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Appetecchia F, Fabbrizi E, Fiorentino F, Consalvi S, Biava M, Poce G, Rotili D. Transmission-Blocking Strategies for Malaria Eradication: Recent Advances in Small-Molecule Drug Development. Pharmaceuticals (Basel) 2024; 17:962. [PMID: 39065810 PMCID: PMC11279868 DOI: 10.3390/ph17070962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 07/11/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024] Open
Abstract
Malaria drug research and development efforts have resurged in the last decade following the decelerating rate of mortality and malaria cases in endemic regions. The inefficiency of malaria interventions is largely driven by the spreading resistance of the Plasmodium falciparum parasite to current drug regimens and that of the malaria vector, the Anopheles mosquito, to insecticides. In response to the new eradication agenda, drugs that act by breaking the malaria transmission cycle (transmission-blocking drugs), which has been recognized as an important and additional target for intervention, are being developed. These drugs take advantage of the susceptibility of Plasmodium during population bottlenecks before transmission (gametocytes) and in the mosquito vector (gametes, zygotes, ookinetes, oocysts, sporozoites). To date, compounds targeting stage V gametocytes predominate in the chemical library of transmission-blocking drugs, and some of them have entered clinical trials. The targeting of Plasmodium mosquito stages has recently renewed interest in the development of innovative malaria control tools, which hold promise for the application of compounds effective at these stages. In this review, we highlight the major achievements and provide an update on the research of transmission-blocking drugs, with a particular focus on their chemical scaffolds, antiplasmodial activity, and transmission-blocking potential.
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Affiliation(s)
| | | | | | | | | | - Giovanna Poce
- Department of Drug Chemistry and Technologies, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy; (F.A.); (E.F.); (F.F.); (S.C.); (M.B.)
| | - Dante Rotili
- Department of Drug Chemistry and Technologies, Sapienza University of Rome, P.le A. Moro 5, 00185 Rome, Italy; (F.A.); (E.F.); (F.F.); (S.C.); (M.B.)
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2
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Greyling N, van der Watt M, Gwarinda H, van Heerden A, Greenhouse B, Leroy D, Niemand J, Birkholtz LM. Genetic complexity alters drug susceptibility of asexual and gametocyte stages of Plasmodium falciparum to antimalarial candidates. Antimicrob Agents Chemother 2024; 68:e0129123. [PMID: 38259087 PMCID: PMC10916389 DOI: 10.1128/aac.01291-23] [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: 10/13/2023] [Accepted: 12/06/2023] [Indexed: 01/24/2024] Open
Abstract
Malaria elimination requires interventions able to target both the asexual blood stage (ABS) parasites and transmissible gametocyte stages of Plasmodium falciparum. Lead antimalarial candidates are evaluated against clinical isolates to address key concerns regarding efficacy and to confirm that the current, circulating parasites from endemic regions lack resistance against these candidates. While this has largely been performed on ABS parasites, limited data are available on the transmission-blocking efficacy of compounds with multistage activity. Here, we evaluated the efficacy of lead antimalarial candidates against both ABS parasites and late-stage gametocytes side-by-side, against clinical P. falciparum isolates from southern Africa. We additionally correlated drug efficacy to the genetic diversity of the clinical isolates as determined with a panel of well-characterized, genome-spanning microsatellite markers. Our data indicate varying sensitivities of the isolates to key antimalarial candidates, both for ABS parasites and gametocyte stages. While ABS parasites were efficiently killed, irrespective of genetic complexity, antimalarial candidates lost some gametocytocidal efficacy when the gametocytes originated from genetically complex, multiple-clone infections. This suggests a fitness benefit to multiclone isolates to sustain transmission and reduce drug susceptibility. In conclusion, this is the first study to investigate the efficacy of antimalarial candidates on both ABS parasites and gametocytes from P. falciparum clinical isolates where the influence of parasite genetic complexity is highlighted, ultimately aiding the malaria elimination agenda.
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Affiliation(s)
- Nicola Greyling
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Mariëtte van der Watt
- Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Hazel Gwarinda
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Ashleigh van Heerden
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Bryan Greenhouse
- Department of Medicine, University of California-San Francisco, San Francisco, California, USA
| | - Didier Leroy
- Medicines for Malaria Venture, Geneva, Switzerland
| | - Jandeli Niemand
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Lyn-Marié Birkholtz
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
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3
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Mi Y, Ding W, Xu L, Lu M, Yan R, Li X, Song X. Protective Efficacy Induced by the Common Eimeria Antigen Elongation Factor 2 against Challenge with Three Eimeria Species in Chickens. Vaccines (Basel) 2023; 12:18. [PMID: 38250831 PMCID: PMC10819859 DOI: 10.3390/vaccines12010018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 12/20/2023] [Accepted: 12/21/2023] [Indexed: 01/23/2024] Open
Abstract
Avian coccidiosis arises from co-infection involving multiple Eimeria species, which could give rise to substantial economic losses in the global poultry industry. As a result, multivalent anticoccidial vaccines containing common Eimeria antigens offer considerable promise for controlling co-infection in clinical practice. In our previous study, Elongation factor 2 (EF2) was deemed as an immunogenic common antigen across various Eimeria species. This current investigation aimed to further assess the immunogenicity and protective efficacy of EF2 in recombinant subunit vaccine format against three Eimeria species. The EF2 gene cloned from Eimeria maxima (E. maxima) cDNA was designated as EF2 of E. maxima (EmEF2). The immunogenicity of the recombinant protein EmEF2 (rEmEF2) was assessed through Western blot analysis. The evaluation of the vaccine-induced immune response encompassed the determination of T lymphocyte subset proportions, cytokine mRNA transcription levels, and specific IgY concentrations in rEmEF2-vaccinated chickens using flow cytometry, quantitative real-time PCR (qPCR), and indirect enzyme-linked immunosorbent assay (ELISA). Subsequently, the protective efficacy of rEmEF2 was evaluated through vaccination and challenge experiments. The findings demonstrated that rEmEF2 was effectively recognized by the His-tag monoclonal antibody and E. maxima chicken antiserum. Vaccination with rEmEF2 increased the proportions of CD4+ and CD8+ T lymphocytes, elevated IL-4 and IFN-γ mRNA transcription levels, and enhanced IgY antibody levels compared to the control groups. Moreover, compared to the control groups, vaccination with rEmEF2 led to decreased weight loss, reduced oocyst outputs, and alleviated enteric lesions. Furthermore, in the rEmEF2-immunized groups, challenges with E. maxima and E. acervulina resulted in anticoccidial index (ACI) scores of 166.35 and 185.08, showing moderate-to-excellent protective efficacy. Nevertheless, challenges with E. tenella and mixed Eimeria resulted in ACI scores of 144.01 and 127.94, showing low protective efficacy. In conclusion, EmEF2, a common antigen across Eimeria species, demonstrated the capacity to induce a significant cellular and humoral immune response, as well as partial protection against E. maxima, E. acervulina, and E. tenella. These results highlight EmEF2 as a promising candidate antigen for the development of multivalent vaccines targeting mixed infections by Eimeria species.
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Affiliation(s)
| | | | | | | | | | | | - Xiaokai Song
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; (Y.M.); (W.D.); (L.X.); (M.L.); (R.Y.); (X.L.)
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4
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B Henry N, Soulama I, S Sermé S, Bolscher JM, T G Huijs T, S Coulibaly A, Sombié S, Ouédraogo N, Diarra A, Zongo S, Guelbéogo WM, Nébié I, Sirima SB, Tiono AB, Pietro A, Collins KA, Dechering KJ, Bousema T. Assessment of the transmission blocking activity of antimalarial compounds by membrane feeding assays using natural Plasmodium falciparum gametocyte isolates from West-Africa. PLoS One 2023; 18:e0284751. [PMID: 37494413 PMCID: PMC10370769 DOI: 10.1371/journal.pone.0284751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 04/07/2023] [Indexed: 07/28/2023] Open
Abstract
Antimalarial drugs that can block the transmission of Plasmodium gametocytes to mosquito vectors would be highly beneficial for malaria elimination efforts. Identifying transmission-blocking drugs currently relies on evaluation of their activity against gametocyte-producing laboratory parasite strains and would benefit from a testing pipeline with genetically diverse field isolates. The aims of this study were to develop a pipeline to test drugs against P. falciparum gametocyte field isolates and to evaluate the transmission-blocking activity of a set of novel compounds. Two assays were designed so they could identify both the overall transmission-blocking activity of a number of marketed and experimental drugs by direct membrane feeding assays (DMFA), and then also discriminate between those that are active against the gametocytes (gametocyte killing or sterilizing) or those that block development in the mosquito (sporontocidal). These DMFA assays used venous blood samples from naturally infected Plasmodium falciparum gametocyte carriers and locally reared Anopheles gambiae s.s. mosquitoes. Overall transmission-blocking activity was assessed following a 24 hour incubation of compound with gametocyte infected blood (TB-DMFA). Sporontocidal activity was evaluated following addition of compound directly prior to feeding, without incubation (SPORO-DMFA); Gametocyte viability was retained during 24-hour incubation at 37°C when gametocyte infected red blood cells were reconstituted in RPMI/serum. Methylene-blue, MMV693183, DDD107498, atovaquone and P218 showed potent transmission-blocking activity in the TB-DMFA, and both atovaquone and the novel antifolate P218 were potent inhibitors of sporogonic development in the SPORO-DMA. This work establishes a pipeline for the integral use of field isolates to assess the transmission-blocking capacity of antimalarial drugs to block transmission that should be validated in future studies.
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Affiliation(s)
- Noëlie B Henry
- Groupe de Recherche Action en Santé, Ouagadougou, Burkina Faso
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Issiaka Soulama
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
- Institut de Recherche en Sciences de la Santé (IRSS)/CNRST, Ouagadougou, Burkina Faso
| | - Samuel S Sermé
- Groupe de Recherche Action en Santé, Ouagadougou, Burkina Faso
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | | | | | - Aboubacar S Coulibaly
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Salif Sombié
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Nicolas Ouédraogo
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Amidou Diarra
- Groupe de Recherche Action en Santé, Ouagadougou, Burkina Faso
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Soumanaba Zongo
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Wamdaogo M Guelbéogo
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Issa Nébié
- Groupe de Recherche Action en Santé, Ouagadougou, Burkina Faso
| | | | - Alfred B Tiono
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
| | - Alano Pietro
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Roma, Italy
| | - Katharine A Collins
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherland
| | | | - Teun Bousema
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherland
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5
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Calit J, Araújo JE, Deng B, Miura K, Gaitán XA, Araújo MDS, Medeiros JF, Long CA, Simeonov A, Eastman RT, Bargieri DY. Novel Transmission-Blocking Antimalarials Identified by High-Throughput Screening of Plasmodium berghei Ookluc. Antimicrob Agents Chemother 2023; 67:e0146522. [PMID: 36856421 PMCID: PMC10112123 DOI: 10.1128/aac.01465-22] [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: 10/31/2022] [Accepted: 02/09/2023] [Indexed: 03/02/2023] Open
Abstract
Safe and effective malaria transmission-blocking chemotherapeutics would allow a community-level approach to malaria control and eradication efforts by targeting the mosquito sexual stage of the parasite life cycle. However, only a single drug, primaquine, is currently approved for use in reducing transmission, and drug toxicity limits its widespread implementation. To address this limitation in antimalarial chemotherapeutics, we used a recently developed transgenic Plasmodium berghei line, Ookluc, to perform a series of high-throughput in vitro screens for compounds that inhibit parasite fertilization, the initial step of parasite development within the mosquito. Screens of antimalarial compounds, approved drug collections, and drug-like molecule libraries identified 185 compounds that inhibit parasite maturation to the zygote form. Seven compounds were further characterized to block gametocyte activation or to be cytotoxic to formed zygotes. These were further validated in mosquito membrane-feeding assays using Plasmodium falciparum and P. vivax. This work demonstrates that high-throughput screens using the Ookluc line can identify compounds that are active against the two most relevant human Plasmodium species and provides a list of compounds that can be explored for the development of new antimalarials to block transmission.
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Affiliation(s)
- Juliana Calit
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, São Paulo, Brazil
| | - Jessica E. Araújo
- Plataforma de Produção e Infecção de Vetores da Malária-PIVEM, Laboratório de Entomologia, Fundação Oswaldo Cruz-Fiocruz Rondônia, Porto Velho, Rondônia, Brazil
- Programa de Pós-graduação em Biologia Experimental, Universidade Federal de Rondônia/Fiocruz Rondônia, Porto Velho, Rondônia, Brazil
| | - Bingbing Deng
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Xiomara A. Gaitán
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, São Paulo, Brazil
| | - Maisa da Silva Araújo
- Plataforma de Produção e Infecção de Vetores da Malária-PIVEM, Laboratório de Entomologia, Fundação Oswaldo Cruz-Fiocruz Rondônia, Porto Velho, Rondônia, Brazil
| | - Jansen F. Medeiros
- Plataforma de Produção e Infecção de Vetores da Malária-PIVEM, Laboratório de Entomologia, Fundação Oswaldo Cruz-Fiocruz Rondônia, Porto Velho, Rondônia, Brazil
- Programa de Pós-graduação em Biologia Experimental, Universidade Federal de Rondônia/Fiocruz Rondônia, Porto Velho, Rondônia, Brazil
| | - Carole A. Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Anton Simeonov
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, USA
| | - Richard T. Eastman
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, USA
| | - Daniel Y. Bargieri
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, São Paulo, Brazil
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6
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Carucci M, Duez J, Tarning J, García-Barbazán I, Fricot-Monsinjon A, Sissoko A, Dumas L, Gamallo P, Beher B, Amireault P, Dussiot M, Dao M, Hull MV, McNamara CW, Roussel C, Ndour PA, Sanz LM, Gamo FJ, Buffet P. Safe drugs with high potential to block malaria transmission revealed by a spleen-mimetic screening. Nat Commun 2023; 14:1951. [PMID: 37029122 PMCID: PMC10082216 DOI: 10.1038/s41467-023-37359-2] [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: 07/20/2022] [Accepted: 03/15/2023] [Indexed: 04/09/2023] Open
Abstract
Malaria parasites like Plasmodium falciparum multiply in red blood cells (RBC), which are cleared from the bloodstream by the spleen when their deformability is altered. Drug-induced stiffening of Plasmodium falciparum-infected RBC should therefore induce their elimination from the bloodstream. Here, based on this original mechanical approach, we identify safe drugs with strong potential to block the malaria transmission. By screening 13 555 compounds with spleen-mimetic microfilters, we identified 82 that target circulating transmissible form of P. falciparum. NITD609, an orally administered PfATPase inhibitor with known effects on P. falciparum, killed and stiffened transmission stages in vitro at nanomolar concentrations. Short exposures to TD-6450, an orally-administered NS5A hepatitis C virus inhibitor, stiffened transmission parasite stages and killed asexual stages in vitro at high nanomolar concentrations. A Phase 1 study in humans with a primary safety outcome and a secondary pharmacokinetics outcome ( https://clinicaltrials.gov , ID: NCT02022306) showed no severe adverse events either with single or multiple doses. Pharmacokinetic modelling showed that these concentrations can be reached in the plasma of subjects receiving short courses of TD-6450. This physiologically relevant screen identified multiple mechanisms of action, and safe drugs with strong potential as malaria transmission-blocking agents which could be rapidly tested in clinical trials.
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Affiliation(s)
- Mario Carucci
- Université Paris Cité, Inserm, UMR-1134, Biologie Intégré du Globule Rouge, 75015, Paris, France
| | | | - Joel Tarning
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, 10400, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Irene García-Barbazán
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, 28222, Madrid, Spain
| | - Aurélie Fricot-Monsinjon
- Université Paris Cité, Inserm, UMR-1134, Biologie Intégré du Globule Rouge, 75015, Paris, France
| | - Abdoulaye Sissoko
- Université Paris Cité, Inserm, UMR-1134, Biologie Intégré du Globule Rouge, 75015, Paris, France
| | - Lucie Dumas
- Université Paris Cité, Inserm, UMR-1134, Biologie Intégré du Globule Rouge, 75015, Paris, France
| | - Pablo Gamallo
- Global Health Medicines R&D, GlaxoSmith Kline (GSK), 28760, Tres Cantos, Spain
| | - Babette Beher
- Université Paris Cité, Inserm, UMR-1134, Biologie Intégré du Globule Rouge, 75015, Paris, France
| | - Pascal Amireault
- Université Paris Cité, Inserm, UMR-1134, Biologie Intégré du Globule Rouge, 75015, Paris, France
- Laboratory of cellular and molecular mechanisms of hematological disorders and therapeutic implications, INSERM, 75014, Paris, France
| | - Michael Dussiot
- Laboratory of cellular and molecular mechanisms of hematological disorders and therapeutic implications, INSERM, 75014, Paris, France
- Laboratoire d'Excellence GR-Ex, Paris, France
| | - Ming Dao
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, MA, 02139, Cambridge, USA
| | - Mitchell V Hull
- Calibr, a division of The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Case W McNamara
- Calibr, a division of The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Camille Roussel
- Université Paris Cité, Inserm, UMR-1134, Biologie Intégré du Globule Rouge, 75015, Paris, France
- Laboratoire d'Excellence GR-Ex, Paris, France
- Laboratoire d'Hématologie générale, Hôpital Universitaire Necker Enfants Malades, Assistance Publique-Hôpitaux de Paris (AP-HP), 75015, Paris, France
| | - Papa Alioune Ndour
- Université Paris Cité, Inserm, UMR-1134, Biologie Intégré du Globule Rouge, 75015, Paris, France
| | - Laura Maria Sanz
- Global Health Medicines R&D, GlaxoSmith Kline (GSK), 28760, Tres Cantos, Spain
| | | | - Pierre Buffet
- Université Paris Cité, Inserm, UMR-1134, Biologie Intégré du Globule Rouge, 75015, Paris, France.
- Department of Infectious & Tropical Disease, AP-HP, Necker Hospital, 75015, Paris, France.
- Centre Médical de l'Institut Pasteur (CMIP), Institut Pasteur, 75015, Paris, France.
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7
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Miglianico M, Bolscher JM, Vos MW, Koolen KJM, de Bruijni M, Rajagopal DS, Chen E, Kiczun M, Gray D, Campo B, Sauerwein RW, Dechering KJ. Assessment of the drugability of initial malaria infection through miniaturized sporozoite assays and high-throughput screening. Commun Biol 2023; 6:216. [PMID: 36823266 PMCID: PMC9950425 DOI: 10.1038/s42003-023-04599-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 02/15/2023] [Indexed: 02/25/2023] Open
Abstract
The sporozoite stages of malaria parasites are the primary cause of infection of the vertebrate host and are targeted by (experimental) vaccines. Yet, little is known about their susceptibility to chemical intervention. Phenotypic high-throughput screens have not been feasible due to a lack of in vitro systems. Here we tested 78 marketed and experimental antimalarial compounds in miniaturized assays addressing sporozoite viability, gliding motility, hepatocyte traversal, and intrahepatocytic schizogony. None potently interfered with sporozoite viability or motility but ten compounds acted at the level of schizogony with IC50s < 100 nM. To identify compounds directly targeting sporozoites, we screened 81,000 compounds from the Global Health Diversity and reFRAME libraries in a sporozoite viability assay using a parasite expressing a luciferase reporter driven by the circumsporozoite promoter. The ionophore gramicidin emerged as the single hit from this screening campaign. Its effect on sporozoite viability translated into reduced gliding motility and an inability of sporozoites to invade human primary hepatocytes and develop into hepatic schizonts. While providing proof of concept for a small molecule sporontocidal mode of action, our combined data indicate that liver schizogony is more accessible to chemical intervention by (candidate) antimalarials.
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Affiliation(s)
| | | | | | | | | | | | - Emily Chen
- Calibr, a division of The Scripps Research Institute, La Jolla, California, United States of America
| | - Michael Kiczun
- Drug Discovery Unit, University of Dundee, Dundee, United Kingdom
| | - David Gray
- Drug Discovery Unit, University of Dundee, Dundee, United Kingdom
| | - Brice Campo
- Medicines for Malaria Venture, Geneva, Switzerland
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8
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Qiu D, Pei JV, Rosling JEO, Thathy V, Li D, Xue Y, Tanner JD, Penington JS, Aw YTV, Aw JYH, Xu G, Tripathi AK, Gnadig NF, Yeo T, Fairhurst KJ, Stokes BH, Murithi JM, Kümpornsin K, Hasemer H, Dennis ASM, Ridgway MC, Schmitt EK, Straimer J, Papenfuss AT, Lee MCS, Corry B, Sinnis P, Fidock DA, van Dooren GG, Kirk K, Lehane AM. A G358S mutation in the Plasmodium falciparum Na + pump PfATP4 confers clinically-relevant resistance to cipargamin. Nat Commun 2022; 13:5746. [PMID: 36180431 PMCID: PMC9525273 DOI: 10.1038/s41467-022-33403-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 09/16/2022] [Indexed: 11/30/2022] Open
Abstract
Diverse compounds target the Plasmodium falciparum Na+ pump PfATP4, with cipargamin and (+)-SJ733 the most clinically-advanced. In a recent clinical trial for cipargamin, recrudescent parasites emerged, with most having a G358S mutation in PfATP4. Here, we show that PfATP4G358S parasites can withstand micromolar concentrations of cipargamin and (+)-SJ733, while remaining susceptible to antimalarials that do not target PfATP4. The G358S mutation in PfATP4, and the equivalent mutation in Toxoplasma gondii ATP4, decrease the sensitivity of ATP4 to inhibition by cipargamin and (+)-SJ733, thereby protecting parasites from disruption of Na+ regulation. The G358S mutation reduces the affinity of PfATP4 for Na+ and is associated with an increase in the parasite's resting cytosolic [Na+]. However, no defect in parasite growth or transmissibility is observed. Our findings suggest that PfATP4 inhibitors in clinical development should be tested against PfATP4G358S parasites, and that their combination with unrelated antimalarials may mitigate against resistance development.
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Affiliation(s)
- Deyun Qiu
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Jinxin V Pei
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - James E O Rosling
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Vandana Thathy
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Dongdi Li
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Yi Xue
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - John D Tanner
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Jocelyn Sietsma Penington
- Bioinformatic Division, The Walter & Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
| | - Yi Tong Vincent Aw
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Jessica Yi Han Aw
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Guoyue Xu
- Department of Molecular Microbiology & Immunology and Johns Hopkins Malaria Institute, Johns Hopkins School of Public Health, Baltimore, MD, 21205, USA
| | - Abhai K Tripathi
- Department of Molecular Microbiology & Immunology and Johns Hopkins Malaria Institute, Johns Hopkins School of Public Health, Baltimore, MD, 21205, USA
| | - Nina F Gnadig
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Tomas Yeo
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Kate J Fairhurst
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Barbara H Stokes
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - James M Murithi
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | | | - Heath Hasemer
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Adelaide S M Dennis
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Melanie C Ridgway
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | | | - Judith Straimer
- Novartis Institute for Tropical Diseases, Emeryville, CA, 94608, USA
| | - Anthony T Papenfuss
- Bioinformatic Division, The Walter & Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3052, Australia
| | - Marcus C S Lee
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK
| | - Ben Corry
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Photini Sinnis
- Department of Molecular Microbiology & Immunology and Johns Hopkins Malaria Institute, Johns Hopkins School of Public Health, Baltimore, MD, 21205, USA
| | - David A Fidock
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
- Center for Malaria Therapeutics and Antimicrobial Resistance, Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Giel G van Dooren
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Kiaran Kirk
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia
| | - Adele M Lehane
- Research School of Biology, Australian National University, Canberra, ACT, 2600, Australia.
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9
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van der Watt ME, Reader J, Birkholtz LM. Adapt or Die: Targeting Unique Transmission-Stage Biology for Malaria Elimination. Front Cell Infect Microbiol 2022; 12:901971. [PMID: 35755845 PMCID: PMC9218253 DOI: 10.3389/fcimb.2022.901971] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 05/06/2022] [Indexed: 12/25/2022] Open
Abstract
Plasmodium parasites have a complex life cycle that includes development in the human host as well as the Anopheles vector. Successful transmission of the parasite between its host and vector therefore requires the parasite to balance its investments in asexual replication and sexual reproduction, varying the frequency of sexual commitment to persist within the human host and generate future opportunities for transmission. The transmission window is extended further by the ability of stage V gametocytes to circulate in peripheral blood for weeks, whereas immature stage I to IV gametocytes sequester in the bone marrow and spleen until final maturation. Due to the low gametocyte numbers in blood circulation and with the ease of targeting such life cycle bottlenecks, transmission represents an efficient target for therapeutic intervention. The biological process of Plasmodium transmission is a multistage, multifaceted process and the past decade has seen a much deeper understanding of the molecular mechanisms and regulators involved. Clearly, specific and divergent processes are used during transmission compared to asexual proliferation, which both poses challenges but also opportunities for discovery of transmission-blocking antimalarials. This review therefore presents an update of our molecular understanding of gametocyte and gamete biology as well as the status of transmission-blocking activities of current antimalarials and lead development compounds. By defining the biological components associated with transmission, considerations for the development of new transmission-blocking drugs to target such untapped but unique biology is suggested as an important, main driver for transmission-blocking drug discovery.
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Affiliation(s)
- Mariëtte E van der Watt
- Institute for Sustainable Malaria Control, School of Health Systems and Public Health, University of Pretoria, Pretoria, South Africa
| | - Janette Reader
- Institute for Sustainable Malaria Control, School of Health Systems and Public Health, University of Pretoria, Pretoria, South Africa.,Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Lyn-Marié Birkholtz
- Institute for Sustainable Malaria Control, School of Health Systems and Public Health, University of Pretoria, Pretoria, South Africa.,Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
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10
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Birkholtz LM, Alano P, Leroy D. Transmission-blocking drugs for malaria elimination. Trends Parasitol 2022; 38:390-403. [DOI: 10.1016/j.pt.2022.01.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 01/19/2022] [Accepted: 01/24/2022] [Indexed: 12/24/2022]
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11
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Siciliano G, Di Paolo V, Rotili D, Migale R, Pedini F, Casella M, Camerini S, Dalzoppo D, Henderson R, Huijs T, Dechering KJ, Mai A, Caccuri AM, Lalle M, Quintieri L, Alano P. The Nitrobenzoxadiazole Derivative NBDHEX Behaves as Plasmodium falciparum Gametocyte Selective Inhibitor with Malaria Parasite Transmission Blocking Activity. Pharmaceuticals (Basel) 2022; 15:ph15020168. [PMID: 35215282 PMCID: PMC8875241 DOI: 10.3390/ph15020168] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/22/2022] [Accepted: 01/27/2022] [Indexed: 02/01/2023] Open
Abstract
This work describes the activity of 6-((7-nitrobenzo[c][1,2,5]oxadiazol-4-yl)thio)hexan-1-ol (NBDHEX) and of its newly identified carboxylic acid metabolite on the human malaria parasite Plasmodium falciparum. NBDHEX has been previously identified as a potent cytotoxic agent against murine and human cancer cells as well as towards the protozoan parasite Giardia duodenalis. We show here that NBDHEX is active in vitro against all blood stages of P. falciparum, with the rare feature of killing the parasite stages transmissible to mosquitoes, the gametocytes, with a 4-fold higher potency than that on the pathogenic asexual stages. This activity importantly translates into blocking parasite transmission through the Anopheles vector in mosquito experimental infections. A mass spectrometry analysis identified covalent NBDHEX modifications in specific cysteine residues of five gametocyte proteins, possibly associated with its antiparasitic effect. The carboxylic acid metabolite of NBDHEX retains the gametocyte preferential inhibitory activity of the parent compound, making this novel P. falciparum transmission-blocking chemotype at least as a new tool to uncover biological processes targetable by gametocyte selective drugs. Both NBDHEX and its carboxylic acid metabolite show very limited in vitro cytotoxicity on VERO cells. This result and previous evidence that NBDHEX shows an excellent in vivo safety profile in mice and is orally active against human cancer xenografts make these molecules potential starting points to develop new P. falciparum transmission-blocking agents, enriching the repertoire of drugs needed to eliminate malaria.
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Affiliation(s)
- Giulia Siciliano
- Department of Infectious Diseases, Istituto Superiore di Sanità, 00161 Rome, Italy; (G.S.); (R.M.)
| | - Veronica Di Paolo
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, 35131 Padua, Italy; (V.D.P.); (D.D.)
| | - Dante Rotili
- Department of Chemistry and Technology of Drugs, “Sapienza” University of Rome, 00185 Rome, Italy; (D.R.); (A.M.)
| | - Rossella Migale
- Department of Infectious Diseases, Istituto Superiore di Sanità, 00161 Rome, Italy; (G.S.); (R.M.)
| | - Francesca Pedini
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy;
| | - Marialuisa Casella
- Core Facilities, Istituto Superiore di Sanità, 00161 Rome, Italy; (M.C.); (S.C.)
| | - Serena Camerini
- Core Facilities, Istituto Superiore di Sanità, 00161 Rome, Italy; (M.C.); (S.C.)
| | - Daniele Dalzoppo
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, 35131 Padua, Italy; (V.D.P.); (D.D.)
| | - Rob Henderson
- TropIQ Health Sciences, 6534 AT Nijmegen, The Netherlands; (R.H.); (T.H.); (K.J.D.)
| | - Tonnie Huijs
- TropIQ Health Sciences, 6534 AT Nijmegen, The Netherlands; (R.H.); (T.H.); (K.J.D.)
| | - Koen J. Dechering
- TropIQ Health Sciences, 6534 AT Nijmegen, The Netherlands; (R.H.); (T.H.); (K.J.D.)
| | - Antonello Mai
- Department of Chemistry and Technology of Drugs, “Sapienza” University of Rome, 00185 Rome, Italy; (D.R.); (A.M.)
| | - Anna Maria Caccuri
- Department of Chemical Sciences and Technologies, University of Tor Vergata, 00133 Rome, Italy;
| | - Marco Lalle
- Department of Infectious Diseases, Istituto Superiore di Sanità, 00161 Rome, Italy; (G.S.); (R.M.)
- Correspondence: (M.L.); (L.Q.); (P.A.)
| | - Luigi Quintieri
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, 35131 Padua, Italy; (V.D.P.); (D.D.)
- Correspondence: (M.L.); (L.Q.); (P.A.)
| | - Pietro Alano
- Department of Infectious Diseases, Istituto Superiore di Sanità, 00161 Rome, Italy; (G.S.); (R.M.)
- Correspondence: (M.L.); (L.Q.); (P.A.)
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12
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Sturm A, Vos MW, Henderson R, Eldering M, Koolen KMJ, Sheshachalam A, Favia G, Samby K, Herreros E, Dechering KJ. Barcoded Asaia bacteria enable mosquito in vivo screens and identify novel systemic insecticides and inhibitors of malaria transmission. PLoS Biol 2021; 19:e3001426. [PMID: 34928952 PMCID: PMC8726507 DOI: 10.1371/journal.pbio.3001426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 01/04/2022] [Accepted: 12/03/2021] [Indexed: 11/18/2022] Open
Abstract
This work addresses the need for new chemical matter in product development for control of pest insects and vector-borne diseases. We present a barcoding strategy that enables phenotypic screens of blood-feeding insects against small molecules in microtiter plate-based arrays and apply this to discovery of novel systemic insecticides and compounds that block malaria parasite development in the mosquito vector. Encoding of the blood meals was achieved through recombinant DNA-tagged Asaia bacteria that successfully colonised Aedes and Anopheles mosquitoes. An arrayed screen of a collection of pesticides showed that chemical classes of avermectins, phenylpyrazoles, and neonicotinoids were enriched for compounds with systemic adulticide activity against Anopheles. Using a luminescent Plasmodium falciparum reporter strain, barcoded screens identified 48 drug-like transmission-blocking compounds from a 400-compound antimicrobial library. The approach significantly increases the throughput in phenotypic screening campaigns using adult insects and identifies novel candidate small molecules for disease control. This study presents a barcoding strategy that enables high-throughput phenotypic screens of blood-feeding insects against small molecules in microtiter plate-based arrays and applies this to the discovery of novel systemic insecticides and compounds that block malaria parasite development in the mosquito vector.
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13
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Multistage and transmission-blocking targeted antimalarials discovered from the open-source MMV Pandemic Response Box. Nat Commun 2021; 12:269. [PMID: 33431834 PMCID: PMC7801607 DOI: 10.1038/s41467-020-20629-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 12/10/2020] [Indexed: 12/30/2022] Open
Abstract
Chemical matter is needed to target the divergent biology associated with the different life cycle stages of Plasmodium. Here, we report the parallel de novo screening of the Medicines for Malaria Venture (MMV) Pandemic Response Box against Plasmodium asexual and liver stage parasites, stage IV/V gametocytes, gametes, oocysts and as endectocides. Unique chemotypes were identified with both multistage activity or stage-specific activity, including structurally diverse gametocyte-targeted compounds with potent transmission-blocking activity, such as the JmjC inhibitor ML324 and the antitubercular clinical candidate SQ109. Mechanistic investigations prove that ML324 prevents histone demethylation, resulting in aberrant gene expression and death in gametocytes. Moreover, the selection of parasites resistant to SQ109 implicates the druggable V-type H+-ATPase for the reduced sensitivity. Our data therefore provides an expansive dataset of compounds that could be redirected for antimalarial development and also point towards proteins that can be targeted in multiple parasite life cycle stages. Here, Reader et al. screen the Medicines for Malaria Venture Pandemic Response Box in parallel against Plasmodiumasexual and liver stage parasites, stage IV/V gametocytes, gametes, oocysts and as endectocides. They identify two potent transmission-blocking drugs: a histone demethylase inhibitor ML324 and the antitubercular SQ109.
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14
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Evaluation and modeling of direct membrane-feeding assay with Plasmodium vivax to support development of transmission blocking vaccines. Sci Rep 2020; 10:12569. [PMID: 32724063 PMCID: PMC7387523 DOI: 10.1038/s41598-020-69513-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 07/09/2020] [Indexed: 02/06/2023] Open
Abstract
Standard and direct membrane-feeding assays (SMFA and DMFA) are fundamental assays to evaluate efficacy of transmission-blocking intervention (TBI) candidates against Plasmodium falciparum and vivax. To compare different candidates precisely, it is crucial to understand the error range of measured activity, usually expressed as percent inhibition in either oocyst intensity (% transmission reducing activity, %TRA), or in prevalence of infected mosquitoes (% transmission blocking activity, %TBA). To this end, mathematical models have been proposed for P. falciparum SMFA (PfSMFA), but such study for DMFA is limited. In this study, we analyzed P. vivax DMFA (PvDMFA) data from 22,236 mosquitoes tested from 96 independent assays. While the two assays are quite different, a zero-inflated negative binomial (ZINB) model could reasonably explain the PvDMFA results, as it has for PfSMFA. Our simulation studies based on the ZINB model revealed it is better to report %TRA values with a proper error range, rather than observed %TBA both in SMFA and DMFA. Furthermore, the simulations help in designing a better assay and aid in estimating an error range of a %TRA value when the uncertainty is not reported. This study strongly supports future TBI development by providing a rational method to compare different candidates.
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15
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Bouwman SA, Zoleko-Manego R, Renner KC, Schmitt EK, Mombo-Ngoma G, Grobusch MP. The early preclinical and clinical development of cipargamin (KAE609), a novel antimalarial compound. Travel Med Infect Dis 2020; 36:101765. [PMID: 32561392 DOI: 10.1016/j.tmaid.2020.101765] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 05/29/2020] [Accepted: 05/30/2020] [Indexed: 11/16/2022]
Abstract
BACKGROUND Cipargamin (KAE609) is a novel spiroindolone class drug for the treatment of malaria, currently undergoing phase 2 clinical development. This review provides an overview and interpretation of the pre-clinical and clinical data of this possible next-generation antimalarial drug published to date. METHODS We systematically searched the literature for studies on the preclinical and clinical development of cipargamin. PubMed and Google Scholar databases were searched using the terms 'cipargamin', 'KAE609' or 'NITD609' in the English language; one additional article was identified during revision. Nineteen of these in total 43 papers identified reported original studies; 13 of those articles were on pre-clinical studies and 6 reported clinical trials. RESULTS A total of 20 studies addressing its preclinical and clinical development have been published on this compound at the time of writing. Cipargamin acts on the PfATP4, which is a P-type Na + ATPase disrupting the Na + homeostasis in the parasite. Cipargamin is a very fast-acting antimalarial, it is active against all intra-erythrocytic stages of the malaria parasite and exerts gametocytocidal activity, with transmission-blocking potential. It is currently undergoing phase 2 clinical trial to assess safety and efficacy, with a special focus on hepatic safety. CONCLUSION In the search for novel antimalarial drugs, cipargamin exhibits promising properties, exerting activity against multiple intra-erythrocytic stages of plasmodia, including gametocytes. It exhibits a favourable pharmacokinetic profile, possibly allowing for single-dose treatment with a suitable combination partner. According to the clinical results of the first studies in Asian malaria patients, a possible safety concern is hepatotoxicity.
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Affiliation(s)
- Suzan Am Bouwman
- Center for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Amsterdam University Medical Centers, Location AMC, Amsterdam Infection & Immunity, Amsterdam Public Health, University of Amsterdam, Meibergdreef 9, 1100 DD, Amsterdam, the Netherlands; Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
| | - Rella Zoleko-Manego
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon; Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany; Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I. Department of Medicine University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Esther K Schmitt
- Novartis Pharma AG, Global Health Development Unit, Basel, Switzerland
| | - Ghyslain Mombo-Ngoma
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon; Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany; Department of Tropical Medicine, Bernhard Nocht Institute for Tropical Medicine & I. Department of Medicine University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Martin P Grobusch
- Center for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Amsterdam University Medical Centers, Location AMC, Amsterdam Infection & Immunity, Amsterdam Public Health, University of Amsterdam, Meibergdreef 9, 1100 DD, Amsterdam, the Netherlands; Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon; Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany.
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16
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Smilkstein MJ, Pou S, Krollenbrock A, Bleyle LA, Dodean RA, Frueh L, Hinrichs DJ, Li Y, Martinson T, Munar MY, Winter RW, Bruzual I, Whiteside S, Nilsen A, Koop DR, Kelly JX, Kappe SHI, Wilder BK, Riscoe MK. ELQ-331 as a prototype for extremely durable chemoprotection against malaria. Malar J 2019; 18:291. [PMID: 31455339 PMCID: PMC6712883 DOI: 10.1186/s12936-019-2921-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 08/17/2019] [Indexed: 12/02/2022] Open
Abstract
Background The potential benefits of long-acting injectable chemoprotection (LAI-C) against malaria have been recently recognized, prompting a call for suitable candidate drugs to help meet this need. On the basis of its known pharmacodynamic and pharmacokinetic profiles after oral dosing, ELQ-331, a prodrug of the parasite mitochondrial electron transport inhibitor ELQ-300, was selected for study of pharmacokinetics and efficacy as LAI-C in mice. Methods Four trials were conducted in which mice were injected with a single intramuscular dose of ELQ-331 or other ELQ-300 prodrugs in sesame oil with 1.2% benzyl alcohol; the ELQ-300 content of the doses ranged from 2.5 to 30 mg/kg. Initial blood stage challenges with Plasmodium yoelii were used to establish the model, but the definitive study measure of efficacy was outcome after sporozoite challenge with a luciferase-expressing P. yoelii, assessed by whole-body live animal imaging. Snapshot determinations of plasma ELQ-300 concentration ([ELQ-300]) were made after all prodrug injections; after the highest dose of ELQ-331 (equivalent to 30 mg/kg ELQ-300), both [ELQ-331] and [ELQ-300] were measured at a series of timepoints from 6 h to 5½ months after injection. Results A single intramuscular injection of ELQ-331 outperformed four other ELQ-300 prodrugs and, at a dose equivalent to 30 mg/kg ELQ-300, protected mice against challenge with P. yoelii sporozoites for at least 4½ months. Pharmacokinetic evaluation revealed rapid and essentially complete conversion of ELQ-331 to ELQ-300, a rapidly achieved (< 6 h) and sustained (4–5 months) effective plasma ELQ-300 concentration, maximum ELQ-300 concentrations far below the estimated threshold for toxicity, and a distinctive ELQ-300 concentration versus time profile. Pharmacokinetic modeling indicates a high-capacity, slow-exchange tissue compartment which serves to accumulate and then slowly redistribute ELQ-300 into blood, and this property facilitates an extremely long period during which ELQ-300 concentration is sustained above a minimum fully-protective threshold (60–80 nM). Conclusions Extrapolation of these results to humans predicts that ELQ-331 should be capable of meeting and far-exceeding currently published duration-of-effect goals for anti-malarial LAI-C. Furthermore, the distinctive pharmacokinetic profile of ELQ-300 after treatment with ELQ-331 may facilitate durable protection and enable protection for far longer than 3 months. These findings suggest that ELQ-331 warrants consideration as a leading prototype for LAI-C.
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Affiliation(s)
- Martin J Smilkstein
- VA Portland Health Care System Research and Development Service, 3710 SW US Veterans Hospital Road, RD-33, Portland, OR, 97239, USA.
| | - Sovitj Pou
- VA Portland Health Care System Research and Development Service, 3710 SW US Veterans Hospital Road, RD-33, Portland, OR, 97239, USA
| | - Alina Krollenbrock
- Department of Physiology and Pharmacology, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Lisa A Bleyle
- Bioanalytical Shared Resource Core Pharmacokinetics, Department of Physiology and Pharmacology, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, L334, Portland, OR, 97239, USA
| | - Rozalia A Dodean
- VA Portland Health Care System Research and Development Service, 3710 SW US Veterans Hospital Road, RD-33, Portland, OR, 97239, USA.,Department of Chemistry, Portland State University, PO Box 751, Portland, OR, 97207, USA
| | - Lisa Frueh
- VA Portland Health Care System Research and Development Service, 3710 SW US Veterans Hospital Road, RD-33, Portland, OR, 97239, USA
| | - David J Hinrichs
- VA Portland Health Care System Research and Development Service, 3710 SW US Veterans Hospital Road, RD-33, Portland, OR, 97239, USA
| | - Yuexin Li
- VA Portland Health Care System Research and Development Service, 3710 SW US Veterans Hospital Road, RD-33, Portland, OR, 97239, USA
| | - Thomas Martinson
- Vaccine & Gene Therapy Institute (VGTI), Oregon Health and Science University (West Campus), 505 NW 185th Avenue, #1, Beaverton, OR, 97006, USA
| | - Myrna Y Munar
- Oregon State University/Oregon Health and Science University College of Pharmacy, 2730 SW Moody Avenue, CL5CP, Portland, OR, 97201, USA
| | - Rolf W Winter
- VA Portland Health Care System Research and Development Service, 3710 SW US Veterans Hospital Road, RD-33, Portland, OR, 97239, USA.,Department of Chemistry, Portland State University, PO Box 751, Portland, OR, 97207, USA
| | - Igor Bruzual
- VA Portland Health Care System Research and Development Service, 3710 SW US Veterans Hospital Road, RD-33, Portland, OR, 97239, USA
| | - Samantha Whiteside
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, 307 Westlake Ave N., Suite 500, Seattle, WA, USA
| | - Aaron Nilsen
- VA Portland Health Care System Research and Development Service, 3710 SW US Veterans Hospital Road, RD-33, Portland, OR, 97239, USA
| | - Dennis R Koop
- Bioanalytical Shared Resource Core Pharmacokinetics, Department of Physiology and Pharmacology, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, L334, Portland, OR, 97239, USA
| | - Jane X Kelly
- VA Portland Health Care System Research and Development Service, 3710 SW US Veterans Hospital Road, RD-33, Portland, OR, 97239, USA.,Department of Chemistry, Portland State University, PO Box 751, Portland, OR, 97207, USA
| | - Stefan H I Kappe
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, 307 Westlake Ave N., Suite 500, Seattle, WA, USA
| | - Brandon K Wilder
- Vaccine & Gene Therapy Institute (VGTI), Oregon Health and Science University (West Campus), 505 NW 185th Avenue, #1, Beaverton, OR, 97006, USA
| | - Michael K Riscoe
- VA Portland Health Care System Research and Development Service, 3710 SW US Veterans Hospital Road, RD-33, Portland, OR, 97239, USA.,Department of Molecular Microbiology and Immunology, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
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17
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Miura K, Swihart BJ, Deng B, Zhou L, Pham TP, Diouf A, Fay MP, Long CA. Strong concordance between percent inhibition in oocyst and sporozoite intensities in a Plasmodium falciparum standard membrane-feeding assay. Parasit Vectors 2019; 12:206. [PMID: 31060594 PMCID: PMC6501457 DOI: 10.1186/s13071-019-3470-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 04/29/2019] [Indexed: 11/22/2022] Open
Abstract
Background Effective malaria transmission-blocking vaccines (TBVs) can support malaria eradication programmes, and the standard membrane-feeding assay (SMFA) has been used as a “gold standard” assay for TBV development. However, in SMFA, the inhibitory activity is commonly measured at oocyst stage of parasites, while it is the sporozoites which transmit malaria from a mosquito to a human. A handful of studies have shown that there is a positive correlation between oocyst and sporozoite intensities. However, no study has been completed to compare inhibition levels in oocyst and sporozoite intensities in the presence of transmission-blocking (TB) antibodies. Results Plasmodium falciparum NF54 gametocytes were fed to Anopheles stephensi mosquitoes with or without anti-Pfs25 or anti-Pfs48/45 TB antibodies in 15 independent assays. For each group, a portion of the mosquitoes was dissected for oocyst counts (day 8 after feed), and a portion of the remaining mosquitoes was dissected for sporozoite counts (day 16). This study covered a large range of oocyst and sporozoite intensities: 0.2 to 80.5 on average for oocysts, and 141 to 77,417 for sporozoites. The sporozoite data were well explained by a zero-inflated negative binomial model, regardless of the presence or absence of TB antibodies. Inhibition levels in both oocyst and sporozoite intensities were determined within the same groups in 9 independent assays. When the level of inhibition in sporozoite number (expressed as Log Mean Ratio, LMR; average number in a control group was divided by the one in a test group, then took a log of the ratio) was plotted against LMR in oocyst number, the best-fit slope of a linear regression was not different from 1 (the best estimate, 1.08; 95% confidence interval, 0.87 to 1.29). Furthermore, a Bland–Altman analysis showed a strong agreement between inhibitions in oocysts and in sporozoites. Conclusions The results indicate that percent inhibition in oocyst intensity of a test sample can be directly converted to % inhibition in sporozoite intensity in P. falciparum SMFA. Therefore, if sporozoite intensity determines transmission rate from mosquitoes to humans, the percent inhibition in oocyst intensity measured by SMFA can be used to estimate the TBV efficacy. Electronic supplementary material The online version of this article (10.1186/s13071-019-3470-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, 20852, USA.
| | - Bruce J Swihart
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 5601 Fishers Lane, Rockville, MD, 20852, USA
| | - Bingbing Deng
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, 20852, USA
| | - Luwen Zhou
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, 20852, USA
| | - Thao P Pham
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, 20852, USA
| | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, 20852, USA
| | - Michael P Fay
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 5601 Fishers Lane, Rockville, MD, 20852, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, 20852, USA
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Colmenarejo G, Lozano S, González-Cortés C, Calvo D, Sanchez-Garcia J, Matilla JLP, Leroy D, Rodrigues J. Predicting transmission blocking potential of anti-malarial compounds in the Mosquito Feeding Assay using Plasmodium falciparum Male Gamete Inhibition Assay. Sci Rep 2018; 8:7764. [PMID: 29773818 PMCID: PMC5958111 DOI: 10.1038/s41598-018-26125-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 05/04/2018] [Indexed: 02/01/2023] Open
Abstract
Plasmodium falciparum Standard Membrane Feeding Assay (PfSMFA) is the current gold standard mosquito based confirmatory transmission blocking (TrB) assay for human malaria. However, owing to its complexity only selected gametocytocidal molecules are progressed into SMFA. Predictive tools for evaluation of TrB behavior of compounds in SMFA would be extremely beneficial, but lack of substantially large data sets from many mosquito feeds preempts the ability to perform correlations between outcomes from in vitro assays and SMFA. Here, a total of 44 different anti-malarial compounds were screened for inhibitory effect on male gamete formation in exflagellation inhibition assay (EIA) and the same drug-treated parasites were fed to mosquitoes in SMFA. Regression analysis was performed between outcomes of the two assays and regression models were applied to a randomly selected validation set of four compounds indicating no overfitting and good predictive power. In addition, the pIC50 for 11 different compounds obtained in the EIA was also correlated with pIC50’s in SMFA. Resulting regression models provided pIC50 predictions in SMFA with reasonably good accuracy thereby demonstrating the use of a simple in vitro assay to predict TrB of molecules in a complex mosquito based assay.
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Affiliation(s)
- Gonzalo Colmenarejo
- Diseases of the Developing World (DDW), GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, 28760, Madrid, Spain.,Biostatistics and Bioinformatics Unit, IMDEA Food Institute, CEI UAM+CSIC, Ctra Cantoblanco 8, 28049, Madrid, Spain
| | - Sonia Lozano
- Diseases of the Developing World (DDW), GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, 28760, Madrid, Spain
| | - Carolina González-Cortés
- Diseases of the Developing World (DDW), GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, 28760, Madrid, Spain.,Complejo Asistencial Universitario de León. Altos de Nava s/n, 24071, León, Spain
| | - David Calvo
- Diseases of the Developing World (DDW), GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, 28760, Madrid, Spain
| | - Juliana Sanchez-Garcia
- In vivo Science & Delivery (IVSD), GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, 28760, Madrid, Spain
| | - Jesús-Luís Presa Matilla
- Diseases of the Developing World (DDW), GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, 28760, Madrid, Spain
| | - Didier Leroy
- Medicines for Malaria Venture, Route de Pré-Bois 20, 1215, Geneva 15, Switzerland
| | - Janneth Rodrigues
- Diseases of the Developing World (DDW), GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, 28760, Madrid, Spain.
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Luth MR, Gupta P, Ottilie S, Winzeler EA. Using in Vitro Evolution and Whole Genome Analysis To Discover Next Generation Targets for Antimalarial Drug Discovery. ACS Infect Dis 2018; 4:301-314. [PMID: 29451780 PMCID: PMC5848146 DOI: 10.1021/acsinfecdis.7b00276] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
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Although
many new anti-infectives have been discovered and developed solely
using phenotypic cellular screening and assay optimization, most researchers
recognize that structure-guided drug design is more practical and
less costly. In addition, a greater chemical space can be interrogated
with structure-guided drug design. The practicality of structure-guided
drug design has launched a search for the targets of compounds discovered
in phenotypic screens. One method that has been used extensively in
malaria parasites for target discovery and chemical validation is in vitro evolution and whole genome analysis (IVIEWGA).
Here, small molecules from phenotypic screens with demonstrated antiparasitic
activity are used in genome-based target discovery methods. In this
Review, we discuss the newest, most promising druggable targets discovered
or further validated by evolution-based methods, as well as some exceptions.
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Affiliation(s)
- Madeline R. Luth
- Division of Host Pathogen Systems and Therapeutics, Department of Pediatrics, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Purva Gupta
- Division of Host Pathogen Systems and Therapeutics, Department of Pediatrics, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Sabine Ottilie
- Division of Host Pathogen Systems and Therapeutics, Department of Pediatrics, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Elizabeth A. Winzeler
- Division of Host Pathogen Systems and Therapeutics, Department of Pediatrics, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
- Skaggs School of Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
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