Broad spectrum enteropathogen vaccine development

该提案的总体目标是构建一种疫苗，广泛保护多种 肠道病原体对美国人口的公共卫生重要性。这些肠道病原体包括 志贺菌属（包括S. Escheriae 1，一种生物恐怖威胁剂）、肠毒素E.大肠杆菌（ETEC）（主要 引起旅行者腹泻）和新出现的病原体滋贺毒素产生E。大肠杆菌（STEC）（主要原因 溶血性尿毒综合征（HUS）和肠聚集性E.大肠杆菌（EAEC）（最近被认为是 在美国是小儿腹泻病的重要病原体）。这些肠道病原体均为B类风险 生物防御相关的特工针对这一群体的广泛覆盖的疫苗将有利于 美国人口的多个部分，包括：1）访问欠发达国家的成人和儿童旅行者 这些感染高流行的国家; 2）美国某些地区的儿童; 3） 在面对蓄意的生物恐怖活动时，大规模免疫接种传播了大多数病原体。免疫 通过粘膜途径是诱导粘膜和全身免疫应答的有效方法， 被认为是重要的保护对这些肠道病原体。第一次MARGE期间的研究 资金周期揭示了我们的减毒活S.表达Stx 1 B以 在动物模型中诱导高滴度Stx 1中和抗体。细菌1 LPS特异性 这些抗体对于预防链球菌1型疾病至关重要。抗毒素的诱导， 中和Stx 1提示了赋予针对其它表达滋贺毒素的病原体的保护的潜力 例如STEC。在本申请中，我们建议扩展我们的多价活的 表达STEC和EAEC保护性抗原的载体肠疫苗。以理性的方式 Stx 1和Stx 2的滋贺毒素B亚基、嵌合类毒素Stx 2 A1 B和保护性AAF/II 来自EAEC的菌毛抗原将在减毒的S. acidteriae 1和S.福氏 血清型3a和6使用新的ssb稳定的质粒系统，最佳活载体-抗原配置 将评价在兔模型中对STEC感染的保护或对细胞结合的抑制， EAEC形成生物膜。结合正在进行的志贺氏菌-ETEC疫苗构建， 将研制出肠道病原体疫苗。

The overall goal of this proposal is to construct a vaccine that is broadly protective against multiple enteropathogens of public health importance to the U.S. population. These enteropathogens include Shigella (including S. dysenteriae 1, a bioterror threat agent), enterotoxigenic E. coli (ETEC) (the major cause of traveler's diarrhea) and the emerging pathogens shiga toxin producing E. coli (STEC) (main cause of hemolytic uremic syndrome, HUS) and enteroaggregative E. coli (EAEC) (recently recognized as an important agent of pediatric diarrheal disease in the U.S.A). These enteropathogens are all Category B risk agents of biodefense concern. A vaccine with broad coverage against this group would be beneficial to multiple segments of the US population, including: 1) adult and child travelers who visit less developed countries where these infections are hyperendemic; 2) children in certain areas high risk areas of the US; 3) and for mass immunization in the face of deliberate bioterror spread most of these pathogens. Immunization by the mucosal route is an effective method for induction of mucosal and systemic immune responses, believed to be important in protection against these enteropathogens. Studies during the first MARGE funding cycle revealed the ability of our live attenuated S. dysenteriae 1 vaccine strain expressing Stx1 B to induce high titer Stx1 neutralizing antibodies in an animal model, in addition to S. dysenteriae 1 LPS specific antibodies that are critical for protection against S dysenteriae 1 disease. The elicitation of antitoxin that neutralizes Stx1 suggests the potential to confer protection against other Shiga toxin expressing pathogens such as STEC. In this application we propose to extend the spectrum of coverage of our multivalent live vector enteric vaccine by expressing protective antigens from STEC and EAEC. In a rational step-wise manner, Shiga toxin B subunits from Stx1 and Stx2, a chimeric toxoid Stx2A1B, and the protective AAF/II fimbrial antigen from EAEC will be engineered in attenuated derivatives of S. dysenteriae 1, and S. flexneri serotypes 3a and 6 using a novel ssb-stabilized plasmid system, Optimal live vector-antigen configurations will be evaluated for protection against STEC infection in a rabbit model or inhibition of cell binding and biofilm formation by EAEC. Combined with ongoing Shigella-ETEC vaccine constructions, a tetravalent enteropathogen vaccine will be developed.