Broad spectrum enteropathogen vaccine development

这项提议的总体目标是构建一种广泛预防多发性肺炎的疫苗。 对美国人口具有重要公共卫生意义的肠道病原体。这些肠道病原体包括 志贺氏菌(包括生物恐怖威胁因子志贺氏菌1)、产肠毒素大肠杆菌(ETEC)(主要 旅行者腹泻的原因)和产生大肠杆菌的新病原体志贺毒素(STEC)(主要原因 溶血性尿毒症综合征(HUS)和肠聚集性大肠杆菌(EAEC)(最近被认为是一种 美国儿科腹泻病的重要病原体)。这些肠道病原体都是B类风险 关注生物防御的特工。针对这一群体的广泛覆盖的疫苗将有益于 美国人口的多个部分，包括：1)访问欠发达地区的成人和儿童旅行者 这些感染是高度流行的国家；2)美国某些地区高危地区的儿童；3) 而在大规模免疫的情况下，面对故意传播这些病原体的生物恐怖活动。免疫接种 通过粘膜途径是一种有效的诱导粘膜和全身免疫反应的方法， 被认为在预防这些肠道病原体方面很重要。第一次行军中的学习 资金周期显示我们的表达STX1B的减毒沙门氏菌1型疫苗株有能力 在一种动物模型中诱导高滴度的STX1中和抗体，以及对沙门氏菌1型脂多糖的特异性 对于预防S痢疾1号疾病至关重要的抗体。抗毒素的诱导性 中和STX1表明有可能对其他志贺毒素表达的病原体产生保护作用 例如STEC。在此应用程序中，我们建议扩展我们的多价直播的覆盖范围 表达STEC和EAEC保护性抗原的肠道疫苗载体。理性地循序渐进 STX1和Stx2志贺毒素B亚基、嵌合类毒素Stx2A1B和保护性AAF/II 来自EAEC的菌毛抗原将在沙门氏菌1号和福氏沙门氏菌的减毒衍生物中进行工程 使用新的SSB稳定的质粒系统的3a和6型血清，最佳活载体-抗原配置 将在兔模型中评估对STEC感染的保护或对细胞结合的抑制 EAEC生物被膜的形成。结合正在进行的志贺氏菌-ETEC疫苗构建，一种四价 将开发肠道病原体疫苗。

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.