C. elegans as a model for ricin intoxication

线虫作为蓖麻毒素中毒的模型

• 批准号: 7586358
• 负责人: NILGUN E TUMER
• 金额: $ 22.62万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-05 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7586358
• 关键词: Abdominal Pain; Abrin; Acetylgalactosamine; Adenine; Agreement; Animal Model; Animals; Antidotes; Apoptosis; Area; Bacterial Toxins; Binding; Biological; Biological Models; Biological Warfare; Caenorhabditis elegans; Categories; Cell Death; Cell Line; Cell surface; Cells; Centers for Disease Control and Prevention (U.S.); Cessation of life; Cholera Toxin; Clathrin; Conserved Sequence; Coupled; Cytosol; Data; Development; Dissection; Dose; Early Endosome; Endocytosis; Endocytosis Pathway; Endoplasmic Reticulum; Endosomes; Epithelial Cells; Epithelium; Escherichia coli; Extravasation; Foundations; Galactose; Generations; Genes; Genetic; Health; Histocompatibility Testing; Human; Imagery; In Vitro; Individual; Ingestion; Inhalation Exposure; Intestines; Intoxication; Kidney; Knowledge; Lead; Life; Light; Link; Liver; Lysosomes; Mammalian Cell; Mammals; Measures; Mediating; Medicine; Membrane; Modeling; Molecular; Molecular Genetics; Muscle; Nausea and Vomiting; Nerve; Nobel Prize; Organism; Pathway interactions; Phagocytosis; Phylogenetic Analysis; Physiology; Plants; Protein Biosynthesis; Proteins; Pseudomonas aeruginosa toxA protein; RNA Interference; Recombinant Vaccines; Recombinants; Research; Resistance; Respiratory distress; Ribosomal RNA; Ribosomes; Ricin; Ricin A Chain; Ricin B Chain; Ricinus communis; Role; Route; Services; Shiga-Like Toxins; Spleen; System; Testing; Therapeutic; Time; Toxin; Translating; Transmembrane Transport; United States Dept. of Health and Human Services; Vaccines; biological research; cell killing; cytotoxicity; disulfide bond; effective therapy; feeding; holotoxins; in vivo; inhibitor/antagonist; insight; mutant; novel; pathogen; prevent; public health relevance; receptor; trafficking; trait; uptake

DESCRIPTION (provided by applicant): Ricin is a plant toxin produced by the castor bean (Ricinus communis) that is extremely toxic to mammalian cells and is classified as a select agent by the US Department of Health and Human Services (HHS) and a category B priority pathogen by the Center for Disease Control (CDC). Although there have been attempts to generate an effective vaccine against ricin, no recombinant vaccine has yet been approved for human use and there are no effective treatment measures against ricin exposure. Therefore there is an urgent need for therapeutics to protect ricin-exposed individuals. To gain understanding into the mechanism of ricin induced cell death, we will take advantage of the unique experimental features of C. elegans that have made it a leading model organism in nearly all areas of biological research. Our primary objective in this proposal is to establish C. elegans as a new whole animal model to study ricin intoxication and to translate our findings to mammals. In preliminary studies, we fed C. elegans with either E. coli expressing ricin A-chain (RTA) or recombinant RTA purified from E. coli and demonstrated that RTA is lethal to C. elegans at extremely low doses. In agreement with mammalian data, we showed that ricin uses a clathrin and a raft independent endocytosis pathway to enter the C. elegans intestinal epithelial cells and entry to the early endosome is critical for cytotoxicity. We identified a novel role for the two major phagocytosis/engulfment pathways in mediating ricin sensitivity in the C. elegans intestine. These results provided support for the development of C. elegans as a new multicellular model for molecular genetic dissection of the mechanisms of ricin transport and cell death. We will examine transport of ricin in the worm intestine, a classic polarized epithelium, in the context of a living animal. C. elegans mutants defective in intracellular trafficking pathways will be used to validate C. elegans as a relevant model for mechanistic analysis of ricin uptake and transport and to identify critical steps in ricin transport that lead to cytotoxicity. We will exploit powerful features of C. elegans genetics to isolate new mutants defective in ricin intoxication. The proposed studies will lead to elucidation of the molecular details of ricin transport and will lay the foundation for identification of inhibitors that can prevent ricin induced cell death. PUBLIC HEALTH RELEVANCE: Our primary objective in this application is to establish C. elegans as a new model to study the mechanism of ricin intoxication and to translate our findings to humans. These studies are significant because currently there are no vaccines, antidotes or any other treatment measures against ricin exposure. These studies will lay the foundation for identification of inhibitors that can protect ricin exposed individuals.

描述（由申请人提供）：Ricin是由Castor Bean（Ricinus commumis）产生的植物毒素，对哺乳动物细胞极具毒性，并被美国卫生与公共服务部（HHS）和疾病控制中心（CDC）的美国卫生与公共服务部（HHS）和B类优先病原体归类为精选药物。尽管已经试图生成针对赖克蛋白的有效疫苗，但尚未批准重组疫苗用于人类使用，并且没有有效的治疗措施针对Ricin暴露。因此，迫切需要治疗药物来保护易菌素暴露的个体。为了了解Ricin诱导的细胞死亡的机制，我们将利用秀丽隐杆线虫的独特实验特征，这使其成为几乎所有生物学研究领域的领先模型生物。该提案中我们的主要目标是建立秀丽隐杆线虫作为一种新的整个动物模型，以研究ricin中毒并将我们的发现转化为哺乳动物。在初步研究中，我们将秀丽隐杆线虫与大肠杆菌一起喂食，表达ricin a链（RTA）或从大肠杆菌中纯化的重组RTA，并证明RTA对秀丽隐杆线虫对秀丽隐杆菌的极低剂量非常低。与哺乳动物的数据一致，我们表明里奇蛋白使用网格蛋白和筏独立的内吞途径进入秀丽隐杆线虫肠上皮细胞，进入早期内体对于细胞毒性至关重要。我们确定了两种主要的吞噬作用/吞噬途径在介导秀丽隐杆线虫肠中ricin敏感性中的新作用。这些结果为秀丽隐杆线虫的发展提供了支持，它是一种新的多细胞模型，用于分子遗传解剖的Ricin转运和细胞死亡机制。我们将在生物动物的背景下检查ricin在经典的偏振上皮的蠕虫肠道中的运输。秀丽隐杆线虫突变体在细胞内运输途径中有缺陷，将用于验证秀丽隐杆线虫，作为莱西因蛋白摄取和运输机械分析的相关模型，并确定导致细胞毒性的ricin运输中的关键步骤。我们将利用秀丽隐杆线虫遗传学的强大特征分离出新的突变体在里奇蛋白中毒中有缺陷。拟议的研究将导致阐明赖西蛋白转运的分子细节，并为鉴定可以防止赖切蛋白诱导细胞死亡的抑制剂奠定基础。公共卫生相关性：我们在本应用程序中的主要目标是建立秀丽隐杆线虫作为一种新的模型，以研究里奇蛋白中毒的机制并将我们的发现转化为人类。这些研究很重要，因为目前尚无疫苗，解毒剂或任何其他针对Ricin暴露的治疗措施。这些研究将奠定鉴定可以保护ricin暴露个人的抑制剂的基础。