Two DHH Subfamily 1 Proteins Contribute to Pneumococcal Virulence and Confer Protection against Pneumococcal Disease
Two DHH Subfamily 1 Proteins Contribute to Pneumococcal Virulence and Confer Protection against Pneumococcal Disease
复制标题
DOI：
10.1128/iai.01383-10
复制
发表时间：
2011-09-01
影响因子：
3.1
通讯作者：
Hermans, P. W. M.
中科院分区：
文献类型：
--
作者：
Cron, L. E.;Stol, K.;Hermans, P. W. M.
肺炎链球菌是一种重要的人类细菌病原体，可引起肺炎、脑膜炎、败血症和中耳炎等感染。目前基于荚膜多糖的缀合物疫苗保护抵抗已知的超过90种血清型中的一部分，而基于保守的肺炎球菌蛋白的疫苗被认为是有前途的广泛替代品。肺炎球菌基因组编码两种功能未知的保守蛋白，SP1298和SP2205，分类为DHH（Asp-His-His）亚家族1蛋白。在这里，我们研究了他们的贡献，肺炎球菌的发病机制使用单和双敲除突变体在三个不同的菌株：D39，TIGR 4，和BHN 100。缺乏SP1298和SP2205的突变体在粘附人上皮底特律562细胞方面严重受损。重要的是，减弱的表型在缺失基因的遗传互补后恢复。单个和混合的小鼠模型的殖民化，中耳炎，肺炎，菌血症表明，在鼻咽，中耳，肺，和血液中的细菌负荷的突变体感染的小鼠显着减少，从野生型感染的小鼠，具有明显的累加效应后，删除两个基因。观察到较小的菌株特异性表型，即，SP1298的缺失仅影响BHN 100的宿主细胞粘附，SP2205的缺失显著减弱了D39和BHN 100的肺和血液中的毒力，但不影响TIGR 4。最后，用两种DHH亚家族1蛋白的组合皮下接种赋予了对感染TIGR 4的小鼠的鼻咽、肺和血液的保护。我们得出结论，SP1298和SP2205在肺炎球菌感染的几个阶段发挥了重要作用，重要的是，这些蛋白质是多组分蛋白疫苗的潜在候选者。
Streptococcus pneumoniae is an important human bacterial pathogen, causing such infections as pneumonia, meningitis, septicemia, and otitis media. Current capsular polysaccharide-based conjugate vaccines protect against a fraction of the over 90 serotypes known, whereas vaccines based on conserved pneumococcal proteins are considered promising broad-range alternatives. The pneumococcal genome encodes two conserved proteins of an as yet unknown function, SP1298 and SP2205, classified as DHH (Asp-His-His) subfamily 1 proteins. Here we examined their contribution to pneumococcal pathogenesis using single and double knockout mutants in three different strains: D39, TIGR4, and BHN100. Mutants lacking both SP1298 and SP2205 were severely impaired in adherence to human epithelial Detroit 562 cells. Importantly, the attenuated phenotypes were restored upon genetic complementation of the deleted genes. Single and mixed mouse models of colonization, otitis media, pneumonia, and bacteremia showed that bacterial loads in the nasopharynx, middle ears, lungs, and blood of mice infected with the mutants were significantly reduced from those of wild-type-infected mice, with an apparent additive effect upon deletion of both genes. Minor strain-specific phenotypes were observed, i.e., deletion of SP1298 affected host-cell adherence in BHN100 only, and deletion of SP2205 significantly attenuated virulence in lungs and blood in D39 and BHN100 but not TIGR4. Finally, subcutaneous vaccination with a combination of both DHH subfamily 1 proteins conferred protection to nasopharynx, lungs, and blood of mice infected with TIGR4. We conclude that SP1298 and SP2205 play a significant role at several stages of pneumococcal infection, and importantly, these proteins are potential candidates for a multicomponent protein vaccine.