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(申请人提供)：蓖麻毒素是一种由蓖麻产生的植物毒素，对哺乳动物细胞具有极强的毒性，被美国卫生与公众服务部(HHS)列为选择剂，并被疾病控制中心(CDC)列为B类优先病原体。尽管已经尝试生产出一种有效的蓖麻毒素疫苗，但还没有重组疫苗被批准用于人类使用，也没有针对蓖麻毒素暴露的有效治疗措施。因此，迫切需要治疗方法来保护接触蓖麻毒素的个人。为了了解蓖麻毒素诱导细胞死亡的机制，我们将利用线虫独特的实验特征，这些特征使其成为几乎所有生物学研究领域的领先模式生物。我们在这项建议中的主要目标是建立线虫作为一种新的全动物模型来研究蓖麻毒素中毒，并将我们的发现转化为哺乳动物。在初步研究中，我们用表达蓖麻毒素A链(RTA)的大肠杆菌或从大肠杆菌中纯化的重组RTA喂养线虫，并证明RTA在极低的剂量下对线虫是致命的。与哺乳动物的研究结果一致，我们发现蓖麻毒素通过一条网状蛋白和一条非依赖于RAFT的内吞作用途径进入线虫肠道上皮细胞，进入早期的内吞体内是细胞毒性的关键。我们确定了两个主要的吞噬/吞噬途径在调节线虫肠道中蓖麻毒素敏感性方面的新作用。这些结果为线虫作为一种新的多细胞模型的发展提供了支持，该模型可用于分子遗传学研究蓖麻毒素转运和细胞死亡的机制。我们将在活体动物的背景下，研究蓖麻毒素在蠕虫肠道中的运输，蠕虫肠道是一种经典的极化上皮。线虫细胞内转运途径缺陷的突变株将被用于验证线虫作为蓖麻毒素吸收和运输机制分析的相关模型，并确定导致细胞毒性的蓖麻毒素运输的关键步骤。我们将利用线虫强大的遗传学特征，分离出蓖麻毒素中毒缺陷的新突变体。所提出的研究将有助于阐明蓖麻毒素转运的分子细节，并将为鉴定能够防止蓖麻毒素诱导的细胞死亡的抑制剂奠定基础。公共卫生相关性：我们在这项应用中的主要目标是建立线虫作为研究蓖麻毒素中毒机制的新模型，并将我们的发现转化为人类。这些研究意义重大，因为目前还没有针对蓖麻毒素暴露的疫苗、解毒剂或任何其他治疗措施。这些研究将为鉴定能够保护蓖麻毒素暴露个体的抑制剂奠定基础。