Carboxyl-Terminal Residues N478 and V479 Required for the Cytolytic Activity of Listeriolysin O Play a Critical Role in Listeria monocytogenes Pathogenicity.
Carboxyl-Terminal Residues N478 and V479 Required for the Cytolytic Activity of Listeriolysin O Play a Critical Role in Listeria monocytogenes Pathogenicity.
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李斯特菌溶血素 O 的溶细胞活性所需的羧基末端残基 N478 和 V479 在单增李斯特菌致病性中发挥着关键作用。
DOI：
10.3389/fimmu.2017.01439
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发表时间：
2017
影响因子：
7.3
通讯作者：
Song H
中科院分区：
文献类型：
--
作者：
Cheng C;Jiang L;Ma T;Wang H;Han X;Sun J;Yang Y;Chen Z;Yu H;Hang Y;Liu F;Wang B;Fang W;Huang H;Fang C;Cai C;Freitag N;Song H
单核细胞增多性李斯特菌是一种兼性胞内病原体，其分泌使细菌能够穿过吞噬体膜的溶细胞素β-溶血素O（LLO）。L.单核细胞增生调节吞噬体中的LLO活性并使其在宿主胞质溶胶中的活性最小化。不能区室化LLO活性的突变体具有细胞毒性并且具有减弱的毒力。在这里，我们表明LLO的残基N478和V479是LLO溶血活性和细菌毒力所需的。单个N478 A突变（LLON 478 A）显著增加了LLO在中性pH下的溶血活性，而与野生型LLO相比，在最适酸性pH下没有观察到差异。相反，突变体LLOV 479 A在酸性pH下表现出较低的溶血活性，但在中性pH下不表现出溶血活性。双突变体LLON 478 AV 479 A在酸性和中性pH下均表现出溶血活性的更大降低。有趣的是，产生LLON 478 A或LLOV 479 A的菌株与野生型菌株类似地裂解红细胞。令人惊讶的是，分泌细菌的LLON 478 AV 479 A几乎没有可检测到的溶血活性，但表现出宿主细胞的细胞毒性，从吞噬体逃逸，在细胞内生长，并以与野生型菌株相同的效率在细胞间扩散，但在小鼠中的毒力高度减弱。这些数据表明，这两个残基是小鼠中LLO溶血活性和致病性所需的，但不是逃离吞噬体和细胞间扩散所需的。几乎不溶血的LLON 478 AV 479 A突变体在细胞内生长的发现表明，毒力决定簇的诱变是开发活疫苗株的新方法。
Listeria monocytogenes is a facultative intracellular pathogen that secretes the cytolysin listeriolysin O (LLO), which enables the bacteria to cross the phagosomal membrane. L. monocytogenes regulates LLO activity in the phagosome and minimizes its activity in the host cytosol. Mutants that fail to compartmentalize LLO activity are cytotoxic and have attenuated virulence. Here, we showed that residues N478 and V479 of LLO are required for LLO hemolytic activity and bacterial virulence. A single N478A mutation (LLON478A) significantly increased the hemolytic activity of LLO at a neutral pH, while no difference was observed at the optimum acidic pH, compared with wild-type LLO. Conversely, the mutant LLOV479A exhibited lower hemolytic activity at the acidic pH, but not at the neutral pH. The double mutant LLON478AV479A showed a greater decrease in hemolytic activity at both the acidic and neutral pHs. Interestingly, strains producing LLON478A or LLOV479A lysed erythrocytes similarly to the wild-type strain. Surprisingly, bacteria-secreting LLON478AV479A had barely detectable hemolytic activity, but exhibited host cell cytotoxicity, escaped from the phagosome, grew intracellularly, and spread cell-to-cell with the same efficiency as the wild-type strain, but were highly attenuated in virulence in mice. These data demonstrate that these two residues are required for LLO hemolytic activity and pathogenicity in mice, but not for escape from the phagosome and cell-to-cell spreading. The finding that the nearly non-hemolytic LLON478AV479A mutant grew intracellularly indicates that mutagenesis of a virulence determinant is a novel approach for the development of live vaccine strains.
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DOI：
10.1083/jcb.200201081
发表时间：
2002-03-18
期刊：
The Journal of cell biology
影响因子：
--
作者：
Glomski IJ;Gedde MM;Tsang AW;Swanson JA;Portnoy DA
通讯作者：
Portnoy DA
硫氧还蛋白 A 对于运动至关重要，并通过氧化还原相互作用促进单核细胞增生李斯特菌的宿主感染。
影响因子：
5.7
作者：
Cheng C;Dong Z;Han X;Wang H;Jiang L;Sun J;Yang Y;Ma T;Shao C;Wang X;Chen Z;Fang W;Freitag NE;Huang H;Song H
通讯作者：
Song H
影响因子：
3.1
作者：
KUHN, M;PREVOST, MC;SANSONETTI, PJ
通讯作者：
SANSONETTI, PJ
影响因子：
4.8
作者：
Cheng, Changyong;Chen, Jianshun;Fang, Weihuan
通讯作者：
Fang, Weihuan
影响因子：
3.1
作者：
JONES, S;PORTNOY, DA
通讯作者：
PORTNOY, DA