1
|
Mourot L, Schmitt M, Mouray E, Spichty M, Florent I, Albrecht S. Structure-activity relationship and molecular modelling studies of quinazolinedione derivatives MMV665916 as potential antimalarial agent. Bioorg Med Chem 2021; 51:116513. [PMID: 34798379 DOI: 10.1016/j.bmc.2021.116513] [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: 06/23/2021] [Revised: 10/11/2021] [Accepted: 10/17/2021] [Indexed: 10/19/2022]
Abstract
A series of new quinazolinedione derivatives have been readily synthesized and evaluated for their in vitro antiplasmodial growth inhibition activity. Most of the compounds inhibited P. falciparum FcB1 strain in the low to medium micromolar concentration. The 2-ethoxy 8ag', 2-trifluoromethoxy 8ai' and 4-fluoro-2-methoxy 8ak' showed the best inhibitory activity with EC50 values around 5 µM and were non-toxic to the primary human fibroblast cell line AB943. However, these compounds were less potent than the original hit MMV665916, which showed remarkable growth inhibition with EC50 value of 0.4 µM and presented the highest selectivity index (SI > 250). In addition, a novel approach for determining the docking poses of these quinazolinedione derivatives with their potential protein target, the P. falciparum farnesyltransferase PfFT, was investigated.
Collapse
Affiliation(s)
- Laura Mourot
- Université de Haute-Alsace, Université de Strasbourg, CNRS, LIMA UMR 7042, F-68000 Mulhouse, France
| | - Marjorie Schmitt
- Université de Haute-Alsace, Université de Strasbourg, CNRS, LIMA UMR 7042, F-68000 Mulhouse, France
| | - Elisabeth Mouray
- Unité Molécules de Communication et Adaptation des Micro-organismes, UMR7245, Muséum National d'Histoire Naturelle, CNRS, Sorbonne Universités, Paris, France
| | - Martin Spichty
- Université de Haute-Alsace, Université de Strasbourg, CNRS, LIMA UMR 7042, F-68000 Mulhouse, France
| | - Isabelle Florent
- Unité Molécules de Communication et Adaptation des Micro-organismes, UMR7245, Muséum National d'Histoire Naturelle, CNRS, Sorbonne Universités, Paris, France
| | - Sébastien Albrecht
- Université de Haute-Alsace, Université de Strasbourg, CNRS, LIMA UMR 7042, F-68000 Mulhouse, France.
| |
Collapse
|
2
|
Hermann T, Hochegger P, Dolensky J, Seebacher W, Saf R, Kaiser M, Mäser P, Weis R. New Acyl Derivatives of 3-Aminofurazanes and Their Antiplasmodial Activities. Pharmaceuticals (Basel) 2021; 14:ph14050412. [PMID: 33925485 PMCID: PMC8145535 DOI: 10.3390/ph14050412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/21/2021] [Accepted: 04/24/2021] [Indexed: 11/16/2022] Open
Abstract
An N-acylated furazan-3-amine of a Medicines for Malaria Venture (MMV) project has shown activity against different strains of Plasmodium falciparum. Seventeen new derivatives were prepared and tested in vitro for their activities against blood stages of two strains of Plasmodium falciparum. Several structure-activity relationships were revealed. The activity strongly depended on the nature of the acyl moiety. Only benzamides showed promising activity. The substitution pattern of their phenyl ring affected the activity and the cytotoxicity of compounds. In addition, physicochemical parameters were calculated (log P, log D, ligand efficiency) or determined experimentally (permeability) via a PAMPA. The N-(4-(3,4-diethoxyphenyl)-1,2,5-oxadiazol-3-yl)-3-(trifluoromethyl)benzamide possessed good physicochemical properties and showed high antiplasmodial activity against a chloroquine-sensitive strain (IC50(NF54) = 0.019 µM) and even higher antiplasmodial activity against a multiresistant strain (IC50(K1) = 0.007 µM). Compared to the MMV compound, the permeability and the activity against the multiresistant strain were improved.
Collapse
Affiliation(s)
- Theresa Hermann
- Institute of Pharmaceutical Sciences, Pharmaceutical Chemistry, University of Graz, Schubertstraße 1, A-8010 Graz, Austria; (T.H.); (J.D.); (W.S.); (R.W.)
| | - Patrick Hochegger
- Institute of Pharmaceutical Sciences, Pharmaceutical Chemistry, University of Graz, Schubertstraße 1, A-8010 Graz, Austria; (T.H.); (J.D.); (W.S.); (R.W.)
- Correspondence: ; Tel.: +43-316-380-5379; Fax: +43-316-380-9846
| | - Johanna Dolensky
- Institute of Pharmaceutical Sciences, Pharmaceutical Chemistry, University of Graz, Schubertstraße 1, A-8010 Graz, Austria; (T.H.); (J.D.); (W.S.); (R.W.)
| | - Werner Seebacher
- Institute of Pharmaceutical Sciences, Pharmaceutical Chemistry, University of Graz, Schubertstraße 1, A-8010 Graz, Austria; (T.H.); (J.D.); (W.S.); (R.W.)
| | - Robert Saf
- Institute for Chemistry and Technology of Materials (ICTM), Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria;
| | - Marcel Kaiser
- Swiss Tropical and Public Health Institute, Socinstraße 57, CH-4002 Basel, Switzerland; (M.K.); (P.M.)
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute, Socinstraße 57, CH-4002 Basel, Switzerland; (M.K.); (P.M.)
| | - Robert Weis
- Institute of Pharmaceutical Sciences, Pharmaceutical Chemistry, University of Graz, Schubertstraße 1, A-8010 Graz, Austria; (T.H.); (J.D.); (W.S.); (R.W.)
| |
Collapse
|
3
|
Fabbri C, Trindade AO, Andrade FS, Souza MFD, Ríos-Velásquez CM, Lacerda MVGD, Monteiro WM, Costa FTM, Amino R, Lopes SCP. Transmission-blocking compound candidates against Plasmodium vivax using P. berghei as an initial screening. Mem Inst Oswaldo Cruz 2021; 116:e200513. [PMID: 33566952 PMCID: PMC7874845 DOI: 10.1590/0074-02760200513] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 01/04/2021] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Different strategies for improvement of malaria control and elimination are based on the blockage of malaria parasite transmission to the mosquito vector. These strategies include the drugs that target the plasmodial sexual stages in humans and the early developmental stages inside mosquitoes. OBJECTIVES Here we tested Malaria Box compounds in order to evaluate their activity against male and female gametocytes in Plasmodium berghei, mosquito infection in P. vivax and ookinete formation in both species. METHODS/FINDINGS The membrane feeding assay and the development of ookinetes by a 24 h ex vivo culture and the ookinete yield per 1000 erythrocytes were used to test transmission-blocking potential of the Malaria Box compounds in P. vivax. For P. berghei we used flow cytometry to evaluate male and female gametocyte time course and fluorescence microscopy to check the ookinete development. The two species used in this study showed similar results concerning the compounds’ activity against gametocytes and ookinetes, which were different from those in P. falciparum. In addition, from the eight Malaria Box compounds tested in both species, compounds MMV665830, MMV665878 and MMV665941 were selected as a hit compounds due the high inhibition observed. CONCLUSION Our results showed that P. berghei is suitable as an initial screening system to test compounds against P. vivax.
Collapse
Affiliation(s)
- Camila Fabbri
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Instituto de Pesquisa Clínica Carlos Borborema, Manaus, AM, Brasil.,Universidade do Estado do Amazonas, Programa de Pós-Graduação em Medicina Tropical, Manaus, AM, Brasil.,Centro Universitário Fametro, Manaus, AM, Brasil
| | - Alexandre Oliveira Trindade
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Instituto de Pesquisa Clínica Carlos Borborema, Manaus, AM, Brasil
| | - Francy's Sayara Andrade
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Instituto de Pesquisa Clínica Carlos Borborema, Manaus, AM, Brasil.,Universidade do Estado do Amazonas, Programa de Pós-Graduação em Medicina Tropical, Manaus, AM, Brasil
| | - Macejane Ferreira de Souza
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Instituto de Pesquisa Clínica Carlos Borborema, Manaus, AM, Brasil.,Universidade do Estado do Amazonas, Programa de Pós-Graduação em Medicina Tropical, Manaus, AM, Brasil
| | | | - Marcus Vinicius Guimarães de Lacerda
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Instituto de Pesquisa Clínica Carlos Borborema, Manaus, AM, Brasil.,Universidade do Estado do Amazonas, Programa de Pós-Graduação em Medicina Tropical, Manaus, AM, Brasil.,Fundação Oswaldo Cruz-Fiocruz, Instituto Leônidas e Maria Deane, Manaus, AM, Brasil
| | - Wuelton Marcelo Monteiro
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Instituto de Pesquisa Clínica Carlos Borborema, Manaus, AM, Brasil.,Universidade do Estado do Amazonas, Programa de Pós-Graduação em Medicina Tropical, Manaus, AM, Brasil
| | - Fabio Trindade Maranhão Costa
- Fundação Oswaldo Cruz-Fiocruz, Instituto Leônidas e Maria Deane, Manaus, AM, Brasil.,Universidade Estadual de Campinas, Campinas, SP, Brasil
| | - Rogerio Amino
- Institut Pasteur, Unit of Malaria Infection and Immunity, Department of Parasites and Insect Vectors, Paris, Île-de-France, France
| | - Stefanie Costa Pinto Lopes
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado, Instituto de Pesquisa Clínica Carlos Borborema, Manaus, AM, Brasil.,Universidade do Estado do Amazonas, Programa de Pós-Graduação em Medicina Tropical, Manaus, AM, Brasil.,Fundação Oswaldo Cruz-Fiocruz, Instituto Leônidas e Maria Deane, Manaus, AM, Brasil
| |
Collapse
|
4
|
Álvarez-Bardón M, Pérez-Pertejo Y, Ordóñez C, Sepúlveda-Crespo D, Carballeira NM, Tekwani BL, Murugesan S, Martinez-Valladares M, García-Estrada C, Reguera RM, Balaña-Fouce R. Screening Marine Natural Products for New Drug Leads against Trypanosomatids and Malaria. Mar Drugs 2020; 18:E187. [PMID: 32244488 PMCID: PMC7230869 DOI: 10.3390/md18040187] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 02/06/2023] Open
Abstract
Neglected Tropical Diseases (NTD) represent a serious threat to humans, especially for those living in poor or developing countries. Almost one-sixth of the world population is at risk of suffering from these diseases and many thousands die because of NTDs, to which we should add the sanitary, labor and social issues that hinder the economic development of these countries. Protozoan-borne diseases are responsible for more than one million deaths every year. Visceral leishmaniasis, Chagas disease or sleeping sickness are among the most lethal NTDs. Despite not being considered an NTD by the World Health Organization (WHO), malaria must be added to this sinister group. Malaria, caused by the apicomplexan parasite Plasmodium falciparum, is responsible for thousands of deaths each year. The treatment of this disease has been losing effectiveness year after year. Many of the medicines currently in use are obsolete due to their gradual loss of efficacy, their intrinsic toxicity and the emergence of drug resistance or a lack of adherence to treatment. Therefore, there is an urgent and global need for new drugs. Despite this, the scant interest shown by most of the stakeholders involved in the pharmaceutical industry makes our present therapeutic arsenal scarce, and until recently, the search for new drugs has not been seriously addressed. The sources of new drugs for these and other pathologies include natural products, synthetic molecules or repurposing drugs. The most frequent sources of natural products are microorganisms, e.g., bacteria, fungi, yeasts, algae and plants, which are able to synthesize many drugs that are currently in use (e.g. antimicrobials, antitumor, immunosuppressants, etc.). The marine environment is another well-established source of bioactive natural products, with recent applications against parasites, bacteria and other pathogens which affect humans and animals. Drug discovery techniques have rapidly advanced since the beginning of the millennium. The combination of novel techniques that include the genetic modification of pathogens, bioimaging and robotics has given rise to the standardization of High-Performance Screening platforms in the discovery of drugs. These advancements have accelerated the discovery of new chemical entities with antiparasitic effects. This review presents critical updates regarding the use of High-Throughput Screening (HTS) in the discovery of drugs for NTDs transmitted by protozoa, including malaria, and its application in the discovery of new drugs of marine origin.
Collapse
Affiliation(s)
- María Álvarez-Bardón
- Department of Biomedical Sciences; University of León, 24071 León, Spain; (M.Á.-B.); (Y.P.-P.); (C.O.); (D.S.-C.); (R.M.R.)
| | - Yolanda Pérez-Pertejo
- Department of Biomedical Sciences; University of León, 24071 León, Spain; (M.Á.-B.); (Y.P.-P.); (C.O.); (D.S.-C.); (R.M.R.)
| | - César Ordóñez
- Department of Biomedical Sciences; University of León, 24071 León, Spain; (M.Á.-B.); (Y.P.-P.); (C.O.); (D.S.-C.); (R.M.R.)
| | - Daniel Sepúlveda-Crespo
- Department of Biomedical Sciences; University of León, 24071 León, Spain; (M.Á.-B.); (Y.P.-P.); (C.O.); (D.S.-C.); (R.M.R.)
| | - Nestor M. Carballeira
- Department of Chemistry, University of Puerto Rico, Río Piedras 00925-2537, San Juan, Puerto Rico;
| | - Babu L. Tekwani
- Department of Infectious Diseases, Division of Drug Discovery, Southern Research, Birmingham, AL 35205, USA;
| | - Sankaranarayanan Murugesan
- Department of Pharmacy, Birla Institute of Technology and Science, Pilani Campus, Vidya Vihar, Pilani 333031, India;
| | - Maria Martinez-Valladares
- Department of Animal Health, Instituto de Ganadería de Montaña (CSIC-Universidad de León), Grulleros, 24346 León, Spain;
| | - Carlos García-Estrada
- INBIOTEC (Instituto de Biotecnología de León), Avda. Real 1-Parque Científico de León, 24006 León, Spain;
| | - Rosa M. Reguera
- Department of Biomedical Sciences; University of León, 24071 León, Spain; (M.Á.-B.); (Y.P.-P.); (C.O.); (D.S.-C.); (R.M.R.)
| | - Rafael Balaña-Fouce
- Department of Biomedical Sciences; University of León, 24071 León, Spain; (M.Á.-B.); (Y.P.-P.); (C.O.); (D.S.-C.); (R.M.R.)
| |
Collapse
|
5
|
van der Watt ME, Reader J, Churchyard A, Nondaba SH, Lauterbach SB, Niemand J, Abayomi S, van Biljon RA, Connacher JI, van Wyk RDJ, Le Manach C, Paquet T, González Cabrera D, Brunschwig C, Theron A, Lozano-Arias S, Rodrigues JFI, Herreros E, Leroy D, Duffy J, Street LJ, Chibale K, Mancama D, Coetzer TL, Birkholtz LM. Potent Plasmodium falciparum gametocytocidal compounds identified by exploring the kinase inhibitor chemical space for dual active antimalarials. J Antimicrob Chemother 2019; 73:1279-1290. [PMID: 29420756 DOI: 10.1093/jac/dky008] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 01/02/2018] [Indexed: 01/06/2023] Open
Abstract
Objectives Novel chemical tools to eliminate malaria should ideally target both the asexual parasites and transmissible gametocytes. Several imidazopyridazines (IMPs) and 2-aminopyridines (2-APs) have been described as potent antimalarial candidates targeting lipid kinases. However, these have not been extensively explored for stage-specific inhibition of gametocytes in Plasmodium falciparum parasites. Here we provide an in-depth evaluation of the gametocytocidal activity of compounds from these chemotypes and identify novel starting points for dual-acting antimalarials. Methods We evaluated compounds against P. falciparum gametocytes using several assay platforms for cross-validation and stringently identified hits that were further profiled for stage specificity, speed of action and ex vivo efficacy. Physicochemical feature extraction and chemogenomic fingerprinting were applied to explore the kinase inhibition susceptibility profile. Results We identified 34 compounds with submicromolar activity against late stage gametocytes, validated across several assay platforms. Of these, 12 were potent at <100 nM (8 were IMPs and 4 were 2-APs) and were also active against early stage gametocytes and asexual parasites, with >1000-fold selectivity towards the parasite over mammalian cells. Front-runner compounds targeted mature gametocytes within 48 h and blocked transmission to mosquitoes. The resultant chemogenomic fingerprint of parasites treated with the lead compounds revealed the importance of targeting kinases in asexual parasites and gametocytes. Conclusions This study encompasses an in-depth evaluation of the kinase inhibitor space for gametocytocidal activity. Potent lead compounds have enticing dual activities and highlight the importance of targeting the kinase superfamily in malaria elimination strategies.
Collapse
Affiliation(s)
- Mariëtte E van der Watt
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Janette Reader
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Alisje Churchyard
- Plasmodium Molecular Research Unit, Wits Research Institute for Malaria, Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg 2193, South Africa
| | - Sindisiwe H Nondaba
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Sonja B Lauterbach
- Plasmodium Molecular Research Unit, Wits Research Institute for Malaria, Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg 2193, South Africa
| | - Jandeli Niemand
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Sijuade Abayomi
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Riëtte A van Biljon
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Jessica I Connacher
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Roelof D J van Wyk
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| | - Claire Le Manach
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Tanya Paquet
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Diego González Cabrera
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Christel Brunschwig
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Anjo Theron
- Biosciences, Council for Scientific and Industrial Research, PO Box 395, Pretoria 0001, South Africa
| | - Sonia Lozano-Arias
- GlaxoSmithKline, Tres Cantos Medicines Development Campus, Severo Ochoa, 2, 28760 Tres Cantos, Madrid, Spain
| | - Janneth F I Rodrigues
- GlaxoSmithKline, Tres Cantos Medicines Development Campus, Severo Ochoa, 2, 28760 Tres Cantos, Madrid, Spain
| | - Esperanza Herreros
- GlaxoSmithKline, Tres Cantos Medicines Development Campus, Severo Ochoa, 2, 28760 Tres Cantos, Madrid, Spain
| | - Didier Leroy
- Medicines for Malaria Venture, International Center Cointrin, Route de Pré-Bois 20, 1215, Geneva, Switzerland
| | - James Duffy
- Medicines for Malaria Venture, International Center Cointrin, Route de Pré-Bois 20, 1215, Geneva, Switzerland
| | - Leslie J Street
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Kelly Chibale
- Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.,South African Medical Research Council, Drug Discovery and Development Research Unit, Department of Chemistry and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
| | - Dalu Mancama
- Biosciences, Council for Scientific and Industrial Research, PO Box 395, Pretoria 0001, South Africa
| | - Theresa L Coetzer
- Plasmodium Molecular Research Unit, Wits Research Institute for Malaria, Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg 2193, South Africa
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Institute for Sustainable Malaria Control and South African Medical Research Council Collaborating Centre for Malaria Research, University of Pretoria, Private Bag x20, Hatfield, Pretoria 0028, South Africa
| |
Collapse
|
6
|
Artemisone and Artemiside Are Potent Panreactive Antimalarial Agents That Also Synergize Redox Imbalance in Plasmodium falciparum Transmissible Gametocyte Stages. Antimicrob Agents Chemother 2018; 62:AAC.02214-17. [PMID: 29866868 DOI: 10.1128/aac.02214-17] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 05/18/2018] [Indexed: 11/20/2022] Open
Abstract
The emergence of resistance toward artemisinin combination therapies (ACTs) by the malaria parasite Plasmodium falciparum has the potential to severely compromise malaria control. Therefore, the development of new artemisinins in combination with new drugs that impart activities toward both intraerythrocytic proliferative asexual and transmissible gametocyte stages, in particular, those of resistant parasites, is urgently required. We define artemisinins as oxidant drugs through their ability to oxidize reduced flavin cofactors of flavin disulfide reductases critical for maintaining redox homeostasis in the malaria parasite. Here we compare the activities of 10-amino artemisinin derivatives toward the asexual and gametocyte stages of P. falciparum parasites. Of these, artemisone and artemiside inhibited asexual and gametocyte stages, particularly stage V gametocytes, in the low-nanomolar range. Further, treatment of both early and late gametocyte stages with artemisone or artemiside combined with the pro-oxidant redox partner methylene blue displayed notable synergism. These data suggest that modulation of redox homeostasis is likely an important druggable process, particularly in gametocytes, and this finding thereby enhances the prospect of using combinations of oxidant and redox drugs for malaria control.
Collapse
|
7
|
Duez J, Carucci M, Garcia-Barbazan I, Corral M, Perez O, Presa JL, Henry B, Roussel C, Ndour PA, Rosa NB, Sanz L, Gamo FJ, Buffet P. High-throughput microsphiltration to assess red blood cell deformability and screen for malaria transmission–blocking drugs. Nat Protoc 2018; 13:1362-1376. [DOI: 10.1038/nprot.2018.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
8
|
Sinha S, Sarma P, Sehgal R, Medhi B. Development in Assay Methods for in Vitro Antimalarial Drug Efficacy Testing: A Systematic Review. Front Pharmacol 2017; 8:754. [PMID: 29123481 PMCID: PMC5662882 DOI: 10.3389/fphar.2017.00754] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 10/04/2017] [Indexed: 11/13/2022] Open
Abstract
The emergence and spread of drug resistance are the major challenges in malaria eradication mission. Besides various strategies laid down by World Health Organization, such as vector management, source reduction, early case detection, prompt treatment, and development of new diagnostics and vaccines, nevertheless the need for new and efficacious drugs against malaria has become a critical priority on the global malaria research agenda. At several screening stages, millions of compounds are screened (1,000–2,000,000 compounds per screening campaign), before pre-clinical trials to select optimum lead. Carrying out in vitro screening of antimalarials is very difficult as different assay methods are subject to numerous sources of variability across different laboratories around the globe. Despite this, in vitro screening is an essential part of antimalarial drug development as it enables to resource various confounding factors such as host immune response and drug–drug interaction. Therefore, in this article, we try to illustrate the basic necessity behind in vitro study and how new methods are developed and subsequently adopted for high-throughput antimalarial drug screening and its application in achieving the next level of in vitro screening based on the current approaches (such as stem cells).
Collapse
Affiliation(s)
- Shweta Sinha
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Phulen Sarma
- Department of Pharmacology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Rakesh Sehgal
- Department of Medical Parasitology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Bikash Medhi
- Department of Pharmacology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| |
Collapse
|
9
|
The need to compare: assessing the level of agreement of three high-throughput assays against Plasmodium falciparum mature gametocytes. Sci Rep 2017; 7:45992. [PMID: 28378767 PMCID: PMC5380998 DOI: 10.1038/srep45992] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 03/07/2017] [Indexed: 12/22/2022] Open
Abstract
Whole-cell High-Throughput Screening (HTS) is a key tool for the discovery of much needed malaria transmission blocking drugs. Discrepancies in the reported outcomes from various HTS Plasmodium falciparum gametocytocidal assays hinder the direct comparison of data and ultimately the interpretation of the transmission blocking potential of hits. To dissect the underlying determinants of such discrepancies and assess the impact that assay-specific factors have on transmission-blocking predictivity, a 39-compound subset from the Medicines for Malaria Venture Malaria Box was tested in parallel against three distinct mature stage gametocytocidal assays, under strictly controlled parasitological, chemical, temporal and analytical conditions resembling the standard membrane feeding assay (SMFA). Apart from a few assay-specific outliers, which highlighted the value of utilizing multiple complementary approaches, good agreement was observed (average ΔpIC50 of 0.12 ± 0.01). Longer compound incubation times improved the ability of the least sensitive assay to detect actives by 2-fold. Finally, combining the number of actives identified by any single assay with those obtained at longer incubation times yielded greatly improved outcomes and agreement with SMFA. Screening compounds using extended incubation times and using multiple in vitro assay technologies are valid approaches for the efficient identification of biologically relevant malaria transmission blocking hits.
Collapse
|
10
|
Birkholtz LM, Coetzer TL, Mancama D, Leroy D, Alano P. Discovering New Transmission-Blocking Antimalarial Compounds: Challenges and Opportunities. Trends Parasitol 2016; 32:669-681. [PMID: 27209388 DOI: 10.1016/j.pt.2016.04.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 04/24/2016] [Accepted: 04/26/2016] [Indexed: 01/08/2023]
Abstract
The ability to target human-mosquito parasite transmission challenges global malaria elimination. However, it is not obvious what a transmission-blocking drug will look like; should it target only parasite transmission stages; be combined with a partner drug killing the pathogenic asexual stages; or kill both the sexual and asexual blood stages, preferably displaying polypharmacology? The development of transmission-blocking antimalarials requires objective analyses of the current strategies. Here, pertinent issues and questions regarding the target candidate profile of a transmission-blocking compound, and its role in malaria elimination strategies, are highlighted and novel perspectives proposed. The essential role of a test cascade that integrates screening and validation strategies to identify next-generation transmission-blocking antimalarials is emphasised.
Collapse
Affiliation(s)
- Lyn-Marie Birkholtz
- Department of Biochemistry, Centre for Sustainable Malaria Control, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa.
| | - Theresa L Coetzer
- Department of Molecular Medicine and Haematology, Wits Research Institute for Malaria, Faculty of Health Sciences, University of the Witwatersrand, National Health Laboratory Service, Johannesburg, South Africa.
| | - Dalu Mancama
- Department of Biochemistry, Centre for Sustainable Malaria Control, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa; Biosciences, Council for Scientific and Industrial Research, Pretoria, South Africa.
| | - Didier Leroy
- Medicines for Malaria Venture, Geneva, Switzerland.
| | - Pietro Alano
- Dipartimento di Malattie Infettive, Parassitarie e Immunomediate, Istituto Superiore di Sanità, Rome, Italy.
| |
Collapse
|
11
|
D'Alessandro S, Camarda G, Corbett Y, Siciliano G, Parapini S, Cevenini L, Michelini E, Roda A, Leroy D, Taramelli D, Alano P. A chemical susceptibility profile of the Plasmodium falciparum transmission stages by complementary cell-based gametocyte assays. J Antimicrob Chemother 2016; 71:1148-58. [PMID: 26888912 DOI: 10.1093/jac/dkv493] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 12/19/2015] [Indexed: 01/02/2023] Open
Abstract
OBJECTIVES As most available antimalarial drugs are ineffective against the Plasmodium falciparum transmission stages, new drugs against the parasite's gametocytes are urgently needed to combat malaria globally. The unique biology of gametocytes requires assays that need to be specific, to faithfully monitor anti-gametocyte activity, and to be easy to perform, cheap and scalable to high-throughput screening (HTS). METHODS We developed an HTS cell-based assay with P. falciparum gametocytes specifically expressing a potent luciferase. To confirm HTS hit activity for several parasite genotypes, the luciferase assay and the gametocyte lactate dehydrogenase (LDH) assay, usable on any parasite isolate, were compared by screening antimalarial drugs and determining IC50 values of anti-gametocyte hits from the 'Malaria Box' against early- and late-stage gametocytes. RESULTS Comparison of the two assays, conducted on the early and on late gametocyte stages, revealed an excellent correlation (R(2) > 0.9) for the IC50 values obtained by the respective readouts. Differences in susceptibility to drugs and compounds between the two parasite developmental stages were consistently measured in both assays. CONCLUSIONS This work indicates that the luciferase and gametocyte LDH assays are interchangeable and that their specific advantages can be exploited to design an HTS pipeline leading to new transmission-blocking compounds. Results from these assays consistently defined a gametocyte chemical susceptibility profile, relevant to the planning of future drug discovery strategies.
Collapse
Affiliation(s)
- Sarah D'Alessandro
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| | - Grazia Camarda
- Dipartimento di Malattie Infettive, Parassitarie, Immunomediate, Istituto Superiore di Sanità, Rome, Italy
| | - Yolanda Corbett
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| | - Giulia Siciliano
- Dipartimento di Malattie Infettive, Parassitarie, Immunomediate, Istituto Superiore di Sanità, Rome, Italy
| | - Silvia Parapini
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| | - Luca Cevenini
- Dipartimento di Chimica 'G. Ciamician', Università di Bologna, Bologna, Italy
| | - Elisa Michelini
- Dipartimento di Chimica 'G. Ciamician', Università di Bologna, Bologna, Italy Istituto Nazionale Biostrutture e Biosistemi (INBB), Roma, Italy
| | - Aldo Roda
- Dipartimento di Chimica 'G. Ciamician', Università di Bologna, Bologna, Italy Istituto Nazionale Biostrutture e Biosistemi (INBB), Roma, Italy
| | - Didier Leroy
- Medicines for Malaria Venture, Geneva, Switzerland
| | - Donatella Taramelli
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| | - Pietro Alano
- Dipartimento di Malattie Infettive, Parassitarie, Immunomediate, Istituto Superiore di Sanità, Rome, Italy
| |
Collapse
|
12
|
Salinomycin and other ionophores as a new class of antimalarial drugs with transmission-blocking activity. Antimicrob Agents Chemother 2015; 59:5135-44. [PMID: 26055362 DOI: 10.1128/aac.04332-14] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 05/21/2015] [Indexed: 11/20/2022] Open
Abstract
The drug target profile proposed by the Medicines for Malaria Venture for a malaria elimination/eradication policy focuses on molecules active on both asexual and sexual stages of Plasmodium, thus with both curative and transmission-blocking activities. The aim of the present work was to investigate whether the class of monovalent ionophores, which includes drugs used in veterinary medicine and that were recently proposed as human anticancer agents, meets these requirements. The activity of salinomycin, monensin, and nigericin on Plasmodium falciparum asexual and sexual erythrocytic stages and on the development of the Plasmodium berghei and P. falciparum mosquito stages is reported here. Gametocytogenesis of the P. falciparum strain 3D7 was induced in vitro, and gametocytes at stage II and III or stage IV and V of development were treated for different lengths of time with the ionophores and their viability measured with the parasite lactate dehydrogenase (pLDH) assay. The monovalent ionophores efficiently killed both asexual parasites and gametocytes with a nanomolar 50% inhibitory concentration (IC50). Salinomycin showed a fast speed of kill compared to that of standard drugs, and the potency was higher on stage IV and V than on stage II and III gametocytes. The ionophores inhibited ookinete development and subsequent oocyst formation in the mosquito midgut, confirming their transmission-blocking activity. Potential toxicity due to hemolysis was excluded, since only infected and not normal erythrocytes were damaged by ionophores. Our data strongly support the downstream exploration of monovalent ionophores for repositioning as new antimalarial and transmission-blocking leads.
Collapse
|
13
|
Reader J, Botha M, Theron A, Lauterbach SB, Rossouw C, Engelbrecht D, Wepener M, Smit A, Leroy D, Mancama D, Coetzer TL, Birkholtz LM. Nowhere to hide: interrogating different metabolic parameters of Plasmodium falciparum gametocytes in a transmission blocking drug discovery pipeline towards malaria elimination. Malar J 2015; 14:213. [PMID: 25994518 PMCID: PMC4449569 DOI: 10.1186/s12936-015-0718-z] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 04/22/2015] [Indexed: 12/23/2022] Open
Abstract
Background The discovery of malaria transmission-blocking compounds is seen as key to malaria elimination strategies and gametocyte-screening platforms are critical filters to identify active molecules. However, unlike asexual parasite assays measuring parasite proliferation, greater variability in end-point readout exists between different gametocytocidal assays. This is compounded by difficulties in routinely producing viable, functional and stage-specific gametocyte populations. Here, a parallel evaluation of four assay platforms on the same gametocyte populations was performed for the first time. This allowed the direct comparison of the ability of different assay platforms to detect compounds with gametocytocidal activity and revealed caveats in some assay readouts that interrogate different parasite biological functions. Methods Gametocytogenesis from Plasmodium falciparum (NF54) was optimized with a robust and standardized protocol. ATP, pLDH, luciferase reporter and PrestoBlue® assays were compared in context of a set of 10 reference compounds. The assays were performed in parallel on the same gametocyte preparation (except for luciferase reporter lines) using the same drug preparations (48 h). The remaining parameters for each assay were all comparable. Results A highly robust method for generating viable and functional gametocytes was developed and comprehensively validated resulting in an average gametocytaemia of 4 %. Subsequent parallel assays for gametocytocidal activity indicated that different assay platforms were not able to screen compounds with variant chemical scaffolds similarly. Luciferase reporter assays revealed that synchronized stage-specific gametocyte production is essential for drug discovery, as differential susceptibility in various gametocyte developmental populations is evident. Conclusions With this study, the key parameters for assays aiming at testing the gametocytocidal activity of potential transmission blocking molecules against Plasmodium gametocytes were accurately dissected. This first and uniquely comparative study emphasizes differential effects seen with the use of different assay platforms interrogating variant biological systems. Whilst this data is informative from a biological perspective and may provide indications of the drug mode of action, it does highlight the care that must be taken when screening broad-diversity chemotypes with a single assay platform against gametocytes for which the biology is not clearly understood. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0718-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Janette Reader
- Malaria Parasite Molecular Laboratory, Centre for Sustainable Malaria Control, Department of Biochemistry, University of Pretoria, Private Bag x20, Hatfield, Pretoria, 0028, South Africa.
| | - Mariëtte Botha
- Malaria Parasite Molecular Laboratory, Centre for Sustainable Malaria Control, Department of Biochemistry, University of Pretoria, Private Bag x20, Hatfield, Pretoria, 0028, South Africa.
| | - Anjo Theron
- Biosciences, Council for Scientific and Industrial Research, PO Box 395, Pretoria, 0001, South Africa.
| | - Sonja B Lauterbach
- Plasmodium Molecular Research Unit, Wits Research Institute for Malaria, Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg, 2193, South Africa.
| | - Claire Rossouw
- Biosciences, Council for Scientific and Industrial Research, PO Box 395, Pretoria, 0001, South Africa.
| | - Dewaldt Engelbrecht
- Plasmodium Molecular Research Unit, Wits Research Institute for Malaria, Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg, 2193, South Africa.
| | - Melanie Wepener
- Plasmodium Molecular Research Unit, Wits Research Institute for Malaria, Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg, 2193, South Africa.
| | - Annél Smit
- Malaria Parasite Molecular Laboratory, Centre for Sustainable Malaria Control, Department of Biochemistry, University of Pretoria, Private Bag x20, Hatfield, Pretoria, 0028, South Africa.
| | - Didier Leroy
- Medicines for Malaria Venture, Geneva, Switzerland.
| | - Dalu Mancama
- Biosciences, Council for Scientific and Industrial Research, PO Box 395, Pretoria, 0001, South Africa.
| | - Theresa L Coetzer
- Plasmodium Molecular Research Unit, Wits Research Institute for Malaria, Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and National Health Laboratory Service, Johannesburg, 2193, South Africa.
| | - Lyn-Marie Birkholtz
- Malaria Parasite Molecular Laboratory, Centre for Sustainable Malaria Control, Department of Biochemistry, University of Pretoria, Private Bag x20, Hatfield, Pretoria, 0028, South Africa.
| |
Collapse
|
14
|
Held J, Jeyaraj S, Kreidenweiss A. Antimalarial compounds in Phase II clinical development. Expert Opin Investig Drugs 2015; 24:363-82. [PMID: 25563531 DOI: 10.1517/13543784.2015.1000483] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Malaria is a major health problem in endemic countries and chemotherapy remains the most important tool in combating it. Treatment options are limited and essentially rely on a single drug class - the artemisinins. Efforts are ongoing to restrict the evolving threat of artemisinin resistance but declining sensitivity has been reported. Fueled by the ambitious aim of malaria eradication, novel antimalarial compounds, with improved properties, are now in the progressive phase of drug development. AREAS COVERED Herein, the authors describe antimalarial compounds currently in Phase II clinical development and present the results of these investigations. EXPERT OPINION Thanks to recent efforts, a number of promising antimalarial compounds are now in the pipeline. First safety data have been generated for all of these candidates, although their efficacy as antimalarials is still unclear for most of them. Of particular note are KAE609, KAF156 and DSM265, which are of chemical scaffolds new to malaria chemotherapy and would truly diversify antimalarial options. Apart from SAR97276, which also has a novel chemical scaffold that has had its development stopped, all other compounds in the pipeline belong to already known substance classes, which have been chemically modified. At this moment in time, there is not one standout compound that will revolutionize malaria treatment but several compounds that will add to its control in the future.
Collapse
Affiliation(s)
- Jana Held
- Institut für Tropenmedizin, Eberhard Karls Universität , Wilhelmstraße 27, D-72074 Tübingen , Germany +49 7071 29 85569 ; +49 7071 295189 ;
| | | | | |
Collapse
|
15
|
Leroy D, Campo B, Ding XC, Burrows JN, Cherbuin S. Defining the biology component of the drug discovery strategy for malaria eradication. Trends Parasitol 2014; 30:478-90. [PMID: 25131411 DOI: 10.1016/j.pt.2014.07.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 07/14/2014] [Accepted: 07/15/2014] [Indexed: 10/24/2022]
Abstract
Malaria is still considered a deadly scourge in Africa, Asia, and South America despite improved vector control and curative treatments with new antimalarial combinations. The next challenge is to work towards disease eradication. To achieve this goal it is crucial to develop, validate, and integrate biological assays into test cascades that align with the key target product profiles. For anti-relapse, a parent molecule should kill hypnozoites or cause activation of Plasmodium vivax liver stages. For transmission blocking, dual equal-activity antimalarials killing both the asexual and the sexual parasite stages in human blood are favored. Finally, by assessing cross resistance and generating drug resistance in the laboratory, it is expected that new medicines with acceptable resistance profiles will be forthcoming.
Collapse
Affiliation(s)
- Didier Leroy
- Medicines for Malaria Venture (MMV), PO Box 1826, 20 route de Pré-Bois, 1215 Geneva 15, Switzerland.
| | - Brice Campo
- Medicines for Malaria Venture (MMV), PO Box 1826, 20 route de Pré-Bois, 1215 Geneva 15, Switzerland
| | - Xavier C Ding
- Medicines for Malaria Venture (MMV), PO Box 1826, 20 route de Pré-Bois, 1215 Geneva 15, Switzerland
| | - Jeremy N Burrows
- Medicines for Malaria Venture (MMV), PO Box 1826, 20 route de Pré-Bois, 1215 Geneva 15, Switzerland
| | - Stéphanie Cherbuin
- Medicines for Malaria Venture (MMV), PO Box 1826, 20 route de Pré-Bois, 1215 Geneva 15, Switzerland
| |
Collapse
|
16
|
Abstract
Targeting the redox metabolism of Plasmodium falciparum to create a fatal overload of oxidative stress is a route to explore the discovery of new antimalarial drugs. There are three main possibilities to target the redox metabolism of P. falciparum at the erythrocytic stage: selective targeting and inhibition of a redox P. falciparum protein or enzyme; oxidant drugs targeting essential parasite components and heme by-products; and redox cycler drugs targeting the parasitized red blood cell. Oxidants and redox cycler agents, with or without specific targets, may disrupt the fragile parasitized erythrocyte redox-dependent architecture given that: redox equilibrium plays a vital role at the erythrocytic stage; P. falciparum possesses major NADPH-dependent redox systems, such as glutathione and thioredoxin ones; and the protein-NADPH-dependent phosphorylation-dephosphorylation process is involved in building new permeation pathways and channels for the nutrient-waste import-export traffic of the parasite.
Collapse
|
17
|
Hansen FK, Sumanadasa SDM, Stenzel K, Duffy S, Meister S, Marek L, Schmetter R, Kuna K, Hamacher A, Mordmüller B, Kassack MU, Winzeler EA, Avery VM, Andrews KT, Kurz T. Discovery of HDAC inhibitors with potent activity against multiple malaria parasite life cycle stages. Eur J Med Chem 2014; 82:204-13. [PMID: 24904967 DOI: 10.1016/j.ejmech.2014.05.050] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 05/12/2014] [Accepted: 05/21/2014] [Indexed: 10/25/2022]
Abstract
In this work we investigated the antiplasmodial activity of a series of HDAC inhibitors containing an alkoxyamide connecting-unit linker region. HDAC inhibitor 1a (LMK235), previously shown to be a novel and specific inhibitor of human HDAC4 and 5, was used as a starting point to rapidly construct a mini-library of HDAC inhibitors using a straightforward solid-phase supported synthesis. Several of these novel HDAC inhibitors were found to have potent in vitro activity against asexual stage Plasmodium falciparum malaria parasites. Representative compounds were shown to hyperacetylate P. falciparum histones and to inhibit deacetylase activity of recombinant PfHDAC1 and P. falciparum nuclear extracts. All compounds were also screened in vitro for activity against Plasmodium berghei exo-erythrocytic stages and selected compounds were further tested against late stage (IV and V) P. falciparum gametocytes. Of note, some compounds showed nanomolar activity against all three life cycle stages tested (asexual, exo-erythrocytic and gametocyte stages) and several compounds displayed significantly increased parasite selectivity compared to the reference HDAC inhibitor suberoylanilide hydroxamic acid (SAHA). These data suggest that it may be possible to develop HDAC inhibitors that target multiple malaria parasite life cycle stages.
Collapse
Affiliation(s)
- Finn K Hansen
- Institut für Pharmazeutische und Medizinische Chemie, Heinrich Heine Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Subathdrage D M Sumanadasa
- Eskitis Institute for Drug Discovery, Don Young Road, Nathan Campus, Griffith University, QLD 4111, Australia
| | - Katharina Stenzel
- Institut für Pharmazeutische und Medizinische Chemie, Heinrich Heine Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Sandra Duffy
- Eskitis Institute for Drug Discovery, Don Young Road, Nathan Campus, Griffith University, QLD 4111, Australia
| | - Stephan Meister
- Department of Pediatrics, University of California, San Diego, School of Medicine, 9500 Gilman Drive 0741, La Jolla, CA 92093, USA
| | - Linda Marek
- Institut für Pharmazeutische und Medizinische Chemie, Heinrich Heine Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Rebekka Schmetter
- Institut für Pharmazeutische und Medizinische Chemie, Heinrich Heine Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Krystina Kuna
- Institut für Pharmazeutische und Medizinische Chemie, Heinrich Heine Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Alexandra Hamacher
- Institut für Pharmazeutische und Medizinische Chemie, Heinrich Heine Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Benjamin Mordmüller
- Institut für Tropenmedizin, Eberhard Karls Universität Tübingen, Wilhelmstr. 27, 72074 Tübingen, Germany; Medical Research Laboratory, Albert Schweitzer Hospital, Lambaréné, Gabon
| | - Matthias U Kassack
- Institut für Pharmazeutische und Medizinische Chemie, Heinrich Heine Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Elizabeth A Winzeler
- Department of Pediatrics, University of California, San Diego, School of Medicine, 9500 Gilman Drive 0741, La Jolla, CA 92093, USA
| | - Vicky M Avery
- Eskitis Institute for Drug Discovery, Don Young Road, Nathan Campus, Griffith University, QLD 4111, Australia
| | - Katherine T Andrews
- Eskitis Institute for Drug Discovery, Don Young Road, Nathan Campus, Griffith University, QLD 4111, Australia.
| | - Thomas Kurz
- Institut für Pharmazeutische und Medizinische Chemie, Heinrich Heine Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.
| |
Collapse
|
18
|
Lysine acetylation in sexual stage malaria parasites is a target for antimalarial small molecules. Antimicrob Agents Chemother 2014; 58:3666-78. [PMID: 24733477 DOI: 10.1128/aac.02721-13] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Therapies to prevent transmission of malaria parasites to the mosquito vector are a vital part of the global malaria elimination agenda. Primaquine is currently the only drug with such activity; however, its use is limited by side effects. The development of transmission-blocking strategies requires an understanding of sexual stage malaria parasite (gametocyte) biology and the identification of new drug leads. Lysine acetylation is an important posttranslational modification involved in regulating eukaryotic gene expression and other essential processes. Interfering with this process with histone deacetylase (HDAC) inhibitors is a validated strategy for cancer and other diseases, including asexual stage malaria parasites. Here we confirm the expression of at least one HDAC protein in Plasmodium falciparum gametocytes and show that histone and nonhistone protein acetylation occurs in this life cycle stage. The activity of the canonical HDAC inhibitors trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA; Vorinostat) and a panel of novel HDAC inhibitors on early/late-stage gametocytes and on gamete formation was examined. Several compounds displayed early/late-stage gametocytocidal activity, with TSA being the most potent (50% inhibitory concentration, 70 to 90 nM). In contrast, no inhibitory activity was observed in P. falciparum gametocyte exflagellation experiments. Gametocytocidal HDAC inhibitors caused hyperacetylation of gametocyte histones, consistent with a mode of action targeting HDAC activity. Our data identify HDAC inhibitors as being among a limited number of compounds that target both asexual and sexual stage malaria parasites, making them a potential new starting point for gametocytocidal drug leads and valuable tools for dissecting gametocyte biology.
Collapse
|
19
|
Salcedo-Sora JE, Caamano-Gutierrez E, Ward SA, Biagini GA. The proliferating cell hypothesis: a metabolic framework for Plasmodium growth and development. Trends Parasitol 2014; 30:170-5. [PMID: 24636355 PMCID: PMC3989997 DOI: 10.1016/j.pt.2014.02.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 02/02/2014] [Accepted: 02/03/2014] [Indexed: 12/21/2022]
Abstract
The hypothesis offers a framework to explain the atypical features of parasite metabolism. Aerobic glycolysis is hypothesised to meet the biosynthetic demands of rapid proliferation. Differentiation may be epigenetically regulated in response to nutrient-linked metabolism.
We hypothesise that intraerythrocytic malaria parasite metabolism is not merely fulfilling the need for ATP generation, but is evolved to support rapid proliferation, similar to that seen in other rapidly proliferating cells such as cancer cells. Deregulated glycolytic activity coupled with impaired mitochondrial metabolism is a metabolic strategy to generate glycolytic intermediates essential for rapid biomass generation for schizogony. Further, we discuss the possibility that Plasmodium metabolism is not only a functional consequence of the ‘hard-wired’ genome and argue that metabolism may also have a causal role in triggering the cascade of events that leads to developmental stage transitions. This hypothesis offers a framework to rationalise the observations of aerobic glycolysis, atypical mitochondrial metabolism, and metabolic switching in nonproliferating stages.
Collapse
Affiliation(s)
| | - Eva Caamano-Gutierrez
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK; Warwick Systems Biology Centre, Senate House, University of Warwick, Coventry, CV4 7AL, UK
| | - Stephen A Ward
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Giancarlo A Biagini
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
| |
Collapse
|
20
|
Chemical signatures and new drug targets for gametocytocidal drug development. Sci Rep 2014; 4:3743. [PMID: 24434750 PMCID: PMC3894558 DOI: 10.1038/srep03743] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 12/20/2013] [Indexed: 01/14/2023] Open
Abstract
Control of parasite transmission is critical for the eradication of malaria. However, most antimalarial drugs are not active against P. falciparum gametocytes, responsible for the spread of malaria. Consequently, patients can remain infectious for weeks after the clearance of asexual parasites and clinical symptoms. Here we report the identification of 27 potent gametocytocidal compounds (IC50 < 1 μM) from screening 5,215 known drugs and compounds. All these compounds were active against three strains of gametocytes with different drug sensitivities and geographical origins, 3D7, HB3 and Dd2. Cheminformatic analysis revealed chemical signatures for P. falciparum sexual and asexual stages indicative of druggability and suggesting potential targets. Torin 2, a top lead compound (IC50 = 8 nM against gametocytes in vitro), completely blocked oocyst formation in a mouse model of transmission. These results provide critical new leads and potential targets to expand the repertoire of malaria transmission-blocking reagents.
Collapse
|
21
|
Duffy S, Avery VM. Identification of inhibitors of Plasmodium falciparum gametocyte development. Malar J 2013; 12:408. [PMID: 24206914 PMCID: PMC3842684 DOI: 10.1186/1475-2875-12-408] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 11/05/2013] [Indexed: 12/28/2022] Open
Abstract
Background Plasmodium falciparum gametocytes, specifically mature stages, are the only stage in man transmissible to the mosquito vector responsible for malaria transmission. Anti-malarial drugs capable of killing these forms are considered essential for the eradication of malaria. The comprehensive profiling of in vitro activity of anti-malarial compounds against both early (I-III) and late (IV-V) stage P. falciparum gametocytes, along with the high throughput screening (HTS) outcomes from the MMV malaria box are described. Method Two anti-gametocyte HTS assays based on confocal fluorescence microscopy, utilizing both a gametocyte specific protein (pfs16-Luc-GFP) and a viability marker (MitoTracker Red CM-H2XRos) (MTR), were used for the measurement of anti-gametocytocidal activity. This combination provided a direct observation of gametocyte number per assay well, whilst defining the viability of each gametocyte imaged. Results IC50 values were obtained for 36 current anti-malarial compounds for activities against asexual, early and late stage gametocytes. The MMV malaria box was screened and actives progressed for IC50 evaluation. Seven % of the “drug-like” and 21% of the “probe-like” compounds from the MMV malaria box demonstrated equivalent activity against both asexual and late stage gametocytes. Conclusions The assays described were shown to selectively identify compounds with gametocytocidal activity and have been demonstrated suitable for HTS with the capability of screening in the order of 20,000 compounds per screening campaign, two to three times per seven-day week.
Collapse
Affiliation(s)
| | - Vicky M Avery
- Discovery Biology, Eskitis Institute for Drug Discovery, Griffith University, Nathan, Queensland 4111, Australia.
| |
Collapse
|
22
|
Abstract
Malaria elimination has recently been reinstated as a global health priority but current therapies seem to be insufficient for the task. Elimination efforts require new drug classes that alleviate symptoms, prevent transmission and provide a radical cure. To develop these next-generation medicines, public-private partnerships are funding innovative approaches to identify compounds that target multiple parasite species at multiple stages of the parasite life cycle. In this Review, we discuss the cell-, chemistry- and target-based approaches used to discover new drug candidates that are currently in clinical trials or undergoing preclinical testing.
Collapse
|
23
|
Vial H, Taramelli D, Boulton IC, Ward SA, Doerig C, Chibale K. CRIMALDDI: platform technologies and novel anti-malarial drug targets. Malar J 2013; 12:396. [PMID: 24498961 PMCID: PMC3827883 DOI: 10.1186/1475-2875-12-396] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 10/22/2013] [Indexed: 12/24/2022] Open
Abstract
The Coordination, Rationalization, and Integration of antiMALarial drug Discovery & Development Initiatives (CRIMALDDI) Consortium, funded by the EU Framework Seven Programme, has attempted, through a series of interactive and facilitated workshops, to develop priorities for research to expedite the discovery of new anti-malarials. This paper outlines the recommendations for the development of enabling technologies and the identification of novel targets.Screening systems must be robust, validated, reproducible, and represent human malaria. They also need to be cost-effective. While such systems exist to screen for activity against blood stage Plasmodium falciparum, they are lacking for other Plasmodium spp. and other stages of the parasite's life cycle. Priority needs to be given to developing high-throughput screens that can identify activity against the liver and sexual stages. This in turn requires other enabling technologies to be developed to allow the study of these stages and to allow for the culture of liver cells and the parasite at all stages of its life cycle.As these enabling technologies become available, they will allow novel drug targets to be studied. Currently anti-malarials are mostly targeting the asexual blood stage of the parasite's life cycle. There are many other attractive targets that need to be investigated. The liver stages and the sexual stages will become more important as malaria control moves towards malaria elimination. Sexual development is a process offering multiple targets, even though the mechanisms of differentiation are still not fully understood. However, designing a drug whose effect is not curative but would be used in asymptomatic patients is difficult given current safety thresholds. Compounds active against the liver schizont would have a prophylactic effect and Plasmodium vivax elimination requires effectors against the dormant liver hypnozoites. It may be that drugs to be used in elimination campaigns will also need to have utility in the control phase. Compounds with activity against blood stages need to be screened for activity against other stages.Natural products should also be a valuable source of new compounds. They often occupy non-Lipinski chemical space and so may reveal valuable new chemotypes.
Collapse
Affiliation(s)
| | | | | | - Steve A Ward
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.
| | | | | |
Collapse
|
24
|
Identification of MMV malaria box inhibitors of plasmodium falciparum early-stage gametocytes using a luciferase-based high-throughput assay. Antimicrob Agents Chemother 2013; 57:6050-62. [PMID: 24060871 DOI: 10.1128/aac.00870-13] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The design of new antimalarial combinations to treat Plasmodium falciparum infections requires drugs that, in addition to resolving disease symptoms caused by asexual blood stage parasites, can also interrupt transmission to the mosquito vector. Gametocytes, which are essential for transmission, develop as sexual blood stage parasites in the human host over 8 to 12 days and are the most accessible developmental stage for transmission-blocking drugs. Considerable effort is currently being devoted to identifying compounds active against mature gametocytes. However, investigations on the drug sensitivity of developing gametocytes, as well as screening methods for identifying inhibitors of early gametocytogenesis, remain scarce. We have developed a luciferase-based high-throughput screening (HTS) assay using tightly synchronous stage I to III gametocytes from a recombinant P. falciparum line expressing green fluorescent protein (GFP)-luciferase. The assay has been used to evaluate the early-stage gametocytocidal activity of the MMV Malaria Box, a collection of 400 compounds with known antimalarial (asexual blood stage) activity. Screening this collection against early-stage (I to III) gametocytes yielded 64 gametocytocidal compounds with 50% inhibitory concentrations (IC50s) below 2.5 μM. This assay is reproducible and suitable for the screening of large compound libraries, with an average percent coefficient of variance (%CV) of ≤5%, an average signal-to-noise ratio (S:N) of >30, and a Z' of ∼0.8. Our findings highlight the need for screening efforts directed specifically against early gametocytogenesis and indicate the importance of experimental verification of early-stage gametocytocidal activity in the development of new antimalarial candidates for combination therapy.
Collapse
|
25
|
Sykes ML, Avery VM. Approaches to Protozoan Drug Discovery: Phenotypic Screening. J Med Chem 2013; 56:7727-40. [DOI: 10.1021/jm4004279] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Melissa L. Sykes
- Discovery Biology, Eskitis Institute
for Drug Discovery, Griffith University, Nathan, Queensland, Australia
| | - Vicky M. Avery
- Discovery Biology, Eskitis Institute
for Drug Discovery, Griffith University, Nathan, Queensland, Australia
| |
Collapse
|
26
|
Abstract
Drugs that kill or inhibit the sexual stages of Plasmodium in order to prevent transmission are important components of malaria control programmes. Reducing gametocyte carriage is central to the control of Plasmodium falciparum transmission as infection can result in extended periods of gametocytaemia. Unfortunately the number of drugs with activity against gametocytes is limited. Primaquine is currently the only licensed drug with activity against the sexual stages of malaria parasites and its use is hampered by safety concerns. This shortcoming is likely the result of the technical challenges associated with gametocyte studies together with the focus of previous drug discovery campaigns on asexual parasite stages. However recent emphasis on malaria eradication has resulted in an upsurge of interest in identifying compounds with activity against gametocytes. This review examines the gametocytocidal properties of currently available drugs as well as those in the development pipeline and examines the prospects for discovery of new anti-gametocyte compounds.
Collapse
|
27
|
Teguh SC, Klonis N, Duffy S, Lucantoni L, Avery VM, Hutton CA, Baell JB, Tilley L. Novel Conjugated Quinoline–Indoles Compromise Plasmodium falciparum Mitochondrial Function and Show Promising Antimalarial Activity. J Med Chem 2013; 56:6200-15. [DOI: 10.1021/jm400656s] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | - Sandra Duffy
- Eskitis Institute for Drug Discovery, Brisbane Innovation Park, Griffith University,
Nathan QLD 4111, Australia
| | - Leonardo Lucantoni
- Eskitis Institute for Drug Discovery, Brisbane Innovation Park, Griffith University,
Nathan QLD 4111, Australia
| | - Vicky M. Avery
- Eskitis Institute for Drug Discovery, Brisbane Innovation Park, Griffith University,
Nathan QLD 4111, Australia
| | | | - Jonathan B. Baell
- Medicinal
Chemistry, Monash Institute of Pharmaceutical Science, Parkville
VIC 3052, Australia
| | | |
Collapse
|
28
|
Biamonte MA, Wanner J, Le Roch KG. Recent advances in malaria drug discovery. Bioorg Med Chem Lett 2013; 23:2829-43. [PMID: 23587422 PMCID: PMC3762334 DOI: 10.1016/j.bmcl.2013.03.067] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 03/11/2013] [Accepted: 03/20/2013] [Indexed: 01/18/2023]
Abstract
This digest covers some of the most relevant progress in malaria drug discovery published between 2010 and 2012. There is an urgent need to develop new antimalarial drugs. Such drugs can target the blood stage of the disease to alleviate the symptoms, the liver stage to prevent relapses, and the transmission stage to protect other humans. The pipeline for the blood stage is becoming robust, but this should not be a source of complacency, as the current therapies set a high standard. Drug discovery efforts directed towards the liver and transmission stages are in their infancy but are receiving increasing attention as targeting these stages could be instrumental in eradicating malaria.
Collapse
Affiliation(s)
- Marco A Biamonte
- Drug Discovery for Tropical Diseases, Suite 230, San Diego, CA 92121, USA.
| | | | | |
Collapse
|
29
|
|
30
|
D'Alessandro S, Silvestrini F, Dechering K, Corbett Y, Parapini S, Timmerman M, Galastri L, Basilico N, Sauerwein R, Alano P, Taramelli D. A Plasmodium falciparum screening assay for anti-gametocyte drugs based on parasite lactate dehydrogenase detection. J Antimicrob Chemother 2013; 68:2048-58. [PMID: 23645588 DOI: 10.1093/jac/dkt165] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVES Plasmodium gametocytes, responsible for malaria parasite transmission from humans to mosquitoes, represent a crucial target for new antimalarial drugs to achieve malaria elimination/eradication. We developed a novel colorimetric screening method for anti-gametocyte compounds based on the parasite lactate dehydrogenase (pLDH) assay, already standardized for asexual stages, to measure gametocyte viability and drug susceptibility. METHODS Gametocytogenesis of 3D7 and NF54 Plasmodium falciparum strains was induced in vitro and asexual parasites were depleted with N-acetylglucosamine. Gametocytes were treated with dihydroartemisinin, epoxomicin, methylene blue, primaquine, puromycin or chloroquine in 96-well plates and the pLDH activity was evaluated using a modified Makler protocol. Mosquito infectivity was measured by the standard membrane feeding assay (SMFA). RESULTS A linear correlation was found between gametocytaemia determined by Giemsa staining and pLDH activity. A concentration-dependent reduction in pLDH activity was observed after 72 h of drug treatment, whereas an additional 72 h of incubation without drugs was required to obtain complete inhibition of gametocyte viability. SMFA on treated and control gametocytes confirmed that a reduction in pLDH activity translates into reduced oocyst development in the mosquito vector. CONCLUSIONS The gametocyte pLDH assay is fast, easy to perform, cheap and reproducible and is suitable for screening novel transmission-blocking compounds, which does not require parasite transgenic lines.
Collapse
Affiliation(s)
- Sarah D'Alessandro
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, 20133 Milan, Italy
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Nilsen A, LaCrue AN, White KL, Forquer IP, Cross RM, Marfurt J, Mather MW, Delves MJ, Shackleford DM, Saenz FE, Morrisey JM, Steuten J, Mutka T, Li Y, Wirjanata G, Ryan E, Duffy S, Kelly JX, Sebayang BF, Zeeman AM, Noviyanti R, Sinden RE, Kocken CHM, Price RN, Avery VM, Angulo-Barturen I, Jiménez-Díaz MB, Ferrer S, Herreros E, Sanz LM, Gamo FJ, Bathurst I, Burrows JN, Siegl P, Guy RK, Winter RW, Vaidya AB, Charman SA, Kyle DE, Manetsch R, Riscoe MK. Quinolone-3-diarylethers: a new class of antimalarial drug. Sci Transl Med 2013; 5:177ra37. [PMID: 23515079 PMCID: PMC4227885 DOI: 10.1126/scitranslmed.3005029] [Citation(s) in RCA: 166] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The goal for developing new antimalarial drugs is to find a molecule that can target multiple stages of the parasite's life cycle, thus impacting prevention, treatment, and transmission of the disease. The 4(1H)-quinolone-3-diarylethers are selective potent inhibitors of the parasite's mitochondrial cytochrome bc1 complex. These compounds are highly active against the human malaria parasites Plasmodium falciparum and Plasmodium vivax. They target both the liver and blood stages of the parasite as well as the forms that are crucial for disease transmission, that is, the gametocytes, the zygote, the ookinete, and the oocyst. Selected as a preclinical candidate, ELQ-300 has good oral bioavailability at efficacious doses in mice, is metabolically stable, and is highly active in blocking transmission in rodent models of malaria. Given its predicted low dose in patients and its predicted long half-life, ELQ-300 has potential as a new drug for the treatment, prevention, and, ultimately, eradication of human malaria.
Collapse
Affiliation(s)
- Aaron Nilsen
- VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, USA
| | - Alexis N. LaCrue
- Department of Global Health, College of Public Health, 3720 Spectrum Blvd. (Ste 304), Tampa, FL 33612, USA
| | - Karen L. White
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Isaac P. Forquer
- VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, USA
| | - Richard M. Cross
- Department of Chemistry, University of South Florida, 4202 E. Fowler Avenue, Tampa, FL 33620-5250, USA
| | - Jutta Marfurt
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Michael W. Mather
- Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Michael J. Delves
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - David M. Shackleford
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Fabian E. Saenz
- Department of Global Health, College of Public Health, 3720 Spectrum Blvd. (Ste 304), Tampa, FL 33612, USA
| | - Joanne M. Morrisey
- Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Jessica Steuten
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Tina Mutka
- Department of Global Health, College of Public Health, 3720 Spectrum Blvd. (Ste 304), Tampa, FL 33612, USA
| | - Yuexin Li
- VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, USA
| | - Grennady Wirjanata
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - Eileen Ryan
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Sandra Duffy
- Eskitis Institute for Cell & Molecular Therapies, Brisbane Innovation Park, Nathan campus, Griffith University, QLD 4111, Australia
| | - Jane Xu Kelly
- VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, USA
| | - Boni F. Sebayang
- Eijkman Institute for Molecular Biology, Jl. Diponegoro 69, Jakarta 10430, Indonesia
| | - Anne-Marie Zeeman
- Department of Parasitology, Biomedical Primate Research Centre, P.O. Box 3306, 2280 GH Rijswijk, The Netherlands
| | - Rintis Noviyanti
- Eijkman Institute for Molecular Biology, Jl. Diponegoro 69, Jakarta 10430, Indonesia
| | - Robert E. Sinden
- Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Clemens H. M. Kocken
- Department of Parasitology, Biomedical Primate Research Centre, P.O. Box 3306, 2280 GH Rijswijk, The Netherlands
| | - Ric N. Price
- Global Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
- Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX3 7LJ, UK
| | - Vicky M. Avery
- Eskitis Institute for Cell & Molecular Therapies, Brisbane Innovation Park, Nathan campus, Griffith University, QLD 4111, Australia
| | - Iñigo Angulo-Barturen
- GlaxoSmithKline, Medicines Development Campus, Diseases of the Developing World, Severo Ochoa 2, Tres Cantos 28760, Madrid, Spain
| | - María Belén Jiménez-Díaz
- GlaxoSmithKline, Medicines Development Campus, Diseases of the Developing World, Severo Ochoa 2, Tres Cantos 28760, Madrid, Spain
| | - Santiago Ferrer
- GlaxoSmithKline, Medicines Development Campus, Diseases of the Developing World, Severo Ochoa 2, Tres Cantos 28760, Madrid, Spain
| | - Esperanza Herreros
- GlaxoSmithKline, Medicines Development Campus, Diseases of the Developing World, Severo Ochoa 2, Tres Cantos 28760, Madrid, Spain
| | - Laura M. Sanz
- GlaxoSmithKline, Medicines Development Campus, Diseases of the Developing World, Severo Ochoa 2, Tres Cantos 28760, Madrid, Spain
| | - Francisco-Javier Gamo
- GlaxoSmithKline, Medicines Development Campus, Diseases of the Developing World, Severo Ochoa 2, Tres Cantos 28760, Madrid, Spain
| | - Ian Bathurst
- Medicines for Malaria Venture, 20, route de Pré-Bois, PO Box 1826, 1215 Geneva 15, Switzerland
| | - Jeremy N. Burrows
- Medicines for Malaria Venture, 20, route de Pré-Bois, PO Box 1826, 1215 Geneva 15, Switzerland
| | - Peter Siegl
- Siegl Pharma Consulting LLC, Blue Bell, PA, USA
| | - R. Kiplin Guy
- Chemical Biology & Therapeutics, St. Jude Children’s Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105-3678 USA
| | - Rolf W. Winter
- VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, USA
| | - Akhil B. Vaidya
- Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Susan A. Charman
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Dennis E. Kyle
- Department of Global Health, College of Public Health, 3720 Spectrum Blvd. (Ste 304), Tampa, FL 33612, USA
| | - Roman Manetsch
- Department of Chemistry, University of South Florida, 4202 E. Fowler Avenue, Tampa, FL 33620-5250, USA
| | - Michael K. Riscoe
- VA Medical Center, 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, USA
- Department of Molecular Microbiology and Immunology, 3181 Sam Jackson Blvd., Portland, Oregon 97239, USA
| |
Collapse
|
32
|
|