Oral Immunization Against Malaria with Recombinant Adenoviruses

用重组腺病毒口服免疫疟疾

• 批准号: 7648323
• 负责人: Gary W Ketner
• 金额: $ 62.28万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2009-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7648323
• 关键词: Adenovirus hexon capsid protein; Adenoviruses; Africa South of the Sahara; Animal Model; Animals; Antibodies; Antigens; Aotus primate; Biological Models; Canis familiaris; Capsid; Capsid Proteins; Cells; Cessation of life; Child; Condition; Dose; Economic Burden; Economic Development; Epitopes; Erythrocytes; Evaluation; Facility Construction Funding Category; Fiber; Foundations; Gene Expression; Genes; Genetic; Goals; Growth; Healthcare; Human; Human Adenoviruses; Human Papillomavirus; Immune response; Immunity; Immunization; Immunization Programs; In Vitro; Infection; Laboratories; Licensing; Life; Liver; Location; Macaca; Malaria; Malaria Vaccines; Measures; Mediating; Modeling; Monkeys; Morbidity - disease rate; Mus; Oral; Papillomavirus; Peptides; Plasmodium; Plasmodium falciparum; Primates; Production; Property; Proteins; Public Health; Range; Recombinant Vaccines; Recombinants; Research Infrastructure; Resources; Simulate; Sporozoites; Staging; Structure; Surface; System; Testing; Ursidae Family; Vaccines; Viral; base; cell mediated immune response; circumsporozoite protein; cost; design; experience; immunogenic; immunogenicity; killings; mortality; mutant; neutralizing antibody; novel; particle; research study; response; tissue culture

Malaria kills more than one million people each year. Most malaria deaths occur in sub-Saharan Africa and most of the victims are children under five. An effective, affordable vaccine could greatly reduce the morbidity, mortality, and economic burden imposed by malaria. This proposal will investigate one approach to such a vaccine. The immunization approach that we will explore is modeled on existing programs for immunization against human adenoviruses and will employ live recombinant derivatives of adenovirus vaccine strains that have been used safely and effectively for over three decades. These vaccines are administered orally, are protective in one dose, and are relatively inexpensive to produce, making them promising for use in resource-poor locations that lack strong health-care infrastructures. Recombinants will express two pre-erythrocytic Plasmodium falciparum antigens that induce immunity in animals: circumsporozoite protein (CSP) and liver stage antigen 3 (LSA-3). These antigens will be produced by a novel system developed in this laboratory for high-level expression of genes inserted into the adenovirus major late transcriptional unit (MLTU recombinants), or in the form of fusions with major viral capsid proteins designed to display malaria antigenic determinants on the surface of the recombinant particles (capsid display recombinants). We have extensive experience with viable recombinants that abundantly express human and canine papillomavirus L1 genes from the MLTU and have prepared capsid display recombinants that bear antigenic epitopes of the P. falciparum CSP and HPV L2 proteins. The L1 protein produced by MLTU recombinants assembles into VLPs that induce antibodies in mice, and capsid display recombinant particles expressing CSP or HPV L2 induce neutralizing antibody to malaria sporozoites and HPV, respectively. We will prepare recombinants expressing CSP and LSA-3 that are analogous to existing L1 MLTU recombinants, and a range of CSP capsid display recombinants with varying structures. The recombinants will be characterized in vitro for antigen production and growth properties and then evaluated in two animal model systems for immunogenicity and protective efficacy. Capsid display mutants will first be examined in mice for their ability to induce antibody and protect against a sporozoite challenge and optimal constructs will be identified. Promising capsid display recombinants identified in mice and MLTU recombinants selected for desirable properties in tissue culture then will be assessed for the ability to induce humoral and cell-mediated immune responses in a permissive primate model. We will also attempt to develop a primate model in which protection from experimental challenge can be determined, and will measure protective efficacy if that effort is successful. These studies will provide information that can be used to prepare live recombinant vaccines that express malaria antigens for use in human trials.

疟疾每年杀死100万人。大多数疟疾死亡发生在撒哈拉以南 非洲和大多数受害者是五岁以下的儿童。有效，负担得起的疫苗可以大大减少 疟疾施加的发病率，死亡率和经济负担。该提议将调查一个 这种疫苗的方法。我们将要探索的免疫方法是根据现有的 针对人类腺病毒的免疫计划，并将采用活的重组衍生物 腺病毒疫苗菌株已安全有效地使用了三十年。这些 疫苗是口服施用的，一个剂量的保护性，生产相对便宜， 使他们有望在缺乏强大医疗保健基础设施的资源贫乏的地点使用。 重组者将表达两个诱导的肠细胞前疟原虫恶性疟原虫抗原 动物的免疫力：外孢子岩蛋白（CSP）和肝脏抗原3（LSA-3）。这些抗原会 由在该实验室开发的新系统生产，用于插入的基因的高级表达 腺病毒主要的晚期转录单元（MLTU重组），或以主要病毒的融合形式 衣壳蛋白旨在在重组表面上显示疟疾抗原决定因素 颗粒（衣壳显示重组者）。我们拥有可行的重组者的丰富经验 从MLTU表达大量的人类和犬乳头瘤病毒L1基因，并制备了capsid 显示出恶性疟原虫CSP和HPV L2蛋白的抗原表位的重组。 L1 由MLTU重组产生的蛋白质聚集成诱导小鼠抗体的VLP，capsid 显示表达CSP或HPV L2的重组颗粒诱导对疟疾的中和抗体 Sporozoites和HPV。我们将准备表达CSP和LSA-3的重组者 类似于现有的L1 MLTU重组剂，以及一系列CSP CAPSID显示重组剂，具有不同 结构。重组剂将在体外表征用于抗原生产和生长特性，以及 然后在两个动物模型系统中评估免疫原性和保护功效。衣壳显示 将首先在小鼠中检查突变体，以诱导抗体并预防孢子虫。 将确定挑战和最佳结构。在小鼠中鉴定出的有希望的衣壳显示重组者 然后，将评估选择用于组织培养的理想特性的MLTU重组因素。 在宽松的灵长类动物模型中诱导体液和细胞介导的免疫反应的能力。我们也会 尝试开发一种灵长类动物模型，在该模型中可以确定可以保护免受实验挑战的保护，并且 如果这项努力成功，将衡量保护效果。这些研究将提供可能是 用于制备表达疟疾抗原的活疫苗用于人类试验。