Discovery of novel benzimidazole resistance mechanisms

发现新的苯并咪唑耐药机制

• 批准号: 10438771
• 负责人: Erik Christian Andersen
• 金额: $ 68.21万
• 依托单位: NORTHWESTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10438771
• 关键词: Affect; Albendazole; Alleles; Anthelmintics; Biological Assay; CRISPR/Cas technology; Caenorhabditis elegans; Collaborations; Communities; Drug Design; Drug Targeting; Early Diagnosis; Economic Burden; Enzymes; Evolution; Farm; Future; Generations; Genes; Genetic; Genetic Crosses; Genome; Genomics; Goals; Growth; Haemonchus; Helminths; Hookworms; Human; Knowledge; Laboratories; Longevity; Measures; Medicine; Modeling; Molecular; Monitor; Morbidity - disease rate; Nematoda; Oxides; Parasite resistance; Parasites; Parasitic nematode; Persons; Pharmaceutical Preparations; Phenotype; Phylogenetic Analysis; Poisoning; Population; Production; Proteins; Research; Research Personnel; Resistance; Resources; Ruminants; Sampling; Soil; Structural Biologist; Testing; Time; Tissues; Transgenic Animals; Translating; Veterinary Medicine; X Chromosome; base; benzimidazole; benzimidazole resistance; beta Tubulin; disability-adjusted life years; experimental study; fitness; fitness test; follow-up; gamma Tubulin; gene discovery; genetic approach; genome editing; genome-wide; health economics; mortality; novel; offspring; pathogen; programs; resistance allele; resistance gene; resistance mechanism; success

Project summary: Parasitic nematodes impose a massive health and economic burden across much of the developing world, infecting over one billion people worldwide. The morbidity and mortality inflicted by these devastating pathogens is partly curtailed by mass drug administration (MDA) programs that depend on the continued efficacy of a limited portfolio of anthelmintic drugs. Benzimidazole (BZ) compounds are a widely used class of broad-spectrum anthelmintics that are an indispensable component of this limited chemotherapeutic arsenal. The prospects of BZ resistance pose a serious threat to the future success of nematode control programs. These prospects have been realized in the veterinary domain following intensive BZ use and are predicted to materialize in human medicine with increased selection caused by expanded MDA. Early detection of resistance-associated alleles in nematode parasite populations is essential to the goal of slowing anthelmintic resistance and extending the lifespan of this critical drug class. Based on research in the free-living nematode Caenorhabditis elegans from thirty years ago, parasitic nematode researchers focus on one BZ target, a nematode-specific beta-tubulin. Despite this knowledge, it is still a complete mystery (1) whether any alleles cause resistance (i.e. go beyond correlation), (2) the nematode tissues that are sensitive to BZ poisoning, and (3) the drug-target interactions that cause resistance. In Haemonchus contortus, we have collected both validated sensitive and resistance samples, and longitudinal samples where resistance has developed over time. These samples are not available in any human parasitic nematode species. Using quantitative resistance assays on these resources, we have shown that BZ resistance goes well beyond this single beta- tubulin target. However, we do not know these independent resistance mechanisms in C. elegans or parasite species. In Aim 1, we will test explicitly whether alleles correlated with resistance in parasites actually cause resistance, test the fitness effects of these alleles, identify the tissues targeted by BZ, and characterize the molecular mechanism for how beta-tubulin in affected by benzimidazoles. In Aim 2, we will discover beta- tubulin independent mechanisms of resistance using the tractable C. elegans model nematode. In Aim 3, we will expand our results to H. contortus where genomic and validated strain resources enable discoveries of conserved resistance mechanisms. It is not possible in any parasitic nematode species to accomplish these goals. New discoveries are possible only through this interplay between the model nematode C. elegans and the tractable veterinary parasitic nematode H. contortus. Our results will have direct impacts on how treatments are administered and resistance is monitored in human parasitic nematodes.

项目概要： 寄生线虫给许多发展中国家带来了巨大的健康和经济负担， 感染全球超过十亿人。这些毁灭性的事件造成的发病率和死亡率 大规模药物管理（MDA）计划在一定程度上减少了病原体的传播，而该计划依赖于持续的 有限的驱虫药物组合的功效。苯并咪唑 (BZ) 化合物是一类广泛使用的化合物 广谱驱虫药是这一有限化疗药物中不可或缺的组成部分。 BZ 抗性的前景对线虫控制计划未来的成功构成严重威胁。 随着 BZ 的大量使用，这些前景已在兽医领域实现，预计将 随着 MDA 的扩展导致选择增加，这一点在人类医学中得以实现。及早发现 线虫寄生虫种群中与耐药性相关的等位基因对于减缓驱虫的目标至关重要 耐药性并延长这一关键药物类别的寿命。基于对自由生活线虫的研究 三十年前的秀丽隐杆线虫，寄生线虫研究人员专注于一个 BZ 目标，一个 线虫特异性 β-微管蛋白。尽管有这些知识，但它仍然是一个完全的谜（1）是否有任何等位基因 引起抗性（即超越相关性），（2）对BZ中毒敏感的线虫组织， (3)引起耐药性的药物-靶标相互作用。在捻转血矛线虫中，我们收集了 经过验证的敏感样品和耐药样品，以及耐药性已发展超过的纵向样品 时间。这些样本在任何人类寄生线虫物种中均不可用。使用定量 通过对这些资源的耐药性分析，我们已经证明 BZ 耐药性远远超出了这个单一的 beta- 微管蛋白靶标。然而，我们不知道线虫或寄生虫中的这些独立的抵抗机制 物种。在目标 1 中，我们将明确测试与寄生虫耐药性相关的等位基因是否确实导致 抗性，测试这些等位基因的适应性效应，识别 BZ 靶向的组织，并表征 β-微管蛋白如何受苯并咪唑影响的分子机制。在目标 2 中，我们将发现 beta- 使用易处理的秀丽隐杆线虫模型线虫研究微管蛋白独立的耐药机制。在目标 3 中，我们 将把我们的结果扩展到 H. contortus，其中基因组和经过验证的菌株资源使我们能够发现 保守的耐药机制。任何寄生线虫物种都不可能实现这些 目标。只有通过模型线虫秀丽隐杆线虫和 易于驯服的兽医寄生线虫 H. contortus。我们的结果将直接影响如何 对人类寄生线虫进行治疗并监测其耐药性。