Streptococcus suis Enolase Functions as a Protective Antigen Displayed on the Bacterial Cell Surface
Streptococcus suis Enolase Functions as a Protective Antigen Displayed on the Bacterial Cell Surface
复制标题
猪链球菌烯醇酶作为细菌细胞表面展示的保护性抗原
DOI：
10.1086/644602
复制
发表时间：
2009-11-15
影响因子：
6.4
通讯作者：
Tang, Jiaqi
中科院分区：
文献类型：
--
作者：
Feng, Youjun;Pan, Xiuzhen;Tang, Jiaqi
背景资料。猪链球菌2型(SS2)已演变为一种高度传染性的实体，对公众健康构成了极大的威胁。保护性抗原的筛选和鉴定对开发SS2感染的治疗方法具有重要意义。多种策略被用来研究一种新的表面蛋白，它有可能成为保护性抗原。这些策略包括分子克隆、生化和生物物理分析、酶分析、免疫学方法(如免疫电子显微镜)和动物实验感染。我们从SS2中克隆了一个烯醇化酶基因，并对其蛋白产物--烯醇化酶进行了系统的鉴定。生物物理数据表明，猪链霉烯醇化酶是一种八聚体蛋白质。酶活性测定证实了其催化2-磷酸-D-甘油酸酯脱水生成磷酸烯醇式丙酮酸的能力。鉴于烯醇化酶具有很强的抗原性，建立了一种基于烯醇化酶的SS2感染监测方法。综合证据表明，SS2烯醇化酶可以定位于细菌细胞表面，促进细菌的黏附。此外，我们还发现，烯醇化酶可以完全保护小鼠免受SS2感染，这表明烯醇化酶具有作为疫苗候选的潜力。我们得出结论，猪链球菌烯醇化酶作为一种显示在细菌细胞表面的保护性抗原，可以用来开发新的策略来对抗SS2感染。
Background. Streptococcus suis serotype 2 (SS2) has evolved into a highly infectious entity, posing a great threat to public health. Screening for and identification of protective antigens plays an important role in developing therapies against SS2 infections.Methods. Multiple strategies were used to investigate a new surface protein that has the potential to be a protective antigen. These strategies included molecular cloning, biochemical and biophysical analyses, enzymatic assay, immunological approaches (eg, immunoelectron microscopy), and experimental infections of animals.Results. We identified an enolase gene from SS2 and systematically characterized its protein product, enolase. Biophysical data indicated that S. suis enolase is an octameric protein. Enzymatic assays verified its ability to catalyze the dehydration of 2-phospho-D-glycerate to phosphoenolpyruvate. In consideration of the strong antigenicity of enolase, an efficient enolase-based method was established for monitoring SS2 infections. Combined evidence strongly indicated that SS2 enolase can localize on the bacterial cell surface and facilitate bacterial adherence. Additionally, we found that enolase can confer complete protection against SS2 infection to mice, which suggests that enolase has potential as a vaccine candidate.Conclusions. We conclude that S. suis enolase functions as a protective antigen displayed on the bacterial cell surface and that it can be used to develop new strategies to combat SS2 infections.