Function/optimization of a nematicidal Cry toxin arsenal

杀线虫 Cry 毒素库的功能/优化

• 批准号: 6868472
• 负责人: RAFFI V AROIAN
• 金额: $ 30.84万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6868472
• 关键词: Caenorhabditis elegans; anthelmintics; bacterial toxins; drug screening /evaluation; endotoxins; hamsters; insecticide biological effect; insecticides; laboratory mouse; laboratory rat; protein isoforms; protein structure function

DESCRIPTION (provided by the applicant): Bacillus thuringiensis (Bt) crystal (Cry) proteins have been used for decades to kill insect pests, including mosquitoes and black flies that transmit human diseases. Cry proteins related to those that kill insects have now been discovered to kill nematodes, although they are not currently used for nematode control. Cry proteins are non-toxic to mammals, making them excellent choices as insecticides and potentially as nematicides. Nematicidal Cry proteins intoxicate a wide range of nematodes, including C. elegans and two mammalian parasitic nematodes that infect the intestine. Intestinal nematodes infect over 1/4 of the human population making them an important medical target for Cry proteins. This application proposes to take advantage of the excellent tools available with C. elegans to study in depth how Cry proteins function, how resistance to Cry proteins develop (an important question even for insects), and, for the first time, address whether Cry proteins have utility in controlling mammalian parasitic nematodes. Variants of one Cry protein with better toxicity towards nematodes will be evolved and then tested for altered functions to correlate structure of toxin with function of toxin (Specific Aim I). This application also proposes to explore the mechanism of resistance to a different nematicidal Cry protein in C. elegans and determine whether this nematicidal protein may be an excellent companion therapeutic for other Cry proteins (Specific Aim II). The information and Cry protein variants generated and studied in Specific Aims I and II will then be applied towards therapy of mammalian parasites. Cry proteins, wild type and improved variants, will be orally administered to rodents infected with intestinal parasites (including one that can infect humans) to optimize therapeutic regimens and to determine which Cry proteins can have a therapeutic effect against the nematodes. The goal of these trials is to lay a foundation for future human studies.

描述（由申请人提供）：苏云金芽孢杆菌 (Bt) 晶体 (Cry) 蛋白几十年来一直用于杀死害虫，包括传播人类疾病的蚊子和黑蝇。与杀死昆虫的蛋白相关的 Cry 蛋白现已被发现可以杀死线虫，尽管它们目前尚未用于控制线虫。 Cry 蛋白对哺乳动物无毒，使其成为杀虫剂和潜在杀线虫剂的绝佳选择。杀线虫 Cry 蛋白可使多种线虫中毒，包括秀丽隐杆线虫和两种感染肠道的哺乳动物寄生线虫。肠道线虫感染超过 1/4 的人口，使其成为 Cry 蛋白的重要医学靶点。本申请建议利用秀丽隐杆线虫现有的优秀工具，深入研究 Cry 蛋白的功能、对 Cry 蛋白的抗性如何发展（即使对于昆虫来说也是一个重要问题），并首次解决 Cry 蛋白是否存在的问题。可用于控制哺乳动物寄生线虫。对线虫具有更好毒性的一种 Cry 蛋白变体将被进化，然后测试其功能改变，以将毒素结构与毒素功能相关联（具体目标 I）。该申请还提出探索线虫中对不同杀线虫 Cry 蛋白的抗性机制，并确定该杀线虫蛋白是否可能是其他 Cry 蛋白的优异伴侣治疗剂（具体目标 II）。在特定目标 I 和 II 中生成和研究的信息和 Cry 蛋白变体将应用于哺乳动物寄生虫的治疗。 Cry 蛋白、野生型和改良变体将被口服给予感染肠道寄生虫（包括可感染人类的​​一种）的啮齿动物，以优化治疗方案并确定哪些 Cry 蛋白对线虫具有治疗作用。这些试验的目的是为未来的人类研究奠定基础。