A plant-based oral vaccine to protect against systemic intoxication by Shiga toxin type 2.
A plant-based oral vaccine to protect against systemic intoxication by Shiga toxin type 2.
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DOI：
10.1073/pnas.0510843103
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发表时间：
2006-05
影响因子：
11.1
通讯作者：
Sharon X Wen;L. Teel;Nicole A. Judge;A. O’Brien
中科院分区：
文献类型：
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作者：
Sharon X Wen;L. Teel;Nicole A. Judge;A. O’Brien
溶血性尿毒综合征是儿童肾衰竭的主要原因，通常在肠出血性大肠杆菌感染后发生，并由这些菌株产生的滋贺型毒素，特别是2型（Stx 2）介导。预防这种危及生命的综合征的挑战是刺激感染部位的免疫应答，同时还保护远端部位（如肾脏）免受滋贺中毒。作为应对这一挑战的一种方法，我们试图开发和表征针对Stx 2（一种AB 5毒素）的原型口服递送的基于植物的疫苗。首先，我们遗传失活Stx 2活性A亚基基因，然后优化两个亚基基因在植物中的表达。然后通过根癌农杆菌介导的转化将类毒素基因转化到烟草（Nicotiana tabacum）细胞系NT-1中。在NT-1细胞提取物中检测到类毒素表达，并证实了全类毒素的组装。最后，通过用表达类毒素的NT-1细胞喂养或通过肠胃外免疫随后口服疫苗接种（初免-加强策略）来免疫小鼠。免疫小鼠产生Stx 2特异性粘膜伊加和Stx 2中和性血清IgG。通过用E. coli O 91：H21菌株B2 F1，一种产生Stx 2的可激活变体（Stx 2d）并对小鼠致死的分离物。口服免疫完全保护小鼠免受攻击。这项研究的结果表明，植物为基础的口服疫苗可以提供保护，防止致命的全身中毒。
Hemolytic uremic syndrome, the leading cause of kidney failure in children, often follows infection with enterohemorrhagic Escherichia coli and is mediated by the Shiga type toxins, particularly type 2 (Stx2), produced by such strains. The challenge in protecting against this life-threatening syndrome is to stimulate an immune response at the site of infection while also protecting against Shiga intoxication at distal sites such as the kidney. As one approach to meeting this challenge, we sought to develop and characterize a prototypic orally delivered, plant-based vaccine against Stx2, an AB5 toxin. First, we genetically inactivated the Stx2 active A subunit gene and then optimized both subunit genes for expression in plants. The toxoid genes were then transformed into the Nicotiana tabacum (tobacco) cell line NT-1 by Agrobacterium tumefaciens-mediated transformation. Toxoid expression was detected in NT-1 cell extracts, and the assembly of the holotoxoid was confirmed. Finally, mice were immunized by feeding with the toxoid-expressing NT-1 cells or by parenteral immunization followed by oral vaccination (prime-boost strategy). The immunized mice produced Stx2-specific mucosal IgA and Stx2-neutralizing serum IgG. The protective efficacy of these responses was assessed by challenging the immunized mice with E. coli O91:H21 strain B2F1, an isolate that produces an activatable variant of Stx2 (Stx2d) and is lethal to mice. The oral immunization fully protected mice from the challenge. Results of this study demonstrated that a plant-based oral vaccine can confer protection against lethal systemic intoxication.