Proinflammatory Exoprotein Characterization of Toxic Shock Syndrome Staphylococcus aureus
Proinflammatory Exoprotein Characterization of Toxic Shock Syndrome Staphylococcus aureus
复制标题
DOI：
10.1021/bi200435n
复制
发表时间：
2011-08-23
期刊：
影响因子：
2.9
通讯作者：
Peterson, Marnie L.
中科院分区：
文献类型：
--
作者：
Lin, Ying-Chi;Anderson, Michele J.;Peterson, Marnie L.
脉冲场凝胶电泳 (PFGE) 克隆型 USA200 是鼻内传播最广泛的金黄色葡萄球菌定植菌，也是中毒性休克综合征 (TSS) 的主要原因。人们认为源自这些生物体的外蛋白有助于它们的定殖和人类疾病的致病，但尚未得到充分表征。对分别从肺部流感后 TSS 和月经阴道 TSS 中分离出的两种代表性金黄色葡萄球菌 USA200 分离株 MNPE（α 毒素阳性）和 CDC587（α 毒素突变体）进行了评估。生物化学、免疫生物学和基于细胞的测定（包括质谱分析）被用来鉴定源自负责人阴道上皮细胞促炎和细胞毒性活性的菌株的关键外蛋白。两种菌株均产生与毒力相关的外蛋白，溶细胞素（α毒素和γ毒素）、超抗原和蛋白酶被确定为主要的外蛋白，可引起上皮细胞炎症和细胞毒性。由于高浓度的α-毒素，MNPE 的外蛋白级分比 CDC587 的外蛋白级分更具促炎性和细胞毒性。尽管密码子 113 处存在终止密码子 (TAG)，CDC587 仍产生少量 α-毒素。USA200 菌株的其他外毒素鉴定研究 [S.金黄色葡萄球菌 MN8（α-毒素突变体）]证实，尽管终止密码子相同，MN8 也产生低水平的α-毒素。两种 USA200 菌株毒力因子谱中观察到的差异提供了对选择特定毒力因子的环境因素的深入了解。溶细胞素、超抗原和蛋白酶被确定为潜在靶标，其中毒素中和可以预防或减少与金黄色葡萄球菌相关的上皮损伤。
Pulsed-field gel electrophoresis (PFGE) clonal type USA200 is the most widely disseminated Staphylococcus aureus colonizer of the nose and is a major cause of toxic shock syndrome (TSS). Exoproteins derived from these organisms have been suggested to contribute to their colonization and causation of human diseases but have not been well-characterized. Two representative S. aureus USA200 isolates, MNPE (alpha-toxin positive) and CDC587 (alpha-toxin mutant), isolated from pulmonary post-influenza TSS and menstrual vaginal TSS, respectively, were evaluated. Biochemical, immuno-biological, and cell-based assays, including mass spectrometry, were used to identify key exoproteins derived from the strains that are responsible for proinflammatory and cytotoxic activity on human vaginal epithelial cells. Exoproteins associated with virulence were produced by both strains, and cytolysins (alpha-toxin and gamma-toxin), superantigens, and proteases were identified as the major exoproteins, which caused epithelial cell inflammation and cytotoxicity. Exoprotein fractions from MNPE were more proinflammatory and cytotoxic than those from CDC587 due to high concentrations of alpha-toxin. CDC587 produced a small amount of alpha-toxin, despite the presence of a stop codon (TAG) at codon 113. Additional exotoxin identification studies of USA200 strain [S. aureus MN8 (alpha-toxin mutant)] confirmed that MN8 also produced low levels of alpha-toxin despite the same stop codon. The differences observed in virulence factor profiles of two USA200 strains provide insight into environmental factors that select for specific virulence factors. Cytolysins, superantigens, and proteases were identified as potential targets, where toxin neutralization may prevent or diminish epithelial damage associated with S. aureus.