Monoclonal Antibodies in Biodefense: Ebola Viruses

描述（由申请人提供）：抗体被动免疫已被证明可以预防多种影响人类的病毒、细菌、真菌和寄生虫疾病。事实上，有效的抗体预防是军事需求，以防止武器化的生物战剂和其他具有生物战潜力的人类病原体。该建议为建立保护性人单克隆抗体（mab）的发现和GMP生产过程提供了机制。这一过程可以很容易地适用于其他生物战制剂，并用于应对新出现和再出现的病原体。该提案将侧重于埃博拉病毒（ebov）的人单抗免疫疗法。目前还没有针对埃博拉病毒的疫苗或治疗方法。该方案开发的单克隆抗体可在GMP条件下在植物中生产，作为预防措施，为军事人员或平民提供即时和持续的（人IgG血清半衰期~ 3周）保护，也可能在暴露后预防和/或治疗中具有价值。第一个目标是利用两种互补技术鉴定一组新的抗埃博拉病毒的人单克隆抗体。一种方法从血清阳性幸存者中分离单克隆抗体，另一种方法产生针对自然人类感染中可能不具有免疫原性或免疫优势的表位的多种单克隆抗体。在第二个目标中，新的单克隆抗体将在一个快速的植物表达系统中作为具有恒定区域的各种同型表达，这些同型来自不同的动物物种，其中ebov模型可用。在第三个目标中，将利用体外、小鼠和猕猴埃博拉感染模型确定抗原特异性、抗体同型和抗体来源种类在预防和治疗中的作用。在最终目标中，将选择最佳的单抗用于玉米的GMP生产。由于免疫疗法可能需要储存数百万剂，因此这些产品必须以低廉的价格大量生产。植物生产比哺乳动物细胞培养生产要便宜得多，每英亩玉米可以生产公斤数量的单克隆抗体。只需在现有的农艺做法下种植更多耕作面积的土地上播种，就可以以低廉的成本扩大植物产量，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.