Zhou Yang, Wang Yan, Deng Limei, Zheng Chengkun, Yuan Fangyan, Chen Huanchun, Bei Weicheng, Li Jinquan
State Key Laboratory of Agricultural Microbiology, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, PR China.
State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, PR China.
Vaccine. 2015 May 5;33(19):2254-2260. doi: 10.1016/j.vaccine.2015.03.038. Epub 2015 Mar 25.
Streptococcus suis serotype 2 (S. suis 2) is an important zoonotic pathogen that can also cause epidemics of life-threatening infections in humans. Surface proteins of pathogens play a critical role in the interaction with host system or environment, as they take part in processes like virulence, cytotoxicity, adhesion, signaling or transport, etc. Thus, surface proteins identified by the screening of immunoproteomic techniques are promising vaccine candidates or diagnostic markers. In this study, four membrane associated proteins (MAP) identified by immunoproteomic method were cloned and expressed as recombinant proteins with his-tag. Screening for vaccine candidates were firstly performed by protection assay in vivo and immunization with Sbp markedly protected mice against systemic S. suis 2 infection. The immune responses and protective of Sbp were further evaluated. The results showed that Sbp could elicit a strong humoral antibody response and protect mice from lethal challenge with S. suis 2. The antiserum against Sbp could efficiently impede survival of bacterial in whole blood killing assay and conferred significant protection against S. suis 2 infection in passive immunization assays. The findings indicate that Sbp may serve as an important factor in the pathogenesis of S. suis 2 and would be a promising subunit vaccine candidate.
猪链球菌2型（S. suis 2）是一种重要的人畜共患病原体，也可导致人类危及生命的感染流行。病原体的表面蛋白在与宿主系统或环境的相互作用中起着关键作用，因为它们参与毒力、细胞毒性、黏附、信号传导或运输等过程。因此，通过免疫蛋白质组学技术筛选鉴定出的表面蛋白是有前景的疫苗候选物或诊断标志物。在本研究中，通过免疫蛋白质组学方法鉴定的四种膜相关蛋白（MAP）被克隆并表达为带有组氨酸标签的重组蛋白。首先通过体内保护试验进行疫苗候选物筛选，用Sbp免疫可显著保护小鼠免受全身性S. suis 2感染。进一步评估了Sbp的免疫反应和保护作用。结果表明，Sbp可引发强烈的体液抗体反应，并保护小鼠免受S. suis 2的致死性攻击。抗Sbp血清在全血杀伤试验中可有效阻碍细菌存活，并在被动免疫试验中对S. suis 2感染提供显著保护。这些发现表明，Sbp可能是S. suis 2发病机制中的一个重要因素，有望成为亚单位疫苗候选物。
