2011-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/693405摘要：線毛為類似毛髮的蛋白質結構，存在於許多腸內桿菌的外膜上。鼠傷寒沙門氏菌(Salmonella enterica serotype Typhimurium, S. Typhimurium) 有13種不同線毛的基因組，而第一型線毛 (type 1 fimbriae) 是最常見的線毛種類。已知參與調控S. Typhimurium第一型線毛的基因包含fimZ、fimY、fimW、以及fimU等。利用轉位子插入突變法建構S. Typhimurium insertional library，我們也找出其他可能會調控第一型線毛表現有關之基因。其中lrp與hupA突變株都不產生type 1 fimbriae，呈現type 1 fimbriae lock off現象。stbC與ubiB突變株則呈現type 1 fimbriae locked on情形，值得進一步探討。本研究擬利用轉錄體學、分子生物學、染色質免疫沉澱分析、表面電漿共振生物分子感測系統、電子顯微鏡等技術繼續探討這些個基因在type 1 fimbriae表現調控所扮演的角色。另外，會利用細胞培養技術，測試type 1 fimbrial locked on/off的菌株，與不同上皮細胞株的作用反應，包括type 1 fimbriae會與哪一型的Toll-like receptor及NACHT-LRRs (NLRs) 作用，誘發哪些與炎症反應有關之物質，探討宿主可能產生之免疫反應。也會利用實驗小鼠探討調控type 1 fimbriae能力在致病性所扮演的角色。由於傳統抗生素治療衍生之細菌抗藥性問題日益嚴重，若能往拮抗致病因子方向研究，例如拮抗細菌線毛的吸附、合成，或調控機制，或許未來可篩選或設計出抑制性小分子物質，做為治療的選項之ㄧ。因此，深入了S. Typhimurium type 1 fimbriae調控機制有其重要性。<br> Abstract: Fimbriae are hair-like proteinous structures present on the outer membrane of many members of the family Enterobacteriaceae. There are at least 13 fimbrial operons in Salmonella enterica serotype Typhimurium (S. Typhimurium). Type 1 fimbriae are the most commonly found fimbrial type on S. Typhimurium. Phenotypic regulation of type 1 fimbrial production involves several fim genes including fimZ, fimY, fimW, and fimU. Our previous study using transposon mutagenesis had shown that some genetic elements outside the fim operon were also associated with the regulatory network of type 1 fimbrial expression of S. Typhimurium, among which lrp, hupA, stbC and ubiB mutant posed a further interesting research topic. S. Typhimurium lrp and hupA mutant did not exhibit type 1 fimbrial expression and were regarded as type 1 fimbriae locked off strains whereas the stbC and ubiB mutant were type 1 fimbriae locked on strains. The present study will use transcriptomics, molecular biology, chromatin immunoprecipitation assay, surface plasmon resonance, and electron microscopy to dissect how these genes may participate in the regulatory network of type 1 fimbriae. In addition, S. Typhimurium type 1 fimbriae locked on/off strains will be used to infect a variety of epithelial cell lines. What types of Toll-like receptors and NACHT-LRRs (NLRs) of the cell may interact with type 1 fimbriae and what subsequent proinfammatory mediators may produce will be determined to better understand the host immune response. The pathogenic role that S. Typhimurium has the ability to modulate type 1 fimbrial expression may play will also be evaluated in a murine model. The emergences of bacterial strains that are resistant to available antibiotics demand other therapeutic approaches such as anti-virulence strategy. Elucidation of the mechanisms that block the fimbrial adherence, biosynthesis, and regulatory pathway may shed light on developing inhibitory small molecules in the future, which will provide one of the alternative treatments. Therefore detail investigation of type 1 fimbrial regulation in S. Typhimurium is warranted.鼠傷寒沙門氏菌線毛第一型線毛Salmonella enterica serotype Typhimuriumfimbriaetype 1 fimbriae