Heat-Labile- and Heat-Stable-Toxoid Fusions (LTR192G-STaP13F) of Human Enterotoxigenic Escherichia coli Elicit Neutralizing Antitoxin Antibodies
Heat-Labile- and Heat-Stable-Toxoid Fusions (LTR192G-STaP13F) of Human Enterotoxigenic Escherichia coli Elicit Neutralizing Antitoxin Antibodies
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DOI：
10.1128/iai.00165-11
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发表时间：
2011-10-01
影响因子：
3.1
通讯作者：
Zhang, Weiping
中科院分区：
文献类型：
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作者：
Liu, Mei;Ruan, Xiaosai;Zhang, Weiping
产肠毒素大肠杆菌 (ETEC) 菌株是人类和动物腹泻疾病的主要原因。粘附素和肠毒素，包括热不稳定（LT）和热稳定（STa）毒素，是关键的毒力因子。抗原粘附素和 LT 抗原已用于开发 ETEC 腹泻疫苗。然而，STa 因其较差的免疫原性和强毒性而未被包括在内。我们最近的研究表明，猪型 STa 类毒素与全长猪型 LT 类毒素 LTR192G 进行基因融合后，变得具有免疫原性并引发中和性抗 STa 抗体（W.Zhang 等人，Infect.Immun.78：316-325，2010）。在本研究中，我们将与猪型毒素基因高度同源的人型LT和STa基因突变为全长LT类毒素（LTR192G）和全长STa类毒素（STaP13F），并将它们进行基因融合以产生LT192-STa13类毒素融合体。用 LT192-STa13 融合抗原免疫的小鼠产生了抗 LT 和抗 STa IgG（在血清和粪便中）和 IgA 抗体（在粪便中）。此外，免疫小鼠分泌的 IgA 抗体可以中和 T-84 细胞中的 STa 和霍乱毒素。此外，我们将STa13类毒素在N端和C端、A1和A2肽之间、LT192的A和B亚基之间进行融合，以获得不同的融合体，以探索增强STa免疫原性的策略。这项研究表明，人型 LT192-STa13 融合体可诱导中和抗毒素抗体，并为开发针对人 ETEC 腹泻的类毒素疫苗提供了重要信息。
Enterotoxigenic Escherichia coli (ETEC) strains are a major cause of diarrheal disease in humans and animals. Adhesins and enterotoxins, including heat-labile (LT) and heat-stable (STa) toxins, are the key virulence factors. Antigenic adhesin and LT antigens have been used in developing vaccines against ETEC diarrhea. However, STa has not been included because of its poor immunogenicity and potent toxicity. Our recent study showed that porcine-type STa toxoids became immunogenic and elicited neutralizing anti-STa antibodies after being genetically fused to a full-length porcine-type LT toxoid, LTR192G (W. Zhang et al., Infect. Immun. 78: 316-325, 2010). In this study, we mutated human-type LT and STa genes, which are highly homologous to porcine-type toxin genes, for a full-length LT toxoid (LTR192G) and a full-length STa toxoid (STaP13F) and genetically fused them to produce LT192-STa13 toxoid fusions. Mice immunized with LT192-STa13 fusion antigens developed anti-LT and anti-STa IgG (in serum and feces) and IgA antibodies (in feces). Moreover, secretory IgA antibodies from immunized mice were shown to neutralize STa and cholera toxins in T-84 cells. In addition, we fused the STa13 toxoid at the N terminus and C terminus, between the A1 and A2 peptides, and between the A and B subunits of LT192 to obtain different fusions in order to explore strategies for enhancing STa immunogenicity. This study demonstrated that human-type LT192-STa13 fusions induce neutralizing antitoxin antibodies and provided important information for developing toxoid vaccines against human ETEC diarrhea.