Monoclonal Antibodies in Biodefense: Ebola Viruses

描述（由申请人提供）：已证明抗体被动免疫可预防影响人类的各种病毒、细菌、真菌和寄生虫病。实际上，有效的抗体生物活性剂在军事上是需要的，以保护免受武器化的生物战剂和具有生物战潜力的其他人类病原体的侵害。本提案提供了建立保护性人单克隆抗体（Mab）的发现和GMP生产工艺的机制。这一过程可以很容易地适用于其他生物战剂，并用于应对新出现和重新出现的病原体。该提案将重点关注埃博拉病毒（EBOV）的人类单克隆抗体免疫治疗。目前没有针对EBOV的疫苗或疗法。该提案中开发的单克隆抗体可在GMP条件下在工厂中生产，用作预防性对策，为军事人员或平民提供立即和持续的（人IgG血清半衰期约3周）保护，也可能具有暴露后预防和/或治疗价值。第一个目的是使用两种互补技术鉴定一组针对EBOV的新型人单克隆抗体。一种是从血清阳性的幸存者中分离出单克隆抗体，另一种是针对在自然人类感染中可能不是免疫原性或免疫显性的表位产生一组不同的单克隆抗体。在第二个目的中，新的Mab将在快速植物表达系统中表达为具有来自不同动物物种的恒定区的多种同种型，其中EBOV模型是可用的。在第三个目标中，将确定抗原特异性、抗体同种型和抗体来源种类的作用，以使用埃博拉病毒感染的体外、鼠和猕猴模型进行预防和治疗。在最终目标中，将选择最佳Mab用于在玉米中启动GMP生产。由于免疫治疗药物可能需要以数百万剂量储存，因此这些产品必须廉价且大量生产。植物生产比哺乳动物细胞培养生产便宜得多，每英亩玉米可以生产公斤数量的单克隆抗体。植物生产可以通过简单地在更多的耕地上种植种子，以当前的农艺实践来廉价地扩大规模，以满足库存需求。

DESCRIPTION (provided by applicant): Passive immunization with antibodies has been shown to prevent a wide variety of viral, bacterial, fungal, and parasitic diseases that affect humans. Indeed, effective antibody prophylactics are in military demand for protection against weaponized biowarfare agents and other human pathogens with biowarfare potential. This proposal provides the mechanism for establishing a process for the discovery and GMP manufacture of protective human monoclonal antibodies (Mabs). This process can readily be adapted to other biowarfare agents and used to respond to emerging and re-emerging pathogens. This proposal will focus on human Mab immunotherapeutics for the Ebola viruses (EBOVs). There are currently no vaccines or therapies for EBOVs. Mabs developed in the proposal can be produced under GMP conditions in plant for use as prophylactic countermeasures, providing immediate and sustained (human IgG serum half-life ~ 3 weeks) protection of military personnel or civilians, and may also have value in post-exposure prophylaxis and/or therapy. The first aim is to identify a panel of novel human Mabs against EBOVs using two complementary techniques. One isolates Mabs from seropositive survivors and the other generates a diverse panel of Mabs against epitopes that may not be immunogenic or immunodominant in natural human infection. In the second aim, the novel Mabs will be expressed in a rapid plant expression system as a variety of isotypes with constant regions from the different animal species for which EBOVs models are available. In the third aim, the role of antigen specificity, antibody isotype and antibody species of origin will be determined for prophylaxis and therapy using in vitro, murine, and macaque models of Ebola infection. In the final aim, the best Mab(s) will be selected for initiation of GMP production in corn. Since immunotherapeutics may need to be stockpiled in millions of doses, these products must be manufactured inexpensively and in large quantities. Plant production is dramatically cheaper than mammalian cell culture production and kilogram quantities of Mab can be produced per acre of corn. Production in plants can be inexpensively scaled-up to meet stockpile needs by simply planting seed on more farmed acres of land with current agronomic practices.