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Craven HM, Nettesheim G, Cicuta P, Blagborough AM, Merrick CJ. Effects of the G-quadruplex-binding drugs quarfloxin and CX-5461 on the malaria parasite Plasmodium falciparum. Int J Parasitol Drugs Drug Resist 2023; 23:106-119. [PMID: 38041930 PMCID: PMC10711401 DOI: 10.1016/j.ijpddr.2023.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/15/2023] [Accepted: 11/20/2023] [Indexed: 12/04/2023]
Abstract
Plasmodium falciparum is the deadliest causative agent of human malaria. This parasite has historically developed resistance to most drugs, including the current frontline treatments, so new therapeutic targets are needed. Our previous work on guanine quadruplexes (G4s) in the parasite's DNA and RNA has highlighted their influence on parasite biology, and revealed G4 stabilising compounds as promising candidates for repositioning. In particular, quarfloxin, a former anticancer agent, kills blood-stage parasites at all developmental stages, with fast rates of kill and nanomolar potency. Here we explored the molecular mechanism of quarfloxin and its related derivative CX-5461. In vitro, both compounds bound to P. falciparum-encoded G4 sequences. In cellulo, quarfloxin was more potent than CX-5461, and could prevent establishment of blood-stage malaria in vivo in a murine model. CX-5461 showed clear DNA damaging activity, as reported in human cells, while quarfloxin caused weaker signatures of DNA damage. Both compounds caused transcriptional dysregulation in the parasite, but the affected genes were largely different, again suggesting different modes of action. Therefore, CX-5461 may act primarily as a DNA damaging agent in both Plasmodium parasites and mammalian cells, whereas the complete antimalarial mode of action of quarfloxin may be parasite-specific and remains somewhat elusive.
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Affiliation(s)
- Holly M Craven
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Guilherme Nettesheim
- Department of Physics, Cavendish Laboratory University of Cambridge, J.J. Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Pietro Cicuta
- Department of Physics, Cavendish Laboratory University of Cambridge, J.J. Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Andrew M Blagborough
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Catherine J Merrick
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK.
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Iyori M, Blagborough AM, Mizuno T, Abe YI, Nagaoka M, Hori N, Yamagoshi I, Da DF, Gregory WF, Hasyim AA, Yamamoto Y, Sakamoto A, Yoshida K, Mizukami H, Shida H, Yoshida S. Sterile protection and transmission blockade by a multistage anti-malarial vaccine in the pre-clinical study. Front Immunol 2022; 13:1005476. [PMID: 36248835 PMCID: PMC9558734 DOI: 10.3389/fimmu.2022.1005476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 09/12/2022] [Indexed: 11/13/2022] Open
Abstract
The Malaria Vaccine Technology Roadmap 2013 (World Health Organization) aims to develop safe and effective vaccines by 2030 that will offer at least 75% protective efficacy against clinical malaria and reduce parasite transmission. Here, we demonstrate a highly effective multistage vaccine against both the pre-erythrocytic and sexual stages of Plasmodium falciparum that protects and reduces transmission in a murine model. The vaccine is based on a viral-vectored vaccine platform, comprising a highly-attenuated vaccinia virus strain, LC16m8Δ (m8Δ), a genetically stable variant of a licensed and highly effective Japanese smallpox vaccine LC16m8, and an adeno-associated virus (AAV), a viral vector for human gene therapy. The genes encoding P. falciparum circumsporozoite protein (PfCSP) and the ookinete protein P25 (Pfs25) are expressed as a Pfs25-PfCSP fusion protein, and the heterologous m8Δ-prime/AAV-boost immunization regimen in mice provided both 100% protection against PfCSP-transgenic P. berghei sporozoites and up to 100% transmission blocking efficacy, as determined by a direct membrane feeding assay using parasites from P. falciparum-positive, naturally-infected donors from endemic settings. Remarkably, the persistence of vaccine-induced immune responses were over 7 months and additionally provided complete protection against repeated parasite challenge in a murine model. We propose that application of the m8Δ/AAV malaria multistage vaccine platform has the potential to contribute to the landmark goals of the malaria vaccine technology roadmap, to achieve life-long sterile protection and high-level transmission blocking efficacy.
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Affiliation(s)
- Mitsuhiro Iyori
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa University, Ishikawa, Japan
| | | | - Tetsushi Mizuno
- Department of Parasitology, Graduate School of Medical Sciences, Kanazawa University, Ishikawa, Japan
| | - Yu-ichi Abe
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa University, Ishikawa, Japan
| | - Mio Nagaoka
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa University, Ishikawa, Japan
| | - Naoto Hori
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa University, Ishikawa, Japan
| | - Iroha Yamagoshi
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa University, Ishikawa, Japan
| | - Dari F. Da
- Département de Biologie Médicale et Santé Publique, Unité Paludisme et Maladies Tropicales Négligées, Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | - William F. Gregory
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Ammar A. Hasyim
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa University, Ishikawa, Japan
| | - Yutaro Yamamoto
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa University, Ishikawa, Japan
| | - Akihiko Sakamoto
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa University, Ishikawa, Japan
| | - Kunitaka Yoshida
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa University, Ishikawa, Japan
| | - Hiroaki Mizukami
- Division of Gene Therapy, Jichi Medical University, Tochigi, Japan
| | - Hisatoshi Shida
- Institute for Genetic Medicine, Hokkaido University, Hokkaido, Japan
| | - Shigeto Yoshida
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kanazawa University, Ishikawa, Japan
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Feng J, Dong X, DeCosta A, Su Y, Angrisano F, Sala KA, Blagborough AM, Lu C, Springer TA. Structural basis of malaria transmission blockade by a monoclonal antibody to gamete fusogen HAP2. eLife 2021; 10:74707. [PMID: 34939934 PMCID: PMC8806182 DOI: 10.7554/elife.74707] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 12/03/2021] [Indexed: 11/13/2022] Open
Abstract
HAP2 is a transmembrane gamete fusogen found in multiple eukaryotic kingdoms and is structurally homologous to viral class II fusogens. Studies in Plasmodium have suggested that HAP2 is an attractive target for vaccines that block transmission of malaria. HAP2 has three extracellular domains, arranged in the order D2, D1, and D3. Here, we report monoclonal antibodies against the D3 fragment of Plasmodium berghei HAP2 and crystal structures of D3 in complex with Fab fragments of two of these antibodies, one of which blocks fertilization of Plasmodium berghei in vitro and transmission of malaria in mosquitoes. We also show how this Fab binds the complete HAP2 ectodomain with electron microscopy. The two antibodies cross-react with HAP2 among multiple plasmodial species. Our characterization of the Plasmodium D3 structure, HAP2 ectodomain architecture, and mechanism of inhibition provide insights for the development of a vaccine to block malaria transmission.
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Affiliation(s)
- Juan Feng
- Program in Cellular and Molecular Medicine, Boston Children's Hospital
| | | | - Adam DeCosta
- Program in Cellular and Molecular Medicine, Boston Children's Hospital
| | - Yang Su
- Program in Cellular and Molecular Medicine, Boston Children's Hospital
| | | | | | | | - Chafen Lu
- Program in Cellular and Molecular Medicine, Boston Children's Hospital
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Muthui MK, Takashima E, Omondi BR, Kinya C, Muasya WI, Nagaoka H, Mwai KW, Orindi B, Wambua J, Bousema T, Drakeley C, Blagborough AM, Marsh K, Bejon P, Kapulu MC. Characterization of Naturally Acquired Immunity to a Panel of Antigens Expressed in Mature P. falciparum Gametocytes. Front Cell Infect Microbiol 2021; 11:774537. [PMID: 34869075 PMCID: PMC8633105 DOI: 10.3389/fcimb.2021.774537] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction Naturally acquired immune responses against antigens expressed on the surface of mature gametocytes develop in individuals living in malaria-endemic areas. Evidence suggests that such anti-gametocyte immunity can block the development of the parasite in the mosquito, thus playing a role in interrupting transmission. A better comprehension of naturally acquired immunity to these gametocyte antigens can aid the development of transmission-blocking vaccines and improve our understanding of the human infectious reservoir. Methods Antigens expressed on the surface of mature gametocytes that had not previously been widely studied for evidence of naturally acquired immunity were identified for protein expression alongside Pfs230-C using either the mammalian HEK293E or the wheat germ cell-free expression systems. Where there was sequence variation in the candidate antigens (3D7 vs a clinical isolate PfKE04), both variants were expressed. ELISA was used to assess antibody responses against these antigens, as well as against crude stage V gametocyte extract (GE) and AMA1 using archived plasma samples from individuals recruited to participate in malaria cohort studies. We analyzed antibody levels (estimated from optical density units using a standardized ELISA) and seroprevalence (defined as antibody levels greater than three standard deviations above the mean levels of a pool of malaria naïve sera). We described the dynamics of antibody responses to these antigens by identifying factors predictive of antibody levels using linear regression models. Results Of the 25 antigens selected, seven antigens were produced successfully as recombinant proteins, with one variant antigen, giving a total of eight proteins for evaluation. Antibodies to the candidate antigens were detectable in the study population (N = 216), with seroprevalence ranging from 37.0% (95% CI: 30.6%, 43.9%) for PSOP1 to 77.8% (95% CI: 71.6%, 83.1%) for G377 (3D7 variant). Responses to AMA1 and GE were more prevalent than those to the gametocyte proteins at 87.9% (95% CI: 82.8%, 91.9%) and 88.3% (95% CI: 83.1%, 92.4%), respectively. Additionally, both antibody levels and breadth of antibody responses were associated with age and concurrent parasitaemia. Conclusion Age and concurrent parasitaemia remain important determinants of naturally acquired immunity to gametocyte antigens. Furthermore, we identify novel candidates for transmission-blocking activity evaluation.
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Affiliation(s)
- Michelle K Muthui
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Brian R Omondi
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya
| | - Christine Kinya
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya
| | - William I Muasya
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya
| | - Hikaru Nagaoka
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Kennedy W Mwai
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya.,School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Benedict Orindi
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya
| | - Juliana Wambua
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Chris Drakeley
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Andrew M Blagborough
- Division of Microbiology and Parasitology, Department of Pathology, Cambridge University, Tennis Court Road, Cambridge, United Kingdom
| | - Kevin Marsh
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Philip Bejon
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Melissa C Kapulu
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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Minassian AM, Themistocleous Y, Silk SE, Barrett JR, Kemp A, Quinkert D, Nielsen CM, Edwards NJ, Rawlinson TA, Ramos Lopez F, Roobsoong W, Ellis KJ, Cho JS, Aunin E, Otto TD, Reid AJ, Bach FA, Labbé GM, Poulton ID, Marini A, Zaric M, Mulatier M, Lopez Ramon R, Baker M, Mitton CH, Sousa JC, Rachaphaew N, Kumpitak C, Maneechai N, Suansomjit C, Piteekan T, Hou MM, Khozoee B, McHugh K, Roberts DJ, Lawrie AM, Blagborough AM, Nugent FL, Taylor IJ, Johnson KJ, Spence PJ, Sattabongkot J, Biswas S, Rayner JC, Draper SJ. Controlled human malaria infection with a clone of Plasmodium vivax with high quality genome assembly. JCI Insight 2021; 6:152465. [PMID: 34609964 PMCID: PMC8675201 DOI: 10.1172/jci.insight.152465] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Controlled human malaria infection (CHMI) provides a highly informative means to investigate host-pathogen interactions and enable in vivo proof-of-concept efficacy testing of new drugs and vaccines. However, unlike Plasmodium falciparum, well-characterized P. vivax parasites that are safe and suitable for use in modern CHMI models are limited. Here, two healthy malaria-naïve UK adults with universal donor blood group were safely infected with a clone of P. vivax from Thailand by mosquito-bite CHMI. Parasitemia developed in both volunteers and, prior to treatment, each volunteer donated blood to produce a cryopreserved stabilate of infected red blood cells. Following stringent safety screening, the parasite stabilate from one of these donors ("PvW1") was thawed and used to inoculate six healthy malaria-naïve UK adults by blood-stage CHMI, at three different dilutions. Parasitemia developed in all volunteers, who were then successfully drug treated. PvW1 parasite DNA was isolated and sequenced to produce a high quality genome assembly by using a hybrid assembly method. We analysed leading vaccine candidate antigens and multigene families, including the Vivax interspersed repeat (VIR) genes of which we identified 1145 in the PvW1 genome. Our genomic analysis will guide future assessment of candidate vaccines and drugs, as well as experimental medicine studies.
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Affiliation(s)
| | | | - Sarah E Silk
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Jordan R Barrett
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Alison Kemp
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Doris Quinkert
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | | | - Nick J Edwards
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | | | | | | | | | - Jee-Sun Cho
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Eerik Aunin
- Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - Thomas D Otto
- Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - Adam J Reid
- Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - Florian A Bach
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Ian D Poulton
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Arianna Marini
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Marija Zaric
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Margaux Mulatier
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | | | - Megan Baker
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Celia H Mitton
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Jason C Sousa
- Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Maryland, United States of America
| | | | | | | | | | - Tianrat Piteekan
- Mahidol Vivax Research Unit, Mahidol University, Bangkok, Thailand
| | - Mimi M Hou
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Baktash Khozoee
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Kirsty McHugh
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - David J Roberts
- Nuffield Division of Clinical Laboratory Sciences, University of Oxford, Oxford, United Kingdom
| | - Alison M Lawrie
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | | | - Fay L Nugent
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Iona J Taylor
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | | | - Philip J Spence
- Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Sumi Biswas
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Julian C Rayner
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Simon J Draper
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
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6
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Blight J, Sala KA, Atcheson E, Kramer H, El-Turabi A, Real E, Dahalan FA, Bettencourt P, Dickinson-Craig E, Alves E, Salman AM, Janse CJ, Ashcroft FM, Hill AV, Reyes-Sandoval A, Blagborough AM, Baum J. Dissection-independent production of Plasmodium sporozoites from whole mosquitoes. Life Sci Alliance 2021; 4:e202101094. [PMID: 34135099 PMCID: PMC8321652 DOI: 10.26508/lsa.202101094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 01/05/2023] Open
Abstract
Progress towards a protective vaccine against malaria remains slow. To date, only limited protection has been routinely achieved following immunisation with either whole-parasite (sporozoite) or subunit-based vaccines. One major roadblock to vaccine progress, and to pre-erythrocytic parasite biology in general, is the continued reliance on manual salivary gland dissection for sporozoite isolation from infected mosquitoes. Here, we report development of a multi-step method, based on batch processing of homogenised whole mosquitoes, slurry, and density-gradient filtration, which combined with free-flow electrophoresis rapidly produces a pure, infective sporozoite inoculum. Human-infective Plasmodium falciparum and rodent-infective Plasmodium berghei sporozoites produced in this way are two- to threefold more infective than salivary gland dissection sporozoites in in vitro hepatocyte infection assays. In an in vivo rodent malaria model, the same P. berghei sporozoites confer sterile protection from mosquito-bite challenge when immunisation is delivered intravenously or 60-70% protection when delivered intramuscularly. By improving purity, infectivity, and immunogenicity, this method represents a key advancement in capacity to produce research-grade sporozoites, which should impact delivery of a whole-parasite based malaria vaccine at scale in the future.
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Affiliation(s)
- Joshua Blight
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, London, UK
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, UK
| | - Katarzyna A Sala
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, London, UK
| | - Erwan Atcheson
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, UK
| | - Holger Kramer
- Department of Physiology, Anatomy and Genetics, Henry Wellcome Building for Gene Function, University of Oxford, Oxford, UK
- Medical Research Council London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital, London, UK
| | - Aadil El-Turabi
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, UK
| | - Eliana Real
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, London, UK
| | - Farah A Dahalan
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, London, UK
| | - Paulo Bettencourt
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, UK
| | - Emma Dickinson-Craig
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, UK
| | - Eduardo Alves
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, UK
| | - Ahmed M Salman
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, UK
| | - Chris J Janse
- Department of Parasitology, Leiden Malaria Research Group, Center of Infectious Diseases, Leiden University Medical Center, (LUMC, L4-Q), Leiden, The Netherlands
| | - Frances M Ashcroft
- Department of Physiology, Anatomy and Genetics, Henry Wellcome Building for Gene Function, University of Oxford, Oxford, UK
| | - Adrian Vs Hill
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, UK
| | - Arturo Reyes-Sandoval
- The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford, UK
- Instituto Politécnico Nacional, Mexico City, Mexico
| | - Andrew M Blagborough
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, London, UK
- Department of Pathology, University of Cambridge, Cambridge, UK
| | - Jake Baum
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, London, UK
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7
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Sirignano C, Hammami S, El Mokni R, Blagborough AM, Luciano P, Rigano D, Scafati OT. Polyoxygenated germacranes from Daucus carota and their antimalarial transmission blocking activity. Phytochemistry 2021; 183:112632. [PMID: 33360528 DOI: 10.1016/j.phytochem.2020.112632] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 12/08/2020] [Accepted: 12/17/2020] [Indexed: 06/12/2023]
Abstract
Chemical analysis of the aerial parts obtained from a Tunisian specimen of Daucus carota yielded to the isolation of six undescribed polyoxygenated germacranes and one elemanolide, along with one known metabolite. The stereostructures of the undescribed compounds were determined by extensive spectroscopic analysis including 1D and 2D NMR and HR-ESI-MS analysis. Due to their structural similarity with the Plasmodium transmission-blocking agent daucovirgolide G, the isolated metabolites were evaluated for their inhibitory activity on the development of Plasmodium early sporogonic stages. Three compounds proved to inhibit ookinete formation showing a good transmission blocking efficacy, but the low potency exhibited by these compounds when compared to daucovirgolide G further supports the observation that strict structural requirements do exist for the antimalarial activity of germacranolides.
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Affiliation(s)
- Carmina Sirignano
- Department of Pharmacy, School of Medicine and Surgery, University of Naples Federico II, Via Domenico Montesano 49, 80131, Naples, Italy
| | - Saoussen Hammami
- Research Unit Applied Chemistry and Environment 13ES63, Monastir University, Faculty of Sciences of Monastir, 5000, Monastir, Tunisia
| | - Ridha El Mokni
- Laboratory of Botany, Cryptogamy and Plant Biology, Department of Pharmaceutical Sciences "A", Faculty of Pharmacy of Monastir BP 207, Avenue Avicenna, University of Monastir, 5000, Monastir, Tunisia
| | - Andrew M Blagborough
- Division of Microbiology and Parasitology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, United Kingdom
| | - Paolo Luciano
- Department of Pharmacy, School of Medicine and Surgery, University of Naples Federico II, Via Domenico Montesano 49, 80131, Naples, Italy
| | - Daniela Rigano
- Department of Pharmacy, School of Medicine and Surgery, University of Naples Federico II, Via Domenico Montesano 49, 80131, Naples, Italy.
| | - Orazio Taglialatela Scafati
- Department of Pharmacy, School of Medicine and Surgery, University of Naples Federico II, Via Domenico Montesano 49, 80131, Naples, Italy
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8
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Miguel-Blanco C, Murithi JM, Benavente ED, Angrisano F, Sala KA, van Schalkwyk DA, Vanaerschot M, Schwach F, Fuchter MJ, Billker O, Sutherland CJ, Campino SG, Clark TG, Blagborough AM, Fidock DA, Herreros E, Gamo FJ, Baum J, Delves MJ. The antimalarial efficacy and mechanism of resistance of the novel chemotype DDD01034957. Sci Rep 2021; 11:1888. [PMID: 33479319 PMCID: PMC7820608 DOI: 10.1038/s41598-021-81343-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 12/18/2020] [Indexed: 11/09/2022] Open
Abstract
New antimalarial therapeutics are needed to ensure that malaria cases continue to be driven down, as both emerging parasite resistance to frontline chemotherapies and mosquito resistance to current insecticides threaten control programmes. Plasmodium, the apicomplexan parasite responsible for malaria, causes disease pathology through repeated cycles of invasion and replication within host erythrocytes (the asexual cycle). Antimalarial drugs primarily target this cycle, seeking to reduce parasite burden within the host as fast as possible and to supress recrudescence for as long as possible. Intense phenotypic drug screening efforts have identified a number of promising new antimalarial molecules. Particularly important is the identification of compounds with new modes of action within the parasite to combat existing drug resistance and suitable for formulation of efficacious combination therapies. Here we detail the antimalarial properties of DDD01034957-a novel antimalarial molecule which is fast-acting and potent against drug resistant strains in vitro, shows activity in vivo, and possesses a resistance mechanism linked to the membrane transporter PfABCI3. These data support further medicinal chemistry lead-optimization of DDD01034957 as a novel antimalarial chemical class and provide new insights to further reduce in vivo metabolic clearance.
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Affiliation(s)
| | - James M Murithi
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Ernest Diez Benavente
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Fiona Angrisano
- Division of Microbiology and Parasitology, Department of Pathology, Cambridge University, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Katarzyna A Sala
- Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Donelly A van Schalkwyk
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Manu Vanaerschot
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Frank Schwach
- Parasites and Microbes Programme, Wellcome Trust Sanger Institute, Hinxton, CB10 1SA, UK
| | - Matthew J Fuchter
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, White City Campus, Wood Lane, London, W12 OBZ, UK
| | - Oliver Billker
- Parasites and Microbes Programme, Wellcome Trust Sanger Institute, Hinxton, CB10 1SA, UK
- Department of Molecular Biology, The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, 901 87, Umeå, Sweden
| | - Colin J Sutherland
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Susana G Campino
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Taane G Clark
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Andrew M Blagborough
- Division of Microbiology and Parasitology, Department of Pathology, Cambridge University, Tennis Court Road, Cambridge, CB2 1QP, UK
- Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - David A Fidock
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, NY, 10032, USA
- Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Esperanza Herreros
- Global Health, GlaxoSmithKline, Tres Cantos, 28760, Madrid, Spain
- Medicines for Malaria Venture, 20 Route de Pré-Bois, 1215, Geneva 15, Switzerland
| | | | - Jake Baum
- Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Michael J Delves
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK.
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9
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Haltalli MLR, Watcham S, Wilson NK, Eilers K, Lipien A, Ang H, Birch F, Anton SG, Pirillo C, Ruivo N, Vainieri ML, Pospori C, Sinden RE, Luis TC, Langhorne J, Duffy KR, Göttgens B, Blagborough AM, Lo Celso C. Manipulating niche composition limits damage to haematopoietic stem cells during Plasmodium infection. Nat Cell Biol 2020; 22:1399-1410. [PMID: 33230302 PMCID: PMC7611033 DOI: 10.1038/s41556-020-00601-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 10/06/2020] [Indexed: 12/17/2022]
Abstract
Severe infections are a major stress on haematopoiesis, where the consequences for haematopoietic stem cells (HSCs) have only recently started to emerge. HSC function critically depends on the integrity of complex bone marrow (BM) niches; however, what role the BM microenvironment plays in mediating the effects of infection on HSCs remains an open question. Here, using a murine model of malaria and combining single-cell RNA sequencing, mathematical modelling, transplantation assays and intravital microscopy, we show that haematopoiesis is reprogrammed upon infection, whereby the HSC compartment turns over substantially faster than at steady-state and HSC function is drastically affected. Interferon is found to affect both haematopoietic and mesenchymal BM cells and we specifically identify a dramatic loss of osteoblasts and alterations in endothelial cell function. Osteo-active parathyroid hormone treatment abolishes infection-triggered HSC proliferation and-coupled with reactive oxygen species quenching-enables partial rescuing of HSC function.
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Affiliation(s)
- Myriam L R Haltalli
- Department of Life Sciences, Imperial College London, London, UK
- The Francis Crick Institute, London, UK
- Wellcome-Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, UK
- Department of Haematology, Cambridge Institute for Medical Research, Cambridge, UK
| | - Samuel Watcham
- Wellcome-Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, UK
- Department of Haematology, Cambridge Institute for Medical Research, Cambridge, UK
| | - Nicola K Wilson
- Wellcome-Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, UK
- Department of Haematology, Cambridge Institute for Medical Research, Cambridge, UK
| | - Kira Eilers
- Department of Life Sciences, Imperial College London, London, UK
| | - Alexander Lipien
- Department of Life Sciences, Imperial College London, London, UK
| | - Heather Ang
- Department of Life Sciences, Imperial College London, London, UK
| | - Flora Birch
- Department of Life Sciences, Imperial College London, London, UK
- The Francis Crick Institute, London, UK
| | - Sara Gonzalez Anton
- Department of Life Sciences, Imperial College London, London, UK
- The Francis Crick Institute, London, UK
| | - Chiara Pirillo
- Department of Life Sciences, Imperial College London, London, UK
- The Francis Crick Institute, London, UK
| | - Nicola Ruivo
- Department of Life Sciences, Imperial College London, London, UK
| | - Maria L Vainieri
- Department of Life Sciences, Imperial College London, London, UK
- AO Research Institute, Davos Platz, Switzerland
| | - Constandina Pospori
- Department of Life Sciences, Imperial College London, London, UK
- The Francis Crick Institute, London, UK
| | - Robert E Sinden
- Department of Life Sciences, Imperial College London, London, UK
| | - Tiago C Luis
- Department of Life Sciences, Imperial College London, London, UK
| | | | - Ken R Duffy
- Hamilton Institute, Maynooth University, Maynooth, Ireland
| | - Berthold Göttgens
- Wellcome-Medical Research Council Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, UK
- Department of Haematology, Cambridge Institute for Medical Research, Cambridge, UK
| | | | - Cristina Lo Celso
- Department of Life Sciences, Imperial College London, London, UK.
- The Francis Crick Institute, London, UK.
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10
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Muthui MK, Kamau A, Bousema T, Blagborough AM, Bejon P, Kapulu MC. Corrigendum: Immune Responses to Gametocyte Antigens in a Malaria Endemic Population-The African falciparum Context: A Systematic Review and Meta-Analysis. Front Immunol 2020; 11:389. [PMID: 32265905 PMCID: PMC7104801 DOI: 10.3389/fimmu.2020.00389] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 02/19/2020] [Indexed: 11/13/2022] Open
Affiliation(s)
- Michelle K Muthui
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya
| | - Alice Kamau
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya
| | - Teun Bousema
- Immunology and Infection Department, London School of Hygiene and Tropical Medicine, London, United Kingdom.,Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Andrew M Blagborough
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Philip Bejon
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya.,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Melissa C Kapulu
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya.,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
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11
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Angrisano F, Sala KA, Tapanelli S, Christophides GK, Blagborough AM. Male-Specific Protein Disulphide Isomerase Function is Essential for Plasmodium Transmission and a Vulnerable Target for Intervention. Sci Rep 2019; 9:18300. [PMID: 31797966 PMCID: PMC6892906 DOI: 10.1038/s41598-019-54613-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 11/11/2019] [Indexed: 11/10/2022] Open
Abstract
Inhibiting transmission of Plasmodium is an essential strategy in malaria eradication, and the biological process of gamete fusion during fertilization is a proven target for this approach. Lack of knowledge of the mechanisms underlying fertilization have been a hindrance in the development of transmission-blocking interventions. Here we describe a protein disulphide isomerase essential for malarial transmission (PDI-Trans/PBANKA_0820300) to the mosquito. We show that PDI-Trans activity is male-specific, surface-expressed, essential for fertilization/transmission, and exhibits disulphide isomerase activity which is up-regulated post-gamete activation. We demonstrate that PDI-Trans is a viable anti-malarial drug and vaccine target blocking malarial transmission with the use of PDI inhibitor bacitracin (98.21%/92.48% reduction in intensity/prevalence), and anti-PDI-Trans antibodies (66.22%/33.16% reduction in intensity/prevalence). To our knowledge, these results provide the first evidence that PDI function is essential for malarial transmission, and emphasize the potential of anti-PDI agents to act as anti-malarials, facilitating the future development of novel transmission-blocking interventions.
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Affiliation(s)
- Fiona Angrisano
- Division of Microbiology and Parasitology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, United Kingdom
| | - Katarzyna A Sala
- Department of Life Sciences, Imperial College of Science, Technology and Medicine, London, SW7 2AZ, United Kingdom
| | - Sofia Tapanelli
- Department of Life Sciences, Imperial College of Science, Technology and Medicine, London, SW7 2AZ, United Kingdom
| | - George K Christophides
- Department of Life Sciences, Imperial College of Science, Technology and Medicine, London, SW7 2AZ, United Kingdom
| | - Andrew M Blagborough
- Division of Microbiology and Parasitology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, United Kingdom. .,Department of Life Sciences, Imperial College of Science, Technology and Medicine, London, SW7 2AZ, United Kingdom.
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12
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Muthui MK, Kamau A, Bousema T, Blagborough AM, Bejon P, Kapulu MC. Immune Responses to Gametocyte Antigens in a Malaria Endemic Population-The African falciparum Context: A Systematic Review and Meta-Analysis. Front Immunol 2019; 10:2480. [PMID: 31695697 PMCID: PMC6817591 DOI: 10.3389/fimmu.2019.02480] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 10/04/2019] [Indexed: 11/13/2022] Open
Abstract
Background: Malaria elimination remains a priority research agenda with the need for interventions that reduce and/or block malaria transmission from humans to mosquitoes. Transmission-blocking vaccines (TBVs) are in development, most of which target the transmission stage (i.e., gametocyte) antigens Pfs230 and Pfs48/45. For these interventions to be implemented, there is a need to understand the naturally acquired immunity to gametocytes. Several studies have measured the prevalence of immune responses to Pfs230 and Pfs48/45 in populations in malaria-endemic areas. Methods: We conducted a systematic review of studies carried out in African populations that measured the prevalence of immune responses to the gametocyte antigens Pfs230 and Pfs48/45. We assessed seroprevalence of antibody responses to the two antigens and investigated the effects of covariates such as age, transmission intensity/endemicity, season, and parasite prevalence on the prevalence of these antibody responses by meta-regression. Results: We identified 12 studies covering 23 sites for inclusion in the analysis. We found that the range of reported seroprevalence to Pfs230 and Pfs48/45 varied widely across studies, from 0 to 64% for Pfs48/45 and from 6 to 72% for Pfs230. We also found a modest association between increased age and increased seroprevalence to Pfs230: adults were associated with higher seroprevalence estimates in comparison to children (β coefficient 0.21, 95% CI: 0.05-0.38, p = 0.042). Methodological factors were the most significant contributors to heterogeneity between studies which prevented calculation of pooled prevalence estimates. Conclusions: Naturally acquired sexual stage immunity, as detected by antibodies to Pfs230 and Pfs48/45, was present in most studies analyzed. Significant between-study heterogeneity was seen, and methodological factors were a major contributor to this, and prevented further analysis of epidemiological and biological factors. This demonstrates a need for standardized protocols for conducting and reporting seroepidemiological analyses.
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Affiliation(s)
- Michelle K Muthui
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya
| | - Alice Kamau
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya
| | - Teun Bousema
- Immunology and Infection Department, London School of Hygiene and Tropical Medicine, London, United Kingdom.,Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Andrew M Blagborough
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Philip Bejon
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya.,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Melissa C Kapulu
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya.,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
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13
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Kooistra RL, David R, Ruiz AC, Powers SW, Haselton KJ, Kiernan K, Blagborough AM, Solamen L, Olsen KW, Putonti C, Kanzok SM. Characterization of a protozoan Phosducin-like protein-3 (PhLP-3) reveals conserved redox activity. PLoS One 2019; 13:e0209699. [PMID: 30596727 PMCID: PMC6312279 DOI: 10.1371/journal.pone.0209699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 12/09/2018] [Indexed: 11/18/2022] Open
Abstract
We recently identified three novel thioredoxin-like genes in the genome of the protozoan parasite Plasmodium that belong to the Phosducin-like family of proteins (PhLP). PhLPs are small cytosolic proteins hypothesized to function in G-protein signaling and protein folding. Although PhLPs are highly conserved in eukaryotes from yeast to mammals, only a few representatives have been experimentally characterized to date. In addition, while PhLPs contain a thioredoxin domain, they lack a CXXC motif, a strong indicator for redox activity, and it is unclear whether members of the PhLP family are enzymatically active. Here, we describe PbPhLP-3 as the first phosducin-like protein of a protozoan organism, Plasmodium berghei. Initial transcription analysis revealed continuous low-level expression of pbphlp-3 throughout the complex Plasmodium life cycle. Attempts to knockout pbphlp-3 in P. berghei did not yield live parasites, suggesting an essential role for the gene in Plasmodium. We cloned, expressed and purified PbPhLP-3 and determined that the recombinant protein is redox active in vitro in a thioredoxin-coupled redox assay. It also has the capacity to reduce the organic compound tert-Butyl hydroperoxide (TBHP) in vitro, albeit at low efficiency. Sequence analysis, structural modeling, and site-directed mutagenesis revealed a conserved cysteine in the thioredoxin domain to be the redox active residue. Lastly, we provide evidence that recombinant human PhLP-3 exhibits redox activity similar to that of PbPhLP-3 and suggest that redox activity may be conserved in PhLP-3 homologs of other species. Our data provide new insight into the function of PhLP-3, which is hypothesized to act as co-chaperones in the folding and regulation of cytoskeletal proteins. We discuss the potential implications of PhLP-3 as a thioredoxin-target protein and possible links between the cellular redox network and the eukaryotic protein folding machinery.
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Affiliation(s)
- Rachel L. Kooistra
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
| | - Robin David
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
| | - Ana C. Ruiz
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
| | - Sean W. Powers
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
| | - Kyle J. Haselton
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
| | - Kaitlyn Kiernan
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
| | - Andrew M. Blagborough
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, United Kingdom
| | - Ligin Solamen
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
- Bioinformatics Program, Loyola University Chicago, Chicago, IL, United States of America
| | - Kenneth W. Olsen
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, IL, United States of America
| | - Catherine Putonti
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
- Bioinformatics Program, Loyola University Chicago, Chicago, IL, United States of America
- Department of Computer Science, Loyola University Chicago, Chicago, IL, United States of America
| | - Stefan M. Kanzok
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
- Bioinformatics Program, Loyola University Chicago, Chicago, IL, United States of America
- * E-mail:
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14
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Esperança PM, Blagborough AM, Da DF, Dowell FE, Churcher TS. Detection of Plasmodium berghei infected Anopheles stephensi using near-infrared spectroscopy. Parasit Vectors 2018; 11:377. [PMID: 29954424 PMCID: PMC6027764 DOI: 10.1186/s13071-018-2960-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 06/18/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The proportion of mosquitoes infected with malaria is an important entomological metric used to assess the intensity of transmission and the impact of vector control interventions. Currently, the prevalence of mosquitoes with salivary gland sporozoites is estimated by dissecting mosquitoes under a microscope or using molecular methods. These techniques are laborious, subjective, and require either expensive equipment or training. This study evaluates the potential of near-infrared spectroscopy (NIRS) to identify laboratory reared mosquitoes infected with rodent malaria. METHODS Anopheles stephensi mosquitoes were reared in the laboratory and fed on Plasmodium berghei infected blood. After 12 and 21 days post-feeding mosquitoes were killed, scanned and analysed using NIRS and immediately dissected by microscopy to determine the number of oocysts on the midgut wall or sporozoites in the salivary glands. A predictive classification model was used to determine parasite prevalence and intensity status from spectra. RESULTS The predictive model correctly classifies infectious and uninfectious mosquitoes with an overall accuracy of 72%. The false negative and false positive rates were 30 and 26%, respectively. While NIRS was able to differentiate between uninfectious and highly infectious mosquitoes, differentiating between mid-range infectious groups was less accurate. Multiple scans of the same specimen, with repositioning the mosquito between scans, is shown to improve accuracy. On a smaller dataset NIRS was unable to predict whether mosquitoes harboured oocysts. CONCLUSIONS To our knowledge, we provide the first evidence that NIRS can differentiate between infectious and uninfectious mosquitoes. Currently, distinguishing between different intensities of infection is challenging. The classification model provides a flexible framework and allows for different error rates to be optimised, enabling the sensitivity and specificity of the technique to be varied according to requirements.
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Affiliation(s)
- Pedro M. Esperança
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG UK
| | - Andrew M. Blagborough
- Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ UK
| | - Dari F. Da
- Institut de Recherche en Sciences de la Santé, Direction Régionale, 399 Avenue de la liberté, Bobo Dioulasso, 01 01 BP 545 Burkina Faso
| | - Floyd E. Dowell
- USDA, Agricultural Research Service, Center for Grain and Animal Health Research, 1515 College Avenue, Manhattan, KS 66502 USA
| | - Thomas S. Churcher
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG UK
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15
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Sherrard-Smith E, Sala KA, Betancourt M, Upton LM, Angrisano F, Morin MJ, Ghani AC, Churcher TS, Blagborough AM. Synergy in anti-malarial pre-erythrocytic and transmission-blocking antibodies is achieved by reducing parasite density. eLife 2018; 7:35213. [PMID: 29914622 PMCID: PMC6008048 DOI: 10.7554/elife.35213] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 05/18/2018] [Indexed: 01/05/2023] Open
Abstract
Anti-malarial pre-erythrocytic vaccines (PEV) target transmission by inhibiting human infection but are currently partially protective. It has been posited, but never demonstrated, that co-administering transmission-blocking vaccines (TBV) would enhance malaria control. We hypothesized a mechanism that TBV could reduce parasite density in the mosquito salivary glands, thereby enhancing PEV efficacy. This was tested using a multigenerational population assay, passaging Plasmodium berghei to Anopheles stephensi mosquitoes. A combined efficacy of 90.8% (86.7-94.2%) was observed in the PEV +TBV antibody group, higher than the estimated efficacy of 83.3% (95% CrI 79.1-87.0%) if the two antibodies acted independently. Higher PEV efficacy at lower mosquito parasite loads was observed, comprising the first direct evidence that co-administering anti-sporozoite and anti-transmission interventions act synergistically, enhancing PEV efficacy across a range of TBV doses and transmission intensities. Combining partially effective vaccines of differing anti-parasitic classes is a pragmatic, powerful way to accelerate malaria elimination efforts.
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Affiliation(s)
- Ellie Sherrard-Smith
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Katarzyna A Sala
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | | | - Leanna M Upton
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Fiona Angrisano
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | | | - Azra C Ghani
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Thomas S Churcher
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
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16
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Angrisano F, Blagborough AM. Understanding Human-Derived Antibodies Generated by Polymorphic Malaria Vaccine Against Merozoite Surface Protein 2. J Infect Dis 2018; 218:5-6. [PMID: 29584870 DOI: 10.1093/infdis/jiy171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Fiona Angrisano
- Department of Life Sciences, Imperial College of Science, Technology, and Medicine, London, United Kingdom
| | - Andrew M Blagborough
- Department of Life Sciences, Imperial College of Science, Technology, and Medicine, London, United Kingdom
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17
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Brugman VA, Kristan M, Gibbins MP, Angrisano F, Sala KA, Dessens JT, Blagborough AM, Walker T. Detection of malaria sporozoites expelled during mosquito sugar feeding. Sci Rep 2018; 8:7545. [PMID: 29765136 PMCID: PMC5954146 DOI: 10.1038/s41598-018-26010-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/03/2018] [Indexed: 12/17/2022] Open
Abstract
Malaria is a severe disease of global importance transmitted by mosquitoes of the genus Anopheles. The ability to rapidly detect the presence of infectious mosquitoes able to transmit malaria is of vital importance for surveillance, control and elimination efforts. Current methods principally rely on large-scale mosquito collections followed by labour-intensive salivary gland dissections or enzyme-linked immunosorbent (ELISA) methods to detect sporozoites. Using forced salivation, we demonstrate here that Anopheles mosquitoes infected with Plasmodium expel sporozoites during sugar feeding. Expelled sporozoites can be detected on two sugar-soaked substrates, cotton wool and Whatman FTA cards, and sporozoite DNA is detectable using real-time PCR. These results demonstrate a simple and rapid methodology for detecting the presence of infectious mosquitoes with sporozoites and highlight potential laboratory applications for investigating mosquito-malaria interactions. Our results indicate that FTA cards could be used as a simple, effective and economical tool in enhancing field surveillance activities for malaria.
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Affiliation(s)
- V A Brugman
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
- Evolution Biotechnologies, Colworth Science Park, Sharnbrook, Bedford, MK44 1LZ, UK.
| | - M Kristan
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - M P Gibbins
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - F Angrisano
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London, SW7 2AZ, UK
| | - K A Sala
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London, SW7 2AZ, UK
| | - J T Dessens
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - A M Blagborough
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London, SW7 2AZ, UK
| | - T Walker
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
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18
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Yoshida K, Iyori M, Blagborough AM, Salman AM, Dulal P, Sala KA, Yamamoto DS, Khan SM, Janse CJ, Biswas S, Yoshii T, Yusuf Y, Tokoro M, Hill AVS, Yoshida S. Adenovirus-prime and baculovirus-boost heterologous immunization achieves sterile protection against malaria sporozoite challenge in a murine model. Sci Rep 2018; 8:3896. [PMID: 29497047 PMCID: PMC5832798 DOI: 10.1038/s41598-018-21369-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 02/02/2018] [Indexed: 12/16/2022] Open
Abstract
With the increasing prevalence of artemisinin-resistant malaria parasites, a highly efficacious and durable vaccine for malaria is urgently required. We have developed an experimental virus-vectored vaccine platform based on an envelope-modified baculovirus dual-expression system (emBDES). Here, we show a conceptually new vaccine platform based on an adenovirus-prime/emBDES-boost heterologous immunization regimen expressing the Plasmodium falciparum circumsporozoite protein (PfCSP). A human adenovirus 5-prime/emBDES-boost heterologous immunization regimen consistently achieved higher sterile protection against transgenic P. berghei sporozoites expressing PfCSP after a mosquito-bite challenge than reverse-ordered or homologous immunization. This high protective efficacy was also achieved with a chimpanzee adenovirus 63-prime/emBDES-boost heterologous immunization regimen against an intravenous sporozoite challenge. Thus, we show that the adenovirus-prime/emBDES-boost heterologous immunization regimen confers sterile protection against sporozoite challenge by two individual routes, providing a promising new malaria vaccine platform for future clinical use.
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Affiliation(s)
- Kunitaka Yoshida
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kakuma-machi, Kanazawa, 920-1192, Japan.,Kanazawa University Graduate School of Medical Sciences, 13 Takara-machi, Kanazawa, 920-0934, Japan
| | - Mitsuhiro Iyori
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kakuma-machi, Kanazawa, 920-1192, Japan
| | - Andrew M Blagborough
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London, SW7 2AZ, UK
| | - Ahmed M Salman
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK.,Leiden Malaria Research Group, Department of Parasitology, Center of Infectious Diseases, Leiden University Medical Center, (LUMC, L4-Q), Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Pawan Dulal
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Katarzyna A Sala
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London, SW7 2AZ, UK
| | - Daisuke S Yamamoto
- Division of Medical Zoology, Department of Infection and Immunity, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, 329-0431, Tochigi, Japan
| | - Shahid M Khan
- Leiden Malaria Research Group, Department of Parasitology, Center of Infectious Diseases, Leiden University Medical Center, (LUMC, L4-Q), Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Chris J Janse
- Leiden Malaria Research Group, Department of Parasitology, Center of Infectious Diseases, Leiden University Medical Center, (LUMC, L4-Q), Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Sumi Biswas
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Tatsuya Yoshii
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kakuma-machi, Kanazawa, 920-1192, Japan
| | - Yenni Yusuf
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kakuma-machi, Kanazawa, 920-1192, Japan
| | - Masaharu Tokoro
- Kanazawa University Graduate School of Medical Sciences, 13 Takara-machi, Kanazawa, 920-0934, Japan
| | - Adrian V S Hill
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Shigeto Yoshida
- Laboratory of Vaccinology and Applied Immunology, Kanazawa University School of Pharmacy, Kakuma-machi, Kanazawa, 920-1192, Japan.
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19
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Paquet T, Le Manach C, Cabrera DG, Younis Y, Henrich PP, Abraham TS, Lee MCS, Basak R, Ghidelli-Disse S, Lafuente-Monasterio MJ, Bantscheff M, Ruecker A, Blagborough AM, Zakutansky SE, Zeeman AM, White KL, Shackleford DM, Mannila J, Morizzi J, Scheurer C, Angulo-Barturen I, Martínez MS, Ferrer S, Sanz LM, Gamo FJ, Reader J, Botha M, Dechering KJ, Sauerwein RW, Tungtaeng A, Vanachayangkul P, Lim CS, Burrows J, Witty MJ, Marsh KC, Bodenreider C, Rochford R, Solapure SM, Jiménez-Díaz MB, Wittlin S, Charman SA, Donini C, Campo B, Birkholtz LM, Hanson KK, Drewes G, Kocken CHM, Delves MJ, Leroy D, Fidock DA, Waterson D, Street LJ, Chibale K. Antimalarial efficacy of MMV390048, an inhibitor of Plasmodium phosphatidylinositol 4-kinase. Sci Transl Med 2018; 9:9/387/eaad9735. [PMID: 28446690 DOI: 10.1126/scitranslmed.aad9735] [Citation(s) in RCA: 175] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 11/21/2016] [Indexed: 12/13/2022]
Abstract
As part of the global effort toward malaria eradication, phenotypic whole-cell screening revealed the 2-aminopyridine class of small molecules as a good starting point to develop new antimalarial drugs. Stemming from this series, we found that the derivative, MMV390048, lacked cross-resistance with current drugs used to treat malaria. This compound was efficacious against all Plasmodium life cycle stages, apart from late hypnozoites in the liver. Efficacy was shown in the humanized Plasmodium falciparum mouse model, and modest reductions in mouse-to-mouse transmission were achieved in the Plasmodium berghei mouse model. Experiments in monkeys revealed the ability of MMV390048 to be used for full chemoprotection. Although MMV390048 was not able to eliminate liver hypnozoites, it delayed relapse in a Plasmodium cynomolgi monkey model. Both genomic and chemoproteomic studies identified a kinase of the Plasmodium parasite, phosphatidylinositol 4-kinase, as the molecular target of MMV390048. The ability of MMV390048 to block all life cycle stages of the malaria parasite suggests that this compound should be further developed and may contribute to malaria control and eradication as part of a single-dose combination treatment.
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Affiliation(s)
- Tanya Paquet
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Claire Le Manach
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | | | - Yassir Younis
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Philipp P Henrich
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA.,The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA
| | - Tara S Abraham
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA.,Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, 1020 Locust Street, Suite 368, Philadelphia, PA 19107, USA
| | - Marcus C S Lee
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA.,Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1SA, UK
| | - Rajshekhar Basak
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA.,Department of Molecular Biophysics and Biochemistry, Yale University, 266 Whitney Avenue, New Haven, CT 06520-8114, USA
| | - Sonja Ghidelli-Disse
- Cellzome GmbH, Molecular Discovery Research, GlaxoSmithKline, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - María José Lafuente-Monasterio
- Malaria Disease Performance Unit, Tres Cantos Medicines Development Campus, Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Marcus Bantscheff
- Cellzome GmbH, Molecular Discovery Research, GlaxoSmithKline, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Andrea Ruecker
- Department of Life Sciences, Imperial College, London SW7 2AZ, UK
| | | | | | - Anne-Marie Zeeman
- Department of Parasitology, Biomedical Primate Research Centre, 2280 GH Rijswijk, Netherlands
| | - Karen L White
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - David M Shackleford
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Janne Mannila
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia.,Admescope Ltd., Typpitie 1, 90620 Oulu, Finland
| | - Julia Morizzi
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Christian Scheurer
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland.,University of Basel, 4003 Basel, Switzerland
| | - Iñigo Angulo-Barturen
- Malaria Disease Performance Unit, Tres Cantos Medicines Development Campus, Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - María Santos Martínez
- Malaria Disease Performance Unit, Tres Cantos Medicines Development Campus, Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Santiago Ferrer
- Malaria Disease Performance Unit, Tres Cantos Medicines Development Campus, Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Laura María Sanz
- Malaria Disease Performance Unit, Tres Cantos Medicines Development Campus, Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Francisco Javier Gamo
- Malaria Disease Performance Unit, Tres Cantos Medicines Development Campus, Diseases of the Developing World, GlaxoSmithKline, Severo Ochoa 2, 28760 Tres Cantos, Madrid, Spain
| | - Janette Reader
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Mariette Botha
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Koen J Dechering
- TropIQ Health Sciences, Transistorweg 5, 6534 AT Nijmegen, Netherlands
| | - Robert W Sauerwein
- TropIQ Health Sciences, Transistorweg 5, 6534 AT Nijmegen, Netherlands.,Radboud University Medical Center, Department of Medical Microbiology, 6500 HB Nijmegen, Netherlands
| | - Anchalee Tungtaeng
- Department of Veterinary Medicine, Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand
| | - Pattaraporn Vanachayangkul
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand
| | - Chek Shik Lim
- Novartis Institute for Tropical Diseases Pte. Ltd., 10 Biopolis Road, #05-01 Chromos, Singapore 138670, Singapore
| | - Jeremy Burrows
- Medicines for Malaria Venture, International Center Cointrin, Route de Pré-Bois 20, 1215 Geneva, Switzerland
| | - Michael J Witty
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.,Medicines for Malaria Venture, International Center Cointrin, Route de Pré-Bois 20, 1215 Geneva, Switzerland
| | - Kennan C Marsh
- AbbVie, 1 North Waukegan Road, North Chicago, IL 60064-6104, USA
| | - Christophe Bodenreider
- Novartis Institute for Tropical Diseases Pte. Ltd., 10 Biopolis Road, #05-01 Chromos, Singapore 138670, Singapore
| | - Rosemary Rochford
- Departments of Immunology and Microbiology and Environmental and Occupational Health, University of Colorado Denver, Aurora, CO 80045, USA
| | - Suresh M Solapure
- Nagarjuna Gardens, 60 Feet Road, Sahakaranagar, Bangalore 560092, India
| | - María Belén Jiménez-Díaz
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, 1020 Locust Street, Suite 368, Philadelphia, PA 19107, USA
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002 Basel, Switzerland.,University of Basel, 4003 Basel, Switzerland
| | - Susan A Charman
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Cristina Donini
- Medicines for Malaria Venture, International Center Cointrin, Route de Pré-Bois 20, 1215 Geneva, Switzerland
| | - Brice Campo
- Medicines for Malaria Venture, International Center Cointrin, Route de Pré-Bois 20, 1215 Geneva, Switzerland
| | - Lyn-Marie Birkholtz
- Department of Biochemistry, Centre for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Kirsten K Hanson
- Department of Biology and South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX 78249, USA
| | - Gerard Drewes
- Cellzome GmbH, Molecular Discovery Research, GlaxoSmithKline, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Clemens H M Kocken
- Department of Parasitology, Biomedical Primate Research Centre, 2280 GH Rijswijk, Netherlands
| | - Michael J Delves
- Department of Life Sciences, Imperial College, London SW7 2AZ, UK
| | - Didier Leroy
- Medicines for Malaria Venture, International Center Cointrin, Route de Pré-Bois 20, 1215 Geneva, Switzerland
| | - David A Fidock
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA.,Division of Infectious Diseases, Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA
| | - David Waterson
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.,Medicines for Malaria Venture, International Center Cointrin, Route de Pré-Bois 20, 1215 Geneva, Switzerland
| | - Leslie J Street
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - Kelly Chibale
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa. .,South African Medical Research Council Drug Discovery and Development Research Unit, and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa
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20
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Sala KA, Angrisano F, Da DF, Taylor IJ, Churcher TS, Blagborough AM. Immunization with Transgenic Rodent Malaria Parasites Expressing Pfs25 Induces Potent Transmission-Blocking Activity. Sci Rep 2018; 8:1573. [PMID: 29371619 PMCID: PMC5785477 DOI: 10.1038/s41598-017-18831-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 12/14/2017] [Indexed: 12/14/2022] Open
Abstract
An anti-malarial transmission blocking vaccine (TBV) would be an important tool for disease control or elimination, though current candidates have failed to induce high efficacy in clinical studies. The ookinete surface protein P25 is a primary target for TBV development, but heterologous expression of P25 with appropriate conformation is problematic and a pre-requisite for achieving functional titers. A potential alternative to recombinant/sub-unit vaccine is immunization with a non-pathogenic, whole-parasite vaccine. This study examines the ability of a purified transgenic rodent-malaria parasite (PbPfs25DR3), expressing Plasmodium falciparum P25 in native conformation on the P. berghei ookinete surface, to act as a TBV. Vaccination with purified PbPfs25DR3 ookinetes produces a potent anti-Pfs25 response and high transmission-blocking efficacy in the laboratory, findings that are then translated to experimentation on natural field isolates of P. falciparum from infected individuals in Burkina Faso. Efficacy is demonstrated in the lab and the field (up to 93.3%/97.1% reductions in transmission intensity respectively), with both a homologous strategy with one and two boosts, and as part of a prime-boost regime, providing support for the future development of a whole-parasite TBV.
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Affiliation(s)
- K A Sala
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London, SW7 2AZ, UK
| | - F Angrisano
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London, SW7 2AZ, UK
| | - D F Da
- Institut de Recherche en Sciences de la Santé, 399 Avenue de la Liberté, BP 545, Bobo-Dioulasso, Burkina Faso
| | - I J Taylor
- Jenner Institute, The University of Oxford, Roosevelt Road, Oxford, OX9 2PP, UK
| | - T S Churcher
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - A M Blagborough
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London, SW7 2AZ, UK.
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21
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Sherrard-Smith E, Churcher TS, Upton LM, Sala KA, Zakutansky SE, Slater HC, Blagborough AM, Betancourt M. A novel model fitted to multiple life stages of malaria for assessing efficacy of transmission-blocking interventions. Malar J 2017; 16:137. [PMID: 28376897 PMCID: PMC5379616 DOI: 10.1186/s12936-017-1782-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 03/17/2017] [Indexed: 11/15/2022] Open
Abstract
Background Transmission-blocking interventions (TBIs) aim to eliminate malaria by reducing transmission of the parasite between the host and the invertebrate vector. TBIs include transmission-blocking drugs and vaccines that, when given to humans, are taken up by mosquitoes and inhibit parasitic development within the vector. Accurate methodologies are key to assess TBI efficacy to ensure that only the most potent candidates progress to expensive and time-consuming clinical trials. Measuring intervention efficacy can be problematic because there is substantial variation in the number of parasites in both the host and vector populations, which can impact transmission even in laboratory settings. Methods A statistically robust empirical method is introduced for estimating intervention efficacy from standardised population assay experiments. This method will be more reliable than simple summary statistics as it captures changes in parasite density in different life-stages. It also allows efficacy estimates at a finer resolution than previous methods enabling the impact of the intervention over successive generations to be tracked. A major advantage of the new methodology is that it makes no assumptions on the population dynamics of infection. This enables both host-to-vector and vector-to-host transmission to be density-dependent (or other) processes and generates easy-to-understand estimates of intervention efficacy. Results This method increases the precision of intervention efficacy estimates and demonstrates that relying on changes in infection prevalence (the proportion of infected hosts) alone may be insufficient to capture the impact of TBIs, which also suppress parasite density in secondarily infected hosts. Conclusions The method indicates that potentially useful, partially effective TBIs may require multiple infection cycles before substantial reductions in prevalence are observed, despite more rapidly suppressing parasite density. Accurate models to quantify efficacy will have important implications for understanding how TBI candidates might perform in field situations and how they should be evaluated in clinical trials. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1782-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ellie Sherrard-Smith
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, W2 1PG, UK.
| | - Thomas S Churcher
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Leanna M Upton
- Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Katarzyna A Sala
- Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Sara E Zakutansky
- Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Hannah C Slater
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Andrew M Blagborough
- Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ, UK
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22
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Churcher TS, Sinden RE, Edwards NJ, Poulton ID, Rampling TW, Brock PM, Griffin JT, Upton LM, Zakutansky SE, Sala KA, Angrisano F, Hill AVS, Blagborough AM. Probability of Transmission of Malaria from Mosquito to Human Is Regulated by Mosquito Parasite Density in Naïve and Vaccinated Hosts. PLoS Pathog 2017; 13:e1006108. [PMID: 28081253 PMCID: PMC5230737 DOI: 10.1371/journal.ppat.1006108] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 12/02/2016] [Indexed: 11/19/2022] Open
Abstract
Over a century since Ronald Ross discovered that malaria is caused by the bite of an infectious mosquito it is still unclear how the number of parasites injected influences disease transmission. Currently it is assumed that all mosquitoes with salivary gland sporozoites are equally infectious irrespective of the number of parasites they harbour, though this has never been rigorously tested. Here we analyse >1000 experimental infections of humans and mice and demonstrate a dose-dependency for probability of infection and the length of the host pre-patent period. Mosquitoes with a higher numbers of sporozoites in their salivary glands following blood-feeding are more likely to have caused infection (and have done so quicker) than mosquitoes with fewer parasites. A similar dose response for the probability of infection was seen for humans given a pre-erythrocytic vaccine candidate targeting circumsporozoite protein (CSP), and in mice with and without transfusion of anti-CSP antibodies. These interventions prevented infection more efficiently from bites made by mosquitoes with fewer parasites. The importance of parasite number has widespread implications across malariology, ranging from our basic understanding of the parasite, how vaccines are evaluated and the way in which transmission should be measured in the field. It also provides direct evidence for why the only registered malaria vaccine RTS,S was partially effective in recent clinical trials. Malaria is transmitted to humans by the bite of an infectious mosquito though it is unclear whether a mosquito with a high number of parasites is more infectious than one with only a few. Here we show that the greater the number of parasites within the salivary gland of the mosquito following blood-feeding the more likely it is to have transmitted the disease. A clear dose-response is seen with highly infected mosquitoes being more likely to have caused infection (and to have done so quicker) than lightly infected mosquitoes. This suggesting that mosquito-based methods for measuring transmission in the field need to be refined as they currently only consider whether a mosquito is infected or not (and not how heavily infected the mosquito is). Novel transmission reducing drugs and vaccines are tested by experimentally infecting people using infectious mosquitoes. This work indicates that it is important to further standardise infectious dose in malaria experimental infections to enable the efficacy of new interventions to be accurately compared. The work also provides direct evidence to suggest that the world’s first licenced malaria vaccine may be partially effective because it fails to provide protection against highly infected mosquitoes.
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Affiliation(s)
- Thomas S. Churcher
- MRC Centre for Outbreak Analysis and Modelling, Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
- * E-mail:
| | - Robert E. Sinden
- Department of Life Sciences, Imperial College London, South Kensington, London, United Kingdom
- The Jenner Institute, University of Oxford, Roosevelt Drive, Oxford, United Kingdom
| | - Nick J. Edwards
- The Jenner Institute, University of Oxford, Roosevelt Drive, Oxford, United Kingdom
| | - Ian D. Poulton
- The Jenner Institute, University of Oxford, Roosevelt Drive, Oxford, United Kingdom
| | - Thomas W. Rampling
- The Jenner Institute, University of Oxford, Roosevelt Drive, Oxford, United Kingdom
| | - Patrick M. Brock
- MRC Centre for Outbreak Analysis and Modelling, Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Jamie T. Griffin
- MRC Centre for Outbreak Analysis and Modelling, Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Leanna M. Upton
- Department of Life Sciences, Imperial College London, South Kensington, London, United Kingdom
| | - Sara E. Zakutansky
- Department of Life Sciences, Imperial College London, South Kensington, London, United Kingdom
| | - Katarzyna A. Sala
- Department of Life Sciences, Imperial College London, South Kensington, London, United Kingdom
| | - Fiona Angrisano
- Department of Life Sciences, Imperial College London, South Kensington, London, United Kingdom
| | - Adrian V. S. Hill
- The Jenner Institute, University of Oxford, Roosevelt Drive, Oxford, United Kingdom
| | - Andrew M. Blagborough
- Department of Life Sciences, Imperial College London, South Kensington, London, United Kingdom
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23
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Blagborough AM, Musiychuk K, Bi H, Jones RM, Chichester JA, Streatfield S, Sala KA, Zakutansky SE, Upton LM, Sinden RE, Brian I, Biswas S, Sattabonkot J, Yusibov V. Transmission blocking potency and immunogenicity of a plant-produced Pvs25-based subunit vaccine against Plasmodium vivax. Vaccine 2016; 34:3252-9. [PMID: 27177945 PMCID: PMC4915602 DOI: 10.1016/j.vaccine.2016.05.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 04/06/2016] [Accepted: 05/03/2016] [Indexed: 01/18/2023]
Abstract
Malaria transmission blocking (TB) vaccines (TBVs) directed against proteins expressed on the sexual stages of Plasmodium parasites are a potentially effective means to reduce transmission. Antibodies induced by TBVs block parasite development in the mosquito, and thus inhibit transmission to further human hosts. The ookinete surface protein P25 is a primary target for TBV development. Recently, transient expression in plants using hybrid viral vectors has demonstrated potential as a strategy for cost-effective and scalable production of recombinant vaccines. Using a plant virus-based expression system, we produced recombinant P25 protein of Plasmodium vivax (Pvs25) in Nicotiana benthamiana fused to a modified lichenase carrier protein. This candidate vaccine, Pvs25-FhCMB, was purified, characterized and evaluated for immunogenicity and efficacy using multiple adjuvants in a transgenic rodent model. An in vivo TB effect of up to a 65% reduction in intensity and 54% reduction in prevalence was observed using Abisco-100 adjuvant. The ability of this immunogen to induce a TB response was additionally combined with heterologous prime-boost vaccination with viral vectors expressing Pvs25. Significant blockade was observed when combining both platforms, achieving a 74% and 68% reduction in intensity and prevalence, respectively. This observation was confirmed by direct membrane feeding on field P. vivax samples, resulting in reductions in intensity/prevalence of 85.3% and 25.5%. These data demonstrate the potential of this vaccine candidate and support the feasibility of expressing Plasmodium antigens in a plant-based system for the production of TBVs, while demonstrating the potential advantages of combining multiple vaccine delivery systems to maximize efficacy.
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Affiliation(s)
- A M Blagborough
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London SW7 2AZ, UK.
| | - K Musiychuk
- Fraunhofer USA Center for Molecular Biotechnology, Newark, DE, USA
| | - H Bi
- Fraunhofer USA Center for Molecular Biotechnology, Newark, DE, USA
| | - R M Jones
- Fraunhofer USA Center for Molecular Biotechnology, Newark, DE, USA
| | - J A Chichester
- Fraunhofer USA Center for Molecular Biotechnology, Newark, DE, USA
| | - S Streatfield
- Fraunhofer USA Center for Molecular Biotechnology, Newark, DE, USA
| | - K A Sala
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London SW7 2AZ, UK
| | - S E Zakutansky
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London SW7 2AZ, UK
| | - L M Upton
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London SW7 2AZ, UK
| | - R E Sinden
- Jenner Institute, The University of Oxford, Roosevelt Road, Oxford OX9 2PP, UK
| | - I Brian
- Jenner Institute, The University of Oxford, Roosevelt Road, Oxford OX9 2PP, UK
| | - S Biswas
- Jenner Institute, The University of Oxford, Roosevelt Road, Oxford OX9 2PP, UK
| | - J Sattabonkot
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand
| | - V Yusibov
- Fraunhofer USA Center for Molecular Biotechnology, Newark, DE, USA
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24
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Vainieri ML, Blagborough AM, MacLean AL, Haltalli MLR, Ruivo N, Fletcher HA, Stumpf MPH, Sinden RE, Celso CL. Systematic tracking of altered haematopoiesis during sporozoite-mediated malaria development reveals multiple response points. Open Biol 2016; 6:160038. [PMID: 27335321 PMCID: PMC4929935 DOI: 10.1098/rsob.160038] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 05/27/2016] [Indexed: 12/21/2022] Open
Abstract
Haematopoiesis is the complex developmental process that maintains the turnover of all blood cell lineages. It critically depends on the correct functioning of rare, quiescent haematopoietic stem cells (HSCs) and more numerous, HSC-derived, highly proliferative and differentiating haematopoietic progenitor cells (HPCs). Infection is known to affect HSCs, with severe and chronic inflammatory stimuli leading to stem cell pool depletion, while acute, non-lethal infections exert transient and even potentiating effects. Both whether this paradigm applies to all infections and whether the HSC response is the dominant driver of the changes observed during stressed haematopoiesis remain open questions. We use a mouse model of malaria, based on natural, sporozoite-driven Plasmodium berghei infection, as an experimental platform to gain a global view of haematopoietic perturbations during infection progression. We observe coordinated responses by the most primitive HSCs and multiple HPCs, some starting before blood parasitaemia is detected. We show that, despite highly variable inter-host responses, primitive HSCs become highly proliferative, but mathematical modelling suggests that this alone is not sufficient to significantly impact the whole haematopoietic cascade. We observe that the dramatic expansion of Sca-1(+) progenitors results from combined proliferation of direct HSC progeny and phenotypic changes in downstream populations. We observe that the simultaneous perturbation of HSC/HPC population dynamics is coupled with early signs of anaemia onset. Our data uncover a complex relationship between Plasmodium and its host's haematopoiesis and raise the question whether the variable responses observed may affect the outcome of the infection itself and its long-term consequences on the host.
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Affiliation(s)
- Maria L Vainieri
- Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Andrew M Blagborough
- Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Adam L MacLean
- Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Myriam L R Haltalli
- Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Nicola Ruivo
- Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | | | - Michael P H Stumpf
- Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Robert E Sinden
- Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK Jenner Institute, Oxford OX3 7DQ, UK
| | - Cristina Lo Celso
- Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
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Da DF, Churcher TS, Yerbanga RS, Yaméogo B, Sangaré I, Ouedraogo JB, Sinden RE, Blagborough AM, Cohuet A. Experimental study of the relationship between Plasmodium gametocyte density and infection success in mosquitoes; implications for the evaluation of malaria transmission-reducing interventions. Exp Parasitol 2014; 149:74-83. [PMID: 25541384 DOI: 10.1016/j.exppara.2014.12.010] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 12/10/2014] [Accepted: 12/15/2014] [Indexed: 11/29/2022]
Abstract
The evaluation of transmission reducing interventions (TRI) to control malaria widely uses membrane feeding assays. In such assays, the intensity of Plasmodium infection in the vector might affect the measured efficacy of the candidates to block transmission. Gametocyte density in the host blood is a determinant of the infection success in the mosquito, however, uncertain estimates of parasite densities and intrinsic characteristics of the infected blood can induce variability. To reduce this variation, a feasible method is to dilute infectious blood samples. We describe the effect of diluting samples of Plasmodium-containing blood samples to allow accurate relative measures of gametocyte densities and their impact on mosquito infectivity and TRI efficacy. Natural Plasmodium falciparum samples were diluted to generate a wide range of parasite densities, and fed to Anopheles coluzzii mosquitoes. This was compared with parallel dilutions conducted on Plasmodium berghei infections. We examined how blood dilution influences the observed blocking activity of anti-Pbs28 monoclonal antibody using the P. berghei/Anopheles stephensi system. In the natural species combination P. falciparum/An. coluzzii, blood dilution using heat-inactivated, infected blood as diluents, revealed positive near linear relationships, between gametocyte densities and oocyst loads in the range tested. A similar relationship was observed in the P. berghei/An. stephensi system when using a similar dilution method. In contrast, diluting infected mice blood with fresh uninfected blood dramatically increases the infectiousness. This suggests that highly infected mice blood contains inhibitory factors or reduced blood moieties, which impede infection and may in turn, lead to misinterpretation when comparing individual TRI evaluation assays. In the lab system, the transmission blocking activity of an antibody specific for Pbs28 was confirmed to be density-dependent. This highlights the need to carefully interpret evaluations of TRI candidates, regarding gametocyte densities in the P. berghei/An. stephensi system.
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Affiliation(s)
- Dari F Da
- Institut de Recherche en Sciences de la Santé, Direction Régionale, 399 avenue de la liberté, Bobo Dioulasso 01 01 BP 545, Burkina Faso; Institut de Recherche pour le Développement, unité MIVEGEC (UM1-UM2-CNRS 5290-IRD 224), 911 avenue Agropolis, Montpellier Cedex 5 34394, France
| | - Thomas S Churcher
- Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Rakiswendé S Yerbanga
- Institut de Recherche en Sciences de la Santé, Direction Régionale, 399 avenue de la liberté, Bobo Dioulasso 01 01 BP 545, Burkina Faso
| | - Bienvenue Yaméogo
- Institut de Recherche en Sciences de la Santé, Direction Régionale, 399 avenue de la liberté, Bobo Dioulasso 01 01 BP 545, Burkina Faso
| | - Ibrahim Sangaré
- Institut de Recherche en Sciences de la Santé, Direction Régionale, 399 avenue de la liberté, Bobo Dioulasso 01 01 BP 545, Burkina Faso; Institut de Recherche pour le Développement, unité MIVEGEC (UM1-UM2-CNRS 5290-IRD 224), 911 avenue Agropolis, Montpellier Cedex 5 34394, France
| | - Jean Bosco Ouedraogo
- Institut de Recherche en Sciences de la Santé, Direction Régionale, 399 avenue de la liberté, Bobo Dioulasso 01 01 BP 545, Burkina Faso
| | - Robert E Sinden
- Division of Cell and Molecular Biology, Imperial College London, London, United Kingdom; The Jenner Institute, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
| | - Andrew M Blagborough
- Division of Cell and Molecular Biology, Imperial College London, London, United Kingdom
| | - Anna Cohuet
- Institut de Recherche en Sciences de la Santé, Direction Régionale, 399 avenue de la liberté, Bobo Dioulasso 01 01 BP 545, Burkina Faso; Institut de Recherche pour le Développement, unité MIVEGEC (UM1-UM2-CNRS 5290-IRD 224), 911 avenue Agropolis, Montpellier Cedex 5 34394, France.
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Sala KA, Nishiura H, Upton LM, Zakutansky SE, Delves MJ, Iyori M, Mizutani M, Sinden RE, Yoshida S, Blagborough AM. The Plasmodium berghei sexual stage antigen PSOP12 induces anti-malarial transmission blocking immunity both in vivo and in vitro. Vaccine 2014; 33:437-45. [PMID: 25454088 DOI: 10.1016/j.vaccine.2014.11.038] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 11/19/2014] [Accepted: 11/20/2014] [Indexed: 01/15/2023]
Abstract
Anti-malarial transmission-blocking vaccines (TBVs) aim to inhibit the transmission of Plasmodium from humans to mosquitoes by targeting the sexual/ookinete stages of the parasite. Successful use of such interventions will subsequently result in reduced cases of malarial infection within a human population, leading to local elimination. There are currently only five lead TBV candidates under examination. There is a consequent need to identify novel antigens to allow the formulation of new potent TBVs. Here we describe the design and evaluation of a potential TBV (BDES-PbPSOP12) targeting Plasmodium berghei PSOP12 based on the baculovirus dual expression system (BDES), enabling expression of antigens on the surface of viral particles and within infected mammalian cells. In silico studies have previously suggested that PSOP12 (Putative Secreted Ookinete Protein 12) is expressed within the sexual stages of the parasite (gametocytes, gametes and ookinetes), and is a member of the previously characterized 6-Cys family of plasmodial proteins. We demonstrate that PSOP12 is expressed within the sexual/ookinete forms of the parasite, and that sera obtained from mice immunized with BDES-PbPSOP12 can recognize the surface of the male and female gametes, and the ookinete stages of the parasite. Immunization of mice with BDES-PbPSOP12 confers modest but significant transmission-blocking activity in vivo by active immunization (53.1% reduction in oocyst intensity, 10.9% reduction in oocyst prevalence). Further assessment of transmission-blocking potency ex vivo shows a dose-dependent response, with up to a 76.4% reduction in intensity and a 47.2% reduction in prevalence observed. Our data indicates that PSOP12 in Plasmodium spp. could be a potential new TBV target candidate, and that further experimentation to examine the protein within human malaria parasites would be logical.
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Affiliation(s)
- K A Sala
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London SW7 2AZ, UK
| | - H Nishiura
- Laboratory of Vaccinology and Applied Immunology, School of Pharmacy, Kanazawa University, Ishikawa, Japan
| | - L M Upton
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London SW7 2AZ, UK
| | - S E Zakutansky
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London SW7 2AZ, UK
| | - M J Delves
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London SW7 2AZ, UK
| | - M Iyori
- Laboratory of Vaccinology and Applied Immunology, School of Pharmacy, Kanazawa University, Ishikawa, Japan
| | - M Mizutani
- Laboratory of Vaccinology and Applied Immunology, School of Pharmacy, Kanazawa University, Ishikawa, Japan
| | - R E Sinden
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London SW7 2AZ, UK; Jenner Institute, The University of Oxford, Roosevelt Road, Oxford OX9 2PP, UK
| | - S Yoshida
- Laboratory of Vaccinology and Applied Immunology, School of Pharmacy, Kanazawa University, Ishikawa, Japan
| | - A M Blagborough
- Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, South Kensington, London SW7 2AZ, UK.
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Marques SR, Ramakrishnan C, Carzaniga R, Blagborough AM, Delves MJ, Talman AM, Sinden RE. An essential role of the basal body protein SAS-6 in Plasmodium male gamete development and malaria transmission. Cell Microbiol 2014; 17:191-206. [PMID: 25154861 PMCID: PMC4441282 DOI: 10.1111/cmi.12355] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Revised: 07/11/2014] [Accepted: 08/19/2014] [Indexed: 01/07/2023]
Abstract
Gametocytes are the sole Plasmodium parasite stages that infect mosquitoes; therefore development of functional gametes is required for malaria transmission. Flagellum assembly of the Plasmodium male gamete differs from that of most other eukaryotes in that it is intracytoplasmic but retains a key conserved feature: axonemes assemble from basal bodies. The centriole/basal body protein SAS-6 normally regulates assembly and duplication of these organelles and its depletion causes severe flagellar/ciliary abnormalities in a diverse array of eukaryotes. Since basal body and flagellum assembly are intimately coupled to male gamete development in Plasmodium, we hypothesized that SAS-6 disruption may cause gametogenesis defects and perturb transmission. We show that Plasmodium berghei sas6 knockouts display severely abnormal male gametogenesis presenting reduced basal body numbers, axonemal assembly defects and abnormal nuclear allocation. The defects in gametogenesis reduce fertilization and render Pbsas6 knockouts less infectious to mosquitoes. Additionally, we show that lack of Pbsas6 blocks transmission from mosquito to vertebrate host, revealing an additional yet undefined role in ookinete to sporulating oocysts transition. These findings underscore the vulnerability of the basal body/SAS-6 to malaria transmission blocking interventions.
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Affiliation(s)
- Sara R Marques
- Department of Life Sciences, Imperial College of London, London, SW7 2AZ, UK
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Abstract
We provide a series of protocols that have been used for the cyclic transmission of rodent malaria parasites in the laboratory. This is now possible both in vivo and in vitro. We focus on the least "resource intensive" and generic methods that we find applicable to any parasite-host combination. Nonetheless, we recognize that the ability to construct transgenic "reporter" parasites/hosts now permits the use of elegant analytical and imaging technologies both in vitro, ex vivo, and in vivo in specific instances. The descriptions given illustrate methods routinely used for the maintenance of P. berghei; where critical, we note important differences when transmitting other parasite species.
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Sinden RE, Blagborough AM, Churcher T, Ramakrishnan C, Biswas S, Delves MJ. The design and interpretation of laboratory assays measuring mosquito transmission of Plasmodium. Trends Parasitol 2012; 28:457-65. [DOI: 10.1016/j.pt.2012.07.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 07/20/2012] [Accepted: 07/24/2012] [Indexed: 12/14/2022]
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Goodman AL, Blagborough AM, Biswas S, Wu Y, Hill AV, Sinden RE, Draper SJ. A viral vectored prime-boost immunization regime targeting the malaria Pfs25 antigen induces transmission-blocking activity. PLoS One 2011; 6:e29428. [PMID: 22216279 PMCID: PMC3247263 DOI: 10.1371/journal.pone.0029428] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 11/29/2011] [Indexed: 11/18/2022] Open
Abstract
The ookinete surface protein Pfs25 is a macrogamete-to-ookinete/ookinete stage antigen of Plasmodium falciparum, capable of exerting high-level anti-malarial transmission-blocking activity following immunization with recombinant protein-in-adjuvant formulations. Here, this antigen was expressed in recombinant chimpanzee adenovirus 63 (ChAd63), human adenovirus serotype 5 (AdHu5) and modified vaccinia virus Ankara (MVA) viral vectored vaccines. Two immunizations were administered to mice in a heterologous prime-boost regime. Immunization of mice with AdHu5 Pfs25 at week 0 and MVA Pfs25 at week 10 (Ad-MVA Pfs25) resulted in high anti-Pfs25 IgG titers, consisting of predominantly isotypes IgG1 and IgG2a. A single priming immunization with ChAd63 Pfs25 was as effective as AdHu5 Pfs25 with respect to ELISA titers at 8 weeks post-immunization. Sera from Ad-MVA Pfs25 immunized mice inhibited the transmission of P. falciparum to the mosquito both ex vivo and in vivo. In a standard membrane-feeding assay using NF54 strain P. falciparum, oocyst intensity in Anopheles stephensi mosquitoes was significantly reduced in an IgG concentration-dependent manner when compared to control feeds (96% reduction of intensity, 78% reduction in prevalence at a 1 in 5 dilution of sera). In addition, an in vivo transmission-blocking effect was also demonstrated by direct feeding of immunized mice infected with Pfs25DR3, a chimeric P. berghei line expressing Pfs25 in place of endogenous Pbs25. In this assay the density of Pfs25DR3 oocysts was significantly reduced when mosquitoes were fed on vaccinated as compared to control mice (67% reduction of intensity, 28% reduction in prevalence) and specific IgG titer correlated with efficacy. These data confirm the utility of the adenovirus-MVA vaccine platform for the induction of antibodies with transmission-blocking activity, and support the continued development of this alternative approach to transmission-blocking malaria subunit vaccines.
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Affiliation(s)
- Anna L Goodman
- The Jenner Institute, University of Oxford, Oxford, United Kingdom.
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Talman AM, Lacroix C, Marques SR, Blagborough AM, Carzaniga R, Ménard R, Sinden RE. PbGEST mediates malaria transmission to both mosquito and vertebrate host. Mol Microbiol 2011; 82:462-74. [DOI: 10.1111/j.1365-2958.2011.07823.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Ramakrishnan C, Dessens JT, Armson R, Pinto SB, Talman AM, Blagborough AM, Sinden RE. Vital functions of the malarial ookinete protein, CTRP, reside in the A domains. Int J Parasitol 2011; 41:1029-39. [PMID: 21729699 DOI: 10.1016/j.ijpara.2011.05.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 05/04/2011] [Accepted: 05/06/2011] [Indexed: 10/18/2022]
Abstract
The transformation of malaria ookinetes into oocysts occurs in the mosquito midgut and is a major bottleneck for parasite transmission. The secreted ookinete surface protein, circumsporozoite- and thrombospondin-related adhesive protein (TRAP)-related protein (CTRP), is essential for this transition and hence constitutes a potential target for malaria transmission blockade. CTRP is a modular multidomain protein containing six tandem von Willebrand factor A-like (A) domains and seven tandem thrombospondin type I repeat-like (TS) domains. Here we present, to our knowledge, the first structure-function analysis of CTRP using genetically modified Plasmodium berghei parasites expressing mutant versions of the ctrp gene. Our data show that the A domains of CTRP are critical for ookinete gliding motility and oocyst formation whilst, unexpectedly, its TS domains are fully redundant. These results may have important implications for the design of CTRP-based transmission blocking strategies.
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Affiliation(s)
- Chandra Ramakrishnan
- Division of Cell and Molecular Biology, Sir Alexander Fleming Building, Imperial College London, South Kensington Campus, London SW72AZ, UK.
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Blagborough AM, Yoshida S, Sattabongkot J, Tsuboi T, Sinden RE. Intranasal and intramuscular immunization with Baculovirus Dual Expression System-based Pvs25 vaccine substantially blocks Plasmodium vivax transmission. Vaccine 2010; 28:6014-20. [PMID: 20637303 DOI: 10.1016/j.vaccine.2010.06.100] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Revised: 06/28/2010] [Accepted: 06/29/2010] [Indexed: 12/20/2022]
Abstract
We have recently developed a new experimental vaccine vector system based on Autographa californica nucleopolyhedrosis virus (AcNPV) termed the "Baculovirus Dual Expression System", which drives expression of vaccine candidate antigens by a dual promoter that consists of tandemly arranged baculovirus-derived polyhedrin and mammalian-derived CMV promoters. The present study used this system to generate a Plasmodium vivax transmission-blocking immunogen (AcNPV-Dual-Pvs25). AcNPV-Dual-Pvs25 not only displayed Pvs25 on the AcNPV envelope, exhibiting aspects of its native three-dimensional structure, but also expressed appropriately immunogenic protein upon transduction of mammalian cells. Both intranasal and intramuscular immunization of mice with AcNPV-Dual-Pvs25 induced high Pvs25-specific antibody titres, notably of IgG1, IgG2a and IgG2b isotypes, indicating a mixed Th1/Th2 response. Importantly, sera obtained from subcutaneously immunized rabbits exhibited a significant transmission-blocking effect (96% reduction in infection intensity, 24% reduction in prevalence) when challenged with human blood infected with P. vivax gametocytes using the standard membrane feeding assay. Additionally, active immunization (both intranasal and intramuscular routes) of mice followed by challenge using a transgenic P. berghei line expressing Pvs25 in place of native Pbs25 and Pbs28 (clone Pvs25DR3) demonstrates a strong transmission-blocking response, with a 92.1% (intranasal) and 83.8% (intramuscular) reduction in oocyst intensity. Corresponding reductions in prevalence of infection were observed (88.4% and 75.5% respectively). This study offers a novel tool for the development of malarial transmission-blocking vaccines against the sexual stages of the parasite, using the Baculovirus Dual Expression System that functions as both a subunit, and DNA based vaccine.
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Affiliation(s)
- Andrew M Blagborough
- Division of Cell and Molecular Biology, Department of Life Sciences, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, London SW7 2AZ, UK.
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Abstract
The human malaria parasite Plasmodium falciparum is responsible for the majority of malaria-related deaths. Tools allowing the study of the basic biology of P. falciparum throughout the life cycle are critical to the development of new strategies to target the parasite within both human and mosquito hosts. We here present 3D7HT-GFP, a strain of P. falciparum constitutively expressing the Green Fluorescent Protein (GFP) throughout the life cycle, which has retained its capacity to complete sporogonic development. The GFP expressing cassette was inserted in the Pf47 locus. Using this transgenic strain, parasite tracking and population dynamics studies in mosquito stages and exo-erythrocytic schizogony is greatly facilitated. The development of 3D7HT-GFP will permit a deeper understanding of the biology of parasite-host vector interactions, and facilitate the development of high-throughput malaria transmission assays and thus aid development of new intervention strategies against both parasite and mosquito.
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Affiliation(s)
- Arthur M. Talman
- Division of Cell and Molecular Biology, Imperial College London, London, United Kingdom
- * E-mail:
| | - Andrew M. Blagborough
- Division of Cell and Molecular Biology, Imperial College London, London, United Kingdom
| | - Robert E. Sinden
- Division of Cell and Molecular Biology, Imperial College London, London, United Kingdom
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Bass C, Nikou D, Blagborough AM, Vontas J, Sinden RE, Williamson MS, Field LM. PCR-based detection of Plasmodium in Anopheles mosquitoes: a comparison of a new high-throughput assay with existing methods. Malar J 2008; 7:177. [PMID: 18793416 PMCID: PMC2553798 DOI: 10.1186/1475-2875-7-177] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Accepted: 09/15/2008] [Indexed: 12/01/2022] Open
Abstract
Background Detection of the four malaria-causing Plasmodium species (Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale and Plasmodium malariae) within their mosquito hosts is an essential component of vector control programmes. Several PCR protocols have been developed for this purpose. Many of these methods, while sensitive, require multiple PCR reactions to detect and discriminate all four Plasmodium species. In this study a new high-throughput assay was developed and compared with three previously described PCR techniques. Methods A new assay based on TaqMan SNP genotyping was developed to detect all four Plasmodium species and discriminate P. falciparum from P. vivax, P. ovale and P. malariae. The sensitivity and the specificity of the new assay was compared to three alternative PCR approaches and to microscopic dissection of salivary glands in a blind trial of 96 single insect samples that included artificially infected Anopheles stephensi mosquitoes. The performance of the assays was then compared using more than 450 field-collected specimens that had been stored on silica gel, in ethanol or in isopropanol. Results The TaqMan assay was found to be highly specific when using Plasmodium genomic DNA as template. Tests of analytical sensitivity and the results of the blind trial showed the TaqMan assay to be the most sensitive of the four methods followed by the 'gold standard' nested PCR approach and the results generated using these two methods were in good concordance. The sensitivity of the other two methods and their agreement with the nested PCR and TaqMan approaches varied considerably. In trials using field collected specimens two of the methods (including the nested protocol) showed a high degree of non-specific amplification when using DNA derived from mosquitoes stored in ethanol or isopropanol. The TaqMan method appeared unaffected when using the same samples. Conclusion This study describes a new high-throughput TaqMan assay that very effectively detects the four Plasmodium species that cause malaria in humans and discriminates the most deadly species, P. falciparum, from the others. This method is at least as sensitive and specific as the gold standard nested PCR approach and because it has no requirement for post-PCR processing is cheaper, simpler and more rapid to run. In addition this method is not inhibited by the storage of mosquito specimens by drying or in ethanol or isopropanol.
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Affiliation(s)
- Chris Bass
- Department of Biological Chemistry, Center for Sustainable Pest and Disease Management, Rothamsted Research, Harpenden, UK.
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Habtewold T, Povelones M, Blagborough AM, Christophides GK. Transmission blocking immunity in the malaria non-vector mosquito Anopheles quadriannulatus species A. PLoS Pathog 2008; 4:e1000070. [PMID: 18497855 PMCID: PMC2374904 DOI: 10.1371/journal.ppat.1000070] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2007] [Accepted: 04/14/2008] [Indexed: 01/26/2023] Open
Abstract
Despite being phylogenetically very close to Anopheles gambiae, the major mosquito vector of human malaria in Africa, Anopheles quadriannulatus is thought to be a non-vector. Understanding the difference between vector and non-vector mosquitoes can facilitate development of novel malaria control strategies. We demonstrate that An. quadriannulatus is largely resistant to infections by the human parasite Plasmodium falciparum, as well as by the rodent parasite Plasmodium berghei. By using genetics and reverse genetics, we show that resistance is controlled by quantitative heritable traits and manifested by lysis or melanization of ookinetes in the mosquito midgut, as well as by killing of parasites at subsequent stages of their development in the mosquito. Genes encoding two leucine-rich repeat proteins, LRIM1 and LRIM2, and the thioester-containing protein, TEP1, are identified as essential in these immune reactions. Their silencing completely abolishes P. berghei melanization and dramatically increases the number of oocysts, thus transforming An. quadriannulatus into a highly permissive parasite host. We hypothesize that the mosquito immune system is an important cause of natural refractoriness to malaria and that utilization of this innate capacity of mosquitoes could lead to new methods to control transmission of the disease. Malaria is a mosquito-borne infectious disease that threatens almost half of the human population and kills 1 to 3 million people every year. In sub-Saharan Africa, where the vast majority of deaths occur, the capacity of mosquitoes to transmit malaria varies greatly even between closely related species. We compared the ability of malaria parasites to develop in two very closely related mosquitoes, one vector and one non-vector, and found that non-vector mosquitoes kill parasites at various stages, predominantly when they invade the mosquito midgut. This is achieved by parasite clearance, possibly by lysis in the midgut cells and by melanization, both of which are reactions of the mosquito immune system. This phenotype depends on heritable and dominant traits that can be passed on to vector/non-vector mosquito hybrids. We examined whether specific components of the mosquito immune system affect the resistance of these mosquitoes to infection. By silencing the activity of three immunity genes, we transformed mosquitoes of the resistant species into highly susceptible. Our results suggest that the mosquito immune system may affect refractoriness to malaria in non-vector mosquitoes. This innate capacity of mosquitoes to kill malaria parasites could be utilized in future integrated efforts to control and ultimately eradicate the disease.
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Affiliation(s)
- Tibebu Habtewold
- Immunology and Infection, Division of Cell and Molecular Biology, Faculty of Natural Sciences, Imperial College London, London, United Kingdom
| | - Michael Povelones
- Immunology and Infection, Division of Cell and Molecular Biology, Faculty of Natural Sciences, Imperial College London, London, United Kingdom
| | - Andrew M. Blagborough
- Immunology and Infection, Division of Cell and Molecular Biology, Faculty of Natural Sciences, Imperial College London, London, United Kingdom
| | - George K. Christophides
- Immunology and Infection, Division of Cell and Molecular Biology, Faculty of Natural Sciences, Imperial College London, London, United Kingdom
- * E-mail:
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Liu Y, Tewari R, Ning J, Blagborough AM, Garbom S, Pei J, Grishin NV, Steele RE, Sinden RE, Snell WJ, Billker O. The conserved plant sterility gene HAP2 functions after attachment of fusogenic membranes in Chlamydomonas and Plasmodium gametes. Genes Dev 2008; 22:1051-68. [PMID: 18367645 DOI: 10.1101/gad.1656508] [Citation(s) in RCA: 235] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The cellular and molecular mechanisms that underlie species-specific membrane fusion between male and female gametes remain largely unknown. Here, by use of gene discovery methods in the green alga Chlamydomonas, gene disruption in the rodent malaria parasite Plasmodium berghei, and distinctive features of fertilization in both organisms, we report discovery of a mechanism that accounts for a conserved protein required for gamete fusion. A screen for fusion mutants in Chlamydomonas identified a homolog of HAP2, an Arabidopsis sterility gene. Moreover, HAP2 disruption in Plasmodium blocked fertilization and thereby mosquito transmission of malaria. HAP2 localizes at the fusion site of Chlamydomonas minus gametes, yet Chlamydomonas minus and Plasmodium hap2 male gametes retain the ability, using other, species-limited proteins, to form tight prefusion membrane attachments with their respective gamete partners. Membrane dye experiments show that HAP2 is essential for membrane merger. Thus, in two distantly related eukaryotes, species-limited proteins govern access to a conserved protein essential for membrane fusion.
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Affiliation(s)
- Yanjie Liu
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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Dittrich S, Mitchell SL, Blagborough AM, Wang Q, Wang P, Sims PFG, Hyde JE. An atypical orthologue of 6-pyruvoyltetrahydropterin synthase can provide the missing link in the folate biosynthesis pathway of malaria parasites. Mol Microbiol 2007; 67:609-18. [PMID: 18093090 PMCID: PMC2229834 DOI: 10.1111/j.1365-2958.2007.06073.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Folate metabolism in malaria parasites is a long-standing, clinical target for chemotherapy and prophylaxis. However, despite determination of the complete genome sequence of the lethal species Plasmodium falciparum, the pathway of de novo folate biosynthesis remains incomplete, as no candidate gene for dihydroneopterin aldolase (DHNA) could be identified. This enzyme catalyses the third step in the well-characterized pathway of plants, bacteria, and those eukaryotic microorganisms capable of synthesizing their own folate. Utilizing bioinformatics searches based on both primary and higher protein structures, together with biochemical assays, we demonstrate that P. falciparum cell extracts lack detectable DHNA activity, but that the parasite possesses an unusual orthologue of 6-pyruvoyltetrahydropterin synthase (PTPS), which simultaneously gives rise to two products in comparable amounts, the predominant of which is 6-hydroxymethyl-7,8-dihydropterin, the substrate for the fourth step in folate biosynthesis (catalysed by 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase; PPPK). This can provide a bypass for the missing DHNA activity and thus a means of completing the biosynthetic pathway from GTP to dihydrofolate. Supported by site-directed mutagenesis experiments, we ascribe the novel catalytic activity of the malarial PTPS to a Cys to Glu change at its active site relative to all previously characterized PTPS molecules, including that of the human host.
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Affiliation(s)
- Sabine Dittrich
- Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK
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Ramjanee S, Robertson JS, Franke-Fayard B, Sinha R, Waters AP, Janse CJ, Wu Y, Blagborough AM, Saul A, Sinden RE. The use of transgenic Plasmodium berghei expressing the Plasmodium vivax antigen P25 to determine the transmission-blocking activity of sera from malaria vaccine trials. Vaccine 2006; 25:886-94. [PMID: 17049690 DOI: 10.1016/j.vaccine.2006.09.035] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2006] [Revised: 08/15/2006] [Accepted: 09/04/2006] [Indexed: 12/01/2022]
Abstract
P25 is a major surface protein of Plasmodium ookinetes. Antibodies against P25 prevent the formation of oocysts in the mosquito and thereby block transmission of the parasite through an endemic population. Plasmodium vivax transmission-blocking vaccines based on Pv25 have undergone human trials and inhibit transmission significantly. The current assay to determine transmission-blocking activity (TBA) of these sera, the 'standard membrane feeding assay', is complex and can be performed by few groups worldwide that require both mosquito breeding facilities and access to volunteers naturally infected with P.vivax--a costly, and uncontrolled source of parasites. Here we report the development of novel assays to determine TBA using two clones (Pv25DR and Pv25DR3) of transgenic rodent parasites (Plasmodium berghei) expressing Pv25. We show that oocyst development of the transgenic parasites is inhibited by monoclonal antibody against Pv25 with the same kinetics exhibited by wild type parasites when exposed to mouse monoclonal antibodies targeted to a paralogous protein P28. Human transmission-blocking sera from a clinical vaccine trial of Pv25 inhibited oocyst development of Pv25DR and Pv25DR3, whereas non-blocking sera did not. We further show transmission-blocking activity can be determined in a simple assays of ookinete development in vitro, assays that obviate the need for mosquito colonies. These results demonstrate that transgenic rodent malarias expressing proteins from human Plasmodium species can be cheap, safe, and simple tools for testing TBA from sera. To this end the cloned lines have been deposited with, and are freely available from, MR4.
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Affiliation(s)
- Souraya Ramjanee
- Division of Cell and Molecular Biology, Sir Alexander Fleming Building, Imperial College London, Imperial College Road, London SW7 2AZ, UK
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