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Partey FD, Frimpong A, Ofori MF. Collection and Cryopreservation of Plasmodium falciparum Clinical Isolates in the Field. Methods Mol Biol 2022; 2470:11-17. [PMID: 35881334 DOI: 10.1007/978-1-0716-2189-9_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
P. falciparum causes the most severe form of malaria in younger children and pregnant women. In vitro culture systems allow researchers to understand parasite biology, elucidate mechanism of host immunity and test efficacy of antimalarial agents or vaccines in preclinical studies. Most laboratory-adapted parasite strains predate the emergence of artemisinin-based drug combinations and mainly originate from Asia or Europe. To fully understand the biochemical and phenotypic characteristics of parasites, it is imperative that researchers are able to culture parasites circulating in an area to unravel any geographical differences at the population level. Ex vivo culturing of clinical isolates can be challenging when collecting samples in the field and requires technical expertise and equipment. To overcome this challenge, clinical isolates are cryopreserved in the field and transported to a laboratory for in vitro studies. In this protocol, we describe different methods of cryopreserving P. falciparum isolates in the field and thawing them for subsequent in vitro culture.
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Affiliation(s)
| | - Augustina Frimpong
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Michael Fokuo Ofori
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana.
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Rocamora F, Gupta P, Istvan ES, Luth MR, Carpenter EF, Kümpornsin K, Sasaki E, Calla J, Mittal N, Carolino K, Owen E, Llinás M, Ottilie S, Goldberg DE, Lee MCS, Winzeler EA. PfMFR3: A Multidrug-Resistant Modulator in Plasmodium falciparum. ACS Infect Dis 2021; 7:811-825. [PMID: 33715347 PMCID: PMC8042660 DOI: 10.1021/acsinfecdis.0c00676] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
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In
malaria, chemical genetics is a powerful method for assigning
function to uncharacterized genes. MMV085203 and GNF-Pf-3600 are two
structurally related napthoquinone phenotypic screening hits that
kill both blood- and sexual-stage P. falciparum parasites in the low nanomolar to low micromolar range. In order
to understand their mechanism of action, parasites from two different
genetic backgrounds were exposed to sublethal concentrations of MMV085203
and GNF-Pf-3600 until resistance emerged. Whole genome sequencing
revealed all 17 resistant clones acquired nonsynonymous mutations
in the gene encoding the orphan apicomplexan transporter PF3D7_0312500
(pfmfr3) predicted to encode a member of the major
facilitator superfamily (MFS). Disruption of pfmfr3 and testing against a panel of antimalarial compounds showed decreased
sensitivity to MMV085203 and GNF-Pf-3600 as well as other compounds
that have a mitochondrial mechanism of action. In contrast, mutations
in pfmfr3 provided no protection against compounds
that act in the food vacuole or the cytosol. A dihydroorotate dehydrogenase
rescue assay using transgenic parasite lines, however, indicated a
different mechanism of action for both MMV085203 and GNF-Pf-3600 than
the direct inhibition of cytochrome bc1. Green fluorescent protein
(GFP) tagging of PfMFR3 revealed that it localizes to the parasite
mitochondrion. Our data are consistent with PfMFR3 playing roles in
mitochondrial transport as well as drug resistance for clinically
relevant antimalarials that target the mitochondria. Furthermore,
given that pfmfr3 is naturally polymorphic, naturally
occurring mutations may lead to differential sensitivity to clinically
relevant compounds such as atovaquone.
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Affiliation(s)
- Frances Rocamora
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Purva Gupta
- VA San Diego Healthcare System, Medical and Research Sections, La Jolla, California 92161, United States
- Department of Medicine, Division of Pulmonary and Critical Care, University of California, San Diego, La Jolla, California 92037, United States
| | - Eva S. Istvan
- Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63130, United States
| | - Madeline R. Luth
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | | | | | - Erika Sasaki
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Jaeson Calla
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Nimisha Mittal
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Krypton Carolino
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Edward Owen
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Huck Center for Malaria Research, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Manuel Llinás
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Huck Center for Malaria Research, Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Sabine Ottilie
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
| | - Daniel E. Goldberg
- Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63130, United States
| | | | - Elizabeth A. Winzeler
- Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States
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Douglas RG, Reinig M, Neale M, Frischknecht F. Screening for potential prophylactics targeting sporozoite motility through the skin. Malar J 2018; 17:319. [PMID: 30170589 PMCID: PMC6119338 DOI: 10.1186/s12936-018-2469-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 08/27/2018] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Anti-malarial compounds have not yet been identified that target the first obligatory step of infection in humans: the migration of Plasmodium sporozoites in the host dermis. This movement is essential to find and invade a blood vessel in order to be passively transported to the liver. Here, an imaging screening pipeline was established to screen for compounds capable of inhibiting extracellular sporozoites. METHODS Sporozoites expressing the green fluorescent protein were isolated from infected Anopheles mosquitoes, incubated with compounds from two libraries (MMV Malaria Box and a FDA-approved library) and imaged. Effects on in vitro motility or morphology were scored. In vivo efficacy of a candidate drug was investigated by treating mice ears with a gel prior to infectious mosquito bites. Motility was analysed by in vivo imaging and the progress of infection was monitored by daily blood smears. RESULTS Several compounds had a pronounced effect on in vitro sporozoite gliding or morphology. Notably, monensin sodium potently affected sporozoite movement while gramicidin S resulted in rounding up of sporozoites. However, pre-treatment of mice with a topical gel containing gramicidin did not reduce sporozoite motility and infection. CONCLUSIONS This approach shows that it is possible to screen libraries for inhibitors of sporozoite motility and highlighted the paucity of compounds in currently available libraries that inhibit this initial step of a malaria infection. Screening of diverse libraries is suggested to identify more compounds that could serve as leads in developing 'skin-based' malaria prophylactics. Further, strategies need to be developed that will allow compounds to effectively penetrate the dermis and thereby prevent exit of sporozoites from the skin.
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Affiliation(s)
- Ross G Douglas
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany.
| | - Miriam Reinig
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Matthew Neale
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany.
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Schiafino-Ortega S, Baglioni E, Pérez-Moreno G, Marco PR, Marco C, González-Pacanowska D, Ruiz-Pérez LM, Carrasco-Jiménez MP, López-Cara LC. 1,2-Diphenoxiethane salts as potent antiplasmodial agents. Bioorg Med Chem Lett 2018; 28:2485-2489. [PMID: 29880399 DOI: 10.1016/j.bmcl.2018.05.060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 05/25/2018] [Accepted: 05/30/2018] [Indexed: 01/22/2023]
Abstract
In this article we present a series of non-cytotoxic potent human choline kinase (CK) inhibitors that exhibit nanomolar antiplasmodial activity in vitro. The most active antiplasmodial compounds, 10a-b, bearing a pyridinium cationic head were inactive against CK, while compounds 10g and 10j with a quinolinium moiety exhibit moderate inhibition of both the parasite and the enzyme. The results point towards an additional mechanism of action unrelated to CK inhibition that remains to be established.
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Affiliation(s)
- Santiago Schiafino-Ortega
- Departamento de Química Farmacéutica y Orgánica, Facultad de Farmacia, Campus de Cartuja, 18071 Granada, Spain
| | - Eleonora Baglioni
- Departamento de Química Farmacéutica y Orgánica, Facultad de Farmacia, Campus de Cartuja, 18071 Granada, Spain
| | - Guiomar Pérez-Moreno
- Instituto de Parasitología y Biomedicina "López-Neyra", Consejo Superior de Investigaciones Científicas, Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento 17, 18016 Armilla, Granada, Spain
| | - Pablo Rios Marco
- Departamento de Bioquímica y Biología Molecular I, Facultad de Ciencias, Campus Fuentenueva, 18071 Granada, Spain
| | - Carmen Marco
- Departamento de Bioquímica y Biología Molecular I, Facultad de Ciencias, Campus Fuentenueva, 18071 Granada, Spain
| | - Dolores González-Pacanowska
- Instituto de Parasitología y Biomedicina "López-Neyra", Consejo Superior de Investigaciones Científicas, Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento 17, 18016 Armilla, Granada, Spain
| | - Luis Miguel Ruiz-Pérez
- Instituto de Parasitología y Biomedicina "López-Neyra", Consejo Superior de Investigaciones Científicas, Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento 17, 18016 Armilla, Granada, Spain
| | - María Paz Carrasco-Jiménez
- Departamento de Bioquímica y Biología Molecular I, Facultad de Ciencias, Campus Fuentenueva, 18071 Granada, Spain
| | - Luisa Carlota López-Cara
- Departamento de Química Farmacéutica y Orgánica, Facultad de Farmacia, Campus de Cartuja, 18071 Granada, Spain.
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