大肠杆菌感染对小尾寒羊外周血白细胞和乳腺组织中TLRs基因表达的影响

发布时间：2018-03-06 19:51

本文选题：小尾寒羊　切入点：乳房炎　出处：《甘肃农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：Toll样受体(Toll-likereceptors,TLRs)是一类可以识别病原体相关分子模式(pathogen associated molecule patterns,PAMPs),结构中拥有富含亮氨酸重复序列胞外域的I型跨膜蛋白。它可以激活下游炎症通路,诱导机体免疫系统分泌相应细胞因子,以清除或抵御相应的病原微生物。小尾寒羊乳房炎的发生,一直是阻碍养羊业发展的重要原因,如何利用TLR在天然免疫中的重要作用,预防和治疗细菌性乳房炎成为新的研究热点。为研究TLRs在大肠杆菌(Escherichia coli)侵入小尾寒羊(Ovis aries)乳腺组织后在小尾寒羊外周血白细胞和乳腺组织中的表达情况,实验采用人工感染大肠杆菌(O113型),采用qRT-PCR检测大肠杆菌感染乳腺组织12h、24h、36h、48h、72h后,血液和乳腺组织中TLRs基因的相对表达量;利用Western-blot方法对乳腺组织感染大肠杆菌后不同时间段内TLRs蛋白的相对表达量进行研究。结果显示,在大肠杆菌侵入小尾寒羊乳腺后,在小尾寒羊外周血白细胞中,除TLR8外,TLR1~10均有表达,其中在大肠杆菌感染24h后小尾寒羊外周血白细胞中TLR2、3、4、5mRNA均出现显著或极显著升高;感染36h后TLR2、3、4、5、6、7mRNA均出现显著或极显著升高;48h后TLR2、4、5mRNA均出现显著或极显著升高。在小尾寒羊乳腺组织中结果显示TLR1、TLR2、TLR4、TLR5、TLR6、TLR7、TLR10的相对表达量在感染大肠杆菌后均有所升高,其中在12h时TLR1、4、6出现显著升高;24h时TLR2、4出现显著或极显著升高;36h时TLR1、2、4出现显著或极显著升高;48h时TLR1、2、4、6出现显著或极显著升高;72h时TLR2、4、7、10出现显著或极显著升高。各处理组与对照组相比TLRs蛋白表达随感染时间的延长而上调,在感染36h时均出现显著或极显著升高。该结果提示在大肠杆菌刺激后可以明显提高TLRs在小尾寒羊外周血白细胞和乳腺组织中的相对表达量,具有时间依赖性,研究表明小尾寒羊多种TLRs都参与了机体对病原体的识别,为进一步研究不同TLRs在炎症发病过程中的作用机制提供了数据支持和基础资料。
[Abstract]:Toll like receptor (TLRs) is a type I transmembrane protein that recognizes pathogen associated molecule patterns of PAMPs and contains an extracellular domain rich in leucine repeats. It activates the downstream inflammatory pathway. Inducing the immune system to secrete corresponding cytokines in order to remove or resist the corresponding pathogenic microbes. The occurrence of mastitis in small tail Han sheep has been an important reason that hinders the development of sheep industry. How to utilize the important role of TLR in innate immunity, The prevention and treatment of bacterial mastitis has become a new research hotspot. In order to study the expression of TLRs in peripheral blood leukocytes and breast tissues of small tail Han sheep after invasion of Escherichia coli into small tail Han sheep breast tissue, QRT-PCR was used to detect the relative expression of TLRs gene in the blood and mammary gland tissues after infection with E. coli for 12 h, 24 h, 36 h, 48 h and 72 h. The Western-blot method was used to study the relative expression of TLRs protein in breast tissue at different time after infection with E. coli. The results showed that after E. coli invaded the mammary gland of small tail Han sheep, the leucocyte in peripheral blood of small tail Han sheep was detected. The expression of TLR1m10 was found in all the small tail Han sheep with the exception of TLR8, and the expression of TLR2TLR1O10 mRNA in peripheral blood leukocytes of small tail Han sheep was significantly or extremely significantly increased after 24 hours of infection with Escherichia coli. After 36 hours of infection, there was a significant or extremely significant increase in TLR2O4, TLR2, TLR4 and TLR7 mRNA in breast tissue of small tail Han sheep. The results showed that the relative expression of TLR1, TLR2, TLR5, TLR6, TLR7, TLR10 and TLR7TLR10 in small tail Han sheep were all increased after infection, and the results showed that the relative expression of TLR5, TLR6, TLR7 and TLR10 in small tail Han sheep was higher than that in small tail Han sheep. Among them, TLR1O4A4 increased significantly at 12h and TLR2O4 increased significantly or extremely significantly at 24h. TLR1O2O2O2TLR2H4 increased significantly or extremely significantly at 48h. TLR247H10 increased significantly or very significantly at 72 h after treatment. Compared with the control group, the expression of TLRs protein was up-regulated with the prolongation of infection time. The results showed that the relative expression of TLRs in peripheral blood leukocytes and mammary gland of small tail Han sheep was significantly increased after stimulation of E. coli in a time dependent manner. The results showed that a variety of TLRs in small tail Han sheep were involved in the identification of pathogens, which provided data support and basic data for further study on the mechanism of different TLRs in the pathogenesis of inflammation.
【学位授予单位】：甘肃农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S858.26

【相似文献】