HOST RANGE DIVERSITY OF BACTERIOPHAGE FOR Y. PESTIS

鼠疫杆菌噬菌体的宿主范围多样性

• 批准号: 7107657
• 负责人: David William Martin
• 金额: $ 49.5万
• 依托单位: AVIDBIOTICS CORPORATION
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7107657
• 关键词: bacteria; bacterial virus

DESCRIPTION (provided by applicant): Yersinia pestis, the bacterium responsible for plague, is a Category A pathogen, a significant biowarfare agent. If weaponized, it can easily gain direct access to the respiratory system to cause rapid death by pneumonic plague. Pneumonic plague has fatality rates over 50%, is highly contagious, and if the bacteria are engineered to resist antibiotics, is essentially unbeatable. As a countermeasure to such a threat, we propose to develop a library of bacteriophages ("phages") specific for Y. pestis that can kill multiple strains of this bacterium in a highly efficient manner. AvidBiotics has exclusive access to technology to generate families of phage with highly diverse tails capable of binding to mutant forms of bacteria, such as Bordetella. In this application, we propose to develop a library of phage to bind to, infect and kill mutant Y. pestis bacteria, anticipating potential mutations engineered into the bacteria to change their sensitivities to antibiotics or surface receptors for phage. This technology is based on the discovery of a family of diversity-generating retroelements (DGRs) that function to vary DNA sequences and the proteins they encode. These DGRs can be engineered into phages to diversify specifically the amino acid sequence of the precise receptor-binding site of the phage tail fiber, thereby generating a library of phages with more than a trillion different possible tails targeting Y. pestis cell surface receptors. By exposing such a phage library to mutant or weaponized plague bacteria, phages capable of infecting, multiplying and killing the bacteria could be identified, selected, isolated, amplified, aerosolized and then deployed to protect against or treat infections by weaponized Y. pestis. The objective of this application is to demonstrate the ability to utilize the DGR-system to precisely and extensively diversify the phage tail fiber sequences as a means to create novel phage with broad Y. pestis tropism. These studies will provide the foundation for future studies to generate a suitable, formulated pool of highly diverse phages that will serve as a reliable, productive source of diagnostic and therapeutic agents effective against weaponized plague bacteria. We anticipate that a Phase II follow-on project would entail developing a process to GLP manufacture and formulate representative members of the diverse phage library targeting Y. pestis and conduct pre-clinical safety studies to prepare a rapid response counter- terrorism system to manage pneumonic plague in humans.

描述（由申请人提供）：鼠疫耶尔森氏菌是造成鼠疫的细菌，是 A 类病原体，是一种重要的生物战剂。如果武器化，它可以很容易地直接进入呼吸系统，导致肺鼠疫迅速死亡。肺鼠疫的死亡率超过 50%，具有高度传染性，如果细菌经过改造可以抵抗抗生素，则基本上是不可战胜的。作为应对这种威胁的对策，我们建议开发一个针对鼠疫耶尔森氏菌的噬菌体库（“噬菌体”），它可以高效地杀死该细菌的多种菌株。 AvidBiotics 拥有独家技术，可生成具有高度多样化尾部的噬菌体家族，这些噬菌体家族能够与突变型细菌（如博德特氏菌）结合。在此应用中，我们建议开发一个噬菌体库来结合、感染和杀死突变的鼠疫耶尔森氏菌，并预测细菌中可能发生的突变，以改变它们对抗生素或噬菌体表面受体的敏感性。该技术基于一系列多样性生成逆转录元件 (DGR) 的发现，这些逆转录元件的作用是改变 DNA 序列及其编码的蛋白质。这些 DGR 可以被工程化到噬菌体中，以特异性地使噬菌体尾部纤维的精确受体结合位点的氨基酸序列多样化，从而生成一个噬菌体文库，其中包含超过一万亿种可能的针对鼠疫耶尔森氏菌细胞表面受体的不同尾部。通过将这样的噬菌体库暴露于突变型或武器化鼠疫细菌，能够感染、繁殖和杀死细菌的噬菌体可以被鉴定、选择、分离、扩增、雾化，然后用于预防或治疗武器化鼠疫耶尔森氏菌的感染。本应用的目的是展示利用 DGR 系统精确且广泛地多样化噬菌体尾部纤维序列的能力，作为创建具有广泛鼠疫耶尔森氏菌向性的新型噬菌体的手段。这些研究将为未来的研究奠定基础，以产生合适的、高度多样化的噬菌体库，作为有效对抗武器化鼠疫细菌的诊断和治疗剂的可靠、高效的来源。我们预计第二阶段的后续项目将需要开发一个 GLP 生产工艺，并制定针对鼠疫杆菌的多样化噬菌体库的代表性成员，并进行临床前安全研究，以准备一个快速反应反恐系统来管理肺炎人类中的瘟疫。