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.

项目摘要 由疟原虫感染引起的疟疾是世界上巨大的公共卫生负担， 以及发病率明显的原因。抗疟药氯喹是P. 在大多数国家 /地区的Vivax，被证明是高效的。但是，氯喹耐药（CQR）P。vivax 人们广泛报道了感染，严重阻碍了病例管理，疟疾控制工作以及 消除计划。大多数关于抗性机制的工作都集中在恶性疟原虫上，而P。 Vivax的研究仍然很差。然而，vivax构成了根除的主要障碍。分子 CQR的决定因素和对体内疟原虫中其他抗疟疾的抗性仍不清楚，这主要是由于缺乏 体外培养，排除反向遗传学和强大的药物测定。几个候选药物转运蛋白基因 已经在序列和表达水平的多态性的疟原虫中鉴定出来，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，直系同源物 恶性疟原虫PFMDR1，PFCRT和PFMRP1基因的关键决定因素分别 恶性疟原虫中的抗菌敏感性。体内P.体内对氯喹的敏感性与特定有关 在某些但并非全部研究中，多疟原虫药物转运蛋白多态性。尚不清楚这些差异是否 代表寄生虫多样性的区域差异和暴露于药物的历史；或技术导致 差异，因为迄今尚无遗传验证。在这里，我们提出了对 利用两种新型方法利用人畜共患猕猴的药物耐药性多态性 寄生虫疟原虫，比恶性疟原虫在天疟原虫上更接近疟原虫。拥有 具有较高转染效率的优质体外遗传学；重要的是，允许对 抗疟药敏感性。我们旨在利用最先进的进化基因组和实验性 正向遗传筛查以识别抗性疟原虫药物抗性的推定决定因素。我们随后会使用 诺尔斯氏疟原虫中的体外反向遗传方法在功能上评估优先级的遗传遗传的重要性 介导抗疟药耐药性的多态性。我们假设这些多态性是 通过抗疟疾使用对杜瓦克斯的抗疟疾使用，已在世界特定区域中选择了单独或结合。 鉴定介导不同水平易感性氯喹的特定多态性，并且 当前临床用途中的其他抗疟疾化合物，包括青蒿素及其伴侣药物，将是至关重要的 它们用于监视，分子流行病学研究以及延长策略的设计 这些药物的有用性。