Recombinant Attenuated Salmonella Vaccines for Humans

描述(申请人提供)：在过去十年平均每年5700万人的死亡中，约1480万人直接死于传染病，还有数百万人死于感染的继发性影响(65)。每年因感染伤寒沙门氏菌和甲型副伤寒沙门氏菌、乙肝病毒(乙肝)、肺炎链球菌和结核分枝杆菌(Mtb)而死亡的人数差别很大，但可能占总死亡人数的30%左右，由于这些疾病的严重发病率(232)，造成的损失更大。我们相信，改善健康、营养和经济福祉(后者依赖于前两者)是提高全球生活质量、从而减少导致战争和恐怖行为的条件的最佳手段，我们基于我们在使用重组减毒沙门氏菌疫苗(RASV)方面的最新技术发展，提出了一个疫苗开发计划。我们的具体目标是(I)通过增加膜小泡的产生和释放以及通过改变RASV细胞黏附属性来增强对RASV表达的保护性肺炎球菌抗原(作为模型抗原)的粘膜和系统抗体反应的诱导，(Ii)通过确保RASV活毒株在体内特别是在鸟类和动物的肠道中不能持续和/或完全溶解来增强对活RASV毒株的生物遏制，(Iii)设计和构建副伤寒沙门氏菌A作为抗原和DNA疫苗递送载体，具有多种基因指定的特征，以确保用于婴儿和成人免疫时的安全性和有效性，以防止肠道热和其他传染病。以及(Iv)设计、构建和评估重组减毒伤寒沙门氏菌和副伤寒沙门氏菌A疫苗，以通过II型和III型分泌物递送保护性抗原和/或通过体内调节的延迟裂解来防止Mtb感染，其中裂解发生在细胞间以增强MHC第I类或第II类的抗原递呈，并通过调节的细胞质室内的延迟性裂解来释放针对核靶向优化的DNA疫苗，从而导致免疫个体合成和修饰保护性抗原。我们还将添加到我们的主文件中(向FDA提交)，准备并充分描述候选疫苗主种子的稳定性和安全性，准备并提交IRB批准的方案，提交获得IND所需的信息，并执行安排最佳候选疫苗在人类志愿者身上进行临床评估所需的任何其他工作。公共卫生相关性：拟议的研究将进一步开发和完善设计和构建重组减毒沙门氏菌活疫苗(RASV)载体的技术，以在无针口服接种保护性抗原和/或DNA疫苗后提供，以刺激针对细菌、病毒和寄生虫传染病病原体的粘膜、系统和细胞免疫。更具体地说，我们将开发一种安全、有效的甲型副伤寒沙门氏菌疫苗载体，用于新生儿和婴儿的口服免疫。我们将使用这个甲型副伤寒沙门氏菌载体和伤寒沙门氏菌载体构建RASV，以防止结核分枝杆菌的传播和感染。

DESCRIPTION (provided by applicant): Of the average 57 million annual deaths over the past ten years, about 14.8 million are directly due to infectious diseases with millions more due to secondary effects of infections (65). The numbers of annual deaths due to infections by Salmonella Typhi and S. Paratyphi A, hepatitis B virus (HBV), Streptococcus pneumoniae and Mycobacterium tuberculosis (Mtb) vary widely but may account for about 30 percent of the total deaths with an even greater cost being due to the severe morbidity associated with these diseases (232). In the belief that improving health, nutrition and economic well being (the latter dependent on the first two) provides the best means to enhance the quality of life globally and thus reduces conditions that result in warlike and terrorist behavior, we propose a vaccine development program based on our recent technical developments in using recombinant attenuated Salmonella vaccines (RASV). Our Specific Aims are (i) to enhance induction of mucosal and systemic antibody responses to RASV-expressed protective pneumococcal antigens (as a model antigen) by increased production and release of membrane vesicles and by altering RASV cell adherence attributes, (ii) to enhance biological containment of live RASV strains by ensuring inability to persist and/or to completely lyse in vivo and especially in the intestinal tracts of birds and animals, (iii) to design and construct S. Paratyphi A as an antigen and DNA vaccine delivery vector with a diversity of genetically-specified features to ensure safety and efficacy when used to immunize infants and adults to protect against enteric fever and additional infectious diseases, and (iv) to design, construct and evaluate recombinant attenuated S. Typhi and S. Paratyphi A vaccines to prevent infections by Mtb using delivery of protective antigens by Type II and III secretion and/or by regulated delayed lysis in vivo with lysis occurring in cell compartments to enhance antigen presentation either by MHC Class I or Class II and by regulated delayed lysis in vivo in the cytoplasmic compartment to release a DNA vaccine optimized for nuclear targeting leading to synthesis and modification of protective antigens by the immunized individual. We will also add to our Master File (filed with FDA), prepare and fully characterize candidate vaccine Master Seeds for stability and safety, prepare and submit protocols for IRB approvals, submit information necessary to obtain INDs, and perform any other work needed to arrange that the best candidate vaccines be clinically evaluated in human volunteers. PUBLIC HEALTH RELEVANCE: The research proposed will further develop and refine technologies for design and construction of live recombinant attenuated Salmonella vaccine (RASV) vectors to deliver after needle-free oral inoculation protective antigens and/or DNA vaccines to stimulate mucosal, systemic and cellular immunities against bacterial, viral and parasite infectious disease agents. More specifically, we will develop a safe, efficacious S. Paratyphi A vaccine vector for oral immunization of newborns and infants. We will use this S. Paratyphi A vector in addition to an S. Typhi vector to construct RASVs to prevent transmission and infection by Mycobacterium tuberculosis.