Human monoclonal panel mimicking anthrax immune globulin

模拟炭疽免疫球蛋白的人单克隆板

• 批准号: 6998662
• 负责人: Donald C Reason
• 金额: $ 72.24万
• 依托单位: CHILDREN'S HOSPITAL & RES CTR AT OAKLAND
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6998662
• 关键词: Bacillus anthracis; CHO cells; anthrax; antibiotics; enzyme linked immunosorbent assay; immunoglobulins; immunologic substance development /preparation; monoclonal antibody; neutralizing antibody; protein purification; serum; spores; toxin

The mortality rate associated with inhalation anthrax is high, even if antibiotics are administered in a timely manner. Renewed fears that Bacillus anthracis spores may be employed as a biological threat agent have prompted a search for an adjunct therapy that might lower mortality rates in persons known to be exposed. Several lines of evidence suggest that toxin-specific antibodies, acquired either through vaccination or administered passively, work synergistically with antibiotics in post-exposure therapy for inhalation anthrax. We have successfully cloned and expressed the majority of antibodies that comprise the human antibody repertoire specific for the protective antigen (PA) of B. anthracis using B cells from AVA-vaccinated donors. From this collection of fully human, PA-specific monoclonal binding domains, we propose to establish a panel of neutralizing antibodies to be used as an engineered "polyclonal" antibody-based therapeutic to neutralize 8. anthracis toxins. Specifically, we will 1) convert all previously isolated PA-specific antibody clones to a format suitable for expression in eukaryotic systems, 2) identify those paratopes that neutralize toxin in an in vitro cell protection assay, 3) identify a subset of non-competing PA-neutralizing clones, 4) optimize antibody expression both in our bi-cistronic pARC/IRES expression vectors and the established Lonza glutamine synthetase-based antibody expression system. We anticipate a product ready for in vivo testing in an animal model system at the conclusion of the proposed period of support. The PA-specific panel we construct will be molecularly defined and characterized, incorporate the advantages of toxin-specific, polyclonal human sera, and lack the inherent risk associated with blood derived products.

即使及时使用抗生素，与吸入性炭疽相关的死亡率也很高。人们再次担心炭疽芽孢杆菌孢子可能被用作生物威胁剂，这促使人们寻找一种辅助疗法，以降低已知接触者的死亡率。多项证据表明，通过疫苗接种或被动施用获得的毒素特异性抗体在吸入性炭疽暴露后治疗中与抗生素具有协同作用。我们使用来自 AVA 疫苗接种者的 B 细胞成功克隆并表达了大多数抗体，这些抗体包含对炭疽芽孢杆菌保护性抗原 (PA) 具有特异性的人类抗体库。从这个完全人类 PA 特异性单克隆结合域的集合中，我们建议建立一组中和抗体，用作工程化“多克隆”抗体为基础的治疗剂，以中和 8. 炭疽毒素。具体来说，我们将 1) 将所有先前分离的 PA 特异性抗体克隆转化为适合在真核系统中表达的格式，2) 鉴定在体外细胞保护测定中中和毒素的互补位，3) 鉴定非竞争性 PA 中和克隆的子集，4) 优化我们的双顺反子 pARC/IRES 表达载体和已建立的 Lonza 谷氨酰胺中的抗体表达 基于合成酶的抗体表达系统。我们预计在拟议的支持期结束时，产品将准备好在动物模型系统中进行体内测试。我们构建的 PA 特异性面板将进行分子定义和表征，结合毒素特异性、多克隆人血清的优点，并且缺乏与血液衍生产品相关的固有风险。