耐多药结核分枝杆菌感染巨噬细胞对Toll样受体2、4的调节作用

发布时间：2018-06-18 11:35

本文选题：Toll样受体 + 分枝杆菌　；参考：《北京市结核病胸部肿瘤研究所》2009年硕士论文

【摘要】： Toll样受体(Toll-like receptors ,TLRs)是表达在哺乳动物细胞表面的一类重要的模式识别受体(pattern recognition receptor,PRR),是进化中比较保守的一个受体家族,TLRs能特异地识别病原体相关分子模式(pathogen associated molecular patterns,PAMP),不仅在激活天然免疫中发挥着重要的作用,而且还调节获得性免疫,是连接天然免疫与特异性免疫的主要桥梁。研究表明,TLRs是介导宿主对结核分枝杆菌(Mycobacterium tuberculosis,MTB)的识别及抗结核免疫反应的关键分子,与抗结核感染免疫有关的主要是TLR2和TLR4,TLRs通过识别MTB及MTB组分参与机体对结核分枝杆菌的免疫应答,对TLRs的研究有助于阐明结核病的发病机制并为新的治疗方法提供策略。本实验采用MTB敏感株、耐多药(multidrug-resistant,MDR)株分别感染人巨噬细胞(THP-1),模拟细胞体外感染的过程。应用逆转录荧光定量PCR检测感染后不同时间阶段TLR2、TLR4、P50 mRNA表达的变化及细胞因子IFN-γ、IL-12、IL-4 mRNA表达的变化,应用流式细胞术检测感染后TLR2、TLR4表达的变化;应用不同细胞因子刺激THP-1细胞后,应用逆转录荧光定量PCR检测感染后TLR2、TLR4、P50 mRNA表达的变化。探讨MTB敏感株、MDR株对TLR表达的调节作用及TLR活化后细胞因子表达的变化及细胞因子对TLR表达的调节作用,了解不同结核分枝杆菌感染细胞后所引起的免疫应答特点,了解TLRs在结核病免疫应答中的作用。实验结果显示,MTB敏感株、MDR株对TLR2、TLR4表达水平调节能力不同,MDR株上调TLR2、TLR4表达水平弱于敏感株。MTB敏感株、MDR株诱导细胞因子表达的强度也不相同,MTB敏感株诱导细胞因子IL-12、IFN-γ表达能力明显高于MDR株。反过来,细胞因子对TLR表达的调节能力也不相同,IFN-γ使TLR2、TLR4mRNA表达上调,IL-4却使TLR2 mRNA表达下调,对TLR4 mRNA的调节作用并不明显。本实验证明TLR作为细胞表面的PRR之一,能够识别MTB和MTB组分,引起机体的抗结核免疫应答;耐药程度不同的MTB对TLR的调节作用不同,诱导产生的细胞因子也不相同,这些细胞因子也能调节TLR的表达。TLR和细胞因子相互作用、相互影响,通过这种反馈机制更及时、准确、精密的调节机体的免疫应答。
[Abstract]:Toll-like receptors receptor (Toll-like receptors) is an important type of pattern recognition receptor, which is expressed on mammalian cell surface. It is a conservative receptor family that can specifically recognize pathogen associated molecular patterns-pampp. Only play an important role in activating innate immunity, It also regulates acquired immunity, which is the main bridge between innate immunity and specific immunity. It has been shown that TLRs are the key molecules that mediate host recognition of Mycobacterium tuberculosism MTB and its antituberculous immune response. TLR2 and TLR4TLRs are involved in the immune response to Mycobacterium tuberculosis by identifying MTB and MTB components. The study of TLRs is helpful to elucidate the pathogenesis of tuberculosis and provide strategies for new treatment methods. In this experiment, MTB sensitive strain and multidrug resistant multidrug resistance MDR strain were used to infect human macrophages, respectively, to mimic the process of cell infection in vitro. Reverse transcription-fluorescence quantitative PCR (RT-PCR) was used to detect the expression of TLR2TLR4P50 mRNA and cytokine IFN- 纬 -IL-12 IL-4 mRNA at different time stages after infection, flow cytometry was used to detect the expression of TLR2nTLR4, and different cytokines were used to stimulate THP-1 cells. Reverse transcriptase fluorescence quantitative PCR was used to detect the change of P50 mRNA expression in TLR2 and TLR4. To investigate the regulation of TLR expression by MDR strain, the changes of cytokine expression after TLR activation and the regulation effect of cytokines on TLR expression, and to understand the characteristics of immune response induced by different Mycobacterium tuberculosis infection. To understand the role of TLRs in tuberculosis immune response. The results showed that the ability of MDR strain to regulate the expression level of TLR2TLR4 was different. The up-regulation of TLR2TLR4 expression in MDR strain was weaker than that in MDR strain, which was sensitive to MTB, and the intensity of inducing cytokine expression in MDR strain was also different. The expression ability of MDR strain was significantly higher than that of MDR strain. On the other hand, cytokines have different ability to regulate TLR expression. IFN- 纬 can up-regulate TLR2 mRNA expression but down-regulate TLR2 mRNA expression, but the regulation of TLR4 mRNA is not obvious. As one of the PRRs on cell surface, TLR can recognize the components of MTB and MTB and induce anti-tuberculosis immune response, and MTB with different degree of drug resistance has different effects on TLR and induces different cytokines. These cytokines can also regulate the expression of TLR. TLR and cytokines interact with each other, through this feedback mechanism more timely, accurate, precise regulation of the body's immune response.
【学位授予单位】：北京市结核病胸部肿瘤研究所
【学位级别】：硕士
【学位授予年份】：2009
【分类号】：R52;R392

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