Tyrosine tRNA synthetase as a novel extracellular immunomodulatory protein in Streptococcus anginosus
Tyrosine tRNA synthetase as a novel extracellular immunomodulatory protein in Streptococcus anginosus
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酪氨酸 tRNA 合成酶作为咽峡炎链球菌中新型细胞外免疫调节蛋白
DOI：
10.1093/femsle/fnaa153
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发表时间：
2020
影响因子：
2.1
通讯作者：
Sasaki Minoru
中科院分区：
文献类型：
--
作者：
Shimoyama Yu;Ishikawa Taichi;Kodama Yoshitoyo;Kimura Shigenobu;Sasaki Minoru
感染性心内膜炎、脓肿或口腔癌患者常检出血管增生链球菌。虽然。心绞痛被认为是这些疾病的致病病原体，但其致病机制尚不清楚。在此之前，我们提出了一种来自ms的细胞外抗原。anginosus（SAA）通过诱导小鼠巨噬细胞产生一氧化氮作为致病因子。在本研究中，我们使用LC-MS /MS鉴定了SAA，并评估了his标记的重组SAA在小鼠巨噬细胞中的生物活性。SAA是一种酪氨酸tRNA合成酶（SaTyrRS），从s的胞外部分分离得到。心绞痛，但不来自其他口腔链球菌。此外，在重组satyrrs刺激的小鼠巨噬细胞中诱导一氧化氮合酶和TNF-α mRNA的表达。然而，在被截断或热灭活的重组SaTyrRS刺激的巨噬细胞中，它们的mRNA表达并没有被诱导，激活基序被鉴定为Arg264-Thr270。因此，这些结果表明SaTyrRS可能是一种新的特异性免疫调节蛋白inS。anginosus。
Streptococcus anginosusis frequently detected in patients with infective endocarditis, abscesses or oral cancer. AlthoughS. anginosusis considered the causative pathogen of these diseases, the pathogenic mechanisms of the bacterium have remained unclear. Previously, we suggested that an extracellular antigen fromS. anginosus(SAA) serves as a pathogenic factor by inducing nitric oxide production in murine macrophages. In the present study, we identified SAA using LC–MS/MS and assessed the biological activities of His-tagged recombinant SAA in murine macrophages. SAA was identified as a tyrosine tRNA synthetase (SaTyrRS) that was isolated from the extracellular fraction ofS. anginosusbut not from other oral streptococci. In addition, inducible nitric oxide synthase and TNF-α mRNA expression was induced in recombinant SaTyrRS-stimulated murine macrophages. However, their mRNA expression was not induced in macrophages stimulated with truncated or heat-inactivated recombinant SaTyrRS, and the activation motif was identified as Arg264–Thr270. Consequently, these results indicated that SaTyrRS could be a novel and specific immunomodulatory protein inS. anginosus.