發(fā)布時(shí)間：2018-02-23 20:52

  本文關(guān)鍵詞： 鼠疫菌 密度感應(yīng)系統(tǒng) DNA芯片轉(zhuǎn)錄譜 抗體譜 信號(hào)分子　出處：《中國人民解放軍軍事醫(yī)學(xué)科學(xué)院》2005年博士論文　論文類型：學(xué)位論文

【摘要】：背景:鼠疫是由鼠疫耶爾森氏菌(簡稱鼠疫菌)引起的自然疫源性烈性傳染病。鼠疫菌獨(dú)特的致病能力,一直是鼠疫研究工作者關(guān)注的焦點(diǎn)。密度感應(yīng)系統(tǒng)(quorum sensing, QS)是一種細(xì)胞密度依賴性的細(xì)菌胞間信號(hào)傳遞系統(tǒng),通過這種機(jī)制細(xì)菌可以協(xié)調(diào)基因的表達(dá),從而使細(xì)菌可以適應(yīng)環(huán)境、產(chǎn)生毒力因子等,使細(xì)胞的活動(dòng)具有組織性,成為類似于多細(xì)胞生物的群體性活動(dòng)。本文報(bào)道了鼠疫菌密度感應(yīng)系統(tǒng)在鼠疫菌毒力中的作用。 方法:結(jié)合基因突變技術(shù)、高效液相分離、質(zhì)潛鑒定和細(xì)胞凋亡分析實(shí)驗(yàn),從鼠疫菌野生株和QS突變株分離鑒定QS系統(tǒng)的信號(hào)分子及其對(duì)巨噬細(xì)胞的作用;利用全基因組芯片,比較分析QS突變株與野生株轉(zhuǎn)錄譜差異,鑒定QS系統(tǒng)調(diào)控元;利用鼠疫菌毒力相關(guān)蛋白的蛋白芯片,分析QS系統(tǒng)在體內(nèi)對(duì)毒力相關(guān)蛋白表達(dá)的影響;通過一系列表型實(shí)驗(yàn),比較QS突變株在體外、細(xì)胞和動(dòng)物毒力表型的差異。 結(jié)果:從鼠疫菌的培養(yǎng)上清中,分離鑒定了兩種信號(hào)分子,C6-HSL和C8-HSL,并證實(shí)了兩種信號(hào)分子的合成基因。巨噬細(xì)胞毒性實(shí)驗(yàn)證實(shí),這兩種信號(hào)分子對(duì)小鼠巨噬細(xì)胞均具有促凋亡作用。QS系統(tǒng)調(diào)控了大量與細(xì)菌的基礎(chǔ)生理功能和毒力相關(guān)的基因,并在體內(nèi)影響了大量毒力蛋白的表達(dá)。細(xì)胞和動(dòng)物實(shí)驗(yàn)結(jié)果顯示,QS突變株在巨噬細(xì)胞內(nèi)的生存能力下降,對(duì)小鼠的毒力減弱。 結(jié)論:鼠疫菌QS系統(tǒng)合成了兩個(gè)信號(hào)分子,C6-HSL和C8-HSL。信號(hào)分子直接作為毒力因子發(fā)揮作用。QS系統(tǒng)調(diào)控大量基因的表達(dá),包括一些與鼠疫菌基本生理功能和鼠疫菌毒力相關(guān)的基因,QS突變株中這些基因的表達(dá)變化,導(dǎo)致各毒力表型改變,動(dòng)物毒力減弱。
[Abstract]:Background: Yersinia pestis is a natural infectious disease caused by Yersinia pestis. Quorum sensing (QSs) is a cell-density dependent intercellular signaling system through which bacteria can coordinate gene expression and make bacteria adapt to the environment. The production of virulence factors makes the activity of cells organized and becomes a group activity similar to that of multicellular organisms. This paper reports the role of the density sensing system of Yersinia pestis in the virulence of Yersinia pestis. Methods: the signal molecules of QS system were isolated from wild strains and QS mutants of Yersinia pestis by means of gene mutation, high performance liquid phase separation, cytoplasmic potential identification and apoptosis analysis. Compare and analyze the difference of transcription spectrum between QS mutant and wild strain, identify QS system regulator; analyze the effect of QS system on virulence related protein expression in vivo by using protein chip of virulence related protein of Yersinia pestis; through a series of phenotypic experiments, To compare the virulence phenotype of QS mutant in vitro. Results: two signaling molecules, C6-HSL and C8-HSL, were isolated and identified from the culture supernatant of Yersinia pestis. Both of these signaling molecules can promote apoptosis of mouse macrophages. QS system regulates a large number of genes related to the basic physiological function and virulence of bacteria. The results of cell and animal experiments showed that the survival ability of QS mutant in macrophages was decreased, and the virulence to mice was weakened. Conclusion: two signaling molecules, C6-HSL and C8-HSLL, were synthesized by the QS system of Yersinia pestis. The signaling molecules directly act as virulence factors. QS system regulates the expression of a large number of genes. The expression of these genes in the QS mutants related to the basic physiological function of Yersinia pestis and virulence of Yersinia pestis caused the phenotypic changes of virulence and weakened the virulence of animals.
【學(xué)位授予單位】：中國人民解放軍軍事醫(yī)學(xué)科學(xué)院
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2005
【分類號(hào)】：R378

【引證文獻(xiàn)】

相關(guān)博士學(xué)位論文 前1條

1 金丹;新型高抗草甘膦EPSPS基因的克隆及草甘膦N-乙酰轉(zhuǎn)移酶的活性位點(diǎn)鑒定[D];四川大學(xué);2007年

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本文編號(hào)：1527575