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Adams Y, Clausen AS, Jensen PØ, Lager M, Wilhelmsson P, Henningson AJ, Lindgren PE, Faurholt-Jepsen D, Mens H, Kraiczy P, Kragh KN, Bjarnsholt T, Kjaer A, Lebech AM, Jensen AR. 3D blood-brain barrier-organoids as a model for Lyme neuroborreliosis highlighting genospecies dependent organotropism. iScience 2022; 26:105838. [PMID: 36686395 PMCID: PMC9851883 DOI: 10.1016/j.isci.2022.105838] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 11/16/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022] Open
Abstract
Lyme neuroborreliosis (LNB), a tick-borne infection caused by spirochetes within the Borrelia burgdorferi sensu lato (s.L.) complex, is among the most prevalent bacterial central nervous system (CNS) infections in Europe and the US. Here we have screened a panel of low-passage B. burgdorferi s.l. isolates using a novel, human-derived 3D blood-brain barrier (BBB)-organoid model. We show that human-derived BBB-organoids support the entry of Borrelia spirochetes, leading to swelling of the organoids and a loss of their structural integrity. The use of the BBB-organoid model highlights the organotropism between B. burgdorferi s.l. genospecies and their ability to cross the BBB contributing to CNS infection.
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Affiliation(s)
- Yvonne Adams
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Maersk Tower, Blegdamsvej 3B, 2200 Copenhagen N, Denmark,Corresponding author
| | - Anne Skovsbo Clausen
- Department of Clinical Physiology and Nuclear Medicine & Cluster for Molecular Imaging, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark
| | - Peter Østrup Jensen
- Department of Biomedical Sciences, University of Copenhagen, University Hospital-Rigshospitalet, Copenhagen, Denmark,Department of Clinical Microbiology, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark,Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Malin Lager
- National Reference Laboratory for Borrelia and Other Tick-Borne Bacteria, Division of Clinical Microbiology, Laboratory Medicine, Region Jönköping County and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Peter Wilhelmsson
- National Reference Laboratory for Borrelia and Other Tick-Borne Bacteria, Division of Clinical Microbiology, Laboratory Medicine, Region Jönköping County and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden,Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Anna J. Henningson
- National Reference Laboratory for Borrelia and Other Tick-Borne Bacteria, Division of Clinical Microbiology, Laboratory Medicine, Region Jönköping County and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden,Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Per-Eric Lindgren
- National Reference Laboratory for Borrelia and Other Tick-Borne Bacteria, Division of Clinical Microbiology, Laboratory Medicine, Region Jönköping County and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden,Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Daniel Faurholt-Jepsen
- Department of Infectious Diseases, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark
| | - Helene Mens
- Department of Infectious Diseases, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark
| | - Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Goethe University Frankfurt, Frankfurt, Germany
| | - Kasper Nørskov Kragh
- Department of Clinical Microbiology, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark,Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Bjarnsholt
- Department of Clinical Microbiology, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark,Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Andreas Kjaer
- Department of Clinical Physiology and Nuclear Medicine & Cluster for Molecular Imaging, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark
| | - Anne-Mette Lebech
- Department of Infectious Diseases, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Anja R. Jensen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Maersk Tower, Blegdamsvej 3B, 2200 Copenhagen N, Denmark,Corresponding author
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2
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Adams Y, Jensen AR. Cerebral malaria - modelling interactions at the blood-brain barrier in vitro. Dis Model Mech 2022; 15:275963. [PMID: 35815443 PMCID: PMC9302004 DOI: 10.1242/dmm.049410] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The blood–brain barrier (BBB) is a continuous endothelial barrier that is supported by pericytes and astrocytes and regulates the passage of solutes between the bloodstream and the brain. This structure is called the neurovascular unit and serves to protect the brain from blood-borne disease-causing agents and other risk factors. In the past decade, great strides have been made to investigate the neurovascular unit for delivery of chemotherapeutics and for understanding how pathogens can circumvent the barrier, leading to severe and, at times, fatal complications. One such complication is cerebral malaria, in which Plasmodium falciparum-infected red blood cells disrupt the barrier function of the BBB, causing severe brain swelling. Multiple in vitro models of the BBB are available to investigate the mechanisms underlying the pathogenesis of cerebral malaria and other diseases. These range from single-cell monolayer cultures to multicellular BBB organoids and highly complex cerebral organoids. Here, we review the technologies available in malaria research to investigate the interaction between P. falciparum-infected red blood cells and the BBB, and discuss the advantages and disadvantages of each model. Summary: This Review discusses the available in vitro models to investigate the impact of adhesion of Plasmodium falciparum-infected red blood cells on the blood–brain barrier, a process associated with cerebral malaria.
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Affiliation(s)
- Yvonne Adams
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Anja Ramstedt Jensen
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark
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3
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Takashima E, Kanoi BN, Nagaoka H, Morita M, Hassan I, Palacpac NMQ, Egwang TG, Horii T, Gitaka J, Tsuboi T. Meta-Analysis of Human Antibodies Against Plasmodium falciparum Variable Surface and Merozoite Stage Antigens. Front Immunol 2022; 13:887219. [PMID: 35757771 PMCID: PMC9218060 DOI: 10.3389/fimmu.2022.887219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 05/11/2022] [Indexed: 11/30/2022] Open
Abstract
Concerted efforts to fight malaria have caused significant reductions in global malaria cases and mortality. Sustaining this will be critical to avoid rebound and outbreaks of seasonal malaria. Identifying predictive attributes that define clinical malaria will be key to guide development of second-generation tools to fight malaria. Broadly reactive antibodies against variable surface antigens that are expressed on the surface of infected erythrocytes and merozoites stage antigens are targets of naturally acquired immunity and prime candidates for anti-malaria therapeutics and vaccines. However, predicting the relationship between the antigen-specific antibodies and protection from clinical malaria remains unresolved. Here, we used new datasets and multiple approaches combined with re-analysis of our previous data to assess the multi-dimensional and complex relationship between antibody responses and clinical malaria outcomes. We observed 22 antigens (17 PfEMP1 domains, 3 RIFIN family members, merozoite surface protein 3 (PF3D7_1035400), and merozoites-associated armadillo repeats protein (PF3D7_1035900) that were selected across three different clinical malaria definitions (1,000/2,500/5,000 parasites/µl plus fever). In addition, Principal Components Analysis (PCA) indicated that the first three components (Dim1, Dim2 and Dim3 with eigenvalues of 306, 48, and 29, respectively) accounted for 66.1% of the total variations seen. Specifically, the Dim1, Dim2 and Dim3 explained 52.8%, 8.2% and 5% of variability, respectively. We further observed a significant relationship between the first component scores and age with antibodies to PfEMP1 domains being the key contributing variables. This is consistent with a recent proposal suggesting that there is an ordered acquisition of antibodies targeting PfEMP1 proteins. Thus, although limited, and further work on the significance of the selected antigens will be required, these approaches may provide insights for identification of drivers of naturally acquired protective immunity as well as guide development of additional tools for malaria elimination and eradication.
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Affiliation(s)
- Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Bernard N Kanoi
- Centre for Research in Infectious Diseases, Directorate of Research and Innovation, Mount Kenya University, Thika, Kenya
| | - Hikaru Nagaoka
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Masayuki Morita
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Ifra Hassan
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Nirianne M Q Palacpac
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | | | - Toshihiro Horii
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Jesse Gitaka
- Centre for Research in Infectious Diseases, Directorate of Research and Innovation, Mount Kenya University, Thika, Kenya
| | - Takafumi Tsuboi
- Division of Cell-Free Sciences, Proteo-Science Center, Ehime University, Matsuyama, Japan
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4
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Blankson SO, Dadjé DS, Traikia N, Alao MJ, Ayivi S, Amoussou A, Deloron P, Ndam NT, Milet J, Basco LK, Aniweh Y, Tahar R. ICAM-1 Kilifi variant is not associated with cerebral and severe malaria pathogenesis in Beninese children. Malar J 2022; 21:115. [PMID: 35379236 PMCID: PMC8978164 DOI: 10.1186/s12936-022-04139-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 03/22/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Cytoadhesion and sequestration of Plasmodium falciparum infected red blood cells (iRBC) in the microvasculature of vital organs are a major cause of malaria pathology. Several studies have provided evidence on the implication of the human host intercellular adhesion molecule-1 (ICAM-1) as a major receptor for iRBCs binding to P. falciparum erythrocyte membrane protein 1 (PfEMP1) in the development of severe and cerebral malaria. The genetic polymorphism K29M in the immunoglobulin-like domain of ICAM-1, known as ICAM-1Kilifi, has been associated with either increased or decreased risk of developing cerebral malaria.
Methods
To provide more conclusive results, the genetic polymorphism of ICAM-1Kilifi was assessed by PCR and sequencing in blood samples from 215 Beninese children who presented with either mild or severe malaria including cerebral malaria.
Results and conclusions
The results showed that in this cohort of Beninese children, the ICAM-1kilifi variant is present at the frequencies of 0.27, similar to the frequency observed in other African countries. This ICAM-1kilifi variant was not associated with disease severity in agreement with other findings from the Gambia, Tanzania, Malawi, Gabon, and Thailand, suggesting no evidence of a direct link between this polymorphism and the pathogenesis of severe and cerebral malaria.
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5
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Olsen RW, Suurbaar J, Jensen AR. Analysis of Antibody Inhibition of PfEMP1 Binding by Competition ELISA. Methods Mol Biol 2022; 2470:485-491. [PMID: 35881368 DOI: 10.1007/978-1-0716-2189-9_36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Plasmodium falciparum express variant antigens on the surface of infected erythrocytes (IEs). These include proteins of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family. PfEMP1 proteins mediate binding of IEs to various human endothelial receptors and induce antibodies response during natural infections. In this chapter, we describe a competition ELISA that is an assay for antibodies neutralizing binding of PfEMP1 proteins to their cognate receptor.
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Affiliation(s)
- Rebecca W Olsen
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark.
| | - Jennifer Suurbaar
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
- Department of Biochemistry, Cell and Molecular Biology, West Africa Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | - Anja Ramstedt Jensen
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark
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6
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Lennartz F, Higgins MK. Surface Plasmon Resonance Analysis of PfEMP1 Interaction with Receptors. Methods Mol Biol 2022; 2470:467-482. [PMID: 35881367 DOI: 10.1007/978-1-0716-2189-9_35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A detailed understanding of the interaction between the highly variant Plasmodium falciparum erythrocyte membrane proteins 1 (PfEMP1) and their human binding partners is essential to explain their roles in disease development in malaria, as well as to understand how antibodies can inhibit these interactions and how the parasite manages to evade such an immune response. This chapter focuses on using surface plasmon resonance (SPR) as a reproducible, high-throughput method to quantitatively characterize these interactions. We describe how to utilize protein A or A/G and streptavidin for protein immobilization on SPR sensor chips and provide instructions on how to biotinylate proteins for this purpose and how to use SPR for binding competition assays. Since these experiments rely on recombinant proteins, we also present a method to verify their structural integrity using circular dichroism spectroscopy.
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Affiliation(s)
- Frank Lennartz
- Department of Biochemistry, University of Oxford, Oxford, UK.
- Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography, Berlin, Germany.
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7
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Dalgaard N, Barfod L. Production of PfEMP1-Specific Mouse Monoclonal Antibodies. Methods Mol Biol 2022; 2470:391-405. [PMID: 35881361 DOI: 10.1007/978-1-0716-2189-9_29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The PfEMP1 family of proteins expressed on the Plasmodium falciparum-infected erythrocyte (IE) surface is the main target of naturally acquired immunity against malaria. Antibodies capable of opsonizing the IEs and blocking the binding between PfEMP1 and human receptors seems to be one of the main protective mechanisms of the naturally acquired immunity. Therefore this family of antigens is intensively studied. Monoclonal antibodies (mAbs) are a very valuable research tool for studying this diverse family of proteins and their interaction with human receptors. As examples, mAbs can be used to identify protective epitopes, epitopes that are targets of cross-reactive antibodies, and the surface expression of specific PfEMP1 variants. Fusing mouse splenocytes with myeloma cells to generate long-lived antibody secreting hybridoma cell lines have been used since the 1970s for the production of mAbs. In this chapter, we describe a simple, reliable, and relatively fast method for producing PfEMP1-specific mAbs from mouse spleen cells using semisolid HAT selection medium.
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Affiliation(s)
- Nanna Dalgaard
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lea Barfod
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
- Department of Infectious Diseases Copenhagen, University Hospital (Rigshospitalet), Copenhagen, Denmark.
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8
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Adams Y, Olsen RW, Bengtsson A, Dalgaard N, Zdioruk M, Satpathi S, Behera PK, Sahu PK, Lawler SE, Qvortrup K, Wassmer SC, Jensen AT. Plasmodium falciparum erythrocyte membrane protein 1 variants induce cell swelling and disrupt the blood-brain barrier in cerebral malaria. J Exp Med 2021; 218:e20201266. [PMID: 33492344 PMCID: PMC7833209 DOI: 10.1084/jem.20201266] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 11/11/2020] [Accepted: 12/11/2020] [Indexed: 01/08/2023] Open
Abstract
Cerebral malaria (CM) is caused by the binding of Plasmodium falciparum-infected erythrocytes (IEs) to the brain microvasculature, leading to inflammation, vessel occlusion, and cerebral swelling. We have previously linked dual intercellular adhesion molecule-1 (ICAM-1)- and endothelial protein C receptor (EPCR)-binding P. falciparum parasites to these symptoms, but the mechanism driving the pathogenesis has not been identified. Here, we used a 3D spheroid model of the blood-brain barrier (BBB) to determine unexpected new features of IEs expressing the dual-receptor binding PfEMP1 parasite proteins. Analysis of multiple parasite lines shows that IEs are taken up by brain endothelial cells in an ICAM-1-dependent manner, resulting in breakdown of the BBB and swelling of the endothelial cells. Via ex vivo analysis of postmortem tissue samples from CM patients, we confirmed the presence of parasites within brain endothelial cells. Importantly, this discovery points to parasite ingress into the brain endothelium as a contributing factor to the pathology of human CM.
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Affiliation(s)
- Yvonne Adams
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rebecca W. Olsen
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anja Bengtsson
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nanna Dalgaard
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mykola Zdioruk
- Brigham and Women’s Hospital, Boston, MA
- Harvard Medical School, Boston, MA
| | | | | | - Praveen K. Sahu
- Center for the Study of Complex Malaria in India, Ispat General Hospital, Rourkela, India
| | - Sean E. Lawler
- Brigham and Women’s Hospital, Boston, MA
- Harvard Medical School, Boston, MA
| | - Klaus Qvortrup
- Core Facility for Integrated Microscopy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Samuel C. Wassmer
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Anja T.R. Jensen
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Sun H, Ma L, Wang L, Xiao P, Li H, Zhou M, Song D. Research advances in hydrogen-deuterium exchange mass spectrometry for protein epitope mapping. Anal Bioanal Chem 2021; 413:2345-2359. [PMID: 33404742 DOI: 10.1007/s00216-020-03091-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 11/19/2020] [Accepted: 11/23/2020] [Indexed: 12/01/2022]
Abstract
With the development of biomedical technology, epitope mapping of proteins has become critical for developing and evaluating new protein drugs. The application of hydrogen-deuterium exchange for protein epitope mapping holds great potential. Although several reviews addressed the hydrogen-deuterium exchange, to date, only a few systematic reviews have focused on epitope mapping using this technology. Here, we introduce the basic principles, development history, and review research progress in hydrogen-deuterium exchange epitope mapping technology and discuss its advantages. We summarize the main hurdles in applying hydrogen-deuterium exchange epitope mapping technology, combined with relevant examples to provide specific solutions. We describe the epitope mapping of virus assemblies, disease-associated proteins, and polyclonal antibodies as examples of pattern introduction. Finally, we discuss the outlook of hydrogen-deuterium exchange epitope mapping technology. This review will help researchers studying protein epitopes to gain a more comprehensive understanding of this technology.
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Affiliation(s)
- Haofeng Sun
- National Institute of Metrology, Beijing, 100029, China
- College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Lingyun Ma
- National Institute of Metrology, Beijing, 100029, China
| | - Leyu Wang
- College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Peng Xiao
- National Institute of Metrology, Beijing, 100029, China
| | - Hongmei Li
- National Institute of Metrology, Beijing, 100029, China
| | - Min Zhou
- School of Chemical and Engineering, Nanjing University of Science and Technology, Jiangsu, 210094, China.
| | - Dewei Song
- National Institute of Metrology, Beijing, 100029, China.
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10
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Abstract
PfEMP1 is the major antigen involved in Plasmodium falciparum-infected erythrocyte sequestration in cerebrovascular endothelium. While some PfEMP1 domains have been associated with clinical phenotypes of malaria, formal associations between the expression of a specific domain and the adhesion properties of clinical isolates are limited. In this context, 73 cerebral malaria (CM) and 98 uncomplicated malaria (UM) Beninese children were recruited. We attempted to correlate the cytoadherence phenotype of Plasmodium falciparum isolates with the clinical presentation and the expression of specific PfEMP1 domains. Cytoadherence level on Hbec-5i and CHO-ICAM-1 cell lines and var genes expression were measured. We also investigated the prevalence of the ICAM-1-binding amino acid motif and dual receptor-binding domains, described as a potential determinant of cerebral malaria pathophysiology. We finally evaluated IgG levels against PfEMP1 recombinant domains (CIDRα1.4, DBLβ3, and CIDRα1.4-DBLβ3). CM isolates displayed higher cytoadherence levels on both cell lines, and we found a correlation between CIDRα1.4-DBLβ1/3 domain expression and CHO-ICAM-1 cytoadherence level. Endothelial protein C receptor (EPCR)-binding domains were overexpressed in CM isolates compared to UM whereas no difference was found in ICAM-1-binding DBLβ1/3 domain expression. Surprisingly, both CM and UM isolates expressed ICAM-1-binding motif and dual receptor-binding domains. There was no difference in IgG response against DBLβ3 between CM and UM isolates expressing ICAM-1-binding DBLβ1/3 domain. It raises questions about the role of this motif in CM pathophysiology, and further studies are needed, especially on the role of DBLβ1/3 without the ICAM-1-binding motif.IMPORTANCE Cerebral malaria pathophysiology remains unknown despite extensive research. PfEMP1 proteins have been identified as the main Plasmodium antigen involved in cerebrovascular endothelium sequestration, but it is unclear which var gene domain is involved in Plasmodium cytoadhesion. EPCR binding is a major determinant of cerebral malaria whereas the ICAM-1-binding role is still questioned. Our study confirmed the EPCR-binding role in CM pathophysiology with a major overexpression of EPCR-binding domains in CM isolates. In contrast, ICAM-1-binding involvement appears less obvious with A-type ICAM-1-binding and dual receptor-binding domain expression in both CM and UM isolates. We did not find any variations in ICAM-1-binding motif sequences in CM compared to UM isolates. UM and CM patients infected with isolates expressing the ICAM-1-binding motif displayed similar IgG levels against DBLβ3 recombinant protein. Our study raises interrogations about the role of these domains in CM physiopathology and questions their use in vaccine strategies against cerebral malaria.
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11
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Optimization of in vitro trophoblast assay for real-time impedimetric sensing of trophoblast-erythrocyte interactions in Plasmodium falciparum malaria. Anal Bioanal Chem 2020; 412:3915-3923. [PMID: 31989195 DOI: 10.1007/s00216-020-02413-1] [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: 10/31/2019] [Revised: 12/20/2019] [Accepted: 01/13/2020] [Indexed: 10/25/2022]
Abstract
Sequestration of Plasmodium falciparum-infected erythrocytes (IEs) is responsible for the pathophysiology of placental malaria, leading to serious complications such as intrauterine growth restriction and low birth weight. However, it is an experimental challenge to study the biology of human placenta. Conventional cell culture-based in vitro placental models rely on immunostaining techniques and high-magnification microscopy is limited in providing real-time quantitative analysis. Impedimetric sensing in combination with cell culture may offer a useful tool. In this paper, we report that real-time label-free measurement of cellular electrical impedance using xCELLigence technology can be used to quantify the proliferation, syncytial fusion, and long-term response of BeWo cells to IEs cytoadhesion. Specifically, we optimized key experimental parameters of cell seeding density and concentration of forskolin, a compound used to promote cell syncitiation, based on electrical signals and immunostaining results. Prolonged time of infection with IEs that led to cell-cell junction vanishment in BeWo cells and release of inflammatory cytokines were monitored in real time by continuous change in electrical impedance. The results suggest that the impedimetric technique is sensitive and can offer new opportunities for the study of cellular responses of trophoblast cells to IEs. The developed system can provide potentially a high-throughput screening tool of anti-adhesion or anti-inflammatory drugs for placental malaria infections.
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12
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Jensen AR, Adams Y, Hviid L. Cerebral Plasmodium falciparum malaria: The role of PfEMP1 in its pathogenesis and immunity, and PfEMP1-based vaccines to prevent it. Immunol Rev 2020; 293:230-252. [PMID: 31562653 PMCID: PMC6972667 DOI: 10.1111/imr.12807] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 09/04/2019] [Accepted: 09/09/2019] [Indexed: 12/13/2022]
Abstract
Malaria, a mosquito-borne infectious disease caused by parasites of the genus Plasmodium continues to be a major health problem worldwide. The unicellular Plasmodium-parasites have the unique capacity to infect and replicate within host erythrocytes. By expressing variant surface antigens Plasmodium falciparum has evolved to avoid protective immune responses; as a result in endemic areas anti-malaria immunity develops gradually over many years of multiple and repeated infections. We are studying the role of Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) expressed by asexual stages of P. falciparum responsible for the pathogenicity of severe malaria. The immunopathology of falciparum malaria has been linked to cyto-adhesion of infected erythrocytes to specific host receptors. A greater appreciation of the PfEMP1 molecules important for the development of protective immunity and immunopathology is a prerequisite for the rational discovery and development of a safe and protective anti-disease malaria vaccine. Here we review the role of ICAM-1 and EPCR receptor adhering falciparum-parasites in the development of severe malaria; we discuss our current research to understand the factors involved in the pathogenesis of cerebral malaria and the feasibility of developing a vaccine targeted specifically to prevent this disease.
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Affiliation(s)
- Anja Ramstedt Jensen
- Centre for Medical Parasitology at Department of Immunology and MicrobiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Yvonne Adams
- Centre for Medical Parasitology at Department of Immunology and MicrobiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Lars Hviid
- Centre for Medical Parasitology at Department of Immunology and MicrobiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
- Department of Infectious DiseasesRigshospitaletCopenhagenDenmark
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13
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Lennartz F, Smith C, Craig AG, Higgins MK. Structural insights into diverse modes of ICAM-1 binding by Plasmodium falciparum-infected erythrocytes. Proc Natl Acad Sci U S A 2019; 116:20124-20134. [PMID: 31527263 PMCID: PMC6778195 DOI: 10.1073/pnas.1911900116] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
A major determinant of pathogenicity in malaria caused by Plasmodium falciparum is the adhesion of parasite-infected erythrocytes to the vasculature or tissues of infected individuals. This occludes blood flow, leads to inflammation, and increases parasitemia by reducing spleen-mediated clearance of the parasite. This adhesion is mediated by PfEMP1, a multivariant family of around 60 proteins per parasite genome which interact with specific host receptors. One of the most common of these receptors is intracellular adhesion molecule-1 (ICAM-1), which is bound by 2 distinct groups of PfEMP1, A-type and B or C (BC)-type. Here, we present the structure of a domain from a B-type PfEMP1 bound to ICAM-1, revealing a complex binding site. Comparison with the existing structure of an A-type PfEMP1 bound to ICAM-1 shows that the 2 complexes share a globally similar architecture. However, while the A-type PfEMP1 bind ICAM-1 through a highly conserved binding surface, the BC-type PfEMP1 use a binding site that is more diverse in sequence, similar to how PfEMP1 interact with other human receptors. We also show that A- and BC-type PfEMP1 present ICAM-1 at different angles, perhaps influencing the ability of neighboring PfEMP1 domains to bind additional receptors. This illustrates the deep diversity of the PfEMP1 and demonstrates how variations in a single domain architecture can modulate binding to a specific ligand to control function and facilitate immune evasion.
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Affiliation(s)
- Frank Lennartz
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, United Kingdom
| | - Cameron Smith
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, United Kingdom
| | - Alister G Craig
- Liverpool School of Tropical Medicine, L3 5QA Liverpool, United Kingdom
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, OX1 3QU Oxford, United Kingdom;
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14
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MS-Based Approaches Enable the Structural Characterization of Transcription Factor/DNA Response Element Complex. Biomolecules 2019; 9:biom9100535. [PMID: 31561554 PMCID: PMC6843354 DOI: 10.3390/biom9100535] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/18/2019] [Accepted: 09/24/2019] [Indexed: 02/06/2023] Open
Abstract
The limited information available on the structure of complexes involving transcription factors and cognate DNA response elements represents a major obstacle in the quest to understand their mechanism of action at the molecular level. We implemented a concerted structural proteomics approach, which combined hydrogen-deuterium exchange (HDX), quantitative protein-protein and protein-nucleic acid cross-linking (XL), and homology analysis, to model the structure of the complex between the full-length DNA binding domain (DBD) of Forkhead box protein O4 (FOXO4) and its DNA binding element (DBE). The results confirmed that FOXO4-DBD assumes the characteristic forkhead topology shared by these types of transcription factors, but its binding mode differs significantly from those of other members of the family. The results showed that the binding interaction stabilized regions that were rather flexible and disordered in the unbound form. Surprisingly, the conformational effects were not limited only to the interface between bound components, but extended also to distal regions that may be essential to recruiting additional factors to the transcription machinery. In addition to providing valuable new insights into the binding mechanism, this project provided an excellent evaluation of the merits of structural proteomics approaches in the investigation of systems that are not directly amenable to traditional high-resolution techniques.
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15
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Paing MM, Salinas ND, Adams Y, Oksman A, Jensen ATR, Goldberg DE, Tolia NH. Shed EBA-175 mediates red blood cell clustering that enhances malaria parasite growth and enables immune evasion. eLife 2018; 7:e43224. [PMID: 30556808 PMCID: PMC6305201 DOI: 10.7554/elife.43224] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 12/14/2018] [Indexed: 01/22/2023] Open
Abstract
Erythrocyte Binding Antigen of 175 kDa (EBA-175) has a well-defined role in binding to glycophorin A (GpA) during Plasmodium falciparum invasion of erythrocytes. However, EBA-175 is shed post invasion and a role for this shed protein has not been defined. We show that EBA-175 shed from parasites promotes clustering of RBCs, and EBA-175-dependent clusters occur in parasite culture. Region II of EBA-175 is sufficient for clustering RBCs in a GpA-dependent manner. These clusters are capable of forming under physiological flow conditions and across a range of concentrations. EBA-175-dependent RBC clustering provides daughter merozoites ready access to uninfected RBCs enhancing parasite growth. Clustering provides a general method to protect the invasion machinery from immune recognition and disruption as exemplified by protection from neutralizing antibodies that target AMA-1 and RH5. These findings provide a mechanistic framework for the role of shed proteins in RBC clustering, immune evasion, and malaria.
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Affiliation(s)
- May M Paing
- Department of Molecular MicrobiologyWashington University School of MedicineSt. LouisUnited States
| | - Nichole D Salinas
- Department of Molecular MicrobiologyWashington University School of MedicineSt. LouisUnited States
- Laboratory of Malaria Immunology and VaccinologyNational Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesdaUnited States
| | - Yvonne Adams
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Anna Oksman
- Department of MedicineWashington University School of MedicineSt. LouisUnited States
| | - Anja TR Jensen
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Daniel E Goldberg
- Department of MedicineWashington University School of MedicineSt. LouisUnited States
| | - Niraj H Tolia
- Department of Molecular MicrobiologyWashington University School of MedicineSt. LouisUnited States
- Laboratory of Malaria Immunology and VaccinologyNational Institute of Allergy and Infectious Diseases, National Institutes of HealthBethesdaUnited States
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16
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Wang Q, Feng Y, Sun X, Pang W, Fu W, Cao Y. Prophylactic treatment of L-Arg improves malaria outcomes by regulating host immune responses during Plasmodium yoelii 17XL infection. Exp Parasitol 2018; 195:1-7. [DOI: 10.1016/j.exppara.2018.09.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 02/23/2018] [Accepted: 09/20/2018] [Indexed: 12/24/2022]
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17
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Ecklu-Mensah G, Olsen RW, Bengtsson A, Ofori MF, Hviid L, Jensen ATR, Adams Y. Blood outgrowth endothelial cells (BOECs) as a novel tool for studying adhesion of Plasmodium falciparum-infected erythrocytes. PLoS One 2018; 13:e0204177. [PMID: 30300360 PMCID: PMC6177148 DOI: 10.1371/journal.pone.0204177] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 09/03/2018] [Indexed: 11/19/2022] Open
Abstract
The lack of suitable animal models for the study of cytoadhesion of P. falciparum-infected erythrocytes (IEs) has necessitated in vitro studies employing a range of cell lines of either human tumour origin (e.g., BeWo and C32 cells) or non-human origin (e.g., CHO cells). Of the human cells available, many were isolated from adults, or derived from a pool of donors (e.g., HBEC-5i). Here we demonstrate, for the first time, the successful isolation of blood outgrowth endothelial cells (BOECs) from frozen stabilates of peripheral blood mononuclear cells obtained from small-volume peripheral blood samples from paediatric malaria patients. BOECs are a sub-population of human endothelial cells, found within the peripheral blood. We demonstrate that these cells express receptors such as Intercellular Adhesion Molecule 1 (ICAM-1/CD54), Endothelial Protein C Receptor (EPCR/CD201), platelet/endothelial cell adhesion molecule 1 (PECAM-1/CD31), Thrombomodulin (CD141), and support adhesion of P. falciparum IEs.
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Affiliation(s)
- Gertrude Ecklu-Mensah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rebecca W. Olsen
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anja Bengtsson
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael F. Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Lars Hviid
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Anja T. R. Jensen
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Yvonne Adams
- Centre for Medical Parasitology at Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
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18
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Comprehensive analysis of antibody responses to Plasmodium falciparum erythrocyte membrane protein 1 domains. Vaccine 2018; 36:6826-6833. [PMID: 30262245 DOI: 10.1016/j.vaccine.2018.08.058] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 08/03/2018] [Accepted: 08/22/2018] [Indexed: 12/31/2022]
Abstract
Acquired antibodies directed towards antigens expressed on the surface of merozoites and infected erythrocytes play an important role in protective immunity to Plasmodium falciparum malaria. P. falciparum erythrocyte membrane protein 1 (PfEMP1), the major parasite component of the infected erythrocyte surface, has been implicated in malaria pathology, parasite sequestration and host immune evasion. However, the extent to which unique PfEMP1 domains interact with host immune response remains largely unknown. In this study, we sought to comprehensively understand the naturally acquired antibody responses targeting different Duffy binding-like (DBL), and Cysteine-rich interdomain region (CIDR) domains in a Ugandan cohort. Consequently, we created a protein library consisting of full-length DBL (n = 163) and CIDR (n = 108) domains derived from 62-var genes based on 3D7 genome. The proteins were expressed by a wheat germ cell-free system; a system that yields plasmodial proteins that are comparatively soluble, intact, biologically active and immunoreactive to human sera. Our findings suggest that all PfEMP1 DBL and CIDR domains, regardless of PfEMP1 group, are targets of naturally acquired immunity. The breadth of the immune response expands with children's age. We concurrently identified 10 DBL and 8 CIDR domains whose antibody responses were associated with reduced risk to symptomatic malaria in the Ugandan children cohort. This study highlights that only a restricted set of specific domains are essential for eliciting naturally acquired protective immunity in malaria. In light of current data, tandem domains in PfEMP1s PF3D7_0700100 and PF3D7_0425800 (DC4) are recommended for extensive evaluation in larger population cohorts to further assess their potential as alternative targets for malaria vaccine development.
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19
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Antibodies to Intercellular Adhesion Molecule 1-Binding Plasmodium falciparum Erythrocyte Membrane Protein 1-DBLβ Are Biomarkers of Protective Immunity to Malaria in a Cohort of Young Children from Papua New Guinea. Infect Immun 2018; 86:IAI.00485-17. [PMID: 29784862 DOI: 10.1128/iai.00485-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 05/18/2018] [Indexed: 11/20/2022] Open
Abstract
Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) mediates parasite sequestration to the cerebral microvasculature via binding of DBLβ domains to intercellular adhesion molecule 1 (ICAM1) and is associated with severe cerebral malaria. In a cohort of 187 young children from Papua New Guinea (PNG), we examined baseline levels of antibody to the ICAM1-binding PfEMP1 domain, DBLβ3PF11_0521, in comparison to four control antigens, including NTS-DBLα and CIDR1 domains from another group A variant and a group B/C variant. Antibody levels for the group A antigens were strongly associated with age and exposure. Antibody responses to DBLβ3PF11_0521 were associated with a 37% reduced risk of high-density clinical malaria in the follow-up period (adjusted incidence risk ratio [aIRR] = 0.63 [95% confidence interval {CI}, 0.45 to 0.88; P = 0.007]) and a 25% reduction in risk of low-density clinical malaria (aIRR = 0.75 [95% CI, 0.55 to 1.01; P = 0.06]), while there was no such association for other variants. Children who experienced severe malaria also had significantly lower levels of antibody to DBLβ3PF11_0521 and the other group A domains than those that experienced nonsevere malaria. Furthermore, a subset of PNG DBLβ sequences had ICAM1-binding motifs, formed a distinct phylogenetic cluster, and were similar to sequences from other areas of endemicity. PfEMP1 variants associated with these DBLβ domains were enriched for DC4 and DC13 head structures implicated in endothelial protein C receptor (EPCR) binding and severe malaria, suggesting conservation of dual binding specificities. These results provide further support for the development of specific classes of PfEMP1 as vaccine candidates and as biomarkers for protective immunity against clinical P. falciparum malaria.
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20
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Olsen RW, Ecklu-Mensah G, Bengtsson A, Ofori MF, Lusingu JPA, Castberg FC, Hviid L, Adams Y, Jensen ATR. Natural and Vaccine-Induced Acquisition of Cross-Reactive IgG-Inhibiting ICAM-1-Specific Binding of a Plasmodium falciparum PfEMP1 Subtype Associated Specifically with Cerebral Malaria. Infect Immun 2018; 86:e00622-17. [PMID: 29426042 PMCID: PMC5865037 DOI: 10.1128/iai.00622-17] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 01/25/2018] [Indexed: 12/17/2022] Open
Abstract
Cerebral malaria (CM) is a potentially deadly outcome of Plasmodium falciparum malaria that is precipitated by sequestration of infected erythrocytes (IEs) in the brain. The adhesion of IEs to brain endothelial cells is mediated by a subtype of parasite-encoded erythrocyte membrane protein 1 (PfEMP1) that facilitates dual binding to host intercellular adhesion molecule 1 (ICAM-1) and endothelial protein receptor C (EPCR). The PfEMP1 subtype is characterized by the presence of a particular motif (DBLβ_motif) in the constituent ICAM-1-binding DBLβ domain. The rate of natural acquisition of DBLβ_motif-specific IgG antibodies and the ability to induce such antibodies by vaccination are unknown, and the aim of this study was to provide such data. We used an enzyme-linked immunosorbent assay (ELISA) to measure DBLβ-specific IgG in plasma from Ghanaian children with malaria. The ability of human immune plasma and DBLβ-specific rat antisera to inhibit the interaction between ICAM-1 and DBLβ was assessed using ELISA and in vitro assays of IE adhesion under flow. The acquisition of DBLβ_motif-specific IgG coincided with age-specific susceptibility to CM. Broadly cross-reactive antibodies inhibiting the interaction between ICAM-1 and DBLβ_motif domains were detectable in immune plasma and in sera of rats immunized with specific DBLβ_motif antigens. Importantly, antibodies against the DBLβ_motif inhibited ICAM-1-specific in vitro adhesion of erythrocytes infected by four of five P. falciparum isolates from cerebral malaria patients. We conclude that natural exposure to P. falciparum as well as immunization with specific DBLβ_motif antigens can induce cross-reactive antibodies that inhibit the interaction between ICAM-1 and a broad range of DBLβ_motif domains. These findings raise hope that a vaccine designed specifically to prevent CM is feasible.
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MESH Headings
- Adolescent
- Amino Acid Motifs
- Antibodies, Neutralizing/immunology
- Antibodies, Protozoan/immunology
- Antigens, Protozoan/immunology
- Binding Sites
- Child
- Child, Preschool
- Cross Reactions/immunology
- Ghana
- Humans
- Immunoglobulin G/immunology
- Immunoglobulin G/metabolism
- Infant
- Intercellular Adhesion Molecule-1/metabolism
- Malaria Vaccines/immunology
- Malaria, Cerebral/immunology
- Malaria, Cerebral/metabolism
- Malaria, Cerebral/parasitology
- Malaria, Falciparum/immunology
- Malaria, Falciparum/metabolism
- Malaria, Falciparum/parasitology
- Plasmodium falciparum/immunology
- Protein Binding/immunology
- Protein Interaction Domains and Motifs
- Protozoan Proteins/chemistry
- Protozoan Proteins/immunology
- Protozoan Proteins/metabolism
- Tanzania
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Affiliation(s)
- Rebecca W Olsen
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gertrude Ecklu-Mensah
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Anja Bengtsson
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael F Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - John P A Lusingu
- National Institute for Medical Research, Tanga Centre, Tanga City, Tanzania
| | - Filip C Castberg
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Microbiology, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Lars Hviid
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Yvonne Adams
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anja T R Jensen
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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21
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Carrington E, Otto TD, Szestak T, Lennartz F, Higgins MK, Newbold CI, Craig AG. In silico guided reconstruction and analysis of ICAM-1-binding var genes from Plasmodium falciparum. Sci Rep 2018; 8:3282. [PMID: 29459671 PMCID: PMC5818487 DOI: 10.1038/s41598-018-21591-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 02/07/2018] [Indexed: 11/23/2022] Open
Abstract
The Plasmodium falciparum variant surface antigen PfEMP1 expressed on the surface of infected erythrocytes is thought to play a major role in the pathology of severe malaria. As the sequence pool of the var genes encoding PfEMP1 expands there are opportunities, despite the high degree of sequence diversity demonstrated by this gene family, to reconstruct full-length var genes from small sequence tags generated from patient isolates. To test whether this is possible we have used a set of recently laboratory adapted ICAM-1-binding parasite isolates to generate sequence tags and, from these, to identify the full-length PfEMP1 being expressed by them. In a subset of the strains available we were able to produce validated, full-length var gene sequences and use these to conduct biophysical analyses of the ICAM-1 binding regions.
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Affiliation(s)
- Eilidh Carrington
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
- Malaria Gene Regulation Lab, Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051, Basel, Switzerland
| | - Thomas D Otto
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
- Institute of Infection, Immunity and Inflammation, University of Glasgow, College of Medical, Veterinary and Life Sciences, Sir Graeme Davies Building, 120 University Place, Glasgow, G12 8TA, UK
| | - Tadge Szestak
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Frank Lennartz
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Matt K Higgins
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Chris I Newbold
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
- Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
| | - Alister G Craig
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
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22
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Wahlgren M, Goel S, Akhouri RR. Variant surface antigens of Plasmodium falciparum and their roles in severe malaria. Nat Rev Microbiol 2017; 15:479-491. [DOI: 10.1038/nrmicro.2017.47] [Citation(s) in RCA: 142] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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23
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Pehrson C, Heno KK, Adams Y, Resende M, Mathiesen L, Soegaard M, de Jongh WA, Theander TG, Salanti A, Nielsen MA. Comparison of functional assays used in the clinical development of a placental malaria vaccine. Vaccine 2016; 35:610-618. [PMID: 28012775 DOI: 10.1016/j.vaccine.2016.12.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 12/05/2016] [Accepted: 12/08/2016] [Indexed: 01/06/2023]
Abstract
BACKGROUND Malaria in pregnancy is associated with significant morbidity in pregnant women and their offspring. Plasmodium falciparum infected erythrocytes (IE) express VAR2CSA that mediates binding to chondroitin sulphate A (CSA) in the placenta. Two VAR2CSA-based vaccines for placental malaria are in clinical development. The purpose of this study was to evaluate the robustness and comparability of binding inhibition assays used in the clinical development of placental malaria vaccines. METHODS The ability of sera from animals immunised with different VAR2CSA constructs to inhibit IE binding to CSA was investigated in three in vitro assays using 96-well plates, petri dishes, capillary flow and an ex vivo placental perfusion assay. RESULTS The inter-assay variation was not uniform between assays and ranged from above ten-fold in the flow assay to two-fold in the perfusion assay. The intra-assay variation was highest in the petri dish assay. A positive correlation between IE binding avidity and the level of binding after antibody inhibition in the petri dish assay indicate that high avidity IE binding is more difficult to inhibit. The highest binding inhibition sensitivity was found in the 96-well and petri dish assays compared to the flow and perfusion assays where binding inhibition required higher antibody titers. CONCLUSIONS The inhibitory capacity of antibodies is not easily translated between assays and the high sensitivity of the 96-well and petri dish assays stresses the need for comparing serial dilutions of serum. Furthermore, IE binding avidity must be in the same range when comparing data from different days. There was an overall concordance in the capacity of antibody-mediated inhibition, when comparing the in vitro assays with the perfusion assay, which more closely represents in vivo conditions. Importantly the ID1-ID2a protein in a liposomal formulation, currently in a phase I trial, effectively induced antibodies that inhibited IE adhesion in placental tissue.
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Affiliation(s)
- Caroline Pehrson
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Denmark.
| | - Kristine K Heno
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Denmark.
| | - Yvonne Adams
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Denmark.
| | - Mafalda Resende
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Denmark.
| | - Line Mathiesen
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Øster Farimagsgade 5A, 1353 Copenhagen, Denmark.
| | - Max Soegaard
- ExpreS2ion Biotechnologies, SCION-DTU Science Park, Hørsholm, Denmark.
| | - Willem A de Jongh
- ExpreS2ion Biotechnologies, SCION-DTU Science Park, Hørsholm, Denmark.
| | - Thor G Theander
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Denmark.
| | - Ali Salanti
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Denmark.
| | - Morten A Nielsen
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Denmark.
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24
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Abstract
There have been significant decreases in malaria mortality and morbidity in the last 10-15 years, and the most advanced pre-erythrocytic malaria vaccine, RTS,S, received a positive opinion from European regulators in July 2015. However, no blood-stage vaccine has reached a phase III trial. The first part of this review summarizes the pros and cons of various assays and models that have been and will be used to predict the efficacy of blood-stage vaccines. In the second part, blood-stage vaccine candidates that showed some efficacy in human clinical trials or controlled human malaria infection models are discussed. Then, candidates under clinical investigation are described in the third part, and other novel candidates and strategies are reviewed in the last part.
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Affiliation(s)
- Kazutoyo Miura
- a Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases , National Institutes of Health , Rockville , MD , USA
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25
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Guillotte M, Nato F, Juillerat A, Hessel A, Marchand F, Lewit-Bentley A, Bentley GA, Vigan-Womas I, Mercereau-Puijalon O. Functional analysis of monoclonal antibodies against the Plasmodium falciparum PfEMP1-VarO adhesin. Malar J 2016; 15:28. [PMID: 26772184 PMCID: PMC4715314 DOI: 10.1186/s12936-015-1016-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 11/24/2015] [Indexed: 01/30/2023] Open
Abstract
Background Rosetting, namely the capacity of the Plasmodium falciparum-infected red blood cells to bind uninfected RBCs, is commonly observed in African children with severe malaria. Rosetting results from specific interactions between a subset of variant P. falciparum erythrocyte membrane protein 1 (PfEMP1) adhesins encoded by var genes, serum components and RBC receptors. Rosette formation is a redundant phenotype, as there exists more than one var gene encoding a rosette-mediating PfEMP1 in each genome and hence a diverse array of underlying interactions. Moreover, field diversity creates a large panel of rosetting-associated serotypes and studies with human immune sera indicate that surface-reacting antibodies are essentially variant-specific. To gain better insight into the interactions involved in rosetting and map surface epitopes, a panel of monoclonal antibodies (mAbs) was investigated. Methods Monoclonal antibodies were isolated from mice immunized with PfEMP1-VarO recombinant domains. They were characterized using ELISA and reactivity with the native PfEMP1-VarO adhesin on immunoblots of reduced and unreduced extracts, as well as SDS-extracts of Palo Alto 89F5 VarO schizonts. Functionality was assessed using inhibition of Palo Alto 89F5 VarO rosette formation and disruption of Palo Alto 89F5 VarO rosettes. Competition ELISAs were performed with biotinylated antibodies against DBL1 to identify reactivity groups. Specificity of mAbs reacting with the DBL1 adhesion domain was explored using recombinant proteins carrying mutations abolishing RBC binding or binding to heparin, a potent inhibitor of rosette formation. Results Domain-specific, surface-reacting mAbs were obtained for four individual domains (DBL1, CIDR1, DBL2, DBL4). Monoclonal antibodies reacting with DBL1 potently inhibited the formation of rosettes and disrupted Palo Alto 89F5 VarO rosettes. Most surface-reactive mAbs and all mAbs interfering with rosetting reacted on parasite immunoblots with disulfide bond-dependent PfEMP1 epitopes. Based on competition ELISA and binding to mutant DBL1 domains, two distinct binding sites for rosette-disrupting mAbs were identified in close proximity to the RBC-binding site. Conclusions Rosette-inhibitory antibodies bind to conformation-dependent epitopes located close to the RBC-binding site and distant from the heparin-binding site. These results provide novel clues for a rational intervention strategy that targets rosetting. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-1016-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Micheline Guillotte
- Institut Pasteur, Unité d'Immunologie Moléculaire des Parasites, 25-28 rue du Dr ROUX, 75015, Paris, France. .,URA CNRS 2581, 25-28 rue du Dr ROUX, 75015, Paris, France.
| | - Farida Nato
- Institut Pasteur, Plate-forme de Production de Protéines recombinantes et d'Anticorps (PF5), 25-28 rue du Dr ROUX, 75015, Paris, France.
| | - Alexandre Juillerat
- Institut Pasteur, Unité d'Immunologie Structurale, 25-28 rue du Dr ROUX, 75015, Paris, France. .,CNRS URA 2185, 25-28 rue du Dr ROUX, 75015, Paris, France.
| | - Audrey Hessel
- Institut Pasteur, Unité d'Immunologie Moléculaire des Parasites, 25-28 rue du Dr ROUX, 75015, Paris, France. .,Institut Pasteur, Unité d'Immunologie Structurale, 25-28 rue du Dr ROUX, 75015, Paris, France.
| | - Françoise Marchand
- Institut Pasteur, Plate-forme de Production de Protéines recombinantes et d'Anticorps (PF5), 25-28 rue du Dr ROUX, 75015, Paris, France.
| | - Anita Lewit-Bentley
- Institut Pasteur, Unité d'Immunologie Structurale, 25-28 rue du Dr ROUX, 75015, Paris, France. .,CNRS URA 2185, 25-28 rue du Dr ROUX, 75015, Paris, France.
| | - Graham A Bentley
- Institut Pasteur, Unité d'Immunologie Structurale, 25-28 rue du Dr ROUX, 75015, Paris, France. .,CNRS URA 2185, 25-28 rue du Dr ROUX, 75015, Paris, France.
| | - Inès Vigan-Womas
- Institut Pasteur, Unité d'Immunologie Moléculaire des Parasites, 25-28 rue du Dr ROUX, 75015, Paris, France. .,URA CNRS 2581, 25-28 rue du Dr ROUX, 75015, Paris, France. .,Institut Pasteur de Madagascar, Unité d'Immunologie des Maladies Infectieuses, BP 1274, Antananarivo 101, Madagascar.
| | - Odile Mercereau-Puijalon
- Institut Pasteur, Unité d'Immunologie Moléculaire des Parasites, 25-28 rue du Dr ROUX, 75015, Paris, France. .,URA CNRS 2581, 25-28 rue du Dr ROUX, 75015, Paris, France.
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