Mechanism of Infectivity Acquisition in African Trypanosomes

非洲锥虫感染性获得机制

• 批准号: 9010923
• 负责人: CHRISTIAN TSCHUDI
• 金额: $ 41.63万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-03-15 至 2019-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9010923
• 关键词: Address; Adverse effects; Africa South of the Sahara; African; African Trypanosomiasis; Amino Acids; Animals; Applications Grants; Architecture; Arthropods; Biochemical; Biology; Blood; Blood Circulation; Cattle; Cell Culture Techniques; Cells; Cellular Morphology; Communicable Diseases; Complement; Complex; Data; Development; Diptera; Disease; Domestic Pig; Event; Future; Gene Expression; Gene Proteins; Generations; Genes; Genetic Translation; Glossinidae; Goals; Health; High-Throughput Nucleotide Sequencing; Human; Human Biology; Immunoprecipitation; In Vitro; Infectious Agent; Intervention; Investments; Life Cycle Stages; Livestock; Maps; Mass Spectrum Analysis; Membrane; Membrane Glycoproteins; Messenger RNA; Metabolism; Midgut; Mitochondria; Molecular; Molecular Profiling; Monitor; Nature; Parasites; Pathogenesis; Pathway interactions; Pharmaceutical Preparations; Process; Proteins; Proteomics; Protozoa; Proventriculus; Public Health; RNA-Binding Proteins; Regulation; Research; Resources; Salivary Glands; Signaling Protein; Site; Small RNA; Stable Isotope Labeling; Staging; System; Time; Transcript; Translations; Trypanosoma; Trypanosoma brucei brucei; Tsetse Flies; Tubular formation; Vaccines; Variant; cell motility; combat; crosslink; crosslinking and immunoprecipitation sequencing; feeding; fly; gene product; genetic approach; genome-wide; insight; metacyclogenesis; nagana; novel; overexpression; pathogen; programs; research study; ribosome profiling; therapeutic vaccine; transcriptome; transcriptome sequencing; transcriptomics; transmission-blocking vaccine; vector; wasting

DESCRIPTION (provided by applicant): Unraveling the biology of human pathogens is fundamental toward understanding mechanisms of pathogenesis and identifying genes essential for survival in the host. This application focuses on the protozoan parasite Trypanosoma brucei, which causes devastating diseases in humans and animals in sub-Saharan Africa. There are no vaccines, and therapeutic drugs have serious side effects and decreasing efficacy. T. brucei undergoes a complex life cycle between the mammalian host and the blood-feeding tsetse fly vector (Diptera: Glossinidae), which among others involves changes in cell morphology, metabolism, signaling pathways and gene expression. Consequently, these parasites have evolved adaptations to allow for their survival in both the gut and salivary glands of the tsetse fly, as well as in the bloodstream of their mammalian host. Upon feeding on an infected host, the tsetse fly takes up slender, intermediate and stumpy bloodstream forms. In the fly midgut stumpy forms differentiate into non-infectious procyclic forms. Reacquisition of infectivity is achieved through a complex developmental program that culminates in the tsetse salivary glands with the generation of infectious metacyclics. Although the intricate nature of trypanosome development in the fly has been recognized for more than a century, the molecular mechanisms are still mysterious, due in part to the experimental challenges posed by the tsetse fly. We found that overexpression of the T. brucei RNA-binding protein RBP6 in cultured non-infectious procyclic forms initiates differentiation into the developmental stages found in tsetse flies and culminates with the generation of infective metacyclics expressing the variant surface glycoprotein (VSG) coat. Our first goal will be to delineate the mechanism of action of RBP6. As RBP6 appears to be a "master regulator" triggering a cascade of events, it will be critical to identify the primary mRNA targets of RBP6. This will provide crucial information about gene products involved in the early stages of differentiation and for formulating a testable hypothesis about the cellular adaptations occurring in the transition from procyclic to epimastigotes forms. Our second goal will be to provide a transcriptomic and proteomic map of epimastigotes and metacyclics and to decode the biology of metacyclogenesis. Finally, the discovery of novel genes, besides VSG, required for metacyclic differentiation will be a major breakthrough toward deciphering how the process of acquisition of infectivity is brought about. Taken together our research plan provides unique opportunities to illuminate the differentiation program from procyclic to metacyclic and reveal the mode of action of an important RNA binding protein.

描述（由申请人提供）：阐明人类病原体的生物学是理解发病机理的机制和鉴定宿主生存所必需的基因的基础。该应用着重于原生动物寄生虫锥虫瘤，该锥虫在撒哈拉以南非洲引起人类和动物的毁灭性疾病。没有疫苗，治疗药物具有严重的副作用和降低功效。 T. Brucei经历了哺乳动物宿主与喂养采血的TSETSE Fly Vector（Diptera：Glossinidae）之间的复杂生命周期，其中涉及细胞形态，代谢，信号途径和基因表达的变化。因此，这些寄生虫已经发展了适应性，以使其在采摘蝇的肠道和唾液腺以及哺乳动物宿主的血液中生存。在以感染的宿主为食后，采取的蝇会占据细长，中间和笨拙的血液形式。在苍蝇中肠stump形形成了非感染的procyclic形式。通过一个复杂的发展计划来实现感染力的重新计算，该计划通过传染性元学的产生来最终在采摘唾液腺中达到高潮。尽管苍蝇中锥虫发育的复杂性质已被认可了一个多世纪，但分子机制仍然是神秘的，部分原因是TSETSE Fly带来的实验挑战。我们发现，在培养的非感染的procyclic形式中，t. brucei RNA结合蛋白RBP6的过表达引发了Tsetse Flies中发现的发育阶段，并通过表达变化的表面糖蛋白（VSG）涂层的感染性元学的产生，并产生了最终的发育阶段。我们的第一个目标是描述RBP6的作用机理。由于RBP6似乎是触发一系列事件的“主调节器”，因此确定RBP6的主要mRNA靶标将非常重要。这将提供有关分化早期涉及的基因产物的关键信息，并为从procyclic到epimastigotes形式的过渡中进行了可检验的假设。我们的第二个目标是提供表化学和元学的转录组和蛋白质组学图，并解码元观察的生物学。最后，除了VSG之外，新型基因的发现将是元环节分化所需的，这将是解释如何提出感染性过程的重大突破。综上所述，我们的研究计划提供了独特的机会来照亮从procyclic到Metacyclic的分化程序，并揭示重要的RNA结合蛋白的作用方式。