Development of a vaccine for Ebola virus in plant system

描述（由申请人提供）：尽管埃博拉病毒是世界上最可怕的病原体之一，但目前还没有预防埃博拉病毒感染的疫苗。本文提出的研究将推进候选疫苗的开发，重点是开发用于临床前试验的试点疫苗的技术，以及利用转基因植物安全生产战略疫苗储备的节省成本的扩大能力。拟议的研究利用植物细胞表达和积累复杂蛋白质的能力，这是目前无法通过其他表达系统获得的。这项研究建立在国防部正在进行的一项资金投资的基础上，该投资旨在创造一种单克隆抗体（mab）的“鸡尾酒”，用于埃博拉病毒感染的暴露后预防；国防部项目采用转基因植物，因为植物来源的单克隆抗体可以迅速扩大商业生产，而无需对传统的单克隆抗体生产设施进行高资本成本投资。最近的研究表明，在植物细胞中表达的单克隆抗体可以作为抗原蛋白结构域的融合分子，作为抗体重链恒定区c端延伸。当单克隆抗体的可变区识别融合分子的抗原区时，形成高免疫原性重组免疫复合物（RICs）。我们将利用三种不同的单克隆抗体创建含有埃博拉病毒糖蛋白（GP）序列和GP融合物的RICs。原型疫苗的生产数量将足以进行临床前试验。该申请的工业界参与者将开发注射疫苗的纯化技术。现有的小鼠模型将用于免疫原性和激发试验，随后将对主要候选疫苗进行非人灵长类动物疫苗评估。

DESCRIPTION (provided by applicant): There are no vaccines to prevent infections by Ebola virus, although it is among one of the most feared pathogens worldwide. The research proposed herein will advance development of vaccine candidates, with emphasis on technology that will create pilot lots of vaccine for preclinical testing and cost-saving scale-up capability using transgenic plants for safe production of strategic vaccine reserves. The proposed research exploits the facile capacity of plant cells to express and accumulate complex proteins that are not currently available via other expression systems. The research builds upon an ongoing funding investment by DoD directed to the creation of a "cocktail" of monoclonal antibodies (MAbs) to use in post-exposure prophylaxis for Ebola virus infections; the DoD project utilizes transgenic plants because plant-derived MAbs can be rapidly expanded in commercial production without high-capital cost investments for traditional MAb production facilities. Recent research has shown that MAbs expressed in plant cells can be created as fusion molecules with antigenic protein domains as a C-terminal extension of the constant region of the antibody heavy chain. Highly immunogenic recombinant immune complexes (RICs) form when the variable region of the MAb recognizes the antigenic region of the fusion molecule. We will utilize three different MAbs to create RICs containing the sequences of the Ebola virus glycoprotein (GP) as well as GP fusions. Prototype vaccines will be produced in quantities sufficient for preclinical trials. Industrial participants of the application will develop purification technology for injected vaccines. An existing murine model will be utilized for immunogenicity and challenge trials, which will be followed by non-human primate vaccine evaluation of the lead vaccine candidates.