Cytotoxic property of Streptococcus mitis strain producing two different types of cholesterol-dependent cytolysins
Cytotoxic property of Streptococcus mitis strain producing two different types of cholesterol-dependent cytolysins
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产生两种不同类型胆固醇依赖性溶细胞素的轻症链球菌菌株的细胞毒性特性
DOI：
10.1016/j.meegid.2020.104483
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Nagamune Hideaki
中科院分区：
文献类型：
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作者：
Tabata Atsushi;Ohkuni Hisashi;Hino Haruka;Saigo Takuya;Kodama Chihiro;Tang Qing;Tomoyasu Toshifumi;Fukunaga Yoshitaka;Itoh Yasuhiko;Nagamune Hideaki
链球菌混合菌株Nm-65分泌一种非典型的5结构域类型的胆固醇依赖细胞溶素(CDC)。MITS来源的人血小板聚集因子(Sm-hPAF)最初被描述为一种血小板聚集因子。SM-hPAF属于第三类CDC，识别膜胆固醇和人CD59为受体，并对人细胞具有优先活性。基因组分析草案显示，Nm-65菌株还含有一种编码另一种CDC的基因，称为Mitilysin(MLY)。这种CDC属于第一类CDC，它只识别膜胆固醇作为受体，它是肺炎球菌CDC的同系物，肺炎溶血素。编码每个CDC的基因位于Nm-65基因组上，相距约20kb。对这些编码CDC基因的基因组位置的分析表明，编码Sm-hPAF的基因和包括MLY基因在内的区域都插入了CDC基因的特定位点。小基因组。利用编码Nm-65的CDC基因(S)的缺失突变体获得的结果表明，每个CDC对溶血和细胞毒都有贡献，MLY是Nm-65的主要溶血素/细胞溶血素。本研究旨在确定ANS的潜在致病性。产生两种具有不同受体识别特性和分泌模式的CDC的混合菌株。
Streptococcus mitisstrain Nm-65 secretes an atypical 5-domain-type cholesterol-dependent cytolysin (CDC) calledS. mitis-derived human platelet aggregation factor (Sm-hPAF) originally described as a platelet aggregation factor. Sm-hPAF belongs to Group III CDC that recognize both membrane cholesterol and human CD59 as the receptors, and shows preferential activity towards human cells. Draft genome analyses have shown that the Nm-65 strain also harbors a gene encoding another CDC called mitilysin (MLY). This CDC belongs to Group I CDC that recognizes only membrane cholesterol as a receptor, and it is a homolog of the pneumococcal CDC, pneumolysin. The genes encoding each CDC are located about 20 kb apart on the Nm-65 genome. Analysis of the genomic locus of these CDC-encoding genesin silicoshowed that the gene encoding Sm-hPAF and the region including the gene encoding MLY were both inserted into a specific locus of theS. mitisgenome. The results obtained using deletion mutants of the gene(s) encoding CDC in Nm-65 indicated that each CDC contributes to both hemolysis and cytotoxicity, and that MLY is the major hemolysin/cytolysin in Nm-65. The present study aimed to determine the potential pathogenicity of anS. mitisstrain that produces two CDC with different receptor recognition properties and secretion modes.