Investigation of a shipworm endosymbiont compound with activity against the AIDS-associated pathogens Cryptosporidium and Toxoplasma

对具有抗艾滋病相关病原体隐孢子虫和弓形虫活性的船虫内共生化合物的研究

• 批准号: 9267939
• 负责人: ROBERTA M O'CONNOR
• 金额: $ 19万
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-03-01 至 2020-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9267939
• 关键词: Acquired Immunodeficiency Syndrome; Affect; Animal Model; Animals; Antiparasitic Agents; Area; Babesia bovis; Bacteria; Biochemical; Bivalvia; Cell Membrane Permeability; Cells; Cellulose; Chronic; Communities; Cryptosporidiosis; Cryptosporidium; Cryptosporidium parvum; Diet; Digestion; Distant; Drug Kinetics; Drug resistance; Environment; Enzymes; Evaluation; Exhibits; Foundations; Future; Genetic; Genome; Gills; Grant; Growth; Immunocompromised Host; In Vitro; Infection; Investigation; Marines; Medical; Morbidity - disease rate; Morphology; Mus; Neonatal; Nutrient; Organelles; Parasites; Patients; Pharmaceutical Preparations; Pharmacodynamics; Play; Process; Production; Recruitment Activity; Reporting; Role; Source; Sterility; Structure; Structure-Activity Relationship; Symbiosis; Testing; Therapeutic; Toxic effect; Toxoplasma; Toxoplasma gondii; Toxoplasmosis; Treatment Efficacy; Vacuole; Wood material; antimicrobial; antimicrobial drug; cell motility; dosage; drug development; drug discovery; efficacy testing; endosymbiont; evaluation/testing; experimental study; gene product; genetic manipulation; human disease; in vivo; killings; lignocellulose; microbial; microorganism; molecular drug target; mortality; novel therapeutics; pathogen; public health relevance; sugar

 DESCRIPTION (provided by applicant): Cryptosporidium spp. and Toxoplasma gondii are opportunistic apicomplexan parasites that cause significant morbidity and mortality in immunocompromised people. New therapeutics to treat these parasites are a medical imperative. We have identified a compound produced by a mollusk symbiotic bacterium that inhibits intracellular growth of C. parvum and T. gondii without toxicity to the host cell. Shipworms are marine bivalve mollusks that burrow into and voraciously consume wood. Like most xylophagous animals, shipworms digest wood with the assistance of their symbiotic bacteria but in shipworms, the symbionts are housed within the cells of the gill and export cellulolytic enzymes out of the bacterial vacuole, out of the host cell, and into the lumen of the caecum where they effect digestion of the shipworm's woody diet. Despite the nutrient rich environment, the shipworm caecum lacks a bacterial community suggesting the presence of potent anti-microbial compounds. Shipworm symbionts have been shown to produce anti-microbial secondary metabolites in vivo and it is likely these compounds play a role in maintaining the nearly sterile environment of the caecum. We found that the shipworm gill endosymbiont, Teredinibacter turnerae, produces a compound that inhibits intracellular growth of C. parvum and T. gondii at nM levels in vitro and inhibits C. parvum infection in mice. This compound is also active against the related hemoparasite, Babesia bovis, suggesting a broad efficacy against apicomplexans. In this application, we will test the hypothesis that this compound targets a gene product or process common to T. gondii and C. parvum, and that this activity is effective in vivo. To test this hypothesis, we propose the following specific aim: Aim 1A - Identify the T. gondii and C. parvum infection processes targeted by the symbiont compound. We will evaluate the effect of the symbiont compound on specific parasite processes and test the compound against other apicomplexans, including Type II T. gondii tachyzoites and bradyzoites. Aim 1B - Identify the target of the symbiont compound's activity in C. parvum and T. gondii. We will employ both genetic and biochemical approaches to identify the gene products targeted by this compound. Aim 1C - Evaluate the efficacy of the symbiont compound against murine C. parvum infection. These experiments will provide the foundation for future studies involving target verification, structure-activity relationships, pharmacokinetic-pharmacodynamic evaluation and tests of efficacy in other animal models of C. parvum and T. gondii infection. Shipworm symbionts have never before been investigated for their potential to produce anti-parasitic compounds. Thus, these studies have tremendous potential to open up a new area of anti-parasitic drug discovery, holding the promise of new molecular targets for drug development, potentially with broad application to many intractable pathogens.

 描述（由申请人提供）：隐孢子虫属。弓形虫和弓形虫是机会性顶复门寄生虫，可导致免疫功能低下人群显着发病和死亡。治疗这些寄生虫的新疗法是医学上的当务之急。我们已经鉴定出一种由软体动物共生细菌产生的化合物，可以抑制微小弯曲菌和刚地弓形虫的细胞内生长，且对宿主细胞没有毒性。 船蛆是海洋双壳类软体动物，它们会钻入木材中并贪婪地消耗木材。与大多数食木动物一样，船虫在共生细菌的帮助下消化木材，但在船虫中，共生体位于鳃细胞内，并将纤维素分解酶从细菌液泡、宿主细胞中输出，进入盲肠腔，在那里它们影响船虫木质饮食的消化。尽管环境营养丰富，但船蛆盲肠缺乏细菌群落，表明存在有效的抗菌化合物。船虫共生体已被证明可以在体内产生抗微生物次级代谢产物，这些化合物很可能在维持盲肠近乎无菌的环境中发挥作用。我们发现船虫鳃内共生体 Teredinibacter Turnerae 产生一种化合物，可在体外以 nM 水平抑制微小衣原体和刚地弓形虫的细胞内生长，并抑制小鼠体内的微小衣原体感染。该化合物对相关的血液寄生虫牛巴贝虫也有活性，表明对顶复门菌具有广泛的功效。在此应用中，我们将测试以下假设：该化合物针对刚地弓形虫和微小弯曲菌常见的基因产物或过程，并且该活性在体内有效。为了检验这一假设，我们提出以下具体目标： 1A - 识别共生化合物针对的弓形虫和微小弯曲菌感染过程。我们将评估共生化合物对特定寄生虫过程的影响，并测试该化合物对抗其他顶复菌，包括 II 型弓形虫速殖子和缓殖子。 目标 1B - 确定共生体化合物在微小弯曲菌和刚地弓形虫中的活性靶点。我们将采用遗传和生化方法来鉴定该化合物所针对的基因产物。 目标 1C - 评估共生化合物对抗鼠小隐孢子虫感染的功效。 这些实验将为未来的研究奠定基础，包括目标验证、结构-活性关系、药代动力学-药效学评估以及其他小支原体和弓形虫感染动物模型的功效测试。船蛆共生体产生抗寄生虫化合物的潜力此前从未被研究过。因此，这些研究具有开辟抗寄生虫药物发现新领域的巨大潜力，有望为药物开发提供新的分子靶点，并可能广泛应用于许多棘手的病原体。

项目成果

Modelling Cryptosporidium infection in human small intestinal and lung organoids.

• DOI: 10.1038/s41564-018-0177-8
• 发表时间: 2018-07
• 期刊: Nature microbiology
• 影响因子: 28.3
• 作者: Heo I;Dutta D;Schaefer DA;Iakobachvili N;Artegiani B;Sachs N;Boonekamp KE;Bowden G;Hendrickx APA;Willems RJL;Peters PJ;Riggs MW;O'Connor R;Clevers H
• 通讯作者: Clevers H