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

• 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
• 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

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.

项目摘要 疟原虫恶性疟原虫（PF）疟疾病例最近激增，估计在2020年死亡627,000例 主要是在非洲年轻儿童中。减少非洲疾病燃烧的努力包括化学预防 保护脆弱人群和治疗有效青蒿素的症状感染的策略 基于组合疗法。临床研究已经确定了Piperaquine（PPQ）是理想的化学预防 和治疗伴侣药物因其针对无性血液阶段寄生虫的效力，长血浆半衰期和 儿童和孕妇的良好安全性。但是，这两种药物都是一线组合 二氢苯胺蛋白-PPQ在东南亚遇到了宽度的抵抗。给定最近的 在卢旺达和乌干达的抗甲米辛蛋白PF寄生虫中的出现，迫切需要调查 PPQ抵抗是否可以在非洲出现和传播，确定其遗传介体并发展新的方式 中和电阻。在AIM 1中，我们的研究将集中于在背景下出现的新型突变 PF氯喹耐药性转运蛋白PFCRT的氯喹抗性同工型以及扩增 血浆蛋白2和3（PM2/3），这两者都导致了东南部的PPQ耐药性和治疗失败 亚洲。使用基因编辑和过表达方法，我们将确定PPQ抗性是否可以是 通过将个体突变引入非洲特异性PFCRT同工型和评估中，在非洲线上产生 PM2/3拷贝数是否增加了阻力。我们还将评估PM2/3的扩增 为PFCRT突变寄生虫带来健身益处，这可以帮助建立和维持PPQ抗性 高转移非洲环境。在AIM 2中，我们将研究抑制血红素排毒和 浓度依赖性药物排出分别在PPQ作用和抗性中。我们的研究还将测试 假设耐PPQ的PFCRT同工型干扰细胞内血红蛋白衍生的肽水平，这 可以通过PM2/3扩增校正。在AIM 3中，我们提出直接针对PFCRT介导的 电阻代表了保持PPQ效率的高价值方法。利用有关反对的见解 选择性压力，我们将测试将PPQ与其他基于喹啉的药物（氯喹， 氨二喹或甲氟喹）可以消除抗PPQ的寄生虫，并防止抗性的复发 变体。我们还将筛选通过通过突变体PFCRT阻断PPQ外排来反向电阻的抑制剂。 测定将包括ZY19489，这是人类临床试验中的抗疟疾，抑制PFCRT介导的药物外排和 对PF寄生虫过敏到PPQ。同时，我们将进行一个高通量屏幕，旨在识别 新颖的PPQ抗性反转代理。该提案与Niaid的优先支持研究相吻合 在抗菌药物耐药性上，旨在主动预测非洲PPQ耐药性的出现 并确定可以中和抗药性并帮助维持这种必需药物的临床效率的抑制剂。