Immunization with the outer membrane proteins OmpK17 and OmpK36 elicits protection against Klebsiella pneumoniae in the murine infection model
Immunization with the outer membrane proteins OmpK17 and OmpK36 elicits protection against Klebsiella pneumoniae in the murine infection model
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DOI：
10.1016/j.micpath.2018.04.004
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发表时间：
2018-06-01
影响因子：
3.8
通讯作者：
Sheweita, Salah A.
中科院分区：
文献类型：
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作者：
Hussein, Kawther E.;Bahey-El-Din, Mohammed;Sheweita, Salah A.
肺炎克雷伯氏菌是一种革兰氏阴性菌，越来越多的报道是一种严重的医院和社区获得性病原体。在目前的研究中，两个K。在鼠感染模型中研究了肺炎链球菌抗原OmpK 17和OmpK 36以及它们的融合蛋白同源物F36/17作为潜在的疫苗候选物。评价了三种免疫佐剂，即革兰氏阳性增强剂基质（GEM）佐剂、合成的疟原虫色素（Hz）佐剂和不完全弗氏佐剂（IFA）。将OmpK 17和OmpK 36抗原基因及其融合蛋白克隆到大肠杆菌中进行重组表达。用三种佐剂之一佐剂化的单个重组纯化抗原免疫小鼠三次。最后一次加强免疫后两周，用致死剂量的K.评估肺炎和免疫保护参数。用GEM-或HZ-佐剂化的K.肺炎链球菌抗原在细菌攻击时没有显示出显著的保护作用。用皮下IFA佐剂化抗原免疫的动物显示出最好的结果，对于用OmpK 17、OmpK 36和F36/17免疫的组，存活百分比分别为50、60和50%。血清IgGl而不是IgG 2a抗体在疫苗接种后是最普遍的，表明对辅助性T细胞2型（Th 2）免疫应答的偏好。调理吞噬测定证明在用IFA佐剂化抗原免疫的动物的情况下具有显著的杀伤百分比。总体而言，OmpK 17和OmpK 36是有前途的疫苗抗原，值得进一步优化免疫条件，特别是所用的免疫佐剂，以实现对K.肺炎。
Klebsiella pneumoniae is a Gram-negative bacterium that is increasingly reported as a serious nosocomial and community-acquired pathogen. In the current study, two K. pneumoniae antigens, OmpK17 and OmpK36, as well as their fusion protein cognate F36/17 were investigated as potential vaccine candidates in a murine infection model. Three immunoadjuvants, namely the Gram-positive Enhancer Matrix (GEM) adjuvant, synthetic hemozoin (Hz) adjuvant and incomplete Freund's adjuvant (IFA) were evaluated. Genes of OmpK17 and OmpK36 antigens as well as their fusion protein were cloned in Escherichia coli for recombinant expression. Mice were immunized thrice with the individual recombinant purified antigens adjuvanted with one of the three adjuvants. Two weeks after the last booster, animals were challenged with a lethal dose of K. pneumoniae and immune protection parameters were assessed. Animals immunized with GEM- or Hz-adjuvanted K. pneumoniae antigens did not show significant protection upon bacterial challenge. Animals immunized with subcutaneous IFA-adjuvanted antigens showed the best results with survival percentages of 50, 60 and 50% for groups immunized with OmpK17, OmpK36 and F36/17, respectively. Serum IgGl, rather than IgG2a, antibodies were the most prevalent following vaccination indicating bias towards T helper type 2 (Th2) immune response. Opsonophagocytic assays demonstrated significant percentage killing in case of animals immunized with IFA-adjuvanted antigens. Overall, OmpK17 and OmpK36 are promising vaccine antigens which are worthy of further optimization of the immunization conditions, particularly the used immunoadjuvants, in order to achieve full protection against K. pneumoniae.