| 题名 | 女性生殖道乳酸杆菌诱导单核前体细胞表达Langerin/CD207的效应和调控机理研究 |
| 作者 | 宋杰 |
| 学位类别 | 硕士 |
| 答辩日期 | 2013-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 张华堂 |
| 关键词 | HIV-1 Langerin/CD207 乳酸杆菌 肽聚糖 转录因子 |
| 其他题名 | Effects and Regulatory Mechanisms for Induction of Langerin/CD207 Expression on Monocytic Precursor Cells by Vaginal Lactobacilli |
| 学位专业 | 工程硕士专业学位 |
| 中文摘要 | Langerin/CD207是特异表达于Langerhans细胞（LCs）表面的C型凝集素受体（C-Type Lectin Receptors, CLRs），可高效与HIV-1表面糖蛋白gp120结合，在捕获病毒后，可将其引入Birbeck颗粒而直接杀灭，从而强有效地抑制HIV-1的感染和体内播散。 本实验室之前的研究发现，从女性生殖道分离的5种10株革兰氏阳性乳酸杆菌能够强有效地诱导单核前体细胞THP-1高水平表达Langerin/CD207，而第6种（发酵乳酸杆菌）和革兰氏阴性的大肠杆菌则无此效应。这提示我们需要在健康人外周血CD14+单核细胞确证这一特异的实验现象具有的生理意义，从而破解“LCs在后天环境中起源的机理”这一基本免疫学尚未回答的问题，揭示正常菌群诱导LCs产生的确切细胞分子机理。 因此本研究首先在健康人外周血来源的CD14+单核细胞上验证了之前以THP-1作为单核前体细胞发现的实验现象，确证了乳酸杆菌可以诱导Langerin/CD207的高表达，并且下调DEC-205/CD205和MMR/CD206的表达水平。 然后本研究在探索了乳酸杆菌培养上清、细菌素、S-层蛋白、肽聚糖和磷壁酸单独对Langerin/CD207表达的影响后，锁定了乳酸杆菌肽聚糖为诱导Langerin/CD207表达的决定成分，通过对比来自枯草芽孢杆菌肽聚糖对Langerin/CD207表达的影响，提示乳酸杆菌肽聚糖可能具有独特的结构和功能。 最后本研究对乳酸杆菌诱导Langerin/CD207表达调控的的分子机理做出了较为具体可靠的生物信息学分析和初步的实验验证，确认了IL-15、TGF-β1参与的信号通路以及PU.1、TAL1、TIF1γ和POLR2A这4个转录因子在其中发挥着关键作用，并对这四个转录因子的相互关系做出了初步的验证。 综上所述，本研究确定了乳酸杆菌诱导Langerin/CD207表达的决定分子，初步揭示了正常菌群可以诱导LCs产生的分子机理，同时也为乳酸杆菌作为佐剂和粘膜疫苗提送系统的开发利用提供了很好的理论基础。 |
| 英文摘要 | Langerin/CD207, a well known C-type lectin receptor specifically expressed on the surface of Langerhans cells (LCs), captures HIV-1 and subsequently internalizes the virus into Birbeck granules, which leads to degradation of the virus and prevents LC infection. Thus, LCs have a protective function in HIV-1 infection. Our previous study found that 5 strains (10 isolates) of vaginal lactobacilli, but not the 11th isolate or 2 laboratory strains of E. coli, could efficiently induce de novo expression of Langerin/CD207 from the non-expressing monocytic precursor cells after co-culture for 2 days. To evaluate the biological significance of this phenomenon; we should verify this specific effect on CD14+monocytes from human PBMCs(Peripheral Blood Mononuclear Cells). We hypothesize that some commensal strains of vaginal microbiota could be involved in the generation and maintenance of mucosal LCs but the underlying mechanisms are as yet unknown. Firstly, CD14+monocytes were used as monocytic precursor cells of dendritic cells to confirm that 5 strains (10 isolates) of vaginal lactobacilli can induce expression of Langerin/CD207, and down-regulation of DEC-205/CD205 and MMR/CD206. Secondly, we tried to find the inducing molecules among the components of lactobacilli. Induction effects of supernatant, bacteriocin, s-layer proteins, and peptidoglycan from lactobacilli on the monocytic precursor cells were investigated. We found that peptidoglycan from lactobacilli was the dominant component that induced the expression of Langerin/CD207. And this suggested peptidoglycan from lactobacilli may have specific structure and function comparing to peptidoglycan from other bacteria. Finally, molecular mechanisms for induction of Langerin/CD207 expression by lactobacilli was analysed with bioinformatics’ analysis and some experiments had been done to confirm those analyses. We affirmed that cytokines including IL-15, TGF-β1 and transcription factors including PU.1, TAL1, TIF1γ, POLR2A played key roles in this process. We also preliminary clarified the interaction of those transcription factors. To sum up, this study elementarily revealed the molecular mechanisms involved in the process that Langerin/CD207 expression induced by vaginal lactobacilli. Further more, this study would provide theoretical foundation to develop vaginal lactobacilli as adjuvant and vaccine delivery system. |
| 语种 | 中文 |
| 内容类型 | 学位论文 |
| 源URL | [http://159.226.149.26:8080/handle/152453/10157]  |
| 专题 | 昆明动物研究所_分子免疫生物学 |
| 推荐引用方式 GB/T 7714 | 宋杰. 女性生殖道乳酸杆菌诱导单核前体细胞表达Langerin/CD207的效应和调控机理研究[D]. 北京. 中国科学院研究生院. 2013. |
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