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Rodrigues PS, Azeredo MDF, Almeida NDS, de Almeida GGCG, Wanderley JLM, Seabra SH, DaMatta RA. Plasmodium chabaudi Merozoites Obtained through a Simpler Method Do Not Survive in Classically Activated Macrophages. Microorganisms 2024; 12:105. [PMID: 38257932 PMCID: PMC10818340 DOI: 10.3390/microorganisms12010105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/24/2024] Open
Abstract
Malaria is caused by apicomplexan parasites of the Plasmodium genus. Plasmodium chabaudi is an excellent animal model for the study of human malaria caused by P. falciparum. Merozoites invade erythrocytes but are also found in other host cells including macrophages from the spleen and liver. Methodologies for obtaining merozoites usually involve treatment with protease inhibitors. However, merozoites obtained in this way may have their enzymatic profile altered and, therefore, are not ideal for cell-interaction assays. We report the obtainment of P. chabaudi merozoites naturally egressed from a synchronous erythrocyte population infected with schizonts forms. Merozoites had their infectivity and ultrastructure analyzed. Interaction assays were performed with mice erythrocytes and classically activated mice peritoneal macrophages, a very well-established classic model. Obtained merozoites were able to kill mice and efficiently infect erythrocytes. Interestingly, a lower merozoite:erythrocyte ratio resulted in a higher percentage of infected erythrocytes. We describe a simpler method for obtaining viable and infective merozoites. Classically activated macrophages killed merozoites, suggesting that these host cells may not serve as reservoirs for these parasites. These findings have implications for our understanding of P. chabaudi merozoite biology and may improve the comprehension of their host-parasite relationship.
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Affiliation(s)
- Pedro Souto Rodrigues
- Laboratório de Biologia Celular e Tecidual, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes 28013-602, RJ, Brazil; (P.S.R.); (M.d.F.A.); (N.d.S.A.); (G.G.C.G.d.A.)
| | - Milena de Farias Azeredo
- Laboratório de Biologia Celular e Tecidual, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes 28013-602, RJ, Brazil; (P.S.R.); (M.d.F.A.); (N.d.S.A.); (G.G.C.G.d.A.)
| | - Natália de Souza Almeida
- Laboratório de Biologia Celular e Tecidual, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes 28013-602, RJ, Brazil; (P.S.R.); (M.d.F.A.); (N.d.S.A.); (G.G.C.G.d.A.)
| | - Gisela Garcia Cabral Galaxe de Almeida
- Laboratório de Biologia Celular e Tecidual, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes 28013-602, RJ, Brazil; (P.S.R.); (M.d.F.A.); (N.d.S.A.); (G.G.C.G.d.A.)
| | | | - Sergio Henrique Seabra
- Laboratório de Biologia Celular e Tecidual, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes 28013-602, RJ, Brazil; (P.S.R.); (M.d.F.A.); (N.d.S.A.); (G.G.C.G.d.A.)
| | - Renato Augusto DaMatta
- Laboratório de Biologia Celular e Tecidual, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes 28013-602, RJ, Brazil; (P.S.R.); (M.d.F.A.); (N.d.S.A.); (G.G.C.G.d.A.)
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Ezema CA, Okagu IU, Ezeorba TPC. Escaping the enemy's bullets: an update on how malaria parasites evade host immune response. Parasitol Res 2023:10.1007/s00436-023-07868-6. [PMID: 37219610 DOI: 10.1007/s00436-023-07868-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 05/08/2023] [Indexed: 05/24/2023]
Abstract
Malaria continues to cause untold hardship to inhabitants of malaria-endemic regions, causing significant morbidity and mortality that severely impact global health and the economy. Considering the complex life cycle of malaria parasites (MPs) and malaria biology, continued research efforts are ongoing to improve our understanding of the pathogenesis of the diseases. Female Anopheles mosquito injects MPs into its hosts during a blood meal, and MPs invade the host skin and the hepatocytes without causing any serious symptoms. Symptomatic infections occur only during the erythrocytic stage. In most cases, the host's innate immunity (for malaria-naïve individuals) and adaptive immunity (for pre-exposed individuals) mount severe attacks and destroy most MPs. It is increasingly understood that MPs have developed several mechanisms to escape from the host's immune destruction. This review presents recent knowledge on how the host's immune system destroys invading MPs as well as MPs survival or host immune evasion mechanisms. On the invasion of host cells, MPs release molecules that bind to cell surface receptors to reprogram the host in a way to lose the capacity to destroy them. MPs also hide from the host immune cells by inducing the clustering of both infected and uninfected erythrocytes (rosettes), as well as inducing endothelial activation. We hope this review will inspire more research to provide a complete understanding of malaria biology and promote interventions to eradicate the notorious disease.
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Affiliation(s)
- Chinonso Anthony Ezema
- Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Enugu State, 410001, Nigeria
- Division of Soft Matter, Hokkaido University, Sapporo, 060-0810, Japan
| | - Innocent Uzochukwu Okagu
- Department of Biochemistry, Faculty of Biological Sciences, University of Nigeria, Enugu State, 410001, Nigeria
| | - Timothy Prince Chidike Ezeorba
- Department of Biochemistry, Faculty of Biological Sciences, University of Nigeria, Enugu State, 410001, Nigeria.
- Department of Genetics and Biotechnology, Faculty of Biological Sciences, University of Nigeria, Enugu State, 410001, Nigeria.
- Department of Molecular Biotechnology, School of Biosciences, University of Birmingham Edgbaston, Birmingham, B15 2TT, UK.
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Lahree A, Mello-Vieira J, Mota MM. The nutrient games - Plasmodium metabolism during hepatic development. Trends Parasitol 2023; 39:445-460. [PMID: 37061442 DOI: 10.1016/j.pt.2023.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 04/17/2023]
Abstract
Malaria is a febrile illness caused by species of the protozoan parasite Plasmodium and is characterized by recursive infections of erythrocytes, leading to clinical symptoms and pathology. In mammals, Plasmodium parasites undergo a compulsory intrahepatic development stage before infecting erythrocytes. Liver-stage parasites have a metabolic configuration to facilitate the replication of several thousand daughter parasites. Their metabolism is of interest to identify cellular pathways essential for liver infection, to kill the parasite before onset of the disease. In this review, we summarize the current knowledge on nutrient acquisition and biosynthesis by liver-stage parasites mostly generated in murine malaria models, gaps in knowledge, and challenges to create a holistic view of the development and deficiencies in this field.
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Affiliation(s)
- Aparajita Lahree
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - João Mello-Vieira
- Institute of Biochemistry II, School of Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany; Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Maria M Mota
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal.
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Richie TL, Church LWP, Murshedkar T, Billingsley PF, James ER, Chen MC, Abebe Y, KC N, Chakravarty S, Dolberg D, Healy SA, Diawara H, Sissoko MS, Sagara I, Cook DM, Epstein JE, Mordmüller B, Kapulu M, Kreidenweiss A, Franke-Fayard B, Agnandji ST, López Mikue MSA, McCall MBB, Steinhardt L, Oneko M, Olotu A, Vaughan AM, Kublin JG, Murphy SC, Jongo S, Tanner M, Sirima SB, Laurens MB, Daubenberger C, Silva JC, Lyke KE, Janse CJ, Roestenberg M, Sauerwein RW, Abdulla S, Dicko A, Kappe SHI, Lee Sim BK, Duffy PE, Kremsner PG, Hoffman SL. Sporozoite immunization: innovative translational science to support the fight against malaria. Expert Rev Vaccines 2023; 22:964-1007. [PMID: 37571809 PMCID: PMC10949369 DOI: 10.1080/14760584.2023.2245890] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 08/04/2023] [Indexed: 08/13/2023]
Abstract
INTRODUCTION Malaria, a devastating febrile illness caused by protozoan parasites, sickened 247,000,000 people in 2021 and killed 619,000, mostly children and pregnant women in sub-Saharan Africa. A highly effective vaccine is urgently needed, especially for Plasmodium falciparum (Pf), the deadliest human malaria parasite. AREAS COVERED Sporozoites (SPZ), the parasite stage transmitted by Anopheles mosquitoes to humans, are the only vaccine immunogen achieving >90% efficacy against Pf infection. This review describes >30 clinical trials of PfSPZ vaccines in the U.S.A., Europe, Africa, and Asia, based on first-hand knowledge of the trials and PubMed searches of 'sporozoites,' 'malaria,' and 'vaccines.' EXPERT OPINION First generation (radiation-attenuated) PfSPZ vaccines are safe, well tolerated, 80-100% efficacious against homologous controlled human malaria infection (CHMI) and provide 18-19 months protection without boosting in Africa. Second generation chemo-attenuated PfSPZ are more potent, 100% efficacious against stringent heterologous (variant strain) CHMI, but require a co-administered drug, raising safety concerns. Third generation, late liver stage-arresting, replication competent (LARC), genetically-attenuated PfSPZ are expected to be both safe and highly efficacious. Overall, PfSPZ vaccines meet safety, tolerability, and efficacy requirements for protecting pregnant women and travelers exposed to Pf in Africa, with licensure for these populations possible within 5 years. Protecting children and mass vaccination programs to block transmission and eliminate malaria are long-term objectives.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Sara A. Healy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Halimatou Diawara
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Mahamadou S. Sissoko
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Issaka Sagara
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - David M. Cook
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Judith E. Epstein
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Benjamin Mordmüller
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
| | - Melissa Kapulu
- Biosciences Department, Kenya Medical Research Institute KEMRI-Wellcome Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Andrea Kreidenweiss
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | | | - Selidji T. Agnandji
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | | | - Matthew B. B. McCall
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | - Laura Steinhardt
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Martina Oneko
- Kenya Medical Research Institute, Centre for Global Health Research, Kisumu, Kenya
| | - Ally Olotu
- Bagamoyo Research and Training Center, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Ashley M. Vaughan
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - James G. Kublin
- Department of Global Health, University of Washington, Seattle, WA, USA
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Sean C. Murphy
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
- Center for Emerging and Re-emerging Infectious Diseases and Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Said Jongo
- Bagamoyo Research and Training Center, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Marcel Tanner
- Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | - Matthew B. Laurens
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Claudia Daubenberger
- Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Joana C. Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kirsten E. Lyke
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Chris J. Janse
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Meta Roestenberg
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands
| | - Robert W. Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Salim Abdulla
- Bagamoyo Research and Training Center, Ifakara Health Institute, Bagamoyo, Tanzania
| | - Alassane Dicko
- Malaria Research and Training Center, Mali-NIAID ICER, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Stefan H. I. Kappe
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, WA, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | | | - Patrick E. Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Peter G. Kremsner
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
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Singh D, Patri S, Narahari V, Segireddy RR, Dey S, Saurabh A, Macha V, Prabhu NP, Srivastava A, Kolli SK, Kota AK. A Conserved Plasmodium Structural Integrity Maintenance Protein (SIMP) is associated with sporozoite membrane and is essential for maintaining shape and infectivity. Mol Microbiol 2022; 117:1324-1339. [PMID: 35301756 DOI: 10.1111/mmi.14894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 03/07/2022] [Accepted: 03/08/2022] [Indexed: 11/27/2022]
Abstract
Plasmodium sporozoites are extracellular forms introduced during mosquito bite that selectively invade mammalian hepatocytes. Sporozoites are delimited by a cell membrane that is linked to the underlying acto-myosin molecular motor. While membrane proteins with roles in motility and invasion have been well studied, very little is known about proteins that maintain the sporozoite shape. We demonstrate that in Plasmodium berghei (Pb) a conserved hypothetical gene, PBANKA_1422900 specifies sporozoite structural integrity maintenance protein (SIMP) required for maintaining the sporozoite shape and motility. Sporozoites lacking SIMP exhibited loss of regular shape, extensive membrane blebbing at multiple foci and membrane detachment. The mutant sporozoites failed to infect hepatocytes, though the altered shape did not affect the organisation of cytoskeleton or inner membrane complex (IMC). Interestingly, the components of IMC failed to extend under the membrane blebs likely suggesting that SIMP may assist in anchoring the membrane to IMC. Endogenous C-terminal HA tagging localized SIMP to membrane and revealed the C-terminus of the protein to be extracellular. Since SIMP is highly conserved amongst Plasmodium species, these findings have important implications for utilising it as a novel sporozoite specific vaccine candidate.
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Affiliation(s)
- Dipti Singh
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Smita Patri
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Veeda Narahari
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Rameswara R Segireddy
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Sandeep Dey
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Archi Saurabh
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Vijay Macha
- National Institute of Animal Biotechnology, Gachibowli, Hyderabad, 500032, India
| | - N Prakash Prabhu
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Anand Srivastava
- National Institute of Animal Biotechnology, Gachibowli, Hyderabad, 500032, India
| | - Surendra Kumar Kolli
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
| | - Arun Kumar Kota
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India
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Arias CF, Acosta FJ, Fernandez-Arias C. Killing the competition: a theoretical framework for liver-stage malaria. Open Biol 2022; 12:210341. [PMID: 35350863 PMCID: PMC8965401 DOI: 10.1098/rsob.210341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The first stage of malaria infections takes place inside the host's hepatocytes. Remarkably, Plasmodium parasites do not infect hepatocytes immediately after reaching the liver. Instead, they migrate through several hepatocytes before infecting their definitive host cells, thus increasing their chances of immune destruction. Considering that malaria can proceed normally without cell traversal, this is indeed a puzzling behaviour. In fact, the role of hepatocyte traversal remains unknown to date, implying that the current understanding of malaria is incomplete. In this work, we hypothesize that the parasites traverse hepatocytes to actively trigger an immune response in the host. This behaviour would be part of a strategy of superinfection exclusion aimed to reduce intraspecific competition during the blood stage of the infection. Based on this hypothesis, we formulate a comprehensive theory of liver-stage malaria that integrates all the available knowledge about the infection. The interest of this new paradigm is not merely theoretical. It highlights major issues in the current empirical approach to the study of Plasmodium and suggests new strategies to fight malaria.
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Affiliation(s)
- Clemente F. Arias
- Centro de Investigaciones Biológicas (CSIC), Madrid, Spain,Grupo Interdisciplinar de Sistemas Complejos de Madrid, Spain
| | | | - Cristina Fernandez-Arias
- Departamento de Inmunología, Universidad Complutense de Madrid, Spain,Instituto de Medicina Molecular, Universidade de Lisboa, Portugal
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Simwela NV, Waters AP. Current status of experimental models for the study of malaria. Parasitology 2022; 149:1-22. [PMID: 35357277 PMCID: PMC9378029 DOI: 10.1017/s0031182021002134] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 01/09/2023]
Abstract
Infection by malaria parasites (Plasmodium spp.) remains one of the leading causes of morbidity and mortality, especially in tropical regions of the world. Despite the availability of malaria control tools such as integrated vector management and effective therapeutics, these measures have been continuously undermined by the emergence of vector resistance to insecticides or parasite resistance to frontline antimalarial drugs. Whilst the recent pilot implementation of the RTS,S malaria vaccine is indeed a remarkable feat, highly effective vaccines against malaria remain elusive. The barriers to effective vaccines result from the complexity of both the malaria parasite lifecycle and the parasite as an organism itself with consequent major gaps in our understanding of their biology. Historically and due to the practical and ethical difficulties of working with human malaria infections, research into malaria parasite biology has been extensively facilitated by animal models. Animals have been used to study disease pathogenesis, host immune responses and their (dys)regulation and further disease processes such as transmission. Moreover, animal models remain at the forefront of pre-clinical evaluations of antimalarial drugs (drug efficacy, mode of action, mode of resistance) and vaccines. In this review, we discuss commonly used animal models of malaria, the parasite species used and their advantages and limitations which hinder their extrapolation to actual human disease. We also place into this context the most recent developments such as organoid technologies and humanized mice.
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Affiliation(s)
- Nelson V. Simwela
- Institute of Infection, Immunity & Inflammation, Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Andrew P. Waters
- Institute of Infection, Immunity & Inflammation, Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
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Markus MB. Safety and Efficacy of Tafenoquine for Plasmodium vivax Malaria Prophylaxis and Radical Cure: Overview and Perspectives. Ther Clin Risk Manag 2021; 17:989-999. [PMID: 34526770 PMCID: PMC8435617 DOI: 10.2147/tcrm.s269336] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 08/20/2021] [Indexed: 11/23/2022] Open
Abstract
This article is inter alia a brief, first-stop guide to possible adverse events (AEs) associated with tafenoquine (TQ) intake. Safety and efficacy findings for TQ in Plasmodium vivax malaria prophylaxis and radical cure are summarized and some of the latest TQ-related studies (published in 2020 and 2021) are highlighted. In addition, little-known biological and other matters concerning malaria parasites and 8-aminoquinoline (8-AQ) drug action are discussed and some correct terminology pertinent to malaria is explained.
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Affiliation(s)
- Miles B Markus
- School of Animal, Plant and Environmental Sciences, Faculty of Science, University of the Witwatersrand, Johannesburg, South Africa
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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9
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Naturally Acquired Antibodies against Plasmodium falciparum: Friend or Foe? Pathogens 2021; 10:pathogens10070832. [PMID: 34357982 PMCID: PMC8308493 DOI: 10.3390/pathogens10070832] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 06/28/2021] [Accepted: 06/30/2021] [Indexed: 11/17/2022] Open
Abstract
Antibodies are central to acquired immunity against malaria. Plasmodium falciparum elicits antibody responses against many of its protein components, but there is also formation of antibodies against different parts of the red blood cells, in which the parasites spend most of their time. In the absence of a decisive intervention such as a vaccine, people living in malaria endemic regions largely depend on naturally acquired antibodies for protection. However, these antibodies do not confer sterile immunity and the mechanisms of action are still unclear. Most studies have focused on the inhibitory effect of antibodies, but here, we review both the beneficial as well as the potentially harmful roles of naturally acquired antibodies, as well as autoantibodies formed in malaria. We discuss different studies that have sought to understand acquired antibody responses against P. falciparum antigens, and potential problems when different antibodies are combined, such as in naturally acquired immunity.
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10
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Ramasamy R. Mosquito vector proteins homologous to α1-3 galactosyl transferases of tick vectors in the context of protective immunity against malaria and hypersensitivity to vector bites. Parasit Vectors 2021; 14:303. [PMID: 34090497 PMCID: PMC8179703 DOI: 10.1186/s13071-021-04801-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 05/24/2021] [Indexed: 12/18/2022] Open
Abstract
Background An epitope, Galα1-3Galβ1-4GlcNAc-R, termed α-gal, is present in glycoconjugates of New World monkeys (platyrrhines) and other mammals but not in hominoids and Old World monkeys (catarrhines). The difference is due to the inactivation of α1-3 galactosyl transferase (α1-3 GT) genes in catarrhines. Natural antibodies to α-gal are therefore developed in catarrhines but not platyrrhines and other mammals. Hypersensitivity reactions are commonly elicited by mosquito and tick vector bites. IgE antibodies against α-gal cause food allergy to red meat in persons who have been exposed to tick bites. Three enzymes synthesising the terminal α1-3-linked galactose in α-gal, that are homologous to mammalian α and β1-4 GTs but not mammalian α1-3 GTs, were recently identified in the tick vector Ixodes scapularis. IgG and IgM antibodies to α-gal are reported to protect against malaria because mosquito-derived sporozoites of malaria parasites express α-gal on their surface. This article explores the possibility that the α-gal in sporozoites are acquired from glycoconjugates synthesised by mosquitoes rather than through de novo synthesis by sporozoites. Methods The presence of proteins homologous to the three identified tick α1-3 GTs and mammalian α1-3 GTs in two important mosquito vectors, Aedes aegypti and Anopheles gambiae, as well as Plasmodium malaria parasites, was investigated by BLASTp analysis to help clarify the source of the α-gal on sporozoite surfaces. Results Anopheles gambiae and Ae. aegypti possessed several different proteins homologous to the three I. scapularis proteins with α1-3 GT activity, but not mammalian α1-3 GTs. The putative mosquito α1-3 GTs possessed conserved protein domains characteristic of glycosyl transferases. However, the genus Plasmodium lacked proteins homologous to the three I. scapularis proteins with α1-3 GT activity and mammalian α1-3 GTs. Conclusions The putative α1-3 GTs identified in the two mosquito vectors may synthesise glycoconjugates containing α-gal that can be transferred to sporozoite surfaces before they are inoculated into skin during blood feeding. The findings merit further investigation because of their implications for immunity against malaria, hypersensitivity to mosquito bites, primate evolution, and proposals for immunisation against α-gal. Graphic abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-04801-7.
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Affiliation(s)
- Ranjan Ramasamy
- ID-FISH Technology, 556 Gibraltar Drive, Milpitas, CA95035, USA.
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11
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Boulanger N, Wikel S. Induced Transient Immune Tolerance in Ticks and Vertebrate Host: A Keystone of Tick-Borne Diseases? Front Immunol 2021; 12:625993. [PMID: 33643313 PMCID: PMC7907174 DOI: 10.3389/fimmu.2021.625993] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/22/2021] [Indexed: 12/23/2022] Open
Abstract
Ticks and tick transmitted infectious agents are increasing global public health threats due to increasing abundance, expanding geographic ranges of vectors and pathogens, and emerging tick-borne infectious agents. Greater understanding of tick, host, and pathogen interactions will contribute to development of novel tick control and disease prevention strategies. Tick-borne pathogens adapt in multiple ways to very different tick and vertebrate host environments and defenses. Ticks effectively pharmacomodulate by its saliva host innate and adaptive immune defenses. In this review, we examine the idea that successful synergy between tick and tick-borne pathogen results in host immune tolerance that facilitates successful tick infection and feeding, creates a favorable site for pathogen introduction, modulates cutaneous and systemic immune defenses to establish infection, and contributes to successful long-term infection. Tick, host, and pathogen elements examined here include interaction of tick innate immunity and microbiome with tick-borne pathogens; tick modulation of host cutaneous defenses prior to pathogen transmission; how tick and pathogen target vertebrate host defenses that lead to different modes of interaction and host infection status (reservoir, incompetent, resistant, clinically ill); tick saliva bioactive molecules as important factors in determining those pathogens for which the tick is a competent vector; and, the need for translational studies to advance this field of study. Gaps in our understanding of these relationships are identified, that if successfully addressed, can advance the development of strategies to successfully disrupt both tick feeding and pathogen transmission.
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Affiliation(s)
- Nathalie Boulanger
- Fédération de Médecine Translationnelle - UR7290, Early Bacterial Virulence, Group Borrelia, Université de Strasbourg, Strasbourg, France.,Centre National de Référence Borrelia, Centre Hospitalier Universitaire, Strasbourg, France
| | - Stephen Wikel
- Department of Medical Sciences, Frank H. Netter, M.D., School of Medicine, Quinnipiac University, Hamden, CT, United States
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12
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Ferreira LDL, de Araújo FF, Martinelli PM, Teixeira-Carvalho A, Alves-Silva J, Guarneri AA. New features on the survival of human-infective Trypanosoma rangeli in a murine model: Parasite accumulation is observed in lymphoid organs. PLoS Negl Trop Dis 2020; 14:e0009015. [PMID: 33370305 PMCID: PMC7793305 DOI: 10.1371/journal.pntd.0009015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 01/08/2021] [Accepted: 11/27/2020] [Indexed: 12/02/2022] Open
Abstract
Trypanosoma rangeli is a non-pathogenic protozoan parasite that infects mammals, including humans, in Chagas disease-endemic areas of South and Central America. The parasite is transmitted to a mammalian host when an infected triatomine injects metacyclic trypomastigotes into the host's skin during a bloodmeal. Infected mammals behave as parasite reservoirs for several months and despite intensive research, some major aspects of T. rangeli-vertebrate interactions are still poorly understood. In particular, many questions still remain unanswered, e.g. parasite survival and development inside vertebrates, as no parasite multiplication sites have yet been identified. The present study used an insect bite transmission strategy to investigate whether the vector inoculation spot in the skin behave as a parasite-replication site. Histological data from the skin identified extracellular parasites in the dermis and hypodermis of infected mice in the first 24 hours post-infection, as well as the presence of inflammatory infiltrates in a period of up to 7 days. However, qPCR analyses demonstrated that T. rangeli is eliminated from the skin after 7 days of infection despite being still consistently found on circulating blood and secondary lymphoid tissues for up to 30 days post-infection. Interestingly, significant numbers of parasites were found in the spleen and mesenteric lymph nodes of infected mice during different periods of infection and steady basal numbers of flagellates are maintained in the host's bloodstream, which might behave as a transmission source to insect vectors. The presence of parasites in the spleen was confirmed by fluorescent photomicrography of free and cell-associated T. rangeli forms. Altogether our results suggest that this organ could possibly behave as a T. rangeli maintenance hotspot in vertebrates.
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Affiliation(s)
- Luciana de Lima Ferreira
- Vector Behavior and Pathogen Interaction Group, Instituto René Rachou, Fundação Oswaldo Cruz-FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | - Fernanda Fortes de Araújo
- Integrated Research Group in Biomarkers, Instituto René Rachou, Fundação Oswaldo Cruz-FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | - Patricia Massara Martinelli
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Andrea Teixeira-Carvalho
- Integrated Research Group in Biomarkers, Instituto René Rachou, Fundação Oswaldo Cruz-FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | - Juliana Alves-Silva
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Alessandra Aparecida Guarneri
- Vector Behavior and Pathogen Interaction Group, Instituto René Rachou, Fundação Oswaldo Cruz-FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
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13
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Monteiro W, Brito-Sousa JD, Elizalde-Torrent A, Bôtto-Menezes C, Melo GC, Fernandez-Becerra C, Lacerda M, Del Portillo HA. Cryptic Plasmodium chronic infections: was Maurizio Ascoli right? Malar J 2020; 19:440. [PMID: 33256745 PMCID: PMC7708240 DOI: 10.1186/s12936-020-03516-x] [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: 03/04/2020] [Accepted: 11/20/2020] [Indexed: 12/02/2022] Open
Abstract
Cryptic Plasmodium niches outside the liver possibly represent a major source of hypnozoite-unrelated recrudescences in malaria. Maurizio Ascoli, an Italian physician and scientist, suggested that infection was maintained as a result of the persistence of endoerythrocytic parasites in the circulatory bed of some internal organs, mainly the spleen. This would explain a proportion of the recurrences in patients, regardless of the Plasmodium species. Ascoli proposed a method that included the co-administration of adrenaline, in order to induce splenic contraction, and quinine to clear expelled forms in major vessels. Driven by controversy regarding safety and effectiveness, along with the introduction of new drugs, the Ascoli method was abandoned and mostly forgotten by the malaria research community. To date, however, the existence of cryptic parasites outside the liver is gaining supportive data. This work is a historical retrospective of cryptic malaria infections and the Ascoli method, highlighting key knowledge gaps regarding these possible parasite reservoirs.
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Affiliation(s)
- Wuelton Monteiro
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado (FMT-HVD), Manaus, Amazonas, Brazil. .,Universidade Do Estado Do Amazonas (UEA), Manaus, Amazonas, Brazil.
| | - José Diego Brito-Sousa
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado (FMT-HVD), Manaus, Amazonas, Brazil.,Universidade Do Estado Do Amazonas (UEA), Manaus, Amazonas, Brazil
| | - Aleix Elizalde-Torrent
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.,Institut D'Investigació Germans Trias I Pujol (IGTP), Badalona, Barcelona, Spain.,IrsiCaixa AIDS Research Institute, Badalona, Catalonia, Spain
| | - Camila Bôtto-Menezes
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado (FMT-HVD), Manaus, Amazonas, Brazil.,Universidade Do Estado Do Amazonas (UEA), Manaus, Amazonas, Brazil
| | - Gisely Cardoso Melo
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado (FMT-HVD), Manaus, Amazonas, Brazil.,Universidade Do Estado Do Amazonas (UEA), Manaus, Amazonas, Brazil
| | - Carmen Fernandez-Becerra
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain.,Institut D'Investigació Germans Trias I Pujol (IGTP), Badalona, Barcelona, Spain
| | - Marcus Lacerda
- Fundação de Medicina Tropical Dr Heitor Vieira Dourado (FMT-HVD), Manaus, Amazonas, Brazil.,Instituto Leônidas & Maria Deane (ILMD), Fiocruz, Manaus, Amazonas, Brazil
| | - Hernando A Del Portillo
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain. .,Institut D'Investigació Germans Trias I Pujol (IGTP), Badalona, Barcelona, Spain. .,Institució Catalana de Recerca I Estudis Avançats (ICREA), Barcelona, Spain.
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14
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Definition of constitutive and stage-enriched promoters in the rodent malaria parasite, Plasmodium yoelii. Malar J 2020; 19:424. [PMID: 33228734 PMCID: PMC7685602 DOI: 10.1186/s12936-020-03498-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 11/15/2020] [Indexed: 12/21/2022] Open
Abstract
Background Well-defined promoters are essential elements for genetic studies in all organisms, and enable controlled expression of endogenous genes, transgene expression, and gene editing. Despite this, there is a paucity of defined promoters for the rodent-infectious malaria parasites. This is especially true for Plasmodium yoelii, which is often used to study the mosquito and liver stages of malarial infection, as well as host immune responses to infection. Methods Here six promoters were selected from across the parasite’s life cycle (clag-a, dynein heavy chain delta, lap4, trap, uis4, lisp2) that have been invoked in the literature as controlling their genes in a stage-specific manner. A minimal promoter length for the constitutive pybip promoter that confers strong expression levels was also determined, which is useful for expression of reporters and gene editing enzymes. Results Instead, it was observed that these promoters confer stage-enriched gene control, as some parasites also effectively use these promoters in other stages. Thus, when used alone, these promoters could complicate the interpretation of results obtained from promoter swaps, stage-targeted recombination, or gene editing experiments. Conclusions Together these data indicate that achieving stage-specific effects, such as gene editing, is likely best done using a two-component system with independent promoter activities overlapping only in the intended life cycle stage.
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15
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Mello-Vieira J, Enguita FJ, de Koning-Ward TF, Zuzarte-Luís V, Mota MM. Plasmodium translocon component EXP2 facilitates hepatocyte invasion. Nat Commun 2020; 11:5654. [PMID: 33159090 PMCID: PMC7648069 DOI: 10.1038/s41467-020-19492-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 10/08/2020] [Indexed: 12/11/2022] Open
Abstract
Plasmodium parasites possess a translocon that exports parasite proteins into the infected erythrocyte. Although the translocon components are also expressed during the mosquito and liver stage of infection, their function remains unexplored. Here, using a combination of genetic and chemical assays, we show that the translocon component Exported Protein 2 (EXP2) is critical for invasion of hepatocytes. EXP2 is a pore-forming protein that is secreted from the sporozoite upon contact with the host cell milieu. EXP2-deficient sporozoites are impaired in invasion, which can be rescued by the exogenous administration of recombinant EXP2 and alpha-hemolysin (an S. aureus pore-forming protein), as well as by acid sphingomyelinase. The latter, together with the negative impact of chemical and genetic inhibition of acid sphingomyelinase on invasion, reveals that EXP2 pore-forming activity induces hepatocyte membrane repair, which plays a key role in parasite invasion. Overall, our findings establish a novel and critical function for EXP2 that leads to an active participation of the host cell in Plasmodium sporozoite invasion, challenging the current view of the establishment of liver stage infection. While the role of Plasmodium EXP2 protein as translocon component of blood stage parasites is established, its functional role in liver stage parasites remains unclear. Here, Mello-Vieira et al. reveal that EXP2 pore-forming activity induces hepatocyte membrane repair and hence is critical for hepatocyte invasion.
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Affiliation(s)
- João Mello-Vieira
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028, Lisboa, Portugal
| | - Francisco J Enguita
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028, Lisboa, Portugal
| | | | - Vanessa Zuzarte-Luís
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028, Lisboa, Portugal.
| | - Maria M Mota
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028, Lisboa, Portugal.
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16
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Plasmodium sporozoites induce regulatory macrophages. PLoS Pathog 2020; 16:e1008799. [PMID: 32898164 PMCID: PMC7500643 DOI: 10.1371/journal.ppat.1008799] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 09/18/2020] [Accepted: 07/10/2020] [Indexed: 12/23/2022] Open
Abstract
Professional antigen-presenting cells (APCs), like macrophages (Mϕs) and dendritic cells (DCs), are central players in the induction of natural and vaccine-induced immunity to malaria, yet very little is known about the interaction of SPZ with human APCs. Intradermal delivery of whole-sporozoite vaccines reduces their effectivity, possibly due to dermal immunoregulatory effects. Therefore, understanding these interactions could prove pivotal to malaria vaccination. We investigated human APC responses to recombinant circumsporozoite protein (recCSP), SPZ and anti-CSP opsonized SPZ both in monocyte derived MoDCs and MoMϕs. Both MoDCs and MoMϕs readily took up recCSP but did not change phenotype or function upon doing so. SPZ are preferentially phagocytosed by MoMϕs instead of DCs and phagocytosis greatly increased after opsonization. Subsequently MoMϕs show increased surface marker expression of activation markers as well as tolerogenic markers such as Programmed Death-Ligand 1 (PD-L1). Additionally they show reduced motility, produce interleukin 10 and suppressed interferon gamma (IFNγ) production by antigen specific CD8+ T cells. Importantly, we investigated phenotypic responses to SPZ in primary dermal APCs isolated from human skin explants, which respond similarly to their monocyte-derived counterparts. These findings are a first step in enhancing our understanding of pre-erythrocytic natural immunity and the pitfalls of intradermal vaccination-induced immunity. Malaria continues to be the deadliest parasitic disease worldwide, and an effective vaccine yielding sterile immunity does not yet exist. Attenuated parasites can induce sterile protection in both human and rodent models for malaria, but these vaccines need to be administered directly into the bloodstream in order to convey protection; administration via the skin results in a much-reduced efficacy. We hypothesized this is caused by an early immune regulation initiated at the first site of contact with the immune system: the skin. However, the human skin stage of malaria has not been investigated to date. We used human antigen presenting cells as well as whole human skin explants to investigate (dermal) immune responses and found that Plasmodium sporozoites are able to suppress immune responses by inducing regulatory macrophages. Our study provides new insights in the mechanism of early immune regulation exploited by Plasmodium parasites and can help to explain why intradermal vaccination using whole attenuated sporozoites results in reduced protection.
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17
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Osii RS, Otto TD, Garside P, Ndungu FM, Brewer JM. The Impact of Malaria Parasites on Dendritic Cell-T Cell Interaction. Front Immunol 2020; 11:1597. [PMID: 32793231 PMCID: PMC7393936 DOI: 10.3389/fimmu.2020.01597] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 06/16/2020] [Indexed: 12/13/2022] Open
Abstract
Malaria is caused by apicomplexan parasites of the genus Plasmodium. While infection continues to pose a risk for the majority of the global population, the burden of disease mainly resides in Sub-Saharan Africa. Although immunity develops against disease, this requires years of persistent exposure and is not associated with protection against infection. Repeat infections occur due to the parasite's ability to disrupt or evade the host immune responses. However, despite many years of study, the mechanisms of this disruption remain unclear. Previous studies have demonstrated a parasite-induced failure in dendritic cell (DCs) function affecting the generation of helper T cell responses. These T cells fail to help B cell responses, reducing the production of antibodies that are necessary to control malaria infection. This review focuses on our current understanding of the effect of Plasmodium parasite on DC function, DC-T cell interaction, and T cell activation. A better understanding of how parasites disrupt DC-T cell interactions will lead to new targets and approaches to reinstate adaptive immune responses and enhance parasite immunity.
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Affiliation(s)
- Rowland S Osii
- Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom.,KEMRI-CGMRC/Wellcome Trust Research Programme, Kilifi, Kenya
| | - Thomas D Otto
- Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Paul Garside
- Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Francis M Ndungu
- Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom.,KEMRI-CGMRC/Wellcome Trust Research Programme, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - James M Brewer
- Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom
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18
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Schmaler M, Orlova-Fink N, Rutishauser T, Abdulla S, Daubenberger C. Human unconventional T cells in Plasmodium falciparum infection. Semin Immunopathol 2020; 42:265-277. [PMID: 32076813 PMCID: PMC7223888 DOI: 10.1007/s00281-020-00791-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 02/07/2020] [Indexed: 12/22/2022]
Abstract
Malaria is an old scourge of humankind and has a large negative impact on the economic development of affected communities. Recent success in malaria control and reduction of mortality seems to have stalled emphasizing that our current intervention tools need to be complemented by malaria vaccines. Different populations of unconventional T cells such as mucosal-associated invariant T (MAIT) cells, invariant natural killer T (iNKT) cells and γδ T cells are gaining attention in the field of malaria immunology. Significant advances in our basic understanding of unconventional T cell biology in rodent malaria models have been made, however, their roles in humans during malaria are less clear. Unconventional T cells are abundant in skin, gut and liver tissues, and long-lasting expansions and functional alterations were observed upon malaria infection in malaria naïve and malaria pre-exposed volunteers. Here, we review the current understanding of involvement of unconventional T cells in anti-Plasmodium falciparum immunity and highlight potential future research avenues.
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Affiliation(s)
- Mathias Schmaler
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland
| | - Nina Orlova-Fink
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland
| | - Tobias Rutishauser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland
| | - Salim Abdulla
- Ifakara Health Institute, Bagamoyo Clinical Trial Unit, Bagamoyo, Tanzania
| | - Claudia Daubenberger
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland.
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19
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Glennon EKK, Austin LS, Arang N, Kain HS, Mast FD, Vijayan K, Aitchison JD, Kappe SHI, Kaushansky A. Alterations in Phosphorylation of Hepatocyte Ribosomal Protein S6 Control Plasmodium Liver Stage Infection. Cell Rep 2020; 26:3391-3399.e4. [PMID: 30893610 DOI: 10.1016/j.celrep.2019.02.085] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 10/11/2018] [Accepted: 02/21/2019] [Indexed: 12/11/2022] Open
Abstract
Plasmodium parasites are highly selective when infecting hepatocytes and induce many changes within the host cell upon infection. While several host cell factors have been identified that are important for liver infection, our understanding of what facilitates the maintenance of infection remains incomplete. Here, we describe a role for phosphorylated ribosomal protein S6 (Ser235/236) (p-RPS6) in Plasmodium yoelii-infected hepatocytes. Blocking RPS6 phosphorylation prior to infection decreases the number of liver stage parasites within 24 h. Infected hepatocytes exhibit elevated levels of p-RPS6 while simultaneously abrogating the induction of phosphorylation of RPS6 in response to insulin stimulation. This is in contrast with the regulation of p-RPS6 by Toxoplasma gondii, which elevates levels of p-RPS6 after infection but does not alter the response to insulin. Our data support a model in which RPS6 phosphorylation is uncoupled from canonical regulators in Plasmodium-infected hepatocytes and is relied on by the parasite to maintain infection.
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Affiliation(s)
- Elizabeth K K Glennon
- Center for Infectious Disease Research, Seattle, WA 98109, USA; Seattle Children's Research Institute, Seattle, WA 98109, USA; Department of Global Health, University of Washington, Seattle, WA 98109, USA
| | - Laura S Austin
- Center for Infectious Disease Research, Seattle, WA 98109, USA
| | - Nadia Arang
- Center for Infectious Disease Research, Seattle, WA 98109, USA
| | - Heather S Kain
- Center for Infectious Disease Research, Seattle, WA 98109, USA
| | - Fred D Mast
- Center for Infectious Disease Research, Seattle, WA 98109, USA; Seattle Children's Research Institute, Seattle, WA 98109, USA; Institute for Systems Biology, Seattle, WA 98109, USA
| | - Kamalakannan Vijayan
- Center for Infectious Disease Research, Seattle, WA 98109, USA; Seattle Children's Research Institute, Seattle, WA 98109, USA
| | - John D Aitchison
- Center for Infectious Disease Research, Seattle, WA 98109, USA; Seattle Children's Research Institute, Seattle, WA 98109, USA; Institute for Systems Biology, Seattle, WA 98109, USA
| | - Stefan H I Kappe
- Center for Infectious Disease Research, Seattle, WA 98109, USA; Seattle Children's Research Institute, Seattle, WA 98109, USA; Department of Global Health, University of Washington, Seattle, WA 98109, USA
| | - Alexis Kaushansky
- Center for Infectious Disease Research, Seattle, WA 98109, USA; Seattle Children's Research Institute, Seattle, WA 98109, USA; Department of Global Health, University of Washington, Seattle, WA 98109, USA.
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20
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Talman AM, Ouologuem DTD, Love K, Howick VM, Mulamba C, Haidara A, Dara N, Sylla D, Sacko A, Coulibaly MM, Dao F, Sangare CPO, Djimde A, Lawniczak MKN. Uptake of Plasmodium falciparum Gametocytes During Mosquito Bloodmeal by Direct and Membrane Feeding. Front Microbiol 2020; 11:246. [PMID: 32194521 PMCID: PMC7062676 DOI: 10.3389/fmicb.2020.00246] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 02/03/2020] [Indexed: 11/25/2022] Open
Abstract
Plasmodium falciparum remains one of the leading causes of child mortality, and nearly half of the world's population is at risk of contracting malaria. While pathogenesis results from replication of asexual forms in human red blood cells, it is the sexually differentiated forms, gametocytes, which are responsible for the spread of the disease. For transmission to succeed, both mature male and female gametocytes must be taken up by a female Anopheles mosquito during its blood meal for subsequent differentiation into gametes and mating inside the mosquito gut. Observed circulating numbers of gametocytes in the human host are often surprisingly low. A pre-fertilization behavior, such as skin sequestration, has been hypothesized to explain the efficiency of human-to-mosquito transmission but has not been sufficiently tested due to a lack of appropriate tools. In this study, we describe the optimization of a qPCR tool that enables the relative quantification of gametocytes within very small input samples. Such a tool allows for the quantification of gametocytes in different compartments of the host and the vector that could potentially unravel mechanisms that enable highly efficient malaria transmission. We demonstrate the use of our gametocyte quantification method in mosquito blood meals from both direct skin feeding on Plasmodium gametocyte carriers and standard membrane feeding assay. Relative gametocyte abundance was not different between mosquitoes fed through a membrane or directly on the skin suggesting that there is no systematic enrichment of gametocytes picked up in the skin.
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Affiliation(s)
- Arthur M. Talman
- Wellcome Sanger Institute, Hinxton, United Kingdom
- MIVEGEC, IRD, CNRS, University of Montpellier, Montpellier, France
| | - Dinkorma T. D. Ouologuem
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Katie Love
- Wellcome Sanger Institute, Hinxton, United Kingdom
| | | | | | - Aboubecrin Haidara
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Niawanlou Dara
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Daman Sylla
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Adama Sacko
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Mamadou M. Coulibaly
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Francois Dao
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Cheick P. O. Sangare
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Abdoulaye Djimde
- Malaria Research and Training Centre, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
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21
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De Niz M, Meehan GR, Tavares J. Intravital microscopy: Imaging host-parasite interactions in lymphoid organs. Cell Microbiol 2019; 21:e13117. [PMID: 31512335 DOI: 10.1111/cmi.13117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/25/2019] [Accepted: 09/01/2019] [Indexed: 12/11/2022]
Abstract
Intravital microscopy allows imaging of biological phenomena within living animals, including host-parasite interactions. This has advanced our understanding of both, the function of lymphoid organs during parasitic infections, and the effect of parasites on such organs to allow their survival. In parasitic research, recent developments in this technique have been crucial for the direct study of host-parasite interactions within organs at depths, speeds and resolution previously difficult to achieve. Lymphoid organs have gained more attention as we start to understand their function during parasitic infections and the effect of parasites on them. In this review, we summarise technical and biological findings achieved by intravital microscopy with respect to the interaction of various parasites with host lymphoid organs, namely the bone marrow, thymus, lymph nodes, spleen and the mucosa-associated lymphoid tissue, and present a view into possible future applications.
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Affiliation(s)
- Mariana De Niz
- Institute of Cell Biology, Heussler Lab, University of Bern, Bern, Switzerland
| | - Gavin R Meehan
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Joana Tavares
- i3S-Instituto de Investigação e Inovação em Saúde, University of Porto, Porto, Portugal.,IBMC-Instituto de Biologia Molecular e Celular, University of Porto, Porto, Portugal
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22
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De Niz M, Meehan GR, Brancucci NM, Marti M, Rotureau B, Figueiredo LM, Frischknecht F. Intravital imaging of host-parasite interactions in skin and adipose tissues. Cell Microbiol 2019; 21:e13023. [PMID: 30825872 PMCID: PMC6590052 DOI: 10.1111/cmi.13023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 02/06/2019] [Accepted: 02/08/2019] [Indexed: 12/20/2022]
Abstract
Intravital microscopy allows the visualisation of how pathogens interact with host cells and tissues in living animals in real time. This method has enabled key advances in our understanding of host-parasite interactions under physiological conditions. A combination of genetics, microscopy techniques, and image analysis have recently facilitated the understanding of biological phenomena in living animals at cellular and subcellular resolution. In this review, we summarise findings achieved by intravital microscopy of the skin and adipose tissues upon infection with various parasites, and we present a view into possible future applications of this method.
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Affiliation(s)
- Mariana De Niz
- Institute of Cell Biology, Heussler GroupUniversity of BernBernSwitzerland
- Wellcome Centre for Integrative ParasitologyUniversity of GlasgowGlasgowUK
| | - Gavin R. Meehan
- Wellcome Centre for Integrative ParasitologyUniversity of GlasgowGlasgowUK
| | - Nicolas M.B. Brancucci
- Malaria Gene Regulation Unit, Department of Medical Parasitology and Infection BiologySwiss Tropical and Public Health InstituteBaselSwitzerland
- University of BaselBaselSwitzerland
| | - Matthias Marti
- Wellcome Centre for Integrative ParasitologyUniversity of GlasgowGlasgowUK
| | - Brice Rotureau
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, Department of Parasites and Insect Vectors, INSERM U1201Institut PasteurParisFrance
| | - Luisa M. Figueiredo
- Faculdade de Medicina, Instituto de Medicina Molecular João Lobo AntunesUniversidade de LisboaLisbonPortugal
| | - Friedrich Frischknecht
- Integrative Parasitology, Centre for Infectious DiseasesUniversity of Heidelberg Medical SchoolHeidelbergGermany
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23
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Winkel BM, de Korne CM, van Oosterom MN, Staphorst D, Bunschoten A, Langenberg MC, Chevalley-Maurel SC, Janse CJ, Franke-Fayard B, van Leeuwen FW, Roestenberg M. A tracer-based method enables tracking of Plasmodium falciparum malaria parasites during human skin infection. Theranostics 2019; 9:2768-2778. [PMID: 31244921 PMCID: PMC6568182 DOI: 10.7150/thno.33467] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 02/22/2019] [Indexed: 11/10/2022] Open
Abstract
Introduction: The skin stage of malaria is a vital and vulnerable migratory life stage of the parasite. It has been characterised in rodent models, but remains wholly uninvestigated for human malaria parasites. To enable in depth analysis of not genetically modified (non-GMO) Plasmodium falciparum (Pf) sporozoite behaviour in human skin, we devised a labelling technology (Cy5M2, targeting the sporozoite mitochondrion) that supports tracking of individual non-GMO sporozoites in human skin. Methods: Sporozoite labelling with Cy5M2 was performed in vitro as well as via the feed of infected Anopheles mosquitos. Labelling was validated using confocal microscopy and flow cytometry and the fitness of labelled sporozoites was determined by analysis of infectivity to human hepatocytes in vitro, and in vivo in a rodent infection model. Using confocal video microscopy and custom software, single-sporozoite tracking studies in human skin-explants were performed. Results: Both in vitro and in mosquito labelling strategies yielded brightly fluorescent sporozoites of three different Plasmodium species. Cy5M2 uptake colocalized with MitoTracker® green and could be blocked using the known Translocator protein (TSPO)-inhibitor PK11195. This method supported the visualization and subsequent quantitative analysis of the migration patterns of individual non-GMO Pf sporozoites in human skin and did not affect the fitness of sporozoites. Conclusions: The ability to label and image non-GMO Plasmodium sporozoites provides the basis for detailed studies on the human skin stage of malaria with potential for in vivo translation. As such, it is an important tool for development of vaccines based on attenuated sporozoites and their route of administration.
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Affiliation(s)
- Béatrice M.F. Winkel
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
- Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Clarize M. de Korne
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
- Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Matthias N. van Oosterom
- Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Diego Staphorst
- Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Anton Bunschoten
- Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
- Laboratory of BioNanoTechnology Wageningen University and Research, Droevendaalsesteeg 4, 6708 PB Wageningen, The Netherlands
| | - Marijke C.C. Langenberg
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | | | - Chris J. Janse
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Blandine Franke-Fayard
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Fijs W.B. van Leeuwen
- Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Meta Roestenberg
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
- Department of Infectious Diseases, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
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24
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Intravital imaging of skin infections. Cell Immunol 2019; 350:103913. [PMID: 30992120 DOI: 10.1016/j.cellimm.2019.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 02/11/2019] [Accepted: 04/01/2019] [Indexed: 11/23/2022]
Abstract
Intravital imaging of cutaneous immune responses has revealed intricate links between the skin's structural properties, the immune cells that reside therein, and the carefully orchestrated migratory dynamics that enable rapid sensing and subsequent elimination of skin pathogens. In particular, the development of 2-photon intravital microscopy (2P-IVM), which enables the excitation of fluorescent molecules within deep tissue with minimal light scattering and tissue damage, has proven an invaluable tool in the characterization of different cell subset's roles in skin infection. The ability to visualize cells, tissue structures, pathogens and track migratory dynamics at designated times following infection, or during inflammatory responses has been crucial in defining how immune responses in the skin are coordinated, either locally or in concert with circulating immune cells. Skin pathogens affect millions of people worldwide, and skin infections leading to cutaneous pathology have a considerable impact on the quality of life and longevity of people affected. In contrast, pathogens that infect the skin to later cause systemic illness, such as malaria parasites and a variety of arthropod-borne viruses, or infection in distant anatomical sites are a significant cause of morbidity and mortality worldwide. Here, we review recent advances and seminal studies that employed intravital imaging to characterize key immune response mechanisms in the context of viral, bacterial and parasitic skin infections, and provide insights on skin pathogens of global significance that would benefit from such investigative approaches.
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25
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Aliprandini E, Tavares J, Panatieri RH, Thiberge S, Yamamoto MM, Silvie O, Ishino T, Yuda M, Dartevelle S, Traincard F, Boscardin SB, Amino R. Cytotoxic anti-circumsporozoite antibodies target malaria sporozoites in the host skin. Nat Microbiol 2018; 3:1224-1233. [PMID: 30349082 DOI: 10.1038/s41564-018-0254-z] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 08/28/2018] [Indexed: 01/09/2023]
Abstract
The circumsporozoite protein (CSP) is the major surface protein of malaria sporozoites (SPZs), the motile and invasive parasite stage inoculated in the host skin by infected mosquitoes. Antibodies against the central CSP repeats of different plasmodial species are known to block SPZ infectivity1-5, but the precise mechanism by which these effectors operate is not completely understood. Here, using a rodent Plasmodium yoelii malaria model, we show that sterile protection mediated by anti-P. yoelii CSP humoral immunity depends on the parasite inoculation into the host skin, where antibodies inhibit motility and kill P. yoelii SPZs via a characteristic 'dotty death' phenotype. Passive transfer of an anti-repeat monoclonal antibody (mAb) recapitulates the skin inoculation-dependent protection, in a complement- and Fc receptor γ-independent manner. This purified mAb also decreases motility and, notably, induces the dotty death of P. yoelii SPZs in vitro. Cytotoxicity is species-transcendent since cognate anti-CSP repeat mAbs also kill Plasmodium berghei and Plasmodium falciparum SPZs. mAb cytotoxicity requires the actomyosin motor-dependent translocation and stripping of the protective CSP surface coat, rendering the parasite membrane susceptible to the SPZ pore-forming-like protein secreted to wound and traverse the host cell membrane6. The loss of SPZ fitness caused by anti-P. yoelii CSP repeat antibodies is thus a dynamic process initiated in the host skin where SPZs either stop moving7, or migrate and traverse cells to progress through the host tissues7-9 at the eventual expense of their own life.
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Affiliation(s)
| | - Joana Tavares
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Raquel Hoffmann Panatieri
- Unit of Malaria Infection & Immunity, Institut Pasteur, Paris, France.,Parasitology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Sabine Thiberge
- Unit of Malaria Infection & Immunity, Institut Pasteur, Paris, France.,Centre de Production et d'Infection des Anophèles, Institut Pasteur, Paris, France
| | - Marcio Massao Yamamoto
- Parasitology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Olivier Silvie
- Sorbonne Université, INSERM, CNRS, Centre d'Immunologie et des Maladies Infectieuses, CIMI, Paris, France
| | - Tomoko Ishino
- Department of Molecular Parasitology, Ehime University, Ehime, Japan
| | - Masao Yuda
- Department of Medical Zoology, Mie University School of Medicine, Mie, Japan
| | - Sylvie Dartevelle
- Plateforme d'Ingénierie des Anticorps, Institut Pasteur, Paris, France
| | | | - Silvia Beatriz Boscardin
- Parasitology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
| | - Rogerio Amino
- Unit of Malaria Infection & Immunity, Institut Pasteur, Paris, France.
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26
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Markus MB. New Evidence for Hypnozoite-Independent Plasmodium vivax Malarial Recurrences. Trends Parasitol 2018; 34:1015-1016. [PMID: 30213708 DOI: 10.1016/j.pt.2018.08.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 08/27/2018] [Indexed: 10/28/2022]
Abstract
Information provided in recent, related papers has wide-ranging implications concerning, inter alia, the transmission of malaria, drug treatment, and eradication of the disease. Additionally, the research results represent support for the idea that recurrences of Plasmodium vivax malaria can arise from both liver hypnozoites and extravascular merozoites in bone marrow.
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Affiliation(s)
- Miles B Markus
- School of Animal, Plant and Environmental Sciences, Faculty of Science, University of Witwatersrand, Johannesburg, South Africa; Wits Research Institute for Malaria, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa.
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27
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Minkah NK, Schafer C, Kappe SHI. Humanized Mouse Models for the Study of Human Malaria Parasite Biology, Pathogenesis, and Immunity. Front Immunol 2018; 9:807. [PMID: 29725334 PMCID: PMC5917005 DOI: 10.3389/fimmu.2018.00807] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 04/03/2018] [Indexed: 12/25/2022] Open
Abstract
Malaria parasite infection continues to inflict extensive morbidity and mortality in resource-poor countries. The insufficiently understood parasite biology, continuously evolving drug resistance and the lack of an effective vaccine necessitate intensive research on human malaria parasites that can inform the development of new intervention tools. Humanized mouse models have been greatly improved over the last decade and enable the direct study of human malaria parasites in vivo in the laboratory. Nevertheless, no small animal model developed so far is capable of maintaining the complete life cycle of Plasmodium parasites that infect humans. The ultimate goal is to develop humanized mouse systems in which a Plasmodium infection closely reproduces all stages of a parasite infection in humans, including pre-erythrocytic infection, blood stage infection and its associated pathology, transmission as well as the human immune response to infection. Here, we discuss current humanized mouse models and the future directions that should be taken to develop next-generation models for human malaria parasite research.
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Affiliation(s)
- Nana K Minkah
- Center for Infectious Disease Research, Seattle, WA, United States
| | - Carola Schafer
- Center for Infectious Disease Research, Seattle, WA, United States
| | - Stefan H I Kappe
- Center for Infectious Disease Research, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States
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28
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Abstract
A curious aspect of the evolution of the hypnozoite theory of malarial relapse is its transmogrification from theory into 'fact', this being of historical, linguistic, scientific and sociological interest. As far as it goes, the hypnozoite explanation for relapse is almost certainly correct. I contend, however, that many of the genotypically homologous, non-reinfection, relapse-like Plasmodium vivax recurrences that researchers ascribe to hypnozoite activation are probably hypnozoite-independent. Indeed, some malariologists are starting to recognize that homologous P. vivax recurrences have most likely been overattributed to activation of hypnozoites. Hitherto identified, non-hypnozoite, possible plasmodial sources of recurrence that must be considered, besides circulating erythrocytic stages, include parasites in splenic dendritic cells, other cells in the spleen (in addition to infected erythrocytes there), bone marrow (importantly) and the skin. I argue that we need to take into account the possibility of a dual or multiple extra-vascular origin of P. vivax non-reinfection recurrences, not arbitrarily discount it. The existence of a P. vivax reservoir(s) is a topical subject and one of practical importance for malaria eradication. Pertinent drug-associated matters are also discussed, as is the dormancy-related significance of clues provided by blood-stage-induced malarial infection.
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29
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Immunological bases of increased susceptibility to invasive nontyphoidal Salmonella infection in children with malaria and anaemia. Microbes Infect 2017; 20:589-598. [PMID: 29248635 PMCID: PMC6250906 DOI: 10.1016/j.micinf.2017.11.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 11/17/2017] [Accepted: 11/20/2017] [Indexed: 01/01/2023]
Abstract
Malaria and anaemia are key underlying factors for iNTS disease in African children. Knowledge of clinical and epidemiological risk-factors for iNTS disease has not been paralleled by an in-depth knowledge of the immunobiology of the disease. Herein, we review human and animal studies on mechanisms of increased susceptibility to iNTS in children.
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30
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Abstract
Basic science holds enormous power for revealing the biological mechanisms of disease and, in turn, paving the way toward new, effective interventions. Recognizing this power, the 2011 Research Agenda for Malaria Eradication included key priorities in fundamental research that, if attained, could help accelerate progress toward disease elimination and eradication. The Malaria Eradication Research Agenda (malERA) Consultative Panel on Basic Science and Enabling Technologies reviewed the progress, continuing challenges, and major opportunities for future research. The recommendations come from a literature of published and unpublished materials and the deliberations of the malERA Refresh Consultative Panel. These areas span multiple aspects of the Plasmodium life cycle in both the human host and the Anopheles vector and include critical, unanswered questions about parasite transmission, human infection in the liver, asexual-stage biology, and malaria persistence. We believe an integrated approach encompassing human immunology, parasitology, and entomology, and harnessing new and emerging biomedical technologies offers the best path toward addressing these questions and, ultimately, lowering the worldwide burden of malaria.
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31
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Tavares J, Costa DM, Teixeira AR, Cordeiro-da-Silva A, Amino R. In vivo imaging of pathogen homing to the host tissues. Methods 2017; 127:37-44. [PMID: 28522323 DOI: 10.1016/j.ymeth.2017.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 04/19/2017] [Accepted: 05/10/2017] [Indexed: 12/19/2022] Open
Abstract
Hematogenous dissemination followed by tissue tropism is a characteristic of the infectious process of many pathogens including those transmitted by blood-feeding vectors. After entering into the blood circulation, these pathogens must arrest in the target organ before they infect a specific tissue. Here, we describe a non-invasive method to visualize and quantify the homing of pathogens to the host tissues. By using in vivo bioluminescence imaging we quantify the accumulation of luciferase-expressing parasites in the host organs during the first minutes following their intravascular inoculation in mice. Using this technique we show that in the malarial infection, once in the blood circulation, most of bioluminescent Plasmodium berghei sporozoites, the parasite stage transmitted to the host skin by a mosquito bite, rapidly home to the liver where they invade and develop inside hepatocytes. This homing is specific to this developmental stage since blood stage parasites do not accumulate in the liver, as well as extracellular Trypanosoma brucei bloodstream forms and liver-infecting Leishmania infantum amastigotes. Finally, this method can be used to study the dynamics of tissue tropism of parasites, dissect the molecular and cellular basis of their increased arrest in organs and to evaluate immune interventions designed to block this targeted interaction.
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Affiliation(s)
- Joana Tavares
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal.
| | - David Mendes Costa
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal
| | - Ana Rafaela Teixeira
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal
| | - Anabela Cordeiro-da-Silva
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal; Faculdade de Farmácia da Universidade do Porto, Departamento de Ciências Biológicas, Portugal
| | - Rogerio Amino
- Unit of Malaria Infection and Immunity, Institut Pasteur, Paris, France.
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Frischknecht F, Matuschewski K. Plasmodium Sporozoite Biology. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a025478. [PMID: 28108531 DOI: 10.1101/cshperspect.a025478] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Plasmodium sporozoite transmission is a critical population bottleneck in parasite life-cycle progression and, hence, a target for prophylactic drugs and vaccines. The recent progress of a candidate antisporozoite subunit vaccine formulation to licensure highlights the importance of sporozoite transmission intervention in the malaria control portfolio. Sporozoites colonize mosquito salivary glands, migrate through the skin, penetrate blood vessels, breach the liver sinusoid, and invade hepatocytes. Understanding the molecular and cellular mechanisms that mediate the remarkable sporozoite journey in the invertebrate vector and the vertebrate host can inform evidence-based next-generation drug development programs and immune intervention strategies.
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Affiliation(s)
- Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, University of Heidelberg Medical School, 69120 Heidelberg, Germany
| | - Kai Matuschewski
- Department of Molecular Parasitology, Institute of Biology, Humboldt University Berlin, 10115 Berlin, Germany
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33
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Towards a Humanized Mouse Model of Liver Stage Malaria Using Ectopic Artificial Livers. Sci Rep 2017; 7:45424. [PMID: 28361899 PMCID: PMC5374446 DOI: 10.1038/srep45424] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 03/01/2017] [Indexed: 12/11/2022] Open
Abstract
The malaria liver stage is an attractive target for antimalarial development, and preclinical malaria models are essential for testing such candidates. Given ethical concerns and costs associated with non-human primate models, humanized mouse models containing chimeric human livers offer a valuable alternative as small animal models of liver stage human malaria. The best available human liver chimeric mice rely on cellular transplantation into mice with genetically engineered liver injury, but these systems involve a long and variable humanization process, are expensive, and require the use of breeding-challenged mouse strains which are not widely accessible. We previously incorporated primary human hepatocytes into engineered polyethylene glycol (PEG)-based nanoporous human ectopic artificial livers (HEALs), implanted them in mice without liver injury, and rapidly generated human liver chimeric mice in a reproducible and scalable fashion. By re-designing the PEG scaffold to be macroporous, we demonstrate the facile fabrication of implantable porous HEALs that support liver stage human malaria (P. falciparum) infection in vitro, and also after implantation in mice with normal liver function, 60% of the time. This proof-of-concept study demonstrates the feasibility of applying a tissue engineering strategy towards the development of scalable preclinical models of liver stage malaria infection for future applications.
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34
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López C, Yepes-Pérez Y, Hincapié-Escobar N, Díaz-Arévalo D, Patarroyo MA. What Is Known about the Immune Response Induced by Plasmodium vivax Malaria Vaccine Candidates? Front Immunol 2017; 8:126. [PMID: 28243235 PMCID: PMC5304258 DOI: 10.3389/fimmu.2017.00126] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 01/25/2017] [Indexed: 12/15/2022] Open
Abstract
Malaria caused by Plasmodium vivax continues being one of the most important infectious diseases around the world; P. vivax is the second most prevalent species and has the greatest geographic distribution. Developing an effective antimalarial vaccine is considered a relevant control strategy in the search for means of preventing the disease. Studying parasite-expressed proteins, which are essential in host cell invasion, has led to identifying the regions recognized by individuals who are naturally exposed to infection. Furthermore, immunogenicity studies have revealed that such regions can trigger a robust immune response that can inhibit sporozoite (hepatic stage) or merozoite (erythrocyte stage) invasion of a host cell and induce protection. This review provides a synthesis of the most important studies to date concerning the antigenicity and immunogenicity of both synthetic peptide and recombinant protein candidates for a vaccine against malaria produced by P. vivax.
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Affiliation(s)
- Carolina López
- Molecular Biology and Immunology Department, Fundación Instituto de Immunología de Colombia (FIDIC), Bogotá, Colombia; PhD Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Yoelis Yepes-Pérez
- Molecular Biology and Immunology Department, Fundación Instituto de Immunología de Colombia (FIDIC), Bogotá, Colombia; MSc Programme in Microbiology, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Natalia Hincapié-Escobar
- Molecular Biology and Immunology Department, Fundación Instituto de Immunología de Colombia (FIDIC) , Bogotá , Colombia
| | - Diana Díaz-Arévalo
- Molecular Biology and Immunology Department, Fundación Instituto de Immunología de Colombia (FIDIC), Bogotá, Colombia; Universidad de Ciencias Aplicadas y Ambientales (UDCA), Bogotá, Colombia
| | - Manuel A Patarroyo
- Molecular Biology and Immunology Department, Fundación Instituto de Immunología de Colombia (FIDIC), Bogotá, Colombia; Basic Sciences Department, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia
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35
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Sant'Anna MRV, Soares AC, Araujo RN, Gontijo NF, Pereira MH. Triatomines (Hemiptera, Reduviidae) blood intake: Physical constraints and biological adaptations. JOURNAL OF INSECT PHYSIOLOGY 2017; 97:20-26. [PMID: 27521585 DOI: 10.1016/j.jinsphys.2016.08.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 08/05/2016] [Accepted: 08/09/2016] [Indexed: 06/06/2023]
Abstract
In order to efficiently obtain blood from their vertebrate hosts, bloodsucking arthropods have undergone an evolutionary selection process leading to specialist adaptations in their feeding apparatus (mouthparts and suction pumps) and salivary molecules. These adaptations act to counteract haemostasis, inflammation, and immune responses in their vertebrate hosts. The association of haematophagous arthropods with vertebrate hosts during a blood feed allows the transmission of pathogens between their hosts and vectors in a tripartite interaction. Feeding mechanisms in haematophagous arthropod species have been the subject of studies over at least eight decades worldwide, as a consequence of the importance of vector-borne diseases and their impact on human health. Here we review studies of the feeding mechanisms of triatomine bugs, with a particular focus on factors that influence their feeding performance when obtaining a blood meal from different vertebrate hosts.
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Affiliation(s)
- Maurício Roberto Viana Sant'Anna
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Campus Pampulha, Belo Horizonte CEP 31270-901, Brazil
| | - Adriana Coelho Soares
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Campus Pampulha, Belo Horizonte CEP 31270-901, Brazil
| | - Ricardo Nascimento Araujo
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Campus Pampulha, Belo Horizonte CEP 31270-901, Brazil
| | - Nelder Figueiredo Gontijo
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Campus Pampulha, Belo Horizonte CEP 31270-901, Brazil
| | - Marcos Horácio Pereira
- Laboratório de Fisiologia de Insetos Hematófagos, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Campus Pampulha, Belo Horizonte CEP 31270-901, Brazil.
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36
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Jimah JR, Salinas ND, Sala-Rabanal M, Jones NG, Sibley LD, Nichols CG, Schlesinger PH, Tolia NH. Malaria parasite CelTOS targets the inner leaflet of cell membranes for pore-dependent disruption. eLife 2016; 5. [PMID: 27906127 PMCID: PMC5132341 DOI: 10.7554/elife.20621] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 11/14/2016] [Indexed: 01/02/2023] Open
Abstract
Apicomplexan parasites contain a conserved protein CelTOS that, in malaria parasites, is essential for traversal of cells within the mammalian host and arthropod vector. However, the molecular role of CelTOS is unknown because it lacks sequence similarity to proteins of known function. Here, we determined the crystal structure of CelTOS and discovered CelTOS resembles proteins that bind to and disrupt membranes. In contrast to known membrane disruptors, CelTOS has a distinct architecture, specifically binds phosphatidic acid commonly present within the inner leaflet of plasma membranes, and potently disrupts liposomes composed of phosphatidic acid by forming pores. Microinjection of CelTOS into cells resulted in observable membrane damage. Therefore, CelTOS is unique as it achieves nearly universal inner leaflet cellular activity to enable the exit of parasites from cells during traversal. By providing novel molecular insight into cell traversal by apicomplexan parasites, our work facilitates the design of therapeutics against global pathogens.
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Affiliation(s)
- John R Jimah
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Nichole D Salinas
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Monica Sala-Rabanal
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, United States.,Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, Saint Louis, United States
| | - Nathaniel G Jones
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Colin G Nichols
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, United States.,Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, Saint Louis, United States
| | - Paul H Schlesinger
- Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, United States
| | - Niraj H Tolia
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States.,Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, United States
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Abstract
Over the past decade, major advances in imaging techniques have enhanced our understanding of Plasmodium spp. parasites and their interplay with mammalian hosts and mosquito vectors. Cryoelectron tomography, cryo-X-ray tomography and super-resolution microscopy have shifted paradigms of sporozoite and gametocyte structure, the process of erythrocyte invasion by merozoites, and the architecture of Maurer's clefts. Intravital time-lapse imaging has been revolutionary for our understanding of pre-erythrocytic stages of rodent Plasmodium parasites. Furthermore, high-speed imaging has revealed the link between sporozoite structure and motility, and improvements in time-lapse microscopy have enabled imaging of the entire Plasmodium falciparum erythrocytic cycle and the complete Plasmodium berghei pre-erythrocytic stages for the first time. In this Review, we discuss the contribution of key imaging tools to these and other discoveries in the malaria field over the past 10 years.
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38
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Mac-Daniel L, Buckwalter MR, Gueirard P, Ménard R. Myeloid Cell Isolation from Mouse Skin and Draining Lymph Node Following Intradermal Immunization with Live Attenuated Plasmodium Sporozoites. J Vis Exp 2016. [PMID: 27286053 DOI: 10.3791/53796] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Malaria infection begins when the sporozoite stage of Plasmodium is inoculated into the skin of a mammalian host through a mosquito bite. The highly motile parasite not only reaches the liver to invade hepatocytes and transform into erythrocyte-infective form. It also migrates into the skin and to the proximal lymph node draining the injection site, where it can be recognized and degraded by resident and/or recruited myeloid cells. Intravital imaging reported the early recruitment of brightly fluorescent Lys-GFP positive leukocytes in the skin and the interactions between sporozoites and CD11c(+) cells in the draining lymph node. We present here an efficient procedure to recover, identify and enumerate the myeloid cell subsets that are recruited to the mouse skin and draining lymph node following intradermal injection of immunizing doses of sporozoites in a murine model. Phenotypic characterization using multi-parametric flow cytometry provides a reliable assay to assess early dynamic cellular changes during inflammatory response to Plasmodium infection.
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Affiliation(s)
| | | | | | - Robert Ménard
- Unité de Biologie et Génétique du Paludisme, Institut Pasteur;
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39
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Carvalho TG, Morahan B, John von Freyend S, Boeuf P, Grau G, Garcia-Bustos J, Doerig C. The ins and outs of phosphosignalling in Plasmodium: Parasite regulation and host cell manipulation. Mol Biochem Parasitol 2016; 208:2-15. [PMID: 27211241 DOI: 10.1016/j.molbiopara.2016.05.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 05/16/2016] [Indexed: 12/15/2022]
Abstract
Signal transduction and kinomics have been rapidly expanding areas of investigation within the malaria research field. Here, we provide an overview of phosphosignalling pathways that operate in all stages of the Plasmodium life cycle. We review signalling pathways in the parasite itself, in the cells it invades, and in other cells of the vertebrate host with which it interacts. We also discuss the potential of these pathways as novel targets for antimalarial intervention.
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Affiliation(s)
- Teresa Gil Carvalho
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Belinda Morahan
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Simona John von Freyend
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Philippe Boeuf
- Burnet Institute, Melbourne, Victoria 3004, Australia; The University of Melbourne, Department of Medicine, Melbourne, Victoria 3010, Australia; Victorian Infectious Diseases Service, Royal Melbourne Hospital, Melbourne, Victoria 3010, Australia
| | - Georges Grau
- Vascular Immunology Unit, Department of Pathology, Sydney Medical School, University of Sydney, Camperdown, New South Wales 2050, Australia
| | - Jose Garcia-Bustos
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Victoria 3800, Australia
| | - Christian Doerig
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Victoria 3800, Australia.
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40
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Richter J, Franken G, Holtfreter MC, Walter S, Labisch A, Mehlhorn H. Clinical implications of a gradual dormancy concept in malaria. Parasitol Res 2016; 115:2139-48. [PMID: 27079460 DOI: 10.1007/s00436-016-5043-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 04/07/2016] [Indexed: 12/15/2022]
Abstract
Malaria recurrences after an initially successful therapy and malarial fever occurring a long time after infection are well-known problems in malariology. Currently, two distinct types of malaria recurrences are defined: recrudescence and relapse. A recrudescence is thought to originate from circulating Plasmodium blood stages which do not cause fever before a certain level of a microscopically detectable parasitemia is reached. Contrary, a relapse is thought to originate from quiescent intracellular hepatic parasite stages called hypnozoites. Recrudescences would typically occur in infections due to Plasmodium falciparum. Plasmodium knowlesi, and Plasmodium malariae, whereas relapses would be caused exclusively by Plasmodium vivax and Plasmodium ovale. This schematic view is, however, insufficiently supported by experimental evidence. For instance, hypnozoites of P. ovale have never been experimentally documented. On the other hand, the nonfinding of P. malariae hypnozoites turned into the proof for the nonexistence of P. malariae hypnozoites. Clinical relapse-type recurrences have been observed in both P. ovale and P. malariae infections, and decade-long incubation times have also been reported in P. falciparum infections. We propose a gradual hypothesis in accordance with the continuity concept of biological evolution: both, relapse and recrudescence may be potentially caused by all Plasmodium spp. We hypothesize that the difference between the various Plasmodium spp. is quantitative rather than qualitative: there are Plasmodium spp. which frequently cause relapses such as P. vivax, particularly the P.v. Chesson strain, species which cause relapses less frequently, such as P. ovale and sometimes P. malariae, and species which may exceptionally cause relapses such as P. falciparum. All species may cause recrudescences. As clinical consequences, we propose that 8-aminquinolines may be considered in a relapse-type recrudescence regardless of the causal Plasmodium sp., whereas primaquine relapse prevention might not be routinely indicated in malaria due to P. ovale.
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Affiliation(s)
- Joachim Richter
- Tropical Medicine Unit, Department for Gastroenterology, Hepatology and Infectious Diseases, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany.
| | - Gabriele Franken
- Institute for the History of Medicine, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Martha C Holtfreter
- Tropical Medicine Unit, Department for Gastroenterology, Hepatology and Infectious Diseases, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Susanne Walter
- Institute for Zoomorphology, Cell Biology and Parasitology, Faculty of Biology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Alfons Labisch
- Institute for the History of Medicine, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Heinz Mehlhorn
- Institute for Zoomorphology, Cell Biology and Parasitology, Faculty of Biology, Heinrich-Heine-University, Düsseldorf, Germany
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41
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Denny JE, Powell WL, Schmidt NW. Local and Long-Distance Calling: Conversations between the Gut Microbiota and Intra- and Extra-Gastrointestinal Tract Infections. Front Cell Infect Microbiol 2016; 6:41. [PMID: 27148490 PMCID: PMC4826874 DOI: 10.3389/fcimb.2016.00041] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 03/22/2016] [Indexed: 12/12/2022] Open
Abstract
Preservation of health from infectious diseases depends upon both mucosal and systemic immunity via the collaborative effort of innate and adaptive immune responses. The proficiency of host immunity stems from robust defense mechanisms—physical barriers and specialized immune cells—and a failure of these mechanisms leads to pathology. Intriguingly, immunocompetence to pathogens can be shaped by the gut microbiome as recent publications highlight a dynamic interplay between the gut microbiome and host susceptibility to infection. Modulation of host immunity to enteric pathogens has long been studied where gut bacteria shape multiple facts of both innate and adaptive immunity. Conversely, the impact of gut commensals on host immunity to extra-gastrointestinal (GI) tract infections has only recently been recognized. In this context, the gut microbiome can augment host immunity to extra-GI tract bacterial, viral, and parasitic pathogens. This review explores the research that affords insight into the role of the gut microbiome in various infectious diseases, with a particular emphasis on extra-GI tract infections. A better understanding of the link between the gut microbiome and infectious disease will be critical for improving global health in the years ahead.
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Affiliation(s)
- Joshua E Denny
- Department of Microbiology and Immunology, University of Louisville Louisville, KY, USA
| | - Whitney L Powell
- Department of Microbiology and Immunology, University of Louisville Louisville, KY, USA
| | - Nathan W Schmidt
- Department of Microbiology and Immunology, University of Louisville Louisville, KY, USA
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42
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Kaushansky A, Kappe SH. Selection and refinement: the malaria parasite's infection and exploitation of host hepatocytes. Curr Opin Microbiol 2015; 26:71-8. [PMID: 26102161 DOI: 10.1016/j.mib.2015.05.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 05/16/2015] [Accepted: 05/22/2015] [Indexed: 01/23/2023]
Abstract
Plasmodium parasites belong to the Apicomplexan phylum, which consists mostly of obligate intracellular pathogens that vary dramatically in host cell tropism. Plasmodium sporozoites are highly hepatophilic. The specific molecular mechanisms, which facilitate sporozoite selection and successful infection of hepatocytes, remain poorly defined. Here, we discuss the parasite and host factors which are critical to hepatocyte infection. We derive a model where sporozoites initially select host cells that constitute a permissive environment and then further refine the chosen hepatocyte during liver stage development, ensuring life cycle progression. While many unknowns of pre-erythrocytic infection remain, advancing models and technologies that enable analysis of human malaria parasites and of single infected cells will catalyze a comprehensive understanding of the interaction between the malaria parasite and its hepatocyte host.
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Affiliation(s)
- Alexis Kaushansky
- Center for Infectious Disease Research, Formerly Seattle Biomedical Research Institute, 307 Westlake Ave. N, #500, Seattle, WA 98109, United States.
| | - Stefan Hi Kappe
- Center for Infectious Disease Research, Formerly Seattle Biomedical Research Institute, 307 Westlake Ave. N, #500, Seattle, WA 98109, United States; Department of Global Health, University of Washington, Seattle, WA, United States.
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43
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Markus MB. Do hypnozoites cause relapse in malaria? Trends Parasitol 2015; 31:239-45. [DOI: 10.1016/j.pt.2015.02.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/01/2015] [Accepted: 02/20/2015] [Indexed: 12/25/2022]
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44
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Radtke AJ, Tse SW, Zavala F. From the draining lymph node to the liver: the induction and effector mechanisms of malaria-specific CD8+ T cells. Semin Immunopathol 2015; 37:211-20. [PMID: 25917387 PMCID: PMC5600878 DOI: 10.1007/s00281-015-0479-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 03/15/2015] [Indexed: 10/23/2022]
Abstract
Parasitic protozoa cause considerable disease in humans and, due to their intracellular life cycle, induce robust CD8(+) T cell responses. A greater understanding of the factors that promote and maintain CD8(+) T cell-mediated immunity against these pathogens is likely needed for the development of effective vaccines. Immunization with radiation-attenuated sporozoites, the infectious stage of the malaria parasite transmitted by mosquitoes, is an excellent model to study these questions as CD8(+) T cells specific for a single epitope can completely eliminate parasite infection in the liver. Furthermore, live, radiation-attenuated parasites represent the "gold standard" for malaria vaccination. Here, we will highlight recent studies aimed at understanding the factors required for the induction, recruitment, and maintenance of effector and memory CD8(+) T cells against malaria liver stages.
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Affiliation(s)
- Andrea J. Radtke
- Lymphocyte Biology Section, Laboratory of Systems Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sze-Wah Tse
- Program in Cellular and Molecular Medicine of Children’s Hospital Boston, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Fidel Zavala
- Johns Hopkins Malaria Research Institute and Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
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45
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Mo AXY, Pesce J, Hall BF. Exploring immunological mechanisms of the whole sporozoite vaccination against P. falciparum malaria. Vaccine 2015; 33:2851-7. [PMID: 25917675 DOI: 10.1016/j.vaccine.2015.04.056] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 03/13/2015] [Accepted: 04/13/2015] [Indexed: 11/24/2022]
Abstract
Great progress has been made in the development of whole sporozoite vaccines including the manufacturing of cryopreserved Plasmodium falciparum sporozoites (PfSPZ) suitable for clinical application. Such whole sporozoites are being used for clinical studies of controlled human malaria infection (CHMI) as well as for evaluation of candidate vaccine approaches (both attenuated sporozoites and infectious sporozoites administered with chemoprophylaxis) and as reagents for immunology and cell biology assays. CHMI studies with whole sporozoites provide a great opportunity to better understand the intrinsic mechanisms of resistance to P. falciparum (e.g. due to sickle cell trait and other hemoglobinopathies) as well as host responses to an initial P. falciparum infection. High-level protective efficacy has been demonstrated in a small number of volunteers after intravenous (IV) inoculation of radiation-attenuated PfSPZ or in those who were exposed to live PfSPZ while on malaria chemoprophylaxis. These advances and data warrant further investigations of the immunological mechanism(s) whereby whole sporozoite inoculation elicits protective immunity in order to facilitate whole sporozoite vaccine development. The National Institute of Allergy and Infectious Diseases (NIAID) convened a workshop on Sept. 2-3, 2014 involving participation of international experts in the field of malaria vaccine development, and in basic and clinical immunology research. The workshop discussed the current understanding of host immune responses to whole malaria sporozoite inoculation, identified gaps in knowledge, resources to facilitate progress, and applicable new technologies and approaches to accelerate immunologic and vaccinologic studies and biomarker identification. This report summarizes the discussions and major conclusions from the workshop participants.
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Affiliation(s)
- Annie X Y Mo
- National Institute of Allergy and Infectious Diseases (NIAID), National Institute of Health, Department of Health and Human Service, 5601 Fishers Lane, Rockville, MD 20852, USA.
| | - John Pesce
- National Institute of Allergy and Infectious Diseases (NIAID), National Institute of Health, Department of Health and Human Service, 5601 Fishers Lane, Rockville, MD 20852, USA
| | - B Fenton Hall
- National Institute of Allergy and Infectious Diseases (NIAID), National Institute of Health, Department of Health and Human Service, 5601 Fishers Lane, Rockville, MD 20852, USA
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46
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Radtke AJ, Kastenmüller W, Espinosa DA, Gerner MY, Tse SW, Sinnis P, Germain RN, Zavala FP, Cockburn IA. Lymph-node resident CD8α+ dendritic cells capture antigens from migratory malaria sporozoites and induce CD8+ T cell responses. PLoS Pathog 2015; 11:e1004637. [PMID: 25658939 PMCID: PMC4450069 DOI: 10.1371/journal.ppat.1004637] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 12/19/2014] [Indexed: 01/08/2023] Open
Abstract
Malaria infection begins when a female Anopheles mosquito injects Plasmodium sporozoites into the skin of its host during blood feeding. Skin-deposited sporozoites may enter the bloodstream and infect the liver, reside and develop in the skin, or migrate to the draining lymph nodes (DLNs). Importantly, the DLN is where protective CD8+ T cell responses against malaria liver stages are induced after a dermal route of infection. However, the significance of parasites in the skin and DLN to CD8+ T cell activation is largely unknown. In this study, we used genetically modified parasites, as well as antibody-mediated immobilization of sporozoites, to determine that active sporozoite migration to the DLNs is required for robust CD8+ T cell responses. Through dynamic in vivo and static imaging, we show the direct uptake of parasites by lymph-node resident DCs followed by CD8+ T cell-DC cluster formation, a surrogate for antigen presentation, in the DLNs. A few hours after sporozoite arrival to the DLNs, CD8+ T cells are primed by resident CD8α+ DCs with no apparent role for skin-derived DCs. Together, these results establish a critical role for lymph node resident CD8α+ DCs in CD8+ T cell priming to sporozoite antigens while emphasizing a requirement for motile sporozoites in the induction of CD8+ T cell-mediated immunity. Malaria is responsible for the deaths of 0.5–2 million people each year. A safe and effective vaccine is likely needed for the control or eradication of malaria. Immunization with irradiated sporozoites, the infectious stage of the parasite transmitted by mosquitoes, protects people against malaria through the activation of specialized effector cells called CD8+ T cells, which can eliminate live parasites. The induction of such malaria-specific CD8+ T cells is critically dependent on dendritic cells, a diverse population of antigen-presenting cells. It was previously unclear how dendritic cells acquire sporozoite antigens to induce the protective CD8+ T cell response. Using a combination of functional studies and high-resolution imaging, we report here that live sporozoites access skin-draining lymph nodes after infection and directly provide antigens to resident dendritic cells that in turn activate CD8+ T cells. These results underscore the importance of live, motile sporozoites in the induction of protective CD8+ T cell responses and provide a mechanistic understanding for the superior immunogenicity of whole parasite vaccines.
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Affiliation(s)
- Andrea J. Radtke
- Johns Hopkins Malaria Research Institute and Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Wolfgang Kastenmüller
- Lymphocyte Biology Section, Laboratory of Systems Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Diego A. Espinosa
- Johns Hopkins Malaria Research Institute and Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Michael Y. Gerner
- Lymphocyte Biology Section, Laboratory of Systems Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sze-Wah Tse
- Johns Hopkins Malaria Research Institute and Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Photini Sinnis
- Johns Hopkins Malaria Research Institute and Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Ronald N. Germain
- Lymphocyte Biology Section, Laboratory of Systems Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Fidel P. Zavala
- Johns Hopkins Malaria Research Institute and Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- * E-mail: (FPZ); (IAC)
| | - Ian A. Cockburn
- Johns Hopkins Malaria Research Institute and Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- * E-mail: (FPZ); (IAC)
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47
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Rizzo C, Lombardo F, Ronca R, Mangano V, Sirima SB, Nèbiè I, Fiorentino G, Modiano D, Arcà B. Differential antibody response to the Anopheles gambiae gSG6 and cE5 salivary proteins in individuals naturally exposed to bites of malaria vectors. Parasit Vectors 2014; 7:549. [PMID: 25428638 PMCID: PMC4253619 DOI: 10.1186/s13071-014-0549-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 11/20/2014] [Indexed: 12/05/2022] Open
Abstract
Background Mosquito saliva plays crucial roles in blood feeding but also evokes in hosts an anti-saliva antibody response. The IgG response to the Anopheles gambiae salivary protein gSG6 was previously shown to be a reliable indicator of human exposure to Afrotropical malaria vectors. We analyzed here the humoral response to the salivary anti-thrombin cE5 in a group of individuals from a malaria hyperendemic area of Burkina Faso. Methods ELISA was used to measure the anti-cE5 IgG, IgG1 and IgG4 antibody levels in plasma samples collected in the village of Barkoumbilen (Burkina Faso) among individuals of the Rimaibé ethnic group. Anti-gSG6 IgG levels were also determined for comparison. Anopheles vector density in the study area was evaluated by indoor pyrethrum spray catches. Results The cE5 protein was highly immunogenic and triggered in exposed individuals a relatively long-lasting antibody response, as shown by its unchanged persistence after a few months of absent or very low exposure (dry season). In addition cE5 did not induce immune tolerance, as previously suggested for the gSG6 antigen. Finally, IgG subclass analysis suggested that exposed individuals may mount a Th1-type immune response against the cE5 protein. Conclusions The anti-cE5 IgG response is shown here to be a sensitive indicator of human exposure to anopheline vectors and to represent an additional tool for malaria epidemiological studies. It may be especially useful in conditions of low vector density, to monitor transiently exposed individuals (i.e. travellers/workers/soldiers spending a few months in tropical Africa) and to evaluate the impact of insecticide treated nets on vector control. Moreover, the gSG6 and cE5 salivary proteins were shown to trigger in exposed individuals a strikingly different immune response with (i) gSG6 evoking a short-lived IgG response, characterized by high IgG4 levels and most likely induction of immune tolerance, and (ii) cE5 eliciting a longer-living IgG response, dominated by anti-cE5 IgG1 antibodies and not inducing tolerance mechanisms. We believe that these two antigens may represent useful reagents to further investigate the so far overlooked role of Anopheles saliva and salivary proteins in host early immune response to Plasmodium parasites. Electronic supplementary material The online version of this article (doi:10.1186/s13071-014-0549-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Cinzia Rizzo
- Department of Public Health and Infectious Diseases, Division of Parasitology, Sapienza University, Piazzale Aldo Moro 5, 00185, Rome, Italy.
| | - Fabrizio Lombardo
- Department of Public Health and Infectious Diseases, Division of Parasitology, Sapienza University, Piazzale Aldo Moro 5, 00185, Rome, Italy.
| | - Raffaele Ronca
- Department of Biology, "Federico II" University, Naples, Italy.
| | - Valentina Mangano
- Department of Public Health and Infectious Diseases, Division of Parasitology, Sapienza University, Piazzale Aldo Moro 5, 00185, Rome, Italy.
| | | | - Issa Nèbiè
- Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso.
| | | | - David Modiano
- Department of Public Health and Infectious Diseases, Division of Parasitology, Sapienza University, Piazzale Aldo Moro 5, 00185, Rome, Italy.
| | - Bruno Arcà
- Department of Public Health and Infectious Diseases, Division of Parasitology, Sapienza University, Piazzale Aldo Moro 5, 00185, Rome, Italy.
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48
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Plasmodium and mononuclear phagocytes. Microb Pathog 2014; 78:43-51. [PMID: 25450889 DOI: 10.1016/j.micpath.2014.11.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 11/14/2014] [Accepted: 11/19/2014] [Indexed: 01/13/2023]
Abstract
Plasmodium, the causative agent of malaria, initially multiplies inside liver cells and then in successive cycles inside erythrocytes, causing the symptoms of the disease. In this review, we discuss interactions between the extracellular and intracellular forms of the Plasmodium parasite and innate immune cells in the mammalian host, with a special emphasis on mononuclear phagocytes. We overview here what is known about the innate immune cells that interact with parasites, mechanisms used by the parasite to evade them, and the protective or detrimental contribution of these interactions on parasite progression through its life cycle and pathology in the host.
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49
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Crompton PD, Moebius J, Portugal S, Waisberg M, Hart G, Garver LS, Miller LH, Barillas-Mury C, Pierce SK. Malaria immunity in man and mosquito: insights into unsolved mysteries of a deadly infectious disease. Annu Rev Immunol 2014; 32:157-87. [PMID: 24655294 DOI: 10.1146/annurev-immunol-032713-120220] [Citation(s) in RCA: 207] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Malaria is a mosquito-borne disease caused by parasites of the obligate intracellular Apicomplexa phylum the most deadly of which, Plasmodium falciparum, prevails in Africa. Malaria imposes a huge health burden on the world's most vulnerable populations, claiming the lives of nearly one million children and pregnant women each year. Although there is keen interest in eradicating malaria, we do not yet have the necessary tools to meet this challenge, including an effective malaria vaccine and adequate vector control strategies. Here we review what is known about the mechanisms at play in immune resistance to malaria in both the human and mosquito hosts at each step in the parasite's complex life cycle with a view toward developing the tools that will contribute to the prevention of disease and death and, ultimately, to the goal of malaria eradication. In so doing, we hope to inspire immunologists to participate in defeating this devastating disease.
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Morrot A, Rodrigues MM. Tissue signatures influence the activation of intrahepatic CD8(+) T cells against malaria sporozoites. Front Microbiol 2014; 5:440. [PMID: 25202304 PMCID: PMC4141441 DOI: 10.3389/fmicb.2014.00440] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 08/03/2014] [Indexed: 11/19/2022] Open
Abstract
Plasmodium sporozoites and liver stages express antigens that are targeted to the MHC-Class I antigen-processing pathway. After the introduction of Plasmodium sporozoites by Anopheles mosquitoes, bone marrow-derived dendritic cells in skin-draining lymph nodes are the first cells to cross-present parasite antigens and elicit specific CD8+ T cells. One of these antigens is the immunodominant circumsporozoite protein (CSP). The CD8+ T cell-mediated protective immune response against CSP is dependent on the interleukin loop involving IL-4 receptor expression on CD8+ cells and IL-4 secretion by CD4+ T cell helpers. In a few days, these CD8+ T cells re-circulate to secondary lymphoid organs and the liver. In the liver, the hepatic sinusoids are enriched with cells, such as dendritic, sinusoidal endothelial and Kupffer cells, that are able to cross-present MHC class I antigens to intrahepatic CD8+ T cells. Specific CD8+ T cells actively find infected hepatocytes and target intra-cellular parasites through mechanisms that are both interferon-γ-dependent and -independent. Immunity is mediated by CD8+ T effector or effector-memory cells and, when present in high numbers, these cells can provide sterilizing immunity. Human vaccination trials with recombinant formulations or attenuated sporozoites have yet to achieve the high numbers of specific effector T cells that are required for sterilizing immunity. In spite of the limited number of specific CD8+ T cells, attenuated sporozoites provided multiple times by the endovenous route provided a high degree of protective immunity. These observations highlight that CD8+ T cells may be useful for improving antibody-mediated protective immunity to pre-erythrocytic stages of malaria parasites.
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Affiliation(s)
- Alexandre Morrot
- Departamento de Imunologia, Instituro de Microbiologia, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil
| | - Maurício M Rodrigues
- Departmento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina São Paulo, Brazil
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