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Queffeulou M, Leprohon P, Fernandez-Prada C, Ouellette M, Mejía-Jaramillo AM. CRISPR-Cas9 high-throughput screening to study drug resistance in Leishmania infantum. mBio 2024; 15:e0047724. [PMID: 38864609 PMCID: PMC11253630 DOI: 10.1128/mbio.00477-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 04/23/2024] [Indexed: 06/13/2024] Open
Abstract
Parasites of the genus Leishmania pose a global health threat with limited treatment options. New drugs are urgently needed, and genomic screens have the potential to accelerate target discovery, mode of action, and resistance mechanisms against these new drugs. We describe here our effort in developing a genome-wide CRISPR-Cas9 screen in Leishmania, an organism lacking a functional nonhomologous end joining system that must rely on microhomology-mediated end joining, single-strand annealing, or homologous recombination for repairing Cas9-induced double-stranded DNA breaks. A new vector for cloning and expressing single guide RNAs (sgRNAs) was designed and proven to be effective in a small pilot project while enriching specific sgRNAs during drug selection. We then developed a whole-genome library of 49,754 sgRNAs, targeting all the genes of Leishmania infantum. This library was transfected in L. infantum expressing Cas9, and these cells were selected for resistance to two antileishmanials, miltefosine and amphotericin B. The sgRNAs the most enriched in the miltefosine screen targeted the miltefosine transporter gene, but sgRNAs targeting genes coding for a RING-variant protein and a transmembrane protein were also enriched. The sgRNAs the most enriched by amphotericin B targeted the sterol 24 C methyltransferase genes and a hypothetical gene. Through gene disruption experiments, we proved that loss of function of these genes was associated with resistance. This study describes the feasibility of carrying out whole-genome CRISPR-Cas9 screens in Leishmania provided that a strong selective pressure is applied. Such a screen can be used for accelerating the development of urgently needed antileishmanial drugs.IMPORTANCELeishmaniasis, a global health threat, lacks adequate treatment options and drug resistance exacerbates the challenge. This study introduces a CRISPR-Cas9 screening approach in Leishmania infantum, unraveling mechanisms of drug resistance at a genome-wide scale. Our screen was applied against two main antileishmanial drugs, and guides were enriched upon drug selection. These guides targeted known and new targets, hence validating the use of this screen against Leishmania. This strategy provides a powerful tool to expedite drug discovery as well as potential therapeutic targets against this neglected tropical disease.
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Affiliation(s)
- Marine Queffeulou
- Centre de Recherche en Infectiologie du Centre de Recherche du CHU Québec, Université Laval, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, Canada
| | - Philippe Leprohon
- Centre de Recherche en Infectiologie du Centre de Recherche du CHU Québec, Université Laval, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, Canada
| | - Christopher Fernandez-Prada
- Centre de Recherche en Infectiologie du Centre de Recherche du CHU Québec, Université Laval, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, Canada
| | - Marc Ouellette
- Centre de Recherche en Infectiologie du Centre de Recherche du CHU Québec, Université Laval, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, Canada
| | - Ana María Mejía-Jaramillo
- Centre de Recherche en Infectiologie du Centre de Recherche du CHU Québec, Université Laval, Québec, Canada
- Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université Laval, Québec, Canada
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McDermott SM, Pham V, Oliver B, Carnes J, Sather DN, Stuart KD. Deep mutational scanning of the RNase III-like domain in Trypanosoma brucei RNA editing protein KREPB4. Front Cell Infect Microbiol 2024; 14:1381155. [PMID: 38650737 PMCID: PMC11033214 DOI: 10.3389/fcimb.2024.1381155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 03/14/2024] [Indexed: 04/25/2024] Open
Abstract
Kinetoplastid pathogens including Trypanosoma brucei, T. cruzi, and Leishmania species, are early diverged, eukaryotic, unicellular parasites. Functional understanding of many proteins from these pathogens has been hampered by limited sequence homology to proteins from other model organisms. Here we describe the development of a high-throughput deep mutational scanning approach in T. brucei that facilitates rapid and unbiased assessment of the impacts of many possible amino acid substitutions within a protein on cell fitness, as measured by relative cell growth. The approach leverages several molecular technologies: cells with conditional expression of a wild-type gene of interest and constitutive expression of a library of mutant variants, degron-controlled stabilization of I-SceI meganuclease to mediate highly efficient transfection of a mutant allele library, and a high-throughput sequencing readout for cell growth upon conditional knockdown of wild-type gene expression and exclusive expression of mutant variants. Using this method, we queried the effects of amino acid substitutions in the apparently non-catalytic RNase III-like domain of KREPB4 (B4), which is an essential component of the RNA Editing Catalytic Complexes (RECCs) that carry out mitochondrial RNA editing in T. brucei. We measured the impacts of thousands of B4 variants on bloodstream form cell growth and validated the most deleterious variants containing single amino acid substitutions. Crucially, there was no correlation between phenotypes and amino acid conservation, demonstrating the greater power of this method over traditional sequence homology searching to identify functional residues. The bloodstream form cell growth phenotypes were combined with structural modeling, RECC protein proximity data, and analysis of selected substitutions in procyclic form T. brucei. These analyses revealed that the B4 RNaseIII-like domain is essential for maintenance of RECC integrity and RECC protein abundances and is also involved in changes in RECCs that occur between bloodstream and procyclic form life cycle stages.
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Affiliation(s)
- Suzanne M. McDermott
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, United States
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, United States
| | - Vy Pham
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, United States
| | - Brian Oliver
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, United States
| | - Jason Carnes
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, United States
| | - D. Noah Sather
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, United States
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, United States
| | - Kenneth D. Stuart
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, United States
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, United States
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Zahedifard F, Bansal M, Sharma N, Kumar S, Shen S, Singh P, Rathi B, Zoltner M. Phenotypic screening reveals a highly selective phthalimide-based compound with antileishmanial activity. PLoS Negl Trop Dis 2024; 18:e0012050. [PMID: 38527083 PMCID: PMC10994559 DOI: 10.1371/journal.pntd.0012050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 04/04/2024] [Accepted: 03/05/2024] [Indexed: 03/27/2024] Open
Abstract
Pharmacophores such as hydroxyethylamine (HEA) and phthalimide (PHT) have been identified as potential synthons for the development of compounds against various parasitic infections. In order to further advance our progress, we conducted an experiment utilising a collection of PHT and HEA derivatives through phenotypic screening against a diverse set of protist parasites. This approach led to the identification of a number of compounds that exhibited significant effects on the survival of Entamoeba histolytica, Trypanosoma brucei, and multiple life-cycle stages of Leishmania spp. The Leishmania hits were pursued due to the pressing necessity to expand our repertoire of reliable, cost-effective, and efficient medications for the treatment of leishmaniases. Antileishmanials must possess the essential capability to efficiently penetrate the host cells and their compartments in the disease context, to effectively eliminate the intracellular parasite. Hence, we performed a study to assess the effectiveness of eradicating L. infantum intracellular amastigotes in a model of macrophage infection. Among eleven L. infantum growth inhibitors with low-micromolar potency, PHT-39, which carries a trifluoromethyl substitution, demonstrated the highest efficacy in the intramacrophage assay, with an EC50 of 1.2 +/- 3.2 μM. Cytotoxicity testing of PHT-39 in HepG2 cells indicated a promising selectivity of over 90-fold. A chemogenomic profiling approach was conducted using an orthology-based method to elucidate the mode of action of PHT-39. This genome-wide RNA interference library of T. brucei identified sensitivity determinants for PHT-39, which included a P-type ATPase that is crucial for the uptake of miltefosine and amphotericin, strongly indicating a shared route for cellular entry. Notwithstanding the favourable properties and demonstrated efficacy in the Plasmodium berghei infection model, PHT-39 was unable to eradicate L. major infection in a murine infection model of cutaneous leishmaniasis. Currently, PHT-39 is undergoing derivatization to optimize its pharmacological characteristics.
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Affiliation(s)
- Farnaz Zahedifard
- Drug Discovery and Evaluation Unit, Department of Parasitology, Faculty of Science, Charles University in Prague, Biocev, Vestec, Czech Republic
| | - Meenakshi Bansal
- H. G. Khorana Centre for Chemical Biology, Department of Chemistry, Hansraj College, University of Delhi, Delhi, India
- Department of Chemistry, Deenbandhu Chhotu Ram, University of Science & Technology, Murthal, Sonepat Haryana, India
| | - Neha Sharma
- H. G. Khorana Centre for Chemical Biology, Department of Chemistry, Hansraj College, University of Delhi, Delhi, India
| | - Sumit Kumar
- Department of Chemistry, Deenbandhu Chhotu Ram, University of Science & Technology, Murthal, Sonepat Haryana, India
| | - Siqi Shen
- Drug Discovery and Evaluation Unit, Department of Parasitology, Faculty of Science, Charles University in Prague, Biocev, Vestec, Czech Republic
| | - Priyamvada Singh
- Department of Chemistry, Miranda House, University of Delhi, Delhi, India
- Delhi School of Public Health, Institution of Eminence, University of Delhi, Delhi, India
| | - Brijesh Rathi
- H. G. Khorana Centre for Chemical Biology, Department of Chemistry, Hansraj College, University of Delhi, Delhi, India
- Delhi School of Public Health, Institution of Eminence, University of Delhi, Delhi, India
| | - Martin Zoltner
- Drug Discovery and Evaluation Unit, Department of Parasitology, Faculty of Science, Charles University in Prague, Biocev, Vestec, Czech Republic
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Heslop R, Gao M, Brito Lira A, Sternlieb T, Loock M, Sanghi SR, Cestari I. Genome-Wide Libraries for Protozoan Pathogen Drug Target Screening Using Yeast Surface Display. ACS Infect Dis 2023; 9:1078-1091. [PMID: 37083339 PMCID: PMC10187560 DOI: 10.1021/acsinfecdis.2c00568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Indexed: 04/22/2023]
Abstract
The lack of genetic tools to manipulate protozoan pathogens has limited the use of genome-wide approaches to identify drug or vaccine targets and understand these organisms' biology. We have developed an efficient method to construct genome-wide libraries for yeast surface display (YSD) and developed a YSD fitness screen (YSD-FS) to identify drug targets. We show the efficacy of our method by generating genome-wide libraries for Trypanosoma brucei, Trypanosoma cruzi, and Giardia lamblia parasites. Each library has a diversity of ∼105 to 106 clones, representing ∼6- to 30-fold of the parasite's genome. Nanopore sequencing confirmed the libraries' genome coverage with multiple clones for each parasite gene. Western blot and imaging analysis confirmed surface expression of the G. lamblia library proteins in yeast. Using the YSD-FS assay, we identified bonafide interactors of metronidazole, a drug used to treat protozoan and bacterial infections. We also found enrichment in nucleotide-binding domain sequences associated with yeast increased fitness to metronidazole, indicating that this drug might target multiple enzymes containing nucleotide-binding domains. The libraries are valuable biological resources for discovering drug or vaccine targets, ligand receptors, protein-protein interactions, and pathogen-host interactions. The library assembly approach can be applied to other organisms or expression systems, and the YSD-FS assay might help identify new drug targets in protozoan pathogens.
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Affiliation(s)
- Rhiannon Heslop
- Institute
of Parasitology, McGill University, Ste Anne de Bellevue, Montreal, QC H9X 3V9, Canada
- Faculté
de Pharmacie de Tours, 31, Avenue Monge, 37200 Tours, France
| | - Mengjin Gao
- Institute
of Parasitology, McGill University, Ste Anne de Bellevue, Montreal, QC H9X 3V9, Canada
| | - Andressa Brito Lira
- Institute
of Parasitology, McGill University, Ste Anne de Bellevue, Montreal, QC H9X 3V9, Canada
| | - Tamara Sternlieb
- Institute
of Parasitology, McGill University, Ste Anne de Bellevue, Montreal, QC H9X 3V9, Canada
| | - Mira Loock
- Institute
of Parasitology, McGill University, Ste Anne de Bellevue, Montreal, QC H9X 3V9, Canada
| | - Sahil Rao Sanghi
- Institute
of Parasitology, McGill University, Ste Anne de Bellevue, Montreal, QC H9X 3V9, Canada
| | - Igor Cestari
- Institute
of Parasitology, McGill University, Ste Anne de Bellevue, Montreal, QC H9X 3V9, Canada
- Division
of Experimental Medicine, McGill University, Montreal, QC H4A 3J1, Canada
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Fairlamb AH, Wyllie S. The critical role of mode of action studies in kinetoplastid drug discovery. FRONTIERS IN DRUG DISCOVERY 2023; 3:fddsv.2023.1185679. [PMID: 37600222 PMCID: PMC7614965 DOI: 10.3389/fddsv.2023.1185679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Abstract
Understanding the target and mode of action of compounds identified by phenotypic screening can greatly facilitate the process of drug discovery and development. Here, we outline the tools currently available for target identification against the neglected tropical diseases, human African trypanosomiasis, visceral leishmaniasis and Chagas' disease. We provide examples how these tools can be used to identify and triage undesirable mechanisms, to identify potential toxic liabilities in patients and to manage a balanced portfolio of target-based campaigns. We review the primary targets of drugs that are currently in clinical development that were initially identified via phenotypic screening, and whose modes of action affect protein turnover, RNA trans-splicing or signalling in these protozoan parasites.
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Affiliation(s)
- Alan H. Fairlamb
- Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Susan Wyllie
- Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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6
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Targeting trypanosomes: how chemogenomics and artificial intelligence can guide drug discovery. Biochem Soc Trans 2023; 51:195-206. [PMID: 36606702 DOI: 10.1042/bst20220618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/01/2022] [Accepted: 12/05/2022] [Indexed: 01/07/2023]
Abstract
Trypanosomatids are protozoan parasites that cause human and animal neglected diseases. Despite global efforts, effective treatments are still much needed. Phenotypic screens have provided several chemical leads for drug discovery, but the mechanism of action for many of these chemicals is currently unknown. Recently, chemogenomic screens assessing the susceptibility or resistance of parasites carrying genome-wide modifications started to define the mechanism of action of drugs at large scale. In this review, we discuss how genomics is being used for drug discovery in trypanosomatids, how integration of chemical and genomics data from these and other organisms has guided prioritisations of candidate therapeutic targets and additional chemical starting points, and how these data can fuel the expansion of drug discovery pipelines into the era of artificial intelligence.
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7
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Alpizar-Sosa EA, Ithnin NRB, Wei W, Pountain AW, Weidt SK, Donachie AM, Ritchie R, Dickie EA, Burchmore RJS, Denny PW, Barrett MP. Amphotericin B resistance in Leishmania mexicana: Alterations to sterol metabolism and oxidative stress response. PLoS Negl Trop Dis 2022; 16:e0010779. [PMID: 36170238 PMCID: PMC9581426 DOI: 10.1371/journal.pntd.0010779] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 10/19/2022] [Accepted: 08/31/2022] [Indexed: 11/18/2022] Open
Abstract
Amphotericin B is increasingly used in treatment of leishmaniasis. Here, fourteen independent lines of Leishmania mexicana and one L. infantum line were selected for resistance to either amphotericin B or the related polyene antimicrobial, nystatin. Sterol profiling revealed that, in each resistant line, the predominant wild-type sterol, ergosta-5,7,24-trienol, was replaced by other sterol intermediates. Broadly, two different profiles emerged among the resistant lines. Whole genome sequencing then showed that these distinct profiles were due either to mutations in the sterol methyl transferase (C24SMT) gene locus or the sterol C5 desaturase (C5DS) gene. In three lines an additional deletion of the miltefosine transporter gene was found. Differences in sensitivity to amphotericin B were apparent, depending on whether cells were grown in HOMEM, supplemented with foetal bovine serum, or a serum free defined medium (DM). Metabolomic analysis after exposure to AmB showed that a large increase in glucose flux via the pentose phosphate pathway preceded cell death in cells sustained in HOMEM but not DM, indicating the oxidative stress was more significantly induced under HOMEM conditions. Several of the lines were tested for their ability to infect macrophages and replicate as amastigote forms, alongside their ability to establish infections in mice. While several AmB resistant lines showed reduced virulence, at least two lines displayed heightened virulence in mice whilst retaining their resistance phenotype, emphasising the risks of resistance emerging to this critical drug.
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Affiliation(s)
- Edubiel A. Alpizar-Sosa
- Wellcome Centre for Integrative Parasitology, School of Infection & Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Department of Biosciences, Durham University, Durham, United Kingdom
| | - Nur Raihana Binti Ithnin
- Wellcome Centre for Integrative Parasitology, School of Infection & Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Department of Medical Microbiology, Faculty of Medicine & Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Wenbin Wei
- Department of Biosciences, Durham University, Durham, United Kingdom
| | - Andrew W. Pountain
- Wellcome Centre for Integrative Parasitology, School of Infection & Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Institute for Computational Medicine, New York University Grossman School of Medicine, New York City, New York, United States of America
| | - Stefan K. Weidt
- Glasgow Polyomics, College of Medical, Veterinary & Life Sciences, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
| | - Anne M. Donachie
- Wellcome Centre for Integrative Parasitology, School of Infection & Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Ryan Ritchie
- Wellcome Centre for Integrative Parasitology, School of Infection & Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Emily A. Dickie
- Wellcome Centre for Integrative Parasitology, School of Infection & Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Glasgow Polyomics, College of Medical, Veterinary & Life Sciences, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
| | - Richard J. S. Burchmore
- Wellcome Centre for Integrative Parasitology, School of Infection & Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Glasgow Polyomics, College of Medical, Veterinary & Life Sciences, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
| | - Paul W. Denny
- Department of Biosciences, Durham University, Durham, United Kingdom
| | - Michael P. Barrett
- Wellcome Centre for Integrative Parasitology, School of Infection & Immunity, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Glasgow Polyomics, College of Medical, Veterinary & Life Sciences, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
- * E-mail:
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Bettadapur A, Hunter SS, Suleiman RL, Ruyechan MC, Huang W, Barbieri CG, Miller HW, Tam TSY, Settles ML, Ralston KS. Establishment of quantitative RNAi-based forward genetics in Entamoeba histolytica and identification of genes required for growth. PLoS Pathog 2021; 17:e1010088. [PMID: 34843592 PMCID: PMC8716031 DOI: 10.1371/journal.ppat.1010088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 12/29/2021] [Accepted: 11/03/2021] [Indexed: 01/05/2023] Open
Abstract
While Entamoeba histolytica remains a globally important pathogen, it is dramatically understudied. The tractability of E. histolytica has historically been limited, which is largely due to challenging features of its genome. To enable forward genetics, we constructed and validated the first genome-wide E. histolytica RNAi knockdown mutant library. This library allows for Illumina deep sequencing analysis for quantitative identification of mutants that are enriched or depleted after selection. We developed a novel analysis pipeline to precisely define and quantify gene fragments. We used the library to perform the first RNAi screen in E. histolytica and identified slow growth (SG) mutants. Among genes targeted in SG mutants, many had annotated functions consistent with roles in cellular growth or metabolic pathways. Some targeted genes were annotated as hypothetical or lacked annotated domains, supporting the power of forward genetics in uncovering functional information that cannot be gleaned from databases. While the localization of neither of the proteins targeted in SG1 nor SG2 mutants could be predicted by sequence analysis, we showed experimentally that SG1 localized to the cytoplasm and cell surface, while SG2 localized to the cytoplasm. Overexpression of SG1 led to increased growth, while expression of a truncation mutant did not lead to increased growth, and thus aided in defining functional domains in this protein. Finally, in addition to establishing forward genetics, we uncovered new details of the unusual E. histolytica RNAi pathway. These studies dramatically improve the tractability of E. histolytica and open up the possibility of applying genetics to improve understanding of this important pathogen.
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Affiliation(s)
- Akhila Bettadapur
- Department of Microbiology and Molecular Genetics, University of California, Davis, California, United States of America
| | - Samuel S. Hunter
- Genome Center, University of California, Davis, California, United States of America
| | - Rene L. Suleiman
- Department of Microbiology and Molecular Genetics, University of California, Davis, California, United States of America
| | - Maura C. Ruyechan
- Department of Microbiology and Molecular Genetics, University of California, Davis, California, United States of America
| | - Wesley Huang
- Department of Microbiology and Molecular Genetics, University of California, Davis, California, United States of America
| | | | - Hannah W. Miller
- Department of Microbiology and Molecular Genetics, University of California, Davis, California, United States of America
| | - Tammie S. Y. Tam
- Department of Microbiology and Molecular Genetics, University of California, Davis, California, United States of America
| | - Matthew L. Settles
- Genome Center, University of California, Davis, California, United States of America
| | - Katherine S. Ralston
- Department of Microbiology and Molecular Genetics, University of California, Davis, California, United States of America
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9
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Horn D. Genome-scale RNAi screens in African trypanosomes. Trends Parasitol 2021; 38:160-173. [PMID: 34580035 DOI: 10.1016/j.pt.2021.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/31/2021] [Accepted: 09/01/2021] [Indexed: 12/11/2022]
Abstract
Genome-scale genetic screens allow researchers to rapidly identify the genes and proteins that impact a particular phenotype of interest. In African trypanosomes, RNA interference (RNAi) knockdown screens have revealed mechanisms underpinning drug resistance, drug transport, prodrug metabolism, quorum sensing, genome replication, and gene expression control. RNAi screening has also been remarkably effective at highlighting promising potential antitrypanosomal drug targets. The first ever RNAi library screen was implemented in African trypanosomes, and genome-scale RNAi screens and other related approaches continue to have a major impact on trypanosomatid research. Here, I review those impacts in terms of both discovery and translation.
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Affiliation(s)
- David Horn
- The Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
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Vásquez-Ocmín PG, Gadea A, Cojean S, Marti G, Pomel S, Van Baelen AC, Ruiz-Vásquez L, Ruiz Mesia W, Figadère B, Ruiz Mesia L, Maciuk A. Metabolomic approach of the antiprotozoal activity of medicinal Piper species used in Peruvian Amazon. JOURNAL OF ETHNOPHARMACOLOGY 2021; 264:113262. [PMID: 32818574 DOI: 10.1016/j.jep.2020.113262] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/24/2020] [Accepted: 08/07/2020] [Indexed: 06/11/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE In the Peruvian Amazon as in the tropical countries of South America, the use of medicinal Piper species (cordoncillos) is common practice, particularly against symptoms of infection by protozoal parasites. However, there is few documented information about the practical aspects of their use and few scientific validation. The starting point of this work was a set of interviews of people living in six rural communities from the Peruvian Amazon (Alto Amazonas Province) about their uses of plants from Piper genus: one community of Amerindian native people (Shawi community) and five communities of mestizos. Infections caused by parasitic protozoa take a huge toll on public health in the Amazonian communities, who partly fight it using traditional remedies. Validation of these traditional practices contributes to public health care efficiency and may help to identify new antiprotozoal compounds. AIMS OF STUDY To record and validate the use of medicinal Piper species by rural people of Alto Amazonas Province (Peru) and annotate active compounds using a correlation study and a data mining approach. MATERIALS AND METHODS Rural communities were interviewed about traditional medication against parasite infections with medicinal Piper species. Ethnopharmacological surveys were undertaken in five mestizo villages, namely: Nueva Arica, Shucushuyacu, Parinari, Lagunas and Esperanza, and one Shawi community (Balsapuerto village). All communities belong to the Alto Amazonas Province (Loreto region, Peru). Seventeen Piper species were collected according to their traditional use for the treatment of parasitic diseases, 35 extracts (leaves or leaves and stems) were tested in vitro on P. falciparum (3D7 chloroquine-sensitive strain and W2 chloroquine-resistant strain), Leishmania donovani LV9 strain and Trypanosoma brucei gambiense. Assessments were performed on HUVEC cells and RAW 264.7 macrophages. The annotation of active compounds was realized by metabolomic analysis and molecular networking approach. RESULTS Nine extracts were active (IC50 ≤ 10 μg/mL) on 3D7 P. falciparum and only one on W2 P. falciparum, six on L. donovani (axenic and intramacrophagic amastigotes) and seven on Trypanosoma brucei gambiense. Only one extract was active on all three parasites (P. lineatum). After metabolomic analyses and annotation of compounds active on Leishmania, P. strigosum and P. pseudoarboreum were considered as potential sources of leishmanicidal compounds. CONCLUSIONS This ethnopharmacological study and the associated in vitro bioassays corroborated the relevance of use of Piper species in the Amazonian traditional medicine, especially in Peru. A series of Piper species with few previously available phytochemical data have good antiprotozoal activity and could be a starting point for subsequent promising work. Metabolomic approach appears to be a smart, quick but still limited methodology to identify compounds with high probability of biological activity.
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Affiliation(s)
- Pedro G Vásquez-Ocmín
- Université Paris-Saclay, CNRS, BioCIS, 92290, Châtenay-Malabry, France; UMR152 PHARMADEV, IRD, UPS, Université de Toulouse, Toulouse, France.
| | - Alice Gadea
- Université de Paris, CiTCoM, UMR CNRS 8038, Paris, France
| | - Sandrine Cojean
- Université Paris-Saclay, CNRS, BioCIS, 92290, Châtenay-Malabry, France; CNR du Paludisme, AP-HP, Hôpital Bichat - Claude Bernard, F-75018, Paris, France
| | - Guillaume Marti
- Laboratoire de Recherche en Sciences Végétales UMR 5546 UPS/CNRS, Plateforme MetaboHUB - MetaToul - Métabolites Végétaux, Auzeville-Tolosan, France
| | - Sébastien Pomel
- Université Paris-Saclay, CNRS, BioCIS, 92290, Châtenay-Malabry, France
| | | | - Liliana Ruiz-Vásquez
- Laboratorio de Investigación de Productos Naturales Antiparasitarios de la Amazonia (LIPNAA), Universidad Nacional de la Amazonía Peruana (UNAP), AA. HH. "Nuevo San Lorenzo", Pasaje Paujiles S/N, San Juan, Iquitos, Peru
| | - Wilfredo Ruiz Mesia
- Laboratorio de Investigación de Productos Naturales Antiparasitarios de la Amazonia (LIPNAA), Universidad Nacional de la Amazonía Peruana (UNAP), AA. HH. "Nuevo San Lorenzo", Pasaje Paujiles S/N, San Juan, Iquitos, Peru
| | - Bruno Figadère
- Université Paris-Saclay, CNRS, BioCIS, 92290, Châtenay-Malabry, France
| | - Lastenia Ruiz Mesia
- Laboratorio de Investigación de Productos Naturales Antiparasitarios de la Amazonia (LIPNAA), Universidad Nacional de la Amazonía Peruana (UNAP), AA. HH. "Nuevo San Lorenzo", Pasaje Paujiles S/N, San Juan, Iquitos, Peru
| | - Alexandre Maciuk
- Université Paris-Saclay, CNRS, BioCIS, 92290, Châtenay-Malabry, France.
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11
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Ortalli M, Varani S, Cimato G, Veronesi R, Quintavalla A, Lombardo M, Monari M, Trombini C. Evaluation of the Pharmacophoric Role of the O-O Bond in Synthetic Antileishmanial Compounds: Comparison between 1,2-Dioxanes and Tetrahydropyrans. J Med Chem 2020; 63:13140-13158. [PMID: 33091297 PMCID: PMC8018184 DOI: 10.1021/acs.jmedchem.0c01589] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Indexed: 12/17/2022]
Abstract
Leishmaniases are neglected diseases that can be treated with a limited drug arsenal; the development of new molecules is therefore a priority. Recent evidence indicates that endoperoxides, including artemisinin and its derivatives, possess antileishmanial activity. Here, 1,2-dioxanes were synthesized with their corresponding tetrahydropyrans lacking the peroxide bridge, to ascertain if this group is a key pharmacophoric requirement for the antileishmanial bioactivity. Newly synthesized compounds were examined in vitro, and their mechanism of action was preliminarily investigated. Three endoperoxides and their corresponding tetrahydropyrans effectively inhibited the growth of Leishmania donovani promastigotes and amastigotes, and iron did not play a significant role in their activation. Further, reactive oxygen species were produced in both endoperoxide- and tetrahydropyran-treated promastigotes. In conclusion, the peroxide group proved not to be crucial for the antileishmanial bioactivity of endoperoxides, under the tested conditions. Our findings reveal the potential of both 1,2-dioxanes and tetrahydropyrans as lead compounds for novel therapies against Leishmania.
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Affiliation(s)
- Margherita Ortalli
- Unit of Clinical Microbiology, Regional Reference
Centre for Microbiological Emergencies (CRREM), St. Orsola-Malpighi
University Hospital, Via Massarenti 9, 40138 Bologna,
Italy
| | - Stefania Varani
- Unit of Clinical Microbiology, Regional Reference
Centre for Microbiological Emergencies (CRREM), St. Orsola-Malpighi
University Hospital, Via Massarenti 9, 40138 Bologna,
Italy
- Department of Experimental, Diagnostic and Specialty
Medicine, Alma Mater Studiorum - University of Bologna, Via
Massarenti 9, 40138 Bologna, Italy
| | - Giorgia Cimato
- Unit of Clinical Microbiology, Regional Reference
Centre for Microbiological Emergencies (CRREM), St. Orsola-Malpighi
University Hospital, Via Massarenti 9, 40138 Bologna,
Italy
| | - Ruben Veronesi
- Department of Chemistry “G. Ciamician”,
Alma Mater Studiorum - University of Bologna Via Selmi 2,
40126 Bologna, Italy
| | - Arianna Quintavalla
- Department of Chemistry “G. Ciamician”,
Alma Mater Studiorum - University of Bologna Via Selmi 2,
40126 Bologna, Italy
- Centro Interuniversitario di Ricerca sulla Malaria
(CIRM) - Italian Malaria Network (IMN), University of Milan,
20100 Milan, Italy
| | - Marco Lombardo
- Department of Chemistry “G. Ciamician”,
Alma Mater Studiorum - University of Bologna Via Selmi 2,
40126 Bologna, Italy
- Centro Interuniversitario di Ricerca sulla Malaria
(CIRM) - Italian Malaria Network (IMN), University of Milan,
20100 Milan, Italy
| | - Magda Monari
- Department of Chemistry “G. Ciamician”,
Alma Mater Studiorum - University of Bologna Via Selmi 2,
40126 Bologna, Italy
| | - Claudio Trombini
- Department of Chemistry “G. Ciamician”,
Alma Mater Studiorum - University of Bologna Via Selmi 2,
40126 Bologna, Italy
- Centro Interuniversitario di Ricerca sulla Malaria
(CIRM) - Italian Malaria Network (IMN), University of Milan,
20100 Milan, Italy
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12
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Quintana JF, Bueren-Calabuig J, Zuccotto F, de Koning HP, Horn D, Field MC. Instability of aquaglyceroporin (AQP) 2 contributes to drug resistance in Trypanosoma brucei. PLoS Negl Trop Dis 2020; 14:e0008458. [PMID: 32644992 PMCID: PMC7413563 DOI: 10.1371/journal.pntd.0008458] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 08/07/2020] [Accepted: 06/05/2020] [Indexed: 12/26/2022] Open
Abstract
Defining mode of action is vital for both developing new drugs and predicting potential resistance mechanisms. Sensitivity of African trypanosomes to pentamidine and melarsoprol is predominantly mediated by aquaglyceroporin 2 (TbAQP2), a channel associated with water/glycerol transport. TbAQP2 is expressed at the flagellar pocket membrane and chimerisation with TbAQP3 renders parasites resistant to both drugs. Two models for how TbAQP2 mediates pentamidine sensitivity have emerged; that TbAQP2 mediates pentamidine translocation across the plasma membrane or via binding to TbAQP2, with subsequent endocytosis and presumably transport across the endosomal/lysosomal membrane, but as trafficking and regulation of TbAQPs is uncharacterised this remains unresolved. We demonstrate that TbAQP2 is organised as a high order complex, is ubiquitylated and is transported to the lysosome. Unexpectedly, mutation of potential ubiquitin conjugation sites, i.e. cytoplasmic-oriented lysine residues, reduced folding and tetramerization efficiency and triggered ER retention. Moreover, TbAQP2/TbAQP3 chimerisation, as observed in pentamidine-resistant parasites, also leads to impaired oligomerisation, mislocalisation and increased turnover. These data suggest that TbAQP2 stability is highly sensitive to mutation and that instability contributes towards the emergence of drug resistance.
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Affiliation(s)
- Juan F. Quintana
- School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, United Kingdom
| | - Juan Bueren-Calabuig
- School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, United Kingdom
| | - Fabio Zuccotto
- School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, United Kingdom
| | - Harry P. de Koning
- Institute of Infection, Immunity, and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - David Horn
- School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, United Kingdom
| | - Mark C. Field
- School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, United Kingdom
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
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13
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Van den Kerkhof M, Sterckx YGJ, Leprohon P, Maes L, Caljon G. Experimental Strategies to Explore Drug Action and Resistance in Kinetoplastid Parasites. Microorganisms 2020; 8:E950. [PMID: 32599761 PMCID: PMC7356981 DOI: 10.3390/microorganisms8060950] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 06/22/2020] [Indexed: 12/17/2022] Open
Abstract
Kinetoplastids are the causative agents of leishmaniasis, human African trypanosomiasis, and American trypanosomiasis. They are responsible for high mortality and morbidity in (sub)tropical regions. Adequate treatment options are limited and have several drawbacks, such as toxicity, need for parenteral administration, and occurrence of treatment failure and drug resistance. Therefore, there is an urgency for the development of new drugs. Phenotypic screening already allowed the identification of promising new chemical entities with anti-kinetoplastid activity potential, but knowledge on their mode-of-action (MoA) is lacking due to the generally applied whole-cell based approach. However, identification of the drug target is essential to steer further drug discovery and development. Multiple complementary techniques have indeed been used for MoA elucidation. In this review, the different 'omics' approaches employed to define the MoA or mode-of-resistance of current reference drugs and some new anti-kinetoplastid compounds are discussed.
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Affiliation(s)
- Magali Van den Kerkhof
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, 2610 Wilrijk, Belgium; (M.V.d.K.); (L.M.)
| | - Yann G.-J. Sterckx
- Laboratory of Medical Biochemistry (LMB), University of Antwerp, 2610 Wilrijk, Belgium;
| | - Philippe Leprohon
- Centre de Recherche en Infectiologie du Centre de Recherche du Centre Hospitalier Universitaire de Québec, Université Laval, Québec, QC G1V 0A6, Canada;
| | - Louis Maes
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, 2610 Wilrijk, Belgium; (M.V.d.K.); (L.M.)
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, 2610 Wilrijk, Belgium; (M.V.d.K.); (L.M.)
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14
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Altamura F, Rajesh R, Catta-Preta CMC, Moretti NS, Cestari I. The current drug discovery landscape for trypanosomiasis and leishmaniasis: Challenges and strategies to identify drug targets. Drug Dev Res 2020; 83:225-252. [PMID: 32249457 DOI: 10.1002/ddr.21664] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 02/05/2020] [Accepted: 03/13/2020] [Indexed: 12/11/2022]
Abstract
Human trypanosomiasis and leishmaniasis are vector-borne neglected tropical diseases caused by infection with the protozoan parasites Trypanosoma spp. and Leishmania spp., respectively. Once restricted to endemic areas, these diseases are now distributed worldwide due to human migration, climate change, and anthropogenic disturbance, causing significant health and economic burden globally. The current chemotherapy used to treat these diseases has limited efficacy, and drug resistance is spreading. Hence, new drugs are urgently needed. Phenotypic compound screenings have prevailed as the leading method to discover new drug candidates against these diseases. However, the publication of the complete genome sequences of multiple strains, advances in the application of CRISPR/Cas9 technology, and in vivo bioluminescence-based imaging have set the stage for advancing target-based drug discovery. This review analyses the limitations of the narrow pool of available drugs presently used for treating these diseases. It describes the current drug-based clinical trials highlighting the most promising leads. Furthermore, the review presents a focused discussion on the most important biological and pharmacological challenges that target-based drug discovery programs must overcome to advance drug candidates. Finally, it examines the advantages and limitations of modern research tools designed to identify and validate essential genes as drug targets, including genomic editing applications and in vivo imaging.
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Affiliation(s)
- Fernando Altamura
- Institute of Parasitology, McGill University, Ste Anne de Bellevue, Quebec, Canada
| | - Rishi Rajesh
- Institute of Parasitology, McGill University, Ste Anne de Bellevue, Quebec, Canada
| | | | - Nilmar S Moretti
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Igor Cestari
- Institute of Parasitology, McGill University, Ste Anne de Bellevue, Quebec, Canada
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15
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Pountain AW, Barrett MP. Untargeted metabolomics to understand the basis of phenotypic differences in amphotericin B-resistant Leishmania parasites. Wellcome Open Res 2020; 4:176. [PMID: 32133420 PMCID: PMC7041363 DOI: 10.12688/wellcomeopenres.15452.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2019] [Indexed: 11/20/2022] Open
Abstract
Background: Protozoan
Leishmania parasites are responsible for a range of clinical infections that represent a substantial challenge for global health. Amphotericin B (AmB) is increasingly used to treat
Leishmania infection, so understanding the potential for resistance to this drug is an important priority. Previously we described four independently-derived AmB-resistant
L. mexicana lines that exhibited resistance-associated genetic lesions resulting in altered sterol content. However, substantial phenotypic variation between these lines, including differences in virulence attributes, were not fully explained by these changes. Methods: To identify alterations in cellular metabolism potentially related to phenotypic differences between wild-type and AmB-resistant lines, we extracted metabolites and performed untargeted metabolomics by liquid chromatography-mass spectrometry. Results: We observed substantial differences in metabolite abundance between lines, arising in an apparently stochastic manner. Concerted remodeling of central carbon metabolism was not observed; however, in three lines, decreased abundance of several oligohexoses was observed. Given that the oligomannose mannogen is an important virulence factor in
Leishmania, this could relate to loss of virulence in these lines. Increased abundance of the reduced forms of the oxidative stress-protective thiols trypanothione and glutathione was also observed in multiple lines. Conclusions: This dataset will provide a useful resource for understanding the molecular basis of drug resistance in
Leishmania, and suggests a role for metabolic changes separate from the primary mechanism of drug resistance in determining the phenotypic profile of parasite lines subjected to experimental selection of resistance.
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Affiliation(s)
- Andrew W Pountain
- Wellcome Center for Integrative Parasitology, University of Glasgow, Glasgow, G12 8TA, UK.,Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, 77030, USA
| | - Michael P Barrett
- Wellcome Center for Integrative Parasitology, University of Glasgow, Glasgow, G12 8TA, UK.,Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Bearsden, Glasgow, G61 1QH, UK
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