C. elegans as a model for ricin intoxication

线虫作为蓖麻毒素中毒的模型

• 批准号: 7825400
• 负责人: NILGUN E TUMER
• 金额: $ 19.08万
• 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 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7825400
• 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（由申请方提供）：蓖麻毒素是一种由蓖麻子（Ricinus communis）产生的植物毒素，对哺乳动物细胞具有极强毒性，被美国卫生与公众服务部（HHS）归类为选择性病原体，被疾病控制中心（CDC）归类为B类优先病原体。尽管已经尝试产生针对蓖麻毒素的有效疫苗，但尚未批准重组疫苗用于人类使用，并且没有针对蓖麻毒素暴露的有效治疗措施。因此，迫切需要治疗剂来保护暴露于蓖麻毒素的个体。为了深入了解蓖麻毒素诱导细胞死亡的机制，我们将利用蓖麻毒素独特的实验特性。这使得它成为几乎所有生物研究领域的主要模式生物。我们在这个建议中的主要目标是建立C。线虫作为一种新的整体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，我们喂C。elegans与E. coli中表达蓖麻毒素A链（RTA）或从E.大肠杆菌中，证明RTA对C.在极低的剂量下。与哺乳动物的数据一致，我们发现蓖麻毒素通过网格蛋白和筏独立的内吞途径进入C。elegans肠上皮细胞，并且进入早期内体对于细胞毒性是关键的。我们确定了一个新的作用，两个主要的吞噬/吞噬途径介导蓖麻毒素的敏感性，在C。线虫肠这些结果为C.作为一种新的多细胞模型的蓖麻毒素运输和细胞死亡的机制的分子遗传解剖。我们将研究运输蓖麻毒素在蠕虫肠，一个典型的极化上皮细胞，在一个活的动物的背景下。C. elegans细胞内运输途径缺陷突变体将用于验证C. elegans作为蓖麻毒素摄取和转运机制分析的相关模型，并确定蓖麻毒素转运中导致细胞毒性的关键步骤。我们将利用C的强大功能。elegans遗传学分离蓖麻毒素中毒缺陷的新突变体。拟议的研究将导致蓖麻毒素运输的分子细节的阐明，并将奠定基础，识别抑制剂，可以防止蓖麻毒素诱导的细胞死亡。公共卫生相关性：我们在本申请中的主要目标是建立C。线虫作为一种新的模型来研究蓖麻毒素中毒的机制，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。这些研究将为识别能够保护蓖麻毒素暴露个体的抑制剂奠定基础。