Immunogenic characterization of outer membrane porins OmpC and OmpF of porcine extraintestinal pathogenic Escherichia coli
Immunogenic characterization of outer membrane porins OmpC and OmpF of porcine extraintestinal pathogenic Escherichia coli
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猪肠外致病性大肠杆菌外膜孔蛋白OmpC和OmpF的免疫原性特征
DOI：
10.1111/1574-6968.12013
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发表时间：
2012-12-01
影响因子：
2.1
通讯作者：
Chen, Huanchun
中科院分区：
文献类型：
--
作者：
Liu, Canying;Chen, Zhaohui;Chen, Huanchun
肠外致病性大肠杆菌（ExPEC）是一种重要的病原体，可在多种哺乳动物和鸟类中引起全身性感染。到目前为止，针对猪ExPEC感染的商业疫苗很少，而且抗生素耐药性已成为一个严重的临床问题。保护性抗原的鉴定有助于开发潜在有效的疫苗。在本研究中，克隆并表达了猪ExPEC的两种外膜孔蛋白OmpC和OmpF，以研究它们的免疫原性。用纯化的重组蛋白OmpC和OmpF对小鼠进行腹腔免疫，可激发强烈的免疫球蛋白G（IgG）抗体反应。诱导产生了IgG1和IgG2a两个亚类，且以IgG1产生为主。在用2.5×10⁷CFU（5×LD₅₀）的高致病性ExPEC菌株PCN033进行攻毒后，在接种OmpC和OmpF的小鼠中分别观察到62.5%和87.5%的保护率。此外，抗 - OmpC和抗 - OmpF血清均可介导补体依赖性调理吞噬作用。系统发育分析表明，ompC基因在所有大肠杆菌菌株中普遍存在，而ompF基因在某些菌株中发生了突变。此外，选择分析表明ompC基因可能受到强烈的免疫压力。我们的研究结果表明，OmpC是一个针对猪ExPEC感染的有希望的疫苗靶点。
Extraintestinal pathogenic Escherichia coli (ExPEC) is an important pathogen that can cause systemic infections in a broad spectrum of mammals and birds. To date, commercial vaccines against ExPEC infections in pigs are rare and antibiotic resistance has become a serious clinical problem. Identification of protective antigens is helpful for developing potentially effective vaccines. In this study, two outer membrane porins, OmpC and OmpF, of porcine ExPEC were cloned and expressed to investigate their immunogenicity. Intraperitoneal immunization of mice with the purified recombinant proteins OmpC and OmpF stimulated strong immunoglobulin G (IgG) antibody responses. Both IgG1 and IgG2a subclasses were induced, with a predominance of IgG1 production. After challenge with 2.5 x 107 CFU (5 x LD50) of the highly virulent ExPEC strain PCN033, 62.5% and 87.5% protection was observed in mice immunized with OmpC and OmpF, respectively. In addition, both anti-OmpC and anti-OmpF sera can mediate complement-dependent opsonophagocytosis. Phylogenetic analysis showed that the ompC gene was ubiquitously present in all E. coli strains, whereas the ompF gene was mutated in certain strains. Furthermore, the selection analysis indicated that gene ompC may be subject to strong immune pressure. Our results demonstrated that OmpC is a promising vaccine target against ExPEC infections in swine.