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Andolina C, Graumans W, Guelbeogo M, van Gemert GJ, Ramijth J, Harouna S, Soumanaba Z, Stoter R, Vegte-Bolmer M, Pangos M, Sinnis P, Collins K, Staedke SG, Tiono AB, Drakeley C, Lanke K, Bousema T. Quantification of sporozoite expelling by Anopheles mosquitoes infected with laboratory and naturally circulating P. falciparum gametocytes. eLife 2024; 12:RP90989. [PMID: 38517746 PMCID: PMC10959522 DOI: 10.7554/elife.90989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2024] Open
Abstract
It is currently unknown whether all Plasmodium falciparum-infected mosquitoes are equally infectious. We assessed sporogonic development using cultured gametocytes in the Netherlands and naturally circulating strains in Burkina Faso. We quantified the number of sporozoites expelled into artificial skin in relation to intact oocysts, ruptured oocysts, and residual salivary gland sporozoites. In laboratory conditions, higher total sporozoite burden was associated with shorter duration of sporogony (p<0.001). Overall, 53% (116/216) of infected Anopheles stephensi mosquitoes expelled sporozoites into artificial skin with a median of 136 expelled sporozoites (interquartile range [IQR], 34-501). There was a strong positive correlation between ruptured oocyst number and salivary gland sporozoite load (ρ = 0.8; p<0.0001) and a weaker positive correlation between salivary gland sporozoite load and number of sporozoites expelled (ρ = 0.35; p=0.0002). In Burkina Faso, Anopheles coluzzii mosquitoes were infected by natural gametocyte carriers. Among salivary gland sporozoite positive mosquitoes, 89% (33/37) expelled sporozoites with a median of 1035 expelled sporozoites (IQR, 171-2969). Again, we observed a strong correlation between ruptured oocyst number and salivary gland sporozoite load (ρ = 0.9; p<0.0001) and a positive correlation between salivary gland sporozoite load and the number of sporozoites expelled (ρ = 0.7; p<0.0001). Several mosquitoes expelled multiple parasite clones during probing. Whilst sporozoite expelling was regularly observed from mosquitoes with low infection burdens, our findings indicate that mosquito infection burden is positively associated with the number of expelled sporozoites. Future work is required to determine the direct implications of these findings for transmission potential.
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Affiliation(s)
- Chiara Andolina
- Department of Medical Microbiology, Radboud University Nijmegen Medical CentreNijmegenNetherlands
| | - Wouter Graumans
- Department of Medical Microbiology, Radboud University Nijmegen Medical CentreNijmegenNetherlands
| | - Moussa Guelbeogo
- Centre National de Recherche et de Formation sur le PaludismeOuagadougouBurkina Faso
| | - Geert-Jan van Gemert
- Department of Medical Microbiology, Radboud University Nijmegen Medical CentreNijmegenNetherlands
| | - Jordache Ramijth
- Department of Medical Microbiology, Radboud University Nijmegen Medical CentreNijmegenNetherlands
| | - Soré Harouna
- Centre National de Recherche et de Formation sur le PaludismeOuagadougouBurkina Faso
| | - Zongo Soumanaba
- Centre National de Recherche et de Formation sur le PaludismeOuagadougouBurkina Faso
| | - Rianne Stoter
- Department of Medical Microbiology, Radboud University Nijmegen Medical CentreNijmegenNetherlands
| | - Marga Vegte-Bolmer
- Department of Medical Microbiology, Radboud University Nijmegen Medical CentreNijmegenNetherlands
| | - Martina Pangos
- Department of Plastic and Reconstructive Surgery, Azienda Ospedaliero Universitaria GiulianoIsontina TriesteTriesteItaly
| | - Photini Sinnis
- Department of Molecular Microbiology and Immunology, Johns HopkinsBloomberg School of Public HealthBaltimoreUnited States
| | - Katharine Collins
- Department of Medical Microbiology, Radboud University Nijmegen Medical CentreNijmegenNetherlands
| | - Sarah G Staedke
- Liverpool School of Tropical MedicineLiverpoolUnited Kingdom
| | - Alfred B Tiono
- Centre National de Recherche et de Formation sur le PaludismeOuagadougouBurkina Faso
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical MedicineLondonUnited Kingdom
| | - Kjerstin Lanke
- Department of Medical Microbiology, Radboud University Nijmegen Medical CentreNijmegenNetherlands
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Nijmegen Medical CentreNijmegenNetherlands
- Department of Immunology and Infection, London School of Hygiene and Tropical MedicineLondonUnited Kingdom
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2
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Guissou E, Da DF, Hien DFDS, Yameogo KB, Yerbanga SR, Ouédraogo GA, Dabiré KR, Lefèvre T, Cohuet A. Intervention reducing malaria parasite load in vector mosquitoes: No impact on Plasmodium falciparum extrinsic incubation period and the survival of Anopheles gambiae. PLoS Pathog 2023; 19:e1011084. [PMID: 37195964 DOI: 10.1371/journal.ppat.1011084] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Accepted: 04/18/2023] [Indexed: 05/19/2023] Open
Abstract
In the fight against malaria, transmission blocking interventions (TBIs) such as transmission blocking vaccines or drugs, are promising approaches to complement conventional tools. They aim to prevent the infection of vectors and thereby reduce the subsequent exposure of a human population to infectious mosquitoes. The effectiveness of these approaches has been shown to depend on the initial intensity of infection in mosquitoes, often measured as the mean number of oocysts resulting from an infectious blood meal in absence of intervention. In mosquitoes exposed to a high intensity of infection, current TBI candidates are expected to be ineffective at completely blocking infection but will decrease parasite load and therefore, potentially also affect key parameters of vector transmission. The present study investigated the consequences of changes in oocyst intensity on subsequent parasite development and mosquito survival. To address this, we experimentally produced different intensities of infection for Anopheles gambiae females from Burkina Faso by diluting gametocytes from three natural Plasmodium falciparum local isolates and used a newly developed non-destructive method based on the exploitation of mosquito sugar feeding to track parasite and mosquito life history traits throughout sporogonic development. Our results indicate the extrinsic incubation period (EIP) of P. falciparum and mosquito survival did not vary with parasite density but differed significantly between parasite isolates with estimated EIP50 of 16 (95% CI: 15-18), 14 (95% CI: 12-16) and 12 (95% CI: 12-13) days and median longevity of 25 (95% CI: 22-29), 15 (95% CI: 13-15) and 18 (95% CI: 17-19) days for the three isolates respectively. Our results here do not identify unintended consequences of the decrease of parasite loads in mosquitoes on the parasite incubation period or on mosquito survival, two key parameters of vectorial capacity, and hence support the use of transmission blocking strategies to control malaria.
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Affiliation(s)
- Edwige Guissou
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
- MIVEGEC, Montpellier University, IRD, CNRS, Montpellier, France
- Université Nazi Boni, Bobo-Dioulasso, Burkina Faso
- Ecole Normale Supérieure, Koudougou, Burkina Faso
| | - Dari Frédéric Da
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | | | | | | | | | | | - Thierry Lefèvre
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
- MIVEGEC, Montpellier University, IRD, CNRS, Montpellier, France
| | - Anna Cohuet
- MIVEGEC, Montpellier University, IRD, CNRS, Montpellier, France
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3
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Pathak AK, Shiau JC, Franke-Fayard B, Shollenberger LM, Harn DA, Kyle DE, Murdock CC. Streamlining sporozoite isolation from mosquitoes by leveraging the dynamics of migration to the salivary glands. Malar J 2022; 21:264. [PMID: 36100902 PMCID: PMC9472382 DOI: 10.1186/s12936-022-04270-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 08/12/2022] [Indexed: 12/05/2022] Open
Abstract
Background Sporozoites isolated from the salivary glands of Plasmodium-infected mosquitoes are a prerequisite for several basic and pre-clinical applications. Although salivary glands are pooled to maximize sporozoite recovery, insufficient yields pose logistical and analytical hurdles; thus, predicting yields prior to isolation would be valuable. Preceding oocyst densities in the midgut is an obvious candidate. However, it is unclear whether current understanding of its relationship with sporozoite densities can be used to maximize yields, or whether it can capture the potential density-dependence in rates of sporozoite invasion of the salivary glands. Methods This study presents a retrospective analysis of Anopheles stephensi mosquitoes infected with two strains of the rodent-specific Plasmodium berghei. Mean oocyst densities were estimated in the midguts earlier in the infection (11–15 days post-blood meal), with sporozoites pooled from the salivary glands later in the infection (17–29 days). Generalized linear mixed effects models were used to determine if (1) mean oocyst densities can predict sporozoite yields from pooled salivary glands, (2) whether these densities can capture differences in rates of sporozoite invasion of salivary glands, and (3), if the interaction between oocyst densities and time could be leveraged to boost overall yields. Results The non-linear effect of mean oocyst densities confirmed the role of density-dependent constraints in limiting yields beyond certain oocyst densities. Irrespective of oocyst densities however, the continued invasion of salivary glands by the sporozoites boosted recoveries over time (17–29 days post-blood meal) for either parasite strain. Conclusions Sporozoite invasion of the salivary glands over time can be leveraged to maximize yields for P. berghei. In general, however, invasion of the salivary glands over time is a critical fitness determinant for all Plasmodium species (extrinsic incubation period, EIP). Thus, delaying sporozoite collection could, in principle, substantially reduce dissection effort for any parasite within the genus, with the results also alluding to the potential for changes in sporozoites densities over time to modify infectivity for the next host. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04270-y.
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Howard GP, Bender NG, Khare P, López-Gutiérrez B, Nyasembe V, Weiss WJ, Simecka JW, Hamerly T, Mao HQ, Dinglasan RR. Immunopotentiation by Lymph-Node Targeting of a Malaria Transmission-Blocking Nanovaccine. Front Immunol 2021; 12:729086. [PMID: 34512663 PMCID: PMC8432939 DOI: 10.3389/fimmu.2021.729086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/06/2021] [Indexed: 11/13/2022] Open
Abstract
A successful malaria transmission blocking vaccine (TBV) requires the induction of a high antibody titer that leads to abrogation of parasite traversal of the mosquito midgut following ingestion of an infectious bloodmeal, thereby blocking the cascade of secondary human infections. Previously, we developed an optimized construct UF6b that elicits an antigen-specific antibody response to a neutralizing epitope of Anopheline alanyl aminopeptidase N (AnAPN1), an evolutionarily conserved pan-malaria mosquito midgut-based TBV target, as well as established a size-controlled lymph node targeting biodegradable nanoparticle delivery system that leads to efficient and durable antigen-specific antibody responses using the model antigen ovalbumin. Herein, we demonstrate that co-delivery of UF6b with the adjuvant CpG oligodeoxynucleotide immunostimulatory sequence (ODN ISS) 1018 using this biodegradable nanoparticle vaccine delivery system generates an AnAPN1-specific immune response that blocks parasite transmission in a standard membrane feeding assay. Importantly, this platform allows for antigen dose-sparing, wherein lower antigen payloads elicit higher-quality antibodies, therefore less antigen-specific IgG is needed for potent transmission-reducing activity. By targeting lymph nodes directly, the resulting immunopotentiation of AnAPN1 suggests that the de facto assumption that high antibody titers are needed for a TBV to be successful needs to be re-examined. This nanovaccine formulation is stable at -20°C storage for at least 3 months, an important consideration for vaccine transport and distribution in regions with poor healthcare infrastructure. Together, these data support further development of this nanovaccine platform for malaria TBVs.
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Affiliation(s)
- Gregory P Howard
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States.,Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD, United States
| | - Nicole G Bender
- Emerging Pathogens Institute, Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - Prachi Khare
- Emerging Pathogens Institute, Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - Borja López-Gutiérrez
- Emerging Pathogens Institute, Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - Vincent Nyasembe
- Emerging Pathogens Institute, Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - William J Weiss
- Department of Pharmaceutical Sciences and UNTHSC Preclinical Services, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Jerry W Simecka
- Department of Pharmaceutical Sciences and UNTHSC Preclinical Services, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Timothy Hamerly
- Emerging Pathogens Institute, Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - Hai-Quan Mao
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States.,Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD, United States.,Department of Materials Science and Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, United States.,Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore MD, United States
| | - Rhoel R Dinglasan
- Emerging Pathogens Institute, Department of Infectious Diseases & Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
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5
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CRISPR/Cas9-engineered inducible gametocyte producer lines as a valuable tool for Plasmodium falciparum malaria transmission research. Nat Commun 2021; 12:4806. [PMID: 34376675 PMCID: PMC8355313 DOI: 10.1038/s41467-021-24954-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 07/08/2021] [Indexed: 12/18/2022] Open
Abstract
The malaria parasite Plasmodium falciparum replicates inside erythrocytes in the blood of infected humans. During each replication cycle, a small proportion of parasites commits to sexual development and differentiates into gametocytes, which are essential for parasite transmission via the mosquito vector. Detailed molecular investigation of gametocyte biology and transmission has been hampered by difficulties in generating large numbers of these highly specialised cells. Here, we engineer P. falciparum NF54 inducible gametocyte producer (iGP) lines for the routine mass production of synchronous gametocytes via conditional overexpression of the sexual commitment factor GDV1. NF54/iGP lines consistently achieve sexual commitment rates of 75% and produce viable gametocytes that are transmissible by mosquitoes. We also demonstrate that further genetic engineering of NF54/iGP parasites is a valuable tool for the targeted exploration of gametocyte biology. In summary, we believe the iGP approach developed here will greatly expedite basic and applied malaria transmission stage research.
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6
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Broichhagen J, Kilian N. Chemical Biology Tools To Investigate Malaria Parasites. Chembiochem 2021; 22:2219-2236. [PMID: 33570245 PMCID: PMC8360121 DOI: 10.1002/cbic.202000882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/10/2021] [Indexed: 02/06/2023]
Abstract
Parasitic diseases like malaria tropica have been shaping human evolution and history since the beginning of mankind. After infection, the response of the human host ranges from asymptomatic to severe and may culminate in death. Therefore, proper examination of the parasite's biology is pivotal to deciphering unique molecular, biochemical and cell biological processes, which in turn ensure the identification of treatment strategies, such as potent drug targets and vaccine candidates. However, implementing molecular biology methods for genetic manipulation proves to be difficult for many parasite model organisms. The development of fast and straightforward applicable alternatives, for instance small-molecule probes from the field of chemical biology, is essential. In this review, we will recapitulate the highlights of previous molecular and chemical biology approaches that have already created insight and understanding of the malaria parasite Plasmodium falciparum. We discuss current developments from the field of chemical biology and explore how their application could advance research into this parasite in the future. We anticipate that the described approaches will help to close knowledge gaps in the biology of P. falciparum and we hope that researchers will be inspired to use these methods to gain knowledge - with the aim of ending this devastating disease.
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Affiliation(s)
- Johannes Broichhagen
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)Robert-Roessle-Strasse 1013125BerlinGermany
| | - Nicole Kilian
- Centre for Infectious DiseasesParasitologyHeidelberg University HospitalIm Neuenheimer Feld 32469120HeidelbergGermany
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7
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Thai E, Costa G, Weyrich A, Murugan R, Oyen D, Flores-Garcia Y, Prieto K, Bosch A, Valleriani A, Wu NC, Pholcharee T, Scally SW, Wilson IA, Wardemann H, Julien JP, Levashina EA. A high-affinity antibody against the CSP N-terminal domain lacks Plasmodium falciparum inhibitory activity. J Exp Med 2021; 217:152019. [PMID: 32790871 PMCID: PMC7596816 DOI: 10.1084/jem.20200061] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/21/2020] [Accepted: 07/01/2020] [Indexed: 11/04/2022] Open
Abstract
Malaria is a global health concern, and research efforts are ongoing to develop a superior vaccine to RTS,S/AS01. To guide immunogen design, we seek a comprehensive understanding of the protective humoral response against Plasmodium falciparum (Pf) circumsporozoite protein (PfCSP). In contrast to the well-studied responses to the repeat region and the C-terminus, the antibody response against the N-terminal domain of PfCSP (N-CSP) remains obscure. Here, we characterized the molecular recognition and functional efficacy of the N-CSP-specific monoclonal antibody 5D5. The crystal structure at 1.85-Å resolution revealed that 5D5 binds an α-helical epitope in N-CSP with high affinity through extensive shape and charge complementarity and the unusual utilization of an antibody N-linked glycan. Nevertheless, functional studies indicated low 5D5 binding to live Pf sporozoites and lack of sporozoite inhibition in vitro and in vivo. Overall, our data do not support the inclusion of the 5D5 N-CSP epitope into the next generation of CSP-based vaccines.
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Affiliation(s)
- Elaine Thai
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Giulia Costa
- Vector Biology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Anna Weyrich
- Vector Biology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Rajagopal Murugan
- B Cell Immunology, German Cancer Research Institute, Heidelberg, Germany
| | - David Oyen
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA
| | - Yevel Flores-Garcia
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Katherine Prieto
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Alexandre Bosch
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Angelo Valleriani
- Vector Biology Unit, Max Planck Institute for Infection Biology, Berlin, Germany.,Department of Theory and Biosystems, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Nicholas C Wu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA
| | - Tossapol Pholcharee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA
| | - Stephen W Scally
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA.,The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA
| | - Hedda Wardemann
- B Cell Immunology, German Cancer Research Institute, Heidelberg, Germany
| | - Jean-Philippe Julien
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, Ontario, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.,Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Elena A Levashina
- Vector Biology Unit, Max Planck Institute for Infection Biology, Berlin, Germany
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Chali W, Ashine T, Hailemeskel E, Gashaw A, Tafesse T, Lanke K, Esayas E, Kedir S, Shumie G, Behaksra SW, Bradley J, Yewhalaw D, Mamo H, Petros B, Drakeley C, Gadisa E, Bousema T, Tadesse FG. Comparison of infectivity of Plasmodium vivax to wild-caught and laboratory-adapted (colonized) Anopheles arabiensis mosquitoes in Ethiopia. Parasit Vectors 2020; 13:120. [PMID: 32143713 PMCID: PMC7059271 DOI: 10.1186/s13071-020-3998-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/26/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mosquito-feeding assays that assess transmission of Plasmodium from man-to-mosquito typically use laboratory mosquito colonies. The microbiome and genetic background of local mosquitoes may be different and influence Plasmodium transmission efficiency. In order to interpret transmission studies to the local epidemiology, it is therefore crucial to understand the relationship between infectivity in laboratory-adapted and local mosquitoes. METHODS We assessed infectivity of Plasmodium vivax-infected patients from Adama, Ethiopia, using laboratory-adapted (colony) and wild-caught (wild) mosquitoes raised from larval collections in paired feeding experiments. Feeding assays used 4-6 day-old female Anopheles arabiensis mosquitoes after starvation for 12 h (colony) and 18 h (wild). Oocyst development was assessed microscopically 7 days post-feeding. Wild mosquitoes were identified morphologically and confirmed by genotyping. Asexual parasites and gametocytes were quantified in donor blood by microscopy. RESULTS In 36 paired experiments (25 P. vivax infections and 11 co-infections with P. falciparum), feeding efficiency was higher in colony (median: 62.5%; interquartile range, IQR: 47.0-79.0%) compared to wild mosquitoes (median: 27.8%; IQR: 17.0-38.0%; Z = 5.02; P < 0.001). Plasmodium vivax from infectious individuals (51.6%, 16/31) infected a median of 55.0% (IQR: 6.7-85.7%; range: 5.5-96.7%; n = 14) of the colony and 52.7% (IQR: 20.0-80.0%; range: 3.2-95.0%; n = 14) of the wild mosquitoes. A strong association (ρ(16) = 0.819; P < 0.001) was observed between the proportion of infected wild and colony mosquitoes. A positive association was detected between microscopically detected gametocytes and the proportion of infected colony (ρ(31) = 0.452; P = 0.011) and wild (ρ(31) = 0.386; P = 0.032) mosquitoes. CONCLUSIONS Infectivity assessments with colony and wild mosquitoes yielded similar infection results. This finding supports the use of colony mosquitoes for assessments of the infectious reservoir for malaria in this setting whilst acknowledging the importance of mosquito factors influencing sporogonic development of Plasmodium parasites.
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Affiliation(s)
- Wakweya Chali
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Temesgen Ashine
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Elifaged Hailemeskel
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
- Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Abrham Gashaw
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Temesgen Tafesse
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Kjerstin Lanke
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Endashaw Esayas
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Soriya Kedir
- Oromia Regional Laboratory, Oromia Regional Health Bureau, Adama, Ethiopia
| | - Girma Shumie
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Sinknesh Wolde Behaksra
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - John Bradley
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, WC1E 7HT London, UK
| | - Delenasaw Yewhalaw
- Tropical and Infectious Diseases Research Center, Jimma University, P.O.Box 5195, Jimma, Ethiopia
| | - Hassen Mamo
- Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia
| | - Beyene Petros
- Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, WC1E 7HT London, UK
| | - Endalamaw Gadisa
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, WC1E 7HT London, UK
| | - Fitsum G. Tadesse
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Institute of Biotechnology, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia
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9
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Palatnik-de-Sousa CB, Nico D. The Delay in the Licensing of Protozoal Vaccines: A Comparative History. Front Immunol 2020; 11:204. [PMID: 32210953 PMCID: PMC7068796 DOI: 10.3389/fimmu.2020.00204] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 01/27/2020] [Indexed: 11/13/2022] Open
Abstract
Although viruses and bacteria have been known as agents of diseases since 1546, 250 years went by until the first vaccines against these pathogens were developed (1796 and 1800s). In contrast, Malaria, which is a protozoan-neglected disease, has been known since the 5th century BCE and, despite 2,500 years having passed since then, no human vaccine has yet been licensed for Malaria. Additionally, no modern human vaccine is currently licensed against Visceral or Cutaneous leishmaniasis. Vaccination against Malaria evolved from the inoculation of irradiated sporozoites through the bite of Anopheles mosquitoes in 1930's, which failed to give protection, to the use of controlled human Malaria infection (CHMI) provoked by live sporozoites of Plasmodium falciparum and curtailed with specific chemotherapy since 1940's. Although the use of CHMI for vaccination was relatively efficacious, it has some ethical limitations and was substituted by the use of injected recombinant vaccines expressing the main antigens of the parasite cycle, starting in 1980. Pre-erythrocytic (PEV), Blood stage (BSV), transmission-blocking (TBV), antitoxic (AT), and pregnancy-associated Malaria vaccines are under development. Currently, the RTS,S-PEV vaccine, based on the circumsporozoite protein, is the only one that has arrived at the Phase III trial stage. The "R" stands for the central repeat region of Plasmodium (P.) falciparum circumsporozoite protein (CSP); the "T" for the T-cell epitopes of the CSP; and the "S" for hepatitis B surface antigen (HBsAg). In Africa, this latter vaccine achieved only 36.7% vaccine efficacy (VE) in 5-7 years old children and was associated with an increase in clinical cases in one assay. Therefore, in spite of 35 years of research, there is no currently licensed vaccine against Malaria. In contrast, more progress has been achieved regarding prevention of leishmaniasis by vaccine, which also started with the use of live vaccines. For ethical reasons, these were substituted by second-generation subunit or recombinant DNA and protein vaccines. Currently, there is one live vaccine for humans licensed in Uzbekistan, and four licensed veterinary vaccines against visceral leishmaniasis: Leishmune® (76-80% VE) and CaniLeish® (68.4% VE), which give protection against strong endpoints (severe disease and deaths under natural conditions), and, under less severe endpoints (parasitologically and PCR-positive cases), Leishtec® developed 71.4% VE in a low infective pressure area but only 35.7% VE and transient protection in a high infective pressure area, while Letifend® promoted 72% VE. A human recombinant vaccine based on the Nucleoside hydrolase NH36 of Leishmania (L.) donovani, the main antigen of the Leishmune® vaccine, and the sterol 24-c-methyltransferase (SMT) from L. (L.) infantum has reached the Phase I clinical trial phase but has not yet been licensed against the disease. This review describes the history of vaccine development and is focused on licensed formulations that have been used in preventive medicine. Special attention has been given to the delay in the development and licensing of human vaccines against Protozoan infections, which show high incidence worldwide and still remain severe threats to Public Health.
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MESH Headings
- Adult
- Animals
- Child
- Child, Preschool
- Female
- History, 17th Century
- History, 18th Century
- History, 19th Century
- History, 20th Century
- History, 21st Century
- Humans
- Leishmania donovani/immunology
- Leishmaniasis Vaccines/history
- Leishmaniasis Vaccines/immunology
- Leishmaniasis, Visceral/parasitology
- Leishmaniasis, Visceral/prevention & control
- Leishmaniasis, Visceral/veterinary
- Licensure/history
- Malaria Vaccines/history
- Malaria Vaccines/immunology
- Malaria, Falciparum/parasitology
- Malaria, Falciparum/prevention & control
- Mass Vaccination/history
- Mass Vaccination/methods
- Plasmodium falciparum/immunology
- Pregnancy
- Vaccines, Attenuated/history
- Vaccines, Attenuated/immunology
- Vaccines, Live, Unattenuated/history
- Vaccines, Live, Unattenuated/immunology
- Vaccines, Synthetic/history
- Vaccines, Synthetic/immunology
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Affiliation(s)
- Clarisa Beatriz Palatnik-de-Sousa
- Institute of Microbiology Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Institute for Research in Immunology, Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Dirlei Nico
- Institute of Microbiology Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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10
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de Jong RM, Tebeje SK, Meerstein‐Kessel L, Tadesse FG, Jore MM, Stone W, Bousema T. Immunity against sexual stage Plasmodium falciparum and Plasmodium vivax parasites. Immunol Rev 2020; 293:190-215. [PMID: 31840844 PMCID: PMC6973022 DOI: 10.1111/imr.12828] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/30/2019] [Accepted: 11/14/2019] [Indexed: 12/25/2022]
Abstract
The efficient spread of malaria from infected humans to mosquitoes is a major challenge for malaria elimination initiatives. Gametocytes are the only Plasmodium life stage infectious to mosquitoes. Here, we summarize evidence for naturally acquired anti-gametocyte immunity and the current state of transmission blocking vaccines (TBV). Although gametocytes are intra-erythrocytic when present in infected humans, developing Plasmodium falciparum gametocytes may express proteins on the surface of red blood cells that elicit immune responses in naturally exposed individuals. This immune response may reduce the burden of circulating gametocytes. For both P. falciparum and Plasmodium vivax, there is a solid evidence that antibodies against antigens present on the gametocyte surface, when co-ingested with gametocytes, can influence transmission to mosquitoes. Transmission reducing immunity, reducing the burden of infection in mosquitoes, is a well-acknowledged but poorly quantified phenomenon that forms the basis for the development of TBV. Transmission enhancing immunity, increasing the likelihood or intensity of transmission to mosquitoes, is more speculative in nature but is convincingly demonstrated for P. vivax. With the increased interest in malaria elimination, TBV and monoclonal antibodies have moved to the center stage of malaria vaccine development. Methodologies to prioritize and evaluate products are urgently needed.
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MESH Headings
- Antibodies, Blocking/immunology
- Antibodies, Protozoan/immunology
- Host-Parasite Interactions/immunology
- Humans
- Immunity
- Immunomodulation
- Life Cycle Stages
- Malaria Vaccines/immunology
- Malaria, Falciparum/immunology
- Malaria, Falciparum/parasitology
- Malaria, Falciparum/prevention & control
- Malaria, Falciparum/transmission
- Malaria, Vivax/immunology
- Malaria, Vivax/parasitology
- Malaria, Vivax/prevention & control
- Malaria, Vivax/transmission
- Plasmodium falciparum/growth & development
- Plasmodium falciparum/immunology
- Plasmodium vivax/growth & development
- Plasmodium vivax/immunology
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Affiliation(s)
- Roos M. de Jong
- Radboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | | | - Lisette Meerstein‐Kessel
- Radboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
- Centre for Molecular and Biomolecular InformaticsRadboud Institute for Molecular Life SciencesNijmegenThe Netherlands
| | - Fitsum G. Tadesse
- Armauer Hansen Research InstituteAddis AbabaEthiopia
- Radboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - Matthijs M. Jore
- Radboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - Will Stone
- Department of Immunology and InfectionLondon School of Hygiene and Tropical MedicineLondonUK
| | - Teun Bousema
- Radboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
- Department of Immunology and InfectionLondon School of Hygiene and Tropical MedicineLondonUK
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11
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Pathak AK, Shiau JC, Thomas MB, Murdock CC. Field Relevant Variation in Ambient Temperature Modifies Density-Dependent Establishment of Plasmodium falciparum Gametocytes in Mosquitoes. Front Microbiol 2019; 10:2651. [PMID: 31803169 PMCID: PMC6873802 DOI: 10.3389/fmicb.2019.02651] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 10/30/2019] [Indexed: 12/29/2022] Open
Abstract
The relationship between Plasmodium falciparum gametocyte density and infections in mosquitoes is central to understanding the rates of transmission with important implications for control. Here, we determined whether field relevant variation in environmental temperature could also modulate this relationship. Anopheles stephensi were challenged with three densities of P. falciparum gametocytes spanning a ~10-fold gradient, and housed under diurnal/daily temperature range ("DTR") of 9°C (+5°C and -4°C) around means of 20, 24, and 28°C. Vector competence was quantified as the proportion of mosquitoes infected with oocysts in the midguts (oocyst rates) or infectious with sporozoites in the salivary glands (sporozoite rates) at peak periods of infection for each temperature to account for the differences in development rates. In addition, oocyst intensities were also recorded from infected midguts and the overall study replicated across three separate parasite cultures and mosquito cohorts. While vector competence was similar at 20 DTR 9°C and 24 DTR 9°C, oocyst and sporozoite rates were also comparable, with evidence, surprisingly, for higher vector competence in mosquitoes challenged with intermediate gametocyte densities. For the same gametocyte densities however, severe reductions in the sporozoite rates was accompanied by a significant decline in overall vector competence at 28 DTR 9°C, with gametocyte density per se showing a positive and linear effect at this temperature. Unlike vector competence, oocyst intensities decreased with increasing temperatures with a predominantly positive and linear association with gametocyte density, especially at 28 DTR 9°C. Oocyst intensities across individual infected midguts suggested temperature-specific differences in mosquito susceptibility/resistance: at 20 DTR 9°C and 24 DTR 9°C, dispersion (aggregation) increased in a density-dependent manner but not at 28 DTR 9°C where the distributions were consistently random. Limitations notwithstanding, our results suggest that variation in temperature could modify seasonal dynamics of infectious reservoirs with implications for the design and deployment of transmission-blocking vaccines/drugs.
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Affiliation(s)
- Ashutosh K. Pathak
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
- Center for Ecology of Infectious Diseases, University of Georgia, Athens, GA, United States
- Center for Tropical Emerging Global Diseases, University of Georgia, Athens, GA, United States
| | - Justine C. Shiau
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
| | - Matthew B. Thomas
- The Department of Entomology, Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA, United States
| | - Courtney C. Murdock
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
- Center for Ecology of Infectious Diseases, University of Georgia, Athens, GA, United States
- Center for Tropical Emerging Global Diseases, University of Georgia, Athens, GA, United States
- Odum School of Ecology, University of Georgia, Athens, GA, United States
- Center for Vaccines and Immunology, University of Georgia, Athens, GA, United States
- Riverbasin Center, University of Georgia, Athens, GA, United States
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