Molecular basis of antimalarial drug resistance in Plasmodium vivax

间日疟原虫抗疟药物耐药性的分子基础

• 批准号: 10593992
• 负责人: Manoj T Duraisingh
• 金额: $ 73.53万
• 依托单位: HARVARD SCHOOL OF PUBLIC HEALTH
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-18 至 2027-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10593992
• 关键词: Anti-malarial drug resistance; Antimalarials; Artemisinins; Biological Assay; Case Management; Chloroquine; Chloroquine resistance; Clinical; Comparative Genomic Analysis; Country; Development; Drug resistance; Experimental Genetics; Exposure to; Genes; Genetic; Genetic Polymorphism; Genetic Screening; Genomics; In Vitro; Individual; Infection; Libraries; Macaca; Malaria; Mediating; Methods; Molecular; Molecular Analysis; Molecular Epidemiology; Morbidity - disease rate; Orthologous Gene; Parasite resistance; Parasites; Pharmaceutical Preparations; Pharmacotherapy; Phenotype; Phylogenetic Analysis; Plasmodium falciparum; Plasmodium knowlesi; Plasmodium vivax; Policies; Population; Predictive Value; Predisposition; Primaquine; Public Health; Recording of previous events; Reporting; Resistance; Risk Factors; Role; Scanning; Southeastern Asia; Transfection; Treatment outcome; Validation; Variant; Vivax Malaria; Work; Zoonoses; design; drug candidate; epidemiology study; fitness; forward genetics; genomic data; member; novel; novel strategies; overexpression; premature; programs; regional difference; resistance allele; resistance gene; resistance mechanism; reverse genetics

Project Summary Malaria caused by infection with Plasmodium vivax is an enormous public health burden throughout the world, and the cause of significant morbidity. The antimalarial drug chloroquine is the first line of drug treatment for P. vivax in most countries, and has proven highly efficacious. However, chloroquine resistant (CQR) P. vivax infections have been widely reported, seriously hampering case management, malaria control efforts, and elimination programs. Most work on resistance mechanisms has focused on Plasmodium falciparum, while P. vivax remains poorly studied; nevertheless, P. vivax poses a major impediment to eradication. The molecular determinants of CQR and resistance to other antimalarials in P. vivax remain unclear, largely due to the lack of in vitro culture, precluding reverse genetics and robust drug assays. Several candidate drug transporter genes have been identified in P. vivax with polymorphism in sequence and expression level that could be associated with CQR and/or resistance to other antimalarials. These genes include pvmdr1, pvcrt-o and pvmrp1, orthologs of the Plasmodium falciparum pfmdr1, pfcrt and pfmrp1 genes, respectively, that are key determinants of antimalarial susceptibility in P. falciparum. Ex vivo P. vivax susceptibility to chloroquine is associated with specific P. vivax drug transporter polymorphisms in some but not all studies. It is not clear whether these discrepancies represent regional differences in parasite diversity and history of exposure to drugs; or result from technical differences, as no genetic validation has hitherto been possible. Here, we propose a comprehensive analysis of drug-resistance polymorphisms of P. vivax, utilizing two novel approaches leveraging the zoonotic macaque parasite Plasmodium knowlesi, which is much closer to P. vivax phylogenetically than is P. falciparum; possesses superior in vitro genetics with higher transfection efficiencies; and importantly, permits robust determinations of antimalarial drug susceptibility. We aim to utilize both cutting-edge evolutionary genomic and experimental forward genetic screening to identify putative determinants of P. vivax drug-resistance. We will subsequently use in vitro reverse genetic methods in P. knowlesi to functionally assess the importance of prioritized P. vivax genetic polymorphisms in mediating antimalarial drug-resistance. We hypothesize that these polymorphisms, either singly or in combination, have been selected in specific regions of the world by antimalarial use against P. vivax. The identification of specific polymorphisms that mediate different levels of susceptibility to chloroquine, and other antimalarial compounds in current clinical use, including artemisinin and its partner drugs, will be key to their use in surveillance, molecular epidemiological studies, and the design of strategies to prolong the usefulness of these drugs.

项目概要 由间日疟原虫感染引起的疟疾给全世界带来了巨大的公共卫生负担， 以及显着发病的原因。抗疟药氯喹是疟原虫治疗的一线药物。 间日疟原虫在大多数国家都有传播，并已被证明非常有效。然而，氯喹抗性（CQR）间日疟原虫 感染已被广泛报道，严重阻碍了病例管理、疟疾控制工作和 消除计划。大多数关于耐药机制的工作都集中在恶性疟原虫上，而 P. 间日疟原虫的研究仍然很少；然而，间日疟原虫对根除构成了重大障碍。分子 间日疟原虫 CQR 和对其他抗疟药耐药性的决定因素仍不清楚，这主要是由于缺乏 体外培养，排除反向遗传学和稳健的药物测定。几种候选药物转运基因 已在间日疟原虫中鉴定出序列和表达水平多态性，这可能与 具有 CQR 和/或对其他抗疟药的耐药性。这些基因包括 pvmdr1、pvcrt-o 和 pvmrp1、直系同源基因 恶性疟原虫 pfmdr1、pfcrt 和 pfmrp1 基因分别是恶性疟原虫的关键决定因素 恶性疟原虫的抗疟药敏感性。离体间日疟原虫对氯喹的敏感性与特定的 一些但并非所有研究中的间日疟原虫药物转运蛋白多态性。目前尚不清楚这些差异是否 代表寄生虫多样性和药物接触史的区域差异；或技术结果 差异，因为迄今为止还不可能进行基因验证。在此，我们提出全面分析 间日疟原虫的耐药性多态性，利用两种利用人畜共患猕猴的新方法 寄生虫诺氏疟原虫，在系统发育上比恶性疟原虫更接近间日疟原虫；拥有 优越的体外遗传学和更高的转染效率；重要的是，允许稳健的确定 抗疟药物敏感性。我们的目标是利用尖端的进化基因组和实验 正向遗传筛查以确定间日疟原虫耐药性的推定决定因素。我们随后将使用 诺氏疟原虫体外反向遗传方法，以功能性评估优先间日疟原虫遗传的重要性 介导抗疟药物耐药性的多态性。我们假设这些多态性要么 已在世界特定地区通过针对间日疟原虫的抗疟用途而选择了单独或组合的抗疟药。 鉴定介导不同程度的氯喹敏感性的特定多态性，以及 目前临床使用的其他抗疟化合物，包括青蒿素及其伙伴药物，将是 它们在监测、分子流行病学研究以及延长传播策略的设计中的应用 这些药物的用处。