys multiple roles in pharmacological and biological functions such as immunomodulatory effect, antitumor function, reduction of blood pressure and blood lipid.Dendritci cells are professional antigen-presenting cells (APC) playing key roles in the immune sentinels as initiators of T-cell responses against microbial pathogens and tumors. Immature DC capture and process exogenous agents in peripheral tissues and begin to mature. The maturing DC migrate to lymphoid organs, where they stimulate naive T cells through the signals of both major histocompatibility complex (MHC) molecules presenting antigen-peptides and costimulatory molecules.The initial contact between DC and resting T cells may be mediated by a transient high affinity interation between DC-SIGN on the DC and adhesion molecule ICAM-3 on the T cells, followed by interactions through other adhesion molecules and their corresponding ligands (ICAM-1/LFA-1, LFA-3/CD2). Following TCR engagement, an initaimate interaction often referred to as the immunological synapse evolves, where multiple interactions happen between costimulatory molecules on DC and their ligands on T cells result in final DC maturation and T cell activation.However, little is known about immunomodulatory effects of LBPs on murine bone marrow derived dendritic cells (BMDCs). In this study we investigated the effect of LBPs on the phenotypic and functional maturation of murine BMDCs in vitro. Comparing to the BMDCs that only subjected to RPMI1640, the co-expression of I-A/I-E, CDllc and secretion of IL-12 p40 by BMDCs with LBPs (100 ug/ml) stimulation were increased, the endocytosis of FITC-dextran by BMDCs with LBPs (100 ug/ml) was impaired but the activation’of proliferation of allogenic lymphocytes by BMDCs was strengthened. LBPs were shown to promote both the phenotypic and functional maturation of murine BMDCs in vitro.更多还原