Elucidating the molecular basis of piperaquine resistance in Plasmodium falciparum

阐明恶性疟原虫哌喹耐药的分子基础

基本信息

批准号：
10595160
负责人：
David A Fidock
金额：
$ 49.13万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-02-01 至 2027-11-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10595160
关键词：
Africa African Amodiaquine Antimalarials Artemisinins Binding Biological Assay Blood Cessation of life Chemicals Chemoprevention Child Chloroquine Chloroquine resistance Clinical Research Clinical Trials Combined Modality Therapy Computer Models Drug Combinations Drug Efflux Drug Kinetics Drug Metabolic Detoxication Drug Targeting Essential Drugs Falciparum Malaria Funding Genes Genetic Genetic Crosses Genetic Determinism Globin Growth Half-Life Haplotypes Heme Hemoglobin Human In Vitro Individual Infection Investigation Lead Luciferases Malaria Maps Measures Mediating Mediator Mefloquine Metabolism Microbial Drug Resistance Molecular Morbidity - disease rate Mutation National Institute of Allergy and Infectious Disease Parasite resistance Parasites Pathway interactions Peptides Pharmaceutical Preparations Plasma Plasmodium falciparum Population Pregnant Women Prevention strategy Protein Isoforms Recrudescences Research Support Resistance Risk Assessment Role Rwanda Safety Source Southeastern Asia Techniques Testing Transgenes Treatment Failure Uganda Vacuole Variant Vulnerable Populations asexual burden of illness clinical efficacy cost design fighting fitness hemozoin high throughput screening inhibitor innovation insight mortality mutant novel overexpression plasmepsin pressure prevent proteoliposomes quinoline resistance allele resistant Plasmodium falciparum risk prediction success symptom treatment transmission process

项目摘要

PROJECT SUMMARY Plasmodium falciparum (Pf) malaria cases have recently surged, with an estimated 627,000 deaths in 2020, mostly in young African children. Efforts to reduce the burden of disease in Africa include both chemoprevention strategies to protect vulnerable populations and treatment of symptomatic infections with effective artemisinin- based combination therapies. Clinical studies have identified piperaquine (PPQ) as an ideal chemoprevention and treatment partner drug due to its potency against asexual blood stage parasites, long plasma half-life, and good safety profile in children and pregnant women. However, both drugs in the first-line combination of dihydroartemisinin-PPQ have encountered widespread resistance in Southeast Asia. Given the recent emergence in Rwanda and Uganda of artemisinin-resistant Pf parasites, there is a pressing need to investigate whether PPQ resistance can emerge and spread in Africa, identify its genetic mediators, and develop new ways to neutralize resistance. In Aim 1, our studies will focus on novel mutations that emerged on the background of chloroquine-resistant isoforms of the Pf chloroquine resistance transporter PfCRT, as well as the amplification of plasmepsins 2 and 3 (pm2/3), both of which contribute to PPQ resistance and treatment failure in Southeast Asia. Using gene editing and overexpression approaches, we will determine whether PPQ resistance can be generated in African lines by introducing individual mutations into African-specific PfCRT isoforms and assessing whether increased pm2/3 copy numbers augment resistance. We will also assess whether pm2/3 amplifications afford a fitness benefit to PfCRT mutant parasites, which could help establish and maintain PPQ resistance in high-transmission African settings. In Aim 2, we will examine the role of inhibition of heme detoxification and concentration-dependent drug efflux in PPQ action and resistance, respectively. Our studies will also test the hypothesis that PPQ-resistant PfCRT isoforms perturb intracellular hemoglobin-derived peptide levels, which may be corrected by pm2/3 amplification. In Aim 3, we propose that directly targeting PfCRT-mediated resistance represents a high-value approach to retaining PPQ efficacy. Leveraging insights regarding opposing selective pressures, we will test whether combining PPQ with other quinoline-based drugs (chloroquine, amodiaquine or mefloquine) can eliminate PPQ-resistant parasites and prevent the recrudescence of resistant variants. We will also screen for inhibitors that reverse resistance by blocking PPQ efflux via mutant PfCRT. Assays will include ZY19489, an antimalarial in human clinical trials that inhibits PfCRT-mediated drug efflux and hypersensitizes Pf parasites to PPQ. Concurrently, we will conduct a high-throughput screen designed to identify novel PPQ resistance reversal agents. This proposal, which aligns with NIAID’s priority of supporting research on antimicrobial drug resistance, is designed to proactively predict the emergence of PPQ resistance in Africa and to identify inhibitors that can neutralize resistance and help sustain the clinical efficacy of this essential drug.

项目概要恶性疟原虫 (Pf) 疟疾病例最近激增，预计 2020 年将有 627,000 人死亡，减少非洲疾病负担的努力主要包括化学预防。保护弱势群体和使用有效青蒿素治疗症状感染的策略基于联合疗法的临床研究已确定哌喹（PPQ）是一种理想的化学预防方法。和治疗伙伴药物，因为它对无性血期寄生虫具有效力，血浆半衰期长，并且然而，这两种药物在儿童和孕妇中的安全性良好。鉴于最近，双氢青蒿素-PPQ 在东南亚遇到了广泛的阻力。卢旺达和乌干达出现了青蒿素耐药性 Pf 寄生虫，迫切需要进行调查 PPQ 耐药性是否会在非洲出现和传播，确定其遗传介质并开发新方法在目标 1 中，我们的研究将集中于背景下出现的新突变。 Pf 氯喹抗性转运蛋白 PfCRT 的氯喹抗性亚型，以及扩增血浆蛋白酶 2 和 3 (pm2/3)，两者均导致东南部地区的 PPQ 耐药性和治疗失败亚洲。使用基因编辑和过度表达方法，我们将确定是否可以消除 PPQ 耐药性。通过将个体突变引入非洲特有的 PfCRT 同工型并评估，在非洲品系中产生 pm2/3 拷贝数增加是否会增强抵抗力我们还将评估 pm2/3 扩增是否会增加。为 PfCRT 突变寄生虫提供适应性益处，这有助于在体内建立和维持 PPQ 抗性在目标 2 中，我们将研究血红素解毒和抑制的作用。我们的研究还将分别测试 PPQ 作用和耐药性中的浓度依赖性药物流出。假设 PPQ 抗性 PfCRT 亚型扰乱细胞内血红蛋白衍生肽水平，可以通过 pm2/3 扩增来纠正。在目标 3 中，我们建议直接靶向 PfCRT 介导的。抵抗代表了利用有关反对意见的见解来保持 PPQ 功效的高价值方法。选择性压力，我们将测试 PPQ 是否与其他喹啉类药物（氯喹、阿莫地喹或甲氟喹）可以消除 PPQ 耐药寄生虫并防止耐药性复发我们还将筛选通过突变体 PfCRT 阻断 PPQ 外流来逆转耐药性的抑制剂。检测将包括 ZY19489，这是一种在人体临床试验中的抗疟药，可抑制 PfCRT 介导的药物流出和同时，我们将进行旨在识别 Pf 寄生虫的高通量筛选。新型 PPQ 耐药逆转剂该提案符合 NIAID 支持研究的优先事项。关于抗菌药物耐药性的研究，旨在主动预测非洲 PPQ 耐药性的出现并确定可以中和耐药性并有助于维持这种基本药物的临床疗效的抑制剂。