Development of an Adhesin-Toxoid Chimera Vaccine for Enterotoxigenic E. coli

针对产肠毒素大肠杆菌的粘附素-类毒素嵌合疫苗的开发

• 批准号: 7270453
• 负责人: Stephen J Savarino
• 金额: $ 55.07万
• 依托单位: HENRY M. JACKSON FDN FOR THE ADV MIL/MED
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-05 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7270453
• 关键词: A Mouse; Adherence; Adhesives; Adopted; Animals; Antigens; Aotus primate; Bacterial Adhesins; Binding; Biochemical; Biological Products; Bioterrorism; Categories; Cebidae; Child; Chimera organism; Chimeric Proteins; Cholera Toxin Protomer B; Class; Combined Vaccines; Complement; Country; Critical Pathways; Cyclic GMP; Development; Diarrhea; Disease; Dose; Engineering; Enterotoxins; Evaluation; Fermentation; Fimbria of hippocampus; Fimbrial Adhesins; Food; Genes; Goals; Head; Heating; Human; Immune response; Immunity; Immunization; Immunodominant Epitopes; In Vitro; Intestines; Knowledge; Lead; Length; Licensing; Life; Methods; Military Personnel; Minor; Modeling; Monkeys; Mus; Needles; Oral; Oral Administration; Phase I Clinical Trials; Pilum; Process; Production; Public Health; Purpose; Relative (related person); Research Personnel; Resources; Safety; Security; Thermogenesis; Toxoids; Vaccines; Variant; Work; base; colonization factor antigens; design; design and construction; enterotoxigenic Escherichia coli; foodborne; human subject; immunogenic; immunogenicity; inhibiting antibody; nonhuman primate; pathogen; pre-clinical; programs; prototype; receptor binding; scaffold; scale up; waterborne

Project Summary. Enterotoxigenic E. coli (ETEC) is a food and waterborne pathogen that constitutes a bioterrorism and public health threat of global proportion for which no vaccine exists. We propose to develop an adhesin-toxoid chimera vaccine, exploiting the previous work of the partners on each of the two components. We have shown the feasibility of genetically combining genes to express a protein chimera consisting of the binding (B) subunit of cholera toxin and a fusion of CfaE, the minor adhesive subunit of colonization factor antigen I (CFA/I), to the CT A2 anchoring domain (where the adhesin replaces the toxic enzymatic domain of the CT A subunit). This chimera elicits strong humoral immune responses upon mucosal immunization of mice, and antibodies inhibit ETEC adherence in vitro. Our aims are to optimize the CfaE-CTA2/CTB chimera construct for maximal stability and antigenicity. The corresponding CfaE-A2/heat- labile enterotoxin (LT) B subunit chimera will then be made and compared to CfaE-A2/CTB in head-to-head immunogenicity studies in mice for purposes of downselection to the more immunogenic prototype chimera. This lead chimera vaccine component will be evaluated in non-human primates to determine a suitable dose and then to determine its protective efficacy using a monkey oral ETEC challenge model. Guided by these results, two additional sub-aims will be pursued. Using the optimized adhesin-toxoid scaffold, we will develop chimeras with two other ETEC fimbrial adhesins that together with CfaE would constitute a multivalent vaccine to confer broad-based protection. We will also scale up production processes and bring the lead CfaE-toxoid chimera through one campaign of cGMP manufacturing to lay the groundwork for preclinical and Phase I clinical trials in human subjects. Relevance. ETEC causes dehydrating diarrhea and poses a triple threat to potential victims of food bioterrorism, to military and civilian travelers, and to young children in resource-limited countries. This proposal aims to develop a vaccine that combines intestinal adhesins and a nontoxic component of the heat-labile enterotoxin (LT). Related forms of these two antigens have been shown to confer protection against disease in experimental settings. We posit that their combination into a single delivery module for oral administration will constitute a safe, effective vaccine for needle free, oral delivery.

项目摘要。产肠毒素大肠杆菌 (ETEC) 是一种食物和水源性病原体，构成 生物恐怖主义和全球性的公共卫生威胁，目前尚无疫苗可应对。我们建议开发 一种粘附素-类毒素嵌合疫苗，利用了合作伙伴之前对这两种疫苗的研究成果 成分。我们已经证明了通过基因组合基因来表达蛋白质嵌合体的可行性 由霍乱毒素的结合 (B) 亚基和 CfaE 的融合体组成，CfaE 是霍乱毒素的次要粘附亚基 定植因子抗原 I (CFA/I)，连接至 CT A2 锚定结构域（其中粘附素取代了有毒的 C A 亚基的酶结构域）。这种嵌合体在以下情况下引发强烈的体液免疫反应 小鼠粘膜免疫，抗体在体外抑制 ETEC 粘附。我们的目标是优化 CfaE-CTA2/CTB 嵌合体构建体具有最大的稳定性和抗原性。相应的CfaE-A2/heat- 然后将制备不稳定肠毒素 (LT) B 亚基嵌合体，并与 CfaE-A2/CTB 进行头对头比较 在小鼠中进行免疫原性研究，目的是向下选择更具免疫原性的原型嵌合体。 该主要嵌合体疫苗成分将在非人类灵长类动物中进行评估，以确定合适的剂量 然后使用猴子口服 ETEC 攻击模型来确定其保护功效。在这些指导下 结果，将追求另外两个子目标。使用优化的粘附素类毒素支架，我们将 与另外两种 ETEC 菌毛粘附素开发嵌合体，与 CfaE 一起构成 多价疫苗可提供广泛的保护。我们还将扩大生产流程并带来 通过一项 cGMP 生产活动，开发出领先的 CfaE-类毒素嵌合体，为 在人类受试者中进行临床前和 I 期临床试验。关联。 ETEC 会导致脱水性腹泻 对食品生物恐怖主义的潜在受害者、军事和平民旅行者以及年轻人构成三重威胁 资源有限国家的儿童。该提案旨在开发一种结合肠道的疫苗 粘附素和不耐热肠毒素 (LT) 的无毒成分。这两种抗原的相关形式 在实验环境中已被证明可以提供针对疾病的保护作用。我们假设他们的 组合成单一的口服给药模块将构成一种安全、有效的疫苗 无针、口服给药。