A MERS-CoV Receptor Decoy

MERS-CoV 受体诱饵

基本信息

批准号：
8981265
负责人：
KEITH WYCOFF
金额：
$ 80.18万
依托单位：
PLANET BIOTECHNOLOGY, INC.
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-06-01 至 2017-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8981265
关键词：
Active Sites Affinity Amino Acids Antibodies Binding Biotechnology Camels Case Fatality Rates Cell Surface Proteins Cells Cessation of life Contracts Coronavirus Coronavirus Infections Coronavirus spike protein Country Development Dipeptidyl Peptidases Dose Drug Kinetics Enzyme-Linked Immunosorbent Assay Evaluation Extracellular Domain Fc Immunoglobulins Glucose Half-Life Health Human Hydrolase IgA1 IgA2 IgG1 Immunoglobulin Isotypes Immunoglobulins Infection Laboratories Lead Link Middle East Middle East Respiratory Syndrome Coronavirus Modeling Mus Mutate Mutation Peptide Hydrolases Phase Physiological Processes Planets Plants Polysaccharides Process Production Protein Binding Protein S Proteins Rattus Recombinant Proteins Route Safety Serum Site Surface Syndrome System Testing Toxicology Variant Virus base coronavirus receptor design efficacy testing epidemiology study improved in vivo inhibitor/antagonist intraperitoneal novel therapeutics pandemic disease phase 1 study phase 2 study protective efficacy public health relevance receptor respiratory scale up transmission process

项目摘要

DESCRIPTION (provided by applicant): Middle East respiratory syndrome coronavirus (MERS-CoV) is a newly emerging human health threat with a ~35% case fatality rate. MERS-CoV uses dipeptidyl peptidase 4 (DPP4), a cell surface protein, to enter and infect cells. During our Phase I study, using a transient plant expression system, we produced fusions of human DPP4 and the human immunoglobulin Fc sequences of IgG1, IgA1 and IgA2, to produce "receptor decoys" to block cellular infection with MERS-CoV. We demonstrated that DPP4-Fc binds to the S1 domain of MERS-CoV S protein, and that DPP4-Fc is a more potent inhibitor of MERS-CoV cellular infection than soluble DPP4. We showed that a DPP4-Fc fusion based on IgA1 might possibly be more effective than one based on IgG1. In addition, we demonstrated that binding and virus neutralization could be improved by more than 10-fold by modifying a single amino acid where human DPP4 and MERS-CoV spike protein contact. DPP4-Fc is also expected to have superior pharmacokinetics, as Fc will confer a long circulating half-life and the ability to be delivered to airway mucosal surfaces, the site of MERS-CoV infection. In a phase II study, we will produce new DPP4-Fc constructs to improve DPP4's affinity for MERS-CoV spike protein, and eliminate DPP4's peptidase activity by mutating the active site. We will optimize new constructs to improve expression in plants and to produce DPP4-Fc with human-like N-linked glycans. New DPP4-Fc fusions will be ranked for MERS-CoV spike protein-binding by ELISA and tested for the ability to neutralize MERS-CoV infection in susceptible cells. The best performing DPP4-Fc variants will be tested for protective efficacy in a mouse MERS model, evaluating both intraperitoneal and intranasal routes of administration. We will scale up production and purification of our lead molecule to purify 7 grams of DPP4-Fc, which will be used for a pilot 2-week repeat-dose safety/toxicology study in rats. We will evaluate safety and quantify DPP4-Fc in serum to obtain pharmacokinetic parameters. We will also screen for anti-DPP4-Fc antibodies in these studies.

描述（由申请人提供）：中东呼吸综合征冠状病毒 (MERS-CoV) 是一种新出现的人类健康威胁，其病死率约为 35%，它使用二肽基肽酶 4 (DPP4)（一种细胞表面蛋白）来抑制病毒。在我们的第一阶段研究中，我们使用瞬时植物表达系统生产了人 DPP4 与 IgG1、IgA1 和人免疫球蛋白 Fc 序列的融合体。 IgA2，产生“受体诱饵”来阻止 MERS-CoV 的细胞感染，我们证明 DPP4-Fc 与 MERS-CoV S 蛋白的 S1 结构域结合，并且 DPP4-Fc 是 MERS-CoV 细胞的更有效的抑制剂。我们证明基于 IgA1 的 DPP4-Fc 融合体可能比基于 IgG1 的融合体更有效。此外，我们还证明了与病毒的结合。通过修饰单个氨基酸，中和作用可以提高 10 倍以上，其中人 DPP4 和 MERS-CoV 刺突蛋白接触也有望具有优异的药代动力学，因为 Fc 将赋予较长的循环半衰期和在 II 期研究中，我们将生产新的 DPP4-Fc 构建体，以提高 DPP4 对 MERS-CoV 刺突的亲和力。蛋白，并通过突变活性位点消除 DPP4 的肽酶活性。我们将优化新的构建体，以提高在植物中的表达，并生产具有类人 N 连接聚糖的 DPP4-Fc。新的 DPP4-Fc 融合体将针对 MERS-CoV 进行排序。通过 ELISA 进行刺突蛋白结合，并测试中和易感细胞中的 MERS-CoV 感染的能力，将在小鼠 MERS 模型中测试表现最佳的 DPP4-Fc 变体的保护功效，我们将评估腹膜内和鼻内给药途径，扩大我们的先导分子的生产和纯化，以纯化 7 克 DPP4-Fc，将其用于大鼠的为期 2 周的重复剂量安全性/毒理学试验研究。我们将评估安全性并量化血清中的 DPP4-Fc 以获得药代动力学参数。我们还将在这些研究中筛选抗 DPP4-Fc 抗体。