Function/optimization of a nematicidal Cry toxin arsenal

杀线虫 Cry 毒素库的功能/优化

• 批准号: 7341087
• 负责人: RAFFI V AROIAN
• 金额: $ 32.64万
• 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/7341087
• 关键词: Address; Alanine; Ancylostoma (genus); Apical; Bacillus thuringiensis; Bacteria; Binding; Biological Assay; Blood; Caenorhabditis elegans; Classification; Companions; Crying; Culicidae; Defect; Depth; Endocytosis; Escherichia coli; Foundations; Future; Genes; Goals; Hamsters; Hookworms; Human; Insect Control; Insecta; Insecticides; Intestines; Intoxication; Invertebrates; Knowledge; Laboratories; Lead; Mammals; Medical; Midgut; Molecular; Morbidity - disease rate; Mosquito Control; Mus; Mutagenesis; Mutation; Nematoda; Nematode infections; Nippostrongylus; Numbers; Parasites; Parasitic nematode; Pest Control; Polymerase Chain Reaction; Population; Process; Proteins; Proteolytic Processing; Range; Rattus; Resistance; Rodent; Safety; Scanning; Screening procedure; Simuliidae; Solubility; Structure; Structure-Activity Relationship; System; Testing; Therapeutic; Therapeutic Effect; Thinking; Time; Toxic effect; Toxin; Treatment Efficacy; Treatment Protocols; Uncertainty; Variant; Vertebrates; Work; day; feeding; human disease; human study; improved; in vivo; infected vector rodent; killings; mutant; porin; protein function; receptor; resistance mechanism; stem; success; tool; vector

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)：几十年来，苏云金芽孢杆菌(Bt)晶体(Cry)蛋白一直被用于杀死害虫，包括传播人类疾病的蚊子和黑蝇。与杀死昆虫的那些蛋白相关的CORT蛋白现在被发现可以杀死线虫，尽管它们目前还没有用于线虫控制。CRY蛋白对哺乳动物无毒，这使它们成为杀虫剂和潜在的杀线虫剂的绝佳选择。杀线虫Cry蛋白可毒害多种线虫，包括线虫和两种感染肠道的哺乳动物寄生线虫。肠道线虫感染了超过四分之一的人类种群，使它们成为Cry蛋白的重要药物靶标。这项应用建议利用线虫可用的优秀工具来深入研究Cry蛋白是如何发挥作用的，对Cry蛋白的抗性是如何产生的(即使对昆虫来说也是一个重要的问题)，并首次解决Cry蛋白是否有助于控制哺乳动物寄生线虫。对线虫具有更好毒性的一种Cry蛋白的变体将被进化，然后测试其改变的功能，以将毒素的结构与毒素的功能相关联(特定目标I)。本申请还建议探索线虫对一种不同的杀线虫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蛋白的优秀伴生治疗(特异性目标II)。然后，在特定目标I和II中产生和研究的信息和Cry蛋白变体将被应用于哺乳动物寄生虫的治疗。野生型和改良变种的Cry蛋白将被口服给感染肠道寄生虫(包括一种可以感染人类的寄生虫)的啮齿动物，以优化治疗方案，并确定哪些Cry蛋白可以对线虫具有治疗效果。这些试验的目标是为未来的人体研究奠定基础。