Defining P. falciparum resistance to artemisinin-based combination therapies

恶性疟原虫对青蒿素联合疗法的耐药性的定义

• 批准号: 10372215
• 负责人: David A Fidock
• 金额: $ 45.25万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2026-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10372215
• 关键词: Address; Adoption; Africa; African; Alleles; Amodiaquine; Antimalarials; Artemisinins; Asian; Automobile Driving; Bar Codes; Biological; Biological Assay; Biomass; Blood; CRISPR/Cas technology; Cambodia; Cambodian; Candidate Disease Gene; Cessation of life; Chromosome 12; Combined Modality Therapy; Containment; Country; Data; Development; Drug resistance; Drug usage; Effectiveness; Endocytosis; Eritrea; Face; Failure; Falciparum Malaria; Genes; Genetic; Genetic Crosses; Genomics; Geography; Growth; Haplotypes; Heme; Hemoglobin; Immunity; In Vitro; Lead; Malaria; Maps; Mediating; Microbial Drug Resistance; Morbidity - disease rate; Multi-Drug Resistance; Mutation; National Institute of Allergy and Infectious Disease; Parasite resistance; Parasites; Pharmaceutical Preparations; Plasmodium falciparum; Point Mutation; Population; Prevalence; Proteins; Quantitative Trait Loci; Research Support; Resistance; Risk; Rwanda; Southeastern Asia; Structure; Testing; Time; Treatment Failure; Uganda; asexual; base; benflumetol; biomarker identification; cost; deep sequencing; design; drug-sensitive; fitness; genome sequencing; humanized mouse; improved; innovation; insight; loss of function mutation; molecular marker; mortality; mutant; novel; pressure; programs; pyronaridine; resistance mutation; resistant Plasmodium falciparum; resistant strain; tool; transmission process; treatment strategy; whole genome

PROJECT SUMMARY The worldwide adoption of artemisinin (ART)-based combination therapies (ACTs) has been instrumental in halving the global burden of Plasmodium falciparum (Pf) malaria since the early 2000s; however, progress has stalled since 2015. Malaria’s impact remains vast, with an estimated 405,000 deaths in 2018. Now, Pf resistance to ART derivatives and their ACT partner drugs threatens to overwhelm control efforts. Parasites resistant to ART and piperaquine (PPQ), mediated primarily by mutations in the genes k13 and pfcrt respectively, have swept through the low-transmission setting of Southeast Asia. The development of ACT resistance in Africa, with 94% of the global malaria burden, would be calamitous. A major warning sign is the increasing prevalence of an ART resistance-conferring K13 mutant in Rwanda, and of other K13 mutations in nearby countries. Herein we confront the prospect of ACT resistance emerging in Africa. In Aim 1, we will test the hypothesis that African Pf strains rarely pose a biological obstacle to K13 mutations driving ART resistance. By gene editing geographically diverse African strains, we will identify the most resistant mutations and assess the impact of the parasite background, which can substantially influence the levels of resistance and fitness. Having recently completed two Pf genetic crosses between Cambodian ART-resistant K13 mutants and the drug-sensitive African parasite NF54, we will map and confirm secondary ART resistance modulators. We will also test whether resistance can be attributed to loss-of-function mutations that restrict hemoglobin endocytosis in early ring stages. In Aim 2, we will test the hypothesis that mutant K13 will exert a substantial fitness cost in African parasites, which could impede its spread in high-transmission settings. One approach will be to quantify growth rates of barcoded K13 mutant and wild-type isogenic lines. We also hypothesize that ART resistance in Asian parasites evolved via a gain of K13 mutations combined with compensatory fitness mutations, and will use our genetic cross progeny to map and confirm fitness modulators. In Aim 3, we will pursue determinants of Pf resistance to the ACT partner drugs PPQ, lumefantrine (LMF), pyronaridine (PND) and amodiaquine (ADQ) in African parasites. Gene editing will be used to test the hypothesis that PPQ resistance can arise through single point mutations in African PfCRT haplotypes. Efforts to identify determinants of resistance to LMF and PND will employ selections with hyper- mutable African lines. We will also leverage the discovery in one of our genetic crosses of a two-component basis of ADQ resistance that includes pfcrt and an unknown determinant on chromosome 12. The identification of these markers will provide a valuable tool to screen for ADQ resistance. This proposal, which aligns with the NIAID priority of supporting research on antimicrobial drug resistance, is designed to proactively prepare for the dire possibility of ART and ACT resistance emerging in Africa by identifying causal determinants and mutations and assessing whether fitness costs can impede the spread of resistance in African transmission settings.

项目摘要 全球采用阿耳马素（ART）的组合疗法（ACTS）已发挥了作用 自2000年代初以来，全球恶性疟原虫（PF）疟疾的负担减半；但是，进度有所了解 自2015年以来停滞不前。疟疾的影响仍然很大，2018年估计有405,000人死亡。现在，PF阻力 对于艺术衍生品及其ACT伴侣药物，有可能压倒控制工作。抗寄生虫 Art and Piperaquine（PPQ）分别由基因K13和PFCRT中的突变介导的介导 横扫东南亚的低频设置。非洲行动抵抗的发展， 94％的全球疟疾伯恩将是灾难性的。一个主要警告信号是越来越多的患病率 在卢旺达限制K13突变体的艺术抵抗，以及附近国家的其他K13突变。在这里我们 面对非洲抗行为的前景。在AIM 1中，我们将测试非洲PF的假设 菌株很少对K13突变构成抗抗Art抗性的生物学障碍。通过基因编辑地理编辑 潜水非洲菌株，我们将确定最具抵抗力的突变并评估寄生虫的影响 背景，这可能会大大影响抵抗力和适应性的水平。最近完成了 耐柬埔寨的抗毒剂K13突变体和对药物敏感的非洲寄生虫之间的两个PF遗传杂交 NF54，我们将绘制并确认二级艺术电阻调节器。我们还将测试阻力是否可以 归因于限制早期环阶段血红蛋白内吞作用的功能丧失突变。在AIM 2中，我们 将检验以下假设：突变K13将在非洲寄生虫中施加大量的健身成本，这可能 阻碍其在高频设置中的传播。一种方法是量化条形码K13的增长率 突变体和野生型等源线。我们还假设亚洲寄生虫中的艺术抗性通过了 K13突变的获取结合了补偿性适应性突变，并将使用我们的遗传交叉进度 映射并确认健身调节器。在AIM 3中，我们将确定对ACT合作伙伴的PF抵抗 在非洲寄生虫中，药物PPQ，Lumefantrine（LMF），吡喃吡啶（PND）和Amodiaquine（ADQ）。基因编辑 将用于检验以下假设，即通过非洲PFCRT中的单点突变会引起PPQ抗性 单倍型。识别对LMF和PND耐药性的确定剂的优惠将采用超级选择 可变的非洲线路。我们还将在我们的两个组成部分的遗传杂交之一中利用该发现 ADQ抗性的基础，包括PFCRT和染色体12上的未知确定剂。 这些标记中将提供一个有价值的工具来筛选ADQ电阻。该提议与 支持抗菌药物耐药性研究的NIAID优先级，旨在主动为 通过识别因果决定者和突变，在非洲出现了艺术和行动抵抗的可怕可能性 并评估健身成本是否会阻碍抵抗在非洲传输环境中的传播。