Serological Response of Shiga Toxin-Producing Escherichia coli Type III Secreted Proteins in Sera from Vaccinated Rabbits, Naturally Infected Cattle, and Humans
Serological Response of Shiga Toxin-Producing Escherichia coli Type III Secreted Proteins in Sera from Vaccinated Rabbits, Naturally Infected Cattle, and Humans
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DOI：
10.1128/cvi.00068-11
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发表时间：
2011-07-01
影响因子：
--
通讯作者：
Potter, Andrew A.
中科院分区：
文献类型：
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作者：
Asper, David J.;Karmali, Mohamed A.;Potter, Andrew A.
大肠杆菌O157：H7是引起溶血性尿毒综合征（HUS）的重要人兽共患病原体。牛和人类宿主的定殖通过经由III型分泌系统（T3SS）分泌的效应物的作用介导。T3SS和许多分泌的效应物的结构基因位于称为肠上皮细胞消失位点（LEE）的致病岛上。我们克隆并表达了编码66个效应子的基因，并纯化了每个效应子，以测量产滋贺毒素大肠杆菌（STEC）血清型的III型分泌蛋白的交叉反应性。这些包括37个LEE编码的蛋白质和29个非LEE效应物。通过Western印迹分析和酶联免疫吸附测定（ELISA），使用来自用来自四种STEC血清型的III型分泌蛋白（T3SP）免疫的兔的血清、实验感染的牛和来自六名HUS患者的人血清，测量针对每种蛋白的血清学应答。通过Western印迹法，至少一只STEC T3SP接种的兔识别出20种蛋白质。O26、O103、O111和O157特异性血清可识别几种结构蛋白（EspA、EspB和EspD）和一些效应物（Tir、NleA和TccP）。使用针对每种蛋白质的ELISA测试来自实验感染的牛和HUS患者的血清。Tir、EspB、EspD、EspA和NleA被大多数测试样品识别。许多其他蛋白质也被个体血清样品识别。总体而言，诸如Tir、EspB、EspD、NleA和EspA的蛋白质在接种疫苗和自然感染的受试者中具有高度免疫原性，并且可以是交叉保护性STEC疫苗的候选物。
Escherichia coli O157:H7 is an important zoonotic pathogen, causing hemolytic uremic syndrome (HUS). The colonization of cattle and human hosts is mediated through the action of effectors secreted via a type III secretion system (T3SS). The structural genes for the T3SS and many of the secreted effectors are located on a pathogenicity island called the locus of enterocyte effacement (LEE). We cloned and expressed the genes coding for 66 effectors and purified each to measure the cross-reactivity of type III secreted proteins from Shiga toxin-producing Escherichia coli (STEC) serotypes. These included 37 LEE-encoded proteins and 29 non-LEE effectors. The serological response against each protein was measured by Western blot analysis and enzyme-linked immunosorbent assay (ELISA) using sera from rabbits immunized with type III secreted proteins (T3SPs) from four STEC serotypes, experimentally infected cattle, and human sera from six HUS patients. Twenty proteins were recognized by at least one of the STEC T3SP-vaccinated rabbits by Western blotting. Several structural proteins (EspA, EspB, and EspD) and a number of effectors (Tir, NleA, and TccP) were recognized by O26-, O103-, O111-, and O157-specific sera. Sera from experimentally infected cattle and HUS patients were tested using an ELISA against each of the proteins. Tir, EspB, EspD, EspA, and NleA were recognized by the majority of the samples tested. A number of other proteins also were recognized by individual serum samples. Overall, proteins such as Tir, EspB, EspD, NleA, and EspA were highly immunogenic in vaccinated and naturally infected subjects and could be candidates for a cross-protective STEC vaccine.