Molecular mechanisms of intracellular growth of Salmonella

沙门氏菌细胞内生长的分子机制

• 批准号: 16017218
• 负责人: YAMAMOTO Tomoko
• 金额: $ 9.41万
• 依托单位: Chiba University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16017218/
• 关键词: Pathogenesis; Salmonella; Intracellular Growth; Macrophage; マクロファージ内増殖能; ClpXP; PagC; OMV; attenuating virulence factor; 持続感染; アポトーシス; 細胞内寄生菌

Intracellular pathogens, including Salmonella, which maintain long-term resistance within host phagocytes elicit a variety of genetic programs to help them adapt to the hostile environmental conditions encountered within the phagosome. To elucidate the genetic programs for Salmonella pathogenesis expressed in host after infection, a proteome analysis of proteins newly induced in Salmonella after phagocytosis by macrophages was performed. Since prominent among these programs was the heat shock response, the role of molecular chaperones and AAA+ proteases which are members of the heat shock proteins as virulence proteins have been studied.(1)The disruption of C1pXP or Lon of serovar Typhimurium results a loss of virulence to mice. The attenuation could be due to the impaired ability to survive and replicate within macrophage cells, suggesting that C1pXP and Lon are critically important for the systemic Salmonella infection of mice. We found that the C1pXP mutant and Lon mutant persist in … More the BALB/c mice for long periods of time without causing an overwhelming systemic infection, suggesting a possible candidate of Salmonella live vaccine. We therefore examined whether oral immunization with the lon mutant or clpXP mutant protects mice against subsequent oral challenge with virulent serovar Typhimurium. The results suggested that a single oral immunization of the lon and clpXPmutants should be effective to protect against the colonization of wild-type serovar Typhimurium within the intestinal tract.(2) We demonstrated that depletion of ATP-dependent Lon protease in serovar Typhimurium induces rapid and massive apoptosis in macrophages by a mechanism involving both caspases-1 and-3. This excessive induction of apoptosis was abrogated by disruption of invF, which is required for the expression of the Salmonella pathogenicity islandl (SPI1) genes. Expression of MIA, a central regulator of SPI1 transcription, was repressed in the macrophages after phagocytosis, but this gene was continuously expressed when the Lon mutant grew within the macrophages, so the SPI1 proteins accumulated. Thus, the increase in macrophage apoptosis induced by the Lon mutant could be due to continued expression of SPI1 genes under conditions where they are normally repressed.(3) To determine the reasons for the loss of virulence of the C1pXP-deficient mutant, we characterized the mutant grown under the conditions that mimic the intracellular environment of macrophages. Consequently, we elucidated that the PagC protein is increased in its amount by C1pXP-depletion and that the increased level is responsible for the loss of virulence of the C1pXP-deficient cells. Furthermore, we have found that the PagC protein is exported by outer membrane vesicle (OMV) from Salmonella cells. Less

包括沙门氏菌在内的细胞内病原体，这些病原体在宿主吞噬细胞内保持长期抵抗会引起各种遗传程序，以帮助它们适应吞噬体中遇到的敌对环境条件。为了阐明感染后宿主在宿主中表达的沙门氏菌发病机理的遗传程序，对巨噬细胞吞噬后吞噬作用后，对蛋白质新诱导的蛋白质组分析。由于这些程序中突出的是热休克反应，因此分子链烷和AAA+蛋白的作用是热激蛋白的成员，因为病毒蛋白已经研究了。衰减可能是由于在巨噬细胞中生存和复制的能力受损，这表明C1PXP和LON对于小鼠的全身沙门氏菌感染至关重要。我们发现，C1PXP突变体和LON突变体持续存在……更多的BALB/C小鼠长期存在而不会引起压倒性的全身感染，这表明可能是沙门氏菌活疫苗的候选者。因此，我们检查了用LON突变体或ClpxP突变体口服免疫抑制是否可以保护小鼠免受随后的口服毒种typhimurium的口服挑战。 The results suggested that a single oral immunosuppression of the lon and clpXPmutants should be Effective to protect against the colonization of wild-type serovar Typhimurium within the intestinal tract.(2) We demonstrated that depletion of ATP-dependent Lon protein in serovar Typhimurium induces rapid and massive apoptosis in macrophages by a mechanism involving both caspases-1和-3。通过破坏INVF，这种过量的凋亡诱导被废除了，这是沙门氏菌致病性岛（SPI1）基因表达所必需的。吞噬作用后，在巨噬细胞中抑制了MIA的表达，这是SPI1转录的中心调节剂，但是当LON突变体在巨噬细胞内生长时，该基因持续表达，因此SPI1蛋白积累。这是，LON突变体引起的巨噬细胞凋亡的增加可能是由于在正常再现的条件下持续表达SPI1基因。（3）为了确定C1PXP缺陷型突变体损失的原因，我们表征了在模拟遗内环境的情况下生长的突变体。因此，我们阐明了PAGC蛋白通过C1PXP缺乏增加了其量，并且升高的水平是导致C1PXP缺陷细胞病毒丧失的原因。此外，我们发现PAGC蛋白是由沙门氏菌细胞的外膜（OMV）导出的。较少的

项目成果

master regulator proteins for Salmonella flagellum biogenesis, by the ATP-dependent C1pXP protease.

由 ATP 依赖性 C1pXP 蛋白酶控制沙门氏菌鞭毛生物发生的主调节蛋白。

• 发表时间: 2003
• 期刊: Molecular Microbiology 48
• 作者: T.Tomoyasu;A.Takaya;E.Isogai;T.Yamamoto;Turnover of F1hD;F1hC
• 通讯作者: F1hC

Degradation of the Hi1C and Hi1D regulator proteins by ATP-dependent Lon protease leads to down-regulation of Salmonella pathogenicity island 1 gene expression.

ATP 依赖性 Lon 蛋白酶对 Hi1C 和 Hi1D 调节蛋白的降解导致沙门氏菌致病性岛 1 基因表达下调。

• 发表时间: 2005
• 期刊: Molecular Microbiology 55
• 作者: A.Takaya;Y.Kubota;E.Isogai;T.Yamamoto
• 通讯作者: T.Yamamoto

Evaluation of the Lon-deficient Salmonella strain as an oral vaccine candidate

• DOI: 10.1111/j.1348-0421.2005.tb03700.x
• 发表时间: 2005-01-01
• 期刊: MICROBIOLOGY AND IMMUNOLOGY
• 影响因子: 2.6
• 作者: Kodama, C;Eguchi, M;Matsui, H
• 通讯作者: Matsui, H

ClpXP controls the expression of LEE genes in enterohaemorrhagic Escherichia coli

ClpXP控制肠出血性大肠杆菌中LEE基因的表达

• 发表时间: 2005
• 期刊: FEMS Microbiol. Lett 254
• 作者: Tomoyasu;T.;Takaya;A.;Handa;Y;Karata;K.;Yamamoto;T.
• 通讯作者: T.

感染症学:微生物・寄生虫とのかかわり

传染病：与微生物和寄生虫的关系

• 发表时间: 2005
• 作者: 神谷 茂;山本友子 他
• 通讯作者: 山本友子 他