51
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Kanoi BN, Nagaoka H, White MT, Morita M, Palacpac NMQ, Ntege EH, Balikagala B, Yeka A, Egwang TG, Horii T, Tsuboi T, Takashima E. Global Repertoire of Human Antibodies Against Plasmodium falciparum RIFINs, SURFINs, and STEVORs in a Malaria Exposed Population. Front Immunol 2020; 11:893. [PMID: 32477363 PMCID: PMC7235171 DOI: 10.3389/fimmu.2020.00893] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 04/17/2020] [Indexed: 11/15/2022] Open
Abstract
Clinical immunity to malaria develops after repeated exposure to Plasmodium falciparum parasites. Broadly reactive antibodies against parasite antigens expressed on the surface of infected erythrocytes (variable surface antigens; VSAs) are candidates for anti-malaria therapeutics and vaccines. Among the VSAs, several RIFIN, STEVOR, and SURFIN family members have been demonstrated to be targets of naturally acquired immunity against malaria. For example, RIFIN family members are important ligands for opsonization of P. falciparum infected erythrocytes with specific immunoglobulins (IgG) acquiring broad protective reactivity. However, the global repertoire of human anti-VSAs IgG, its variation in children, and the key protective targets remain poorly understood. Here, we report wheat germ cell-free system-based production and serological profiling of a comprehensive library of A-RIFINs, B-RIFINs, STEVORs, and SURFINs derived from the P. falciparum 3D7 parasite strain. We observed that >98% of assayed proteins (n = 265) were immunogenic in malaria-exposed individuals in Uganda. The overall breadth of immune responses was significantly correlated with age but not with clinical malaria outcome among the study volunteers. However, children with high levels of antibodies to four RIFINs (PF3D7_0201000, PF3D7_1254500, PF3D7_1040600, PF3D7_1041100), STEVOR (PF3D7_0732000), and SURFIN 1.2 (PF3D7_0113600) had prospectively reduced the risk of developing febrile malaria, suggesting that the 5 antigens are important targets of protective immunity. Further studies on the significance of repeated exposure to malaria infection and maintenance of such high-level antibodies would contribute to a better understanding of susceptibility and naturally acquired immunity to malaria.
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Affiliation(s)
- Bernard N Kanoi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Hikaru Nagaoka
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Michael T White
- Department of Parasites and Insect Vectors, Pasteur Institute, Paris, France
| | - Masayuki Morita
- 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
| | - Edward H Ntege
- Department of Plastic and Reconstructive Surgery, Graduate School of Medicine and Hospital, University of the Ryukyus, Okinawa, Japan
| | - Betty Balikagala
- Department of Tropical Medicine and Parasitology, School of Medicine, Juntendo University, Tokyo, Japan
| | - Adoke Yeka
- Makerere University School of Public Health, Kampala, Uganda
| | | | - Toshihiro Horii
- Department of Malaria Vaccine Development, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
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52
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Fleckenstein H, Portugal S. Binding brain better-matching var genes and endothelial receptors. EMBO Mol Med 2020; 11:emmm.201810137. [PMID: 30804082 PMCID: PMC6404108 DOI: 10.15252/emmm.201810137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Cerebral malaria remains a major cause of death for African children, and mechanistic insights regarding the establishment of brain pathology are greatly needed. Expression of specific domains of parasite's var genes promoting brain adhesion of infected erythrocytes had been previously identified, but binding specificities and the receptor preference in the brain endothelial cells had not been fully described. The study by Storm et al (2019) in this issue of EMBO Molecular Medicine demonstrates that binding to brain endothelial cells via EPCR and ICAM‐1 is increased in parasites causing cerebral malaria compared to parasites causing uncomplicated malaria. Furthermore, expression levels of var genes encoding the CIDRα1 domain with EPCR affinity correlate with the receptor‐dependent binding to brain, but not dermal endothelial cells, highlighting the important role of EPCR in cerebral malaria pathology.
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Affiliation(s)
- Hannah Fleckenstein
- Center for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
| | - Silvia Portugal
- Center for Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg, Germany
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53
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Harmsen C, Turner L, Thrane S, Sander AF, Theander TG, Lavstsen T. Immunization with virus-like particles conjugated to CIDRα1 domain of Plasmodium falciparum erythrocyte membrane protein 1 induces inhibitory antibodies. Malar J 2020; 19:132. [PMID: 32228596 PMCID: PMC7106694 DOI: 10.1186/s12936-020-03201-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 03/23/2020] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND During the erythrocytic cycle, Plasmodium falciparum malaria parasites express P. falciparum Erythrocyte Membrane Protein 1 (PfEMP1) that anchor the infected erythrocytes (IE) to the vascular lining of the host. The CIDRα1 domain of PfEMP1 is responsible for binding host endothelial protein C receptor (EPCR), and increasing evidence support that this interaction triggers severe malaria, accounting for the majority of malaria-related deaths. In high transmission regions, children develop immunity to severe malaria after the first few infections. This immunity is believed to be mediated by antibodies targeting and inhibiting PfEMP1, causing infected erythrocytes to circulate and be cleared in the spleen. The development of immunity to malaria coincides with acquisition of broad antibody reactivity across the CIDRα1 protein family. Altogether, this identifies CIDRα1 as an important vaccine target. However, the antigenic diversity of the CIDRα1 domain family is a challenge for vaccine development. METHODS Immune responses in mice vaccinated with Virus-Like Particles (VLP) presenting CIDRα1 antigens were investigated. Antibody reactivity was tested to a panel of recombinant CIDRα1 domains, and the antibodies ability to inhibit EPCR binding by the recombinant CIDRα1 domains was tested in Luminex-based multiplex assays. RESULTS VLP-presented CIDRα1.4 antigens induced a rapid and strong IgG response capable of inhibiting EPCR-binding of multiple CIDRα1 domains mainly within the group A CIDRα1.4-7 subgroups. CONCLUSIONS The study observations mirror those from previous CIDRα1 vaccine studies using other vaccine constructs and platforms. This suggests that broad CIDRα1 antibody reactivity may be achieved through vaccination with a limited number of CIDRα1 variants. In addition, this study suggest that this may be achieved through vaccination with a human compatible VLP vaccine platform.
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Affiliation(s)
- Charlotte Harmsen
- Centre for Medical Parasitology, 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
| | - Louise Turner
- Centre for Medical Parasitology, 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
| | - Susan Thrane
- Centre for Medical Parasitology, 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
| | - Adam F Sander
- Centre for Medical Parasitology, 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
| | - Thor G Theander
- Centre for Medical Parasitology, 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
| | - Thomas Lavstsen
- Centre for Medical Parasitology, 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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54
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Tessema SK, Nakajima R, Jasinskas A, Monk SL, Lekieffre L, Lin E, Kiniboro B, Proietti C, Siba P, Felgner PL, Doolan DL, Mueller I, Barry AE. Protective Immunity against Severe Malaria in Children Is Associated with a Limited Repertoire of Antibodies to Conserved PfEMP1 Variants. Cell Host Microbe 2020; 26:579-590.e5. [PMID: 31726028 DOI: 10.1016/j.chom.2019.10.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 08/08/2019] [Accepted: 10/18/2019] [Indexed: 01/31/2023]
Abstract
Extreme diversity of the major Plasmodium falciparum antigen, PfEMP1, poses a barrier to identifying targets of immunity to malaria. Here, we used protein microarrays containing hundreds of variants of the DBLα domain of PfEMP1 to cover the diversity of Papua New Guinean (PNG) parasites. Probing the plasma of a longitudinal cohort of malaria-exposed PNG children showed that group 2 DBLα antibodies were moderately associated with a lower risk of uncomplicated malaria, whereas individual variants were only weakly associated with clinical immunity. In contrast, antibodies to 85 individual group 1 and 2 DBLα variants were associated with a 70%-100% reduction in severe malaria. Of these, 17 variants were strong predictors of severe malaria. Analysis of full-length PfEMP1 sequences from PNG samples shows that these 17 variants are linked to pathogenic CIDR domains. This suggests that whereas immunity to uncomplicated malaria requires a broad repertoire of antibodies, immunity to severe malaria targets a subset of conserved variants. These findings provide insights into antimalarial immunity and potential antibody biomarkers for disease risk.
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Affiliation(s)
- Sofonias K Tessema
- Division of Population Health and Immunity, The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, VIC, Australia; Department of Medical Biology, University of Melbourne, Melbourne 3000, VIC, Australia
| | - Rie Nakajima
- Physiology & Biophysics Department, Vaccine R&D Center, University of California, Irvine, Irvine 92697, CA, USA
| | - Algis Jasinskas
- Physiology & Biophysics Department, Vaccine R&D Center, University of California, Irvine, Irvine 92697, CA, USA
| | - Stephanie L Monk
- Division of Population Health and Immunity, The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, VIC, Australia; Department of Medical Biology, University of Melbourne, Melbourne 3000, VIC, Australia
| | - Lea Lekieffre
- Infectious Diseases Programme, QIMR Berghofer Medical Research Institute, Brisbane 4006, QLD, Australia
| | - Enmoore Lin
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Goroka 441, EHG, Papua New Guinea
| | - Benson Kiniboro
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Goroka 441, EHG, Papua New Guinea
| | - Carla Proietti
- Infectious Diseases Programme, QIMR Berghofer Medical Research Institute, Brisbane 4006, QLD, Australia; Australian Institute of Tropical Health and Medicine, James Cook University, Cairns 4878, QLD, Australia
| | - Peter Siba
- Vector Borne Diseases Unit, Papua New Guinea Institute of Medical Research, Goroka 441, EHG, Papua New Guinea
| | - Philip L Felgner
- Physiology & Biophysics Department, Vaccine R&D Center, University of California, Irvine, Irvine 92697, CA, USA
| | - Denise L Doolan
- Infectious Diseases Programme, QIMR Berghofer Medical Research Institute, Brisbane 4006, QLD, Australia; Australian Institute of Tropical Health and Medicine, James Cook University, Cairns 4878, QLD, Australia
| | - Ivo Mueller
- Division of Population Health and Immunity, The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, VIC, Australia; Department of Medical Biology, University of Melbourne, Melbourne 3000, VIC, Australia; Department of Parasites and Insect Vectors, Institut Pasteur, Paris 75015, France
| | - Alyssa E Barry
- Division of Population Health and Immunity, The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, VIC, Australia; Department of Medical Biology, University of Melbourne, Melbourne 3000, VIC, Australia.
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55
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Cabrera A, Neculai D, Tran V, Lavstsen T, Turner L, Kain KC. Plasmodium falciparum-CD36 Structure-Function Relationships Defined by Ortholog Scanning Mutagenesis. J Infect Dis 2020; 219:945-954. [PMID: 30335152 DOI: 10.1093/infdis/jiy607] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 10/12/2018] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The interaction of Plasmodium falciparum-infected erythrocytes (IEs) with the host receptor CD36 is among the most studied host-parasite interfaces. CD36 is a scavenger receptor that binds numerous ligands including the cysteine-rich interdomain region (CIDR)α domains of the erythrocyte membrane protein 1 family (PfEMP1) expressed on the surface of IEs. CD36 is conserved across species, but orthologs display differential binding of IEs. METHODS In this study, we exploited these differences, combined with the recent crystal structure and 3-dimensional modeling of CD36, to investigate malaria-CD36 structure-function relationships and further define IE-CD36 binding interactions. RESULTS We show that a charged surface in the membrane-distal region of CD36 is necessary for IE binding. Moreover, IE interaction with this binding surface is influenced by additional CD36 domains, both proximal to and at a distance from this site. CONCLUSIONS Our data indicate that subtle sequence and spatial differences in these domains modify receptor conformation and regulate the ability of CD36 to selectively interact with its diverse ligands.
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Affiliation(s)
- Ana Cabrera
- SAR Laboratories, Sandra Rotman Centre, Toronto General Hospital-University Health Network, Ontario, Canada
| | - Dante Neculai
- Department of Cell Biology, Zhejiang University, School of Basic Medical Sciences, Hangzhou, People's Republic of China
| | - Vanessa Tran
- SAR Laboratories, Sandra Rotman Centre, Toronto General Hospital-University Health Network, Ontario, Canada
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Rigshospitalet, Denmark
| | - Louise Turner
- Centre for Medical Parasitology, Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Rigshospitalet, Denmark
| | - Kevin C Kain
- SAR Laboratories, Sandra Rotman Centre, Toronto General Hospital-University Health Network, Ontario, Canada.,Tropical Disease Unit, Division of Infectious Diseases, Department of Medicine, University of TorontoOntarioCanada
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56
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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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57
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Otto TD, Assefa SA, Böhme U, Sanders MJ, Kwiatkowski D, Berriman M, Newbold C. Evolutionary analysis of the most polymorphic gene family in falciparum malaria. Wellcome Open Res 2019; 4:193. [PMID: 32055709 PMCID: PMC7001760 DOI: 10.12688/wellcomeopenres.15590.1] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/26/2019] [Indexed: 12/22/2022] Open
Abstract
The var gene family of the human malaria parasite Plasmodium falciparum encode proteins that are crucial determinants of both pathogenesis and immune evasion and are highly polymorphic. Here we have assembled nearly complete var gene repertoires from 2398 field isolates and analysed a normalised set of 714 from across 12 countries. This therefore represents the first large scale attempt to catalogue the worldwide distribution of var gene sequences We confirm the extreme polymorphism of this gene family but also demonstrate an unexpected level of sequence sharing both within and between continents. We show that this is likely due to both the remnants of selective sweeps as well as a worrying degree of recent gene flow across continents with implications for the spread of drug resistance. We also address the evolution of the var repertoire with respect to the ancestral genes within the Laverania and show that diversity generated by recombination is concentrated in a number of hotspots. An analysis of the subdomain structure indicates that some existing definitions may need to be revised From the analysis of this data, we can now understand the way in which the family has evolved and how the diversity is continuously being generated. Finally, we demonstrate that because the genes are distributed across the genome, sequence sharing between genotypes acts as a useful population genetic marker.
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Affiliation(s)
- Thomas D. Otto
- Parasite Genetics, Wellcome Trust Sanger Institute, Hinxton, UK
- Institute of Infection, Immunity & Inflammation, MVLS, University of Glasgow, Glasgow, UK
| | - Sammy A. Assefa
- Parasite Genetics, Wellcome Trust Sanger Institute, Hinxton, UK
| | - Ulrike Böhme
- Parasite Genetics, Wellcome Trust Sanger Institute, Hinxton, UK
| | | | - Dominic Kwiatkowski
- Parasite Genetics, Wellcome Trust Sanger Institute, Hinxton, UK
- The Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Pf3k consortium
- Parasite Genetics, Wellcome Trust Sanger Institute, Hinxton, UK
- Institute of Infection, Immunity & Inflammation, MVLS, University of Glasgow, Glasgow, UK
- The Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
- Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Matt Berriman
- Parasite Genetics, Wellcome Trust Sanger Institute, Hinxton, UK
| | - Chris Newbold
- Parasite Genetics, Wellcome Trust Sanger Institute, Hinxton, UK
- Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
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58
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Gangnard S, Chêne A, Dechavanne S, Srivastava A, Avril M, Smith JD, Gamain B. VAR2CSA binding phenotype has ancient origin and arose before Plasmodium falciparum crossed to humans: implications in placental malaria vaccine design. Sci Rep 2019; 9:16978. [PMID: 31740695 PMCID: PMC6861233 DOI: 10.1038/s41598-019-53334-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 10/24/2019] [Indexed: 11/09/2022] Open
Abstract
VAR2CSA is a leading candidate for developing a placental malaria (PM) vaccine that would protect pregnant women living in malaria endemic areas against placental infections and improve birth outcomes. Two VAR2CSA-based PM vaccines are currently under clinical trials, but it is still unclear if the use of a single VAR2CSA variant will be sufficient to induce a broad enough humoral response in humans to cross-react with genetically diverse parasite populations. Additional immuno-focusing vaccine strategies may therefore be required to identify functionally conserved antibody epitopes in VAR2CSA. We explored the possibility that conserved epitopes could exist between VAR2CSA from the chimpanzee parasite Plasmodium reichenowi and Plasmodium falciparum sequences. Making use of VAR2CSA recombinant proteins originating from both species, we showed that VAR2CSA from P. reichenowi (Pr-VAR2CSA) binds to the placental receptor CSA with high specificity and affinity. Antibodies raised against Pr-VAR2CSA were able to recognize native VAR2CSA from different P. falciparum genotypes and to inhibit the interaction between CSA and P. falciparum-infected erythrocytes expressing different VAR2CSA variants. Our work revealed the existence of cross-species inhibitory epitopes in VAR2CSA and calls for pre-clinical studies assessing the efficacy of novel VAR2CSA-based cross-species boosting regimens.
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Affiliation(s)
- Stéphane Gangnard
- Université de Paris, UMR_S1134, BIGR, INSERM, F-75015, Paris, France.,Institut National de la Transfusion Sanguine, F-75015, Paris, France.,Laboratory of excellence GR-Ex, F-75015, Paris, France
| | - Arnaud Chêne
- Université de Paris, UMR_S1134, BIGR, INSERM, F-75015, Paris, France.,Institut National de la Transfusion Sanguine, F-75015, Paris, France.,Laboratory of excellence GR-Ex, F-75015, Paris, France
| | - Sébastien Dechavanne
- Université de Paris, UMR_S1134, BIGR, INSERM, F-75015, Paris, France.,Institut National de la Transfusion Sanguine, F-75015, Paris, France.,Laboratory of excellence GR-Ex, F-75015, Paris, France
| | - Anand Srivastava
- Université de Paris, UMR_S1134, BIGR, INSERM, F-75015, Paris, France.,Institut National de la Transfusion Sanguine, F-75015, Paris, France.,Laboratory of excellence GR-Ex, F-75015, Paris, France
| | - Marion Avril
- Seattle Children's Research Institute, Seattle, WA, 98109, USA
| | - Joseph D Smith
- Seattle Children's Research Institute, Seattle, WA, 98109, USA.,Department of Global Health, University of Washington, Seattle, WA, 98195, USA
| | - Benoît Gamain
- Université de Paris, UMR_S1134, BIGR, INSERM, F-75015, Paris, France. .,Institut National de la Transfusion Sanguine, F-75015, Paris, France. .,Laboratory of excellence GR-Ex, F-75015, Paris, France.
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59
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Rambhatla JS, Turner L, Manning L, Laman M, Davis TME, Beeson JG, Mueller I, Warrel J, Theander TG, Lavstsen T, Rogerson SJ. Acquisition of Antibodies Against Endothelial Protein C Receptor-Binding Domains of Plasmodium falciparum Erythrocyte Membrane Protein 1 in Children with Severe Malaria. J Infect Dis 2019; 219:808-818. [PMID: 30365003 DOI: 10.1093/infdis/jiy564] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 09/18/2018] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) mediates parasite sequestration in postcapillary venules in P. falciparum malaria. PfEMP1 types can be classified based on their cysteine-rich interdomain region (CIDR) domains. Antibodies to different PfEMP1 types develop gradually after repeated infections as children age, and antibodies to specific CIDR types may confer protection. METHODS Levels of immunoglobulin G to 35 recombinant CIDR domains were measured by means of Luminex assay in acute-stage (baseline) and convalescent-stage plasma samples from Papua New Guinean children with severe or uncomplicated malaria and in healthy age-matched community controls. RESULTS At baseline, antibody levels were similar across the 3 groups. After infection, children with severe malaria had higher antibody levels than those with uncomplicated malaria against the endothelial protein C receptor (EPCR) binding CIDRα1 domains, and this difference was largely confined to older children. Antibodies to EPCR-binding domains increased from presentation to follow-up in severe malaria, but not in uncomplicated malaria. CONCLUSIONS The acquisition of antibodies against EPCR-binding CIDRα1 domains of PfEMP1 after a severe malaria episode suggest that EPCR-binding PfEMP1 may have a role in the pathogenesis of severe malaria in Papua New Guinea.
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Affiliation(s)
- Janavi S Rambhatla
- Department of Medicine, The Peter Doherty Institute for Infection and Immunity, Parkville
| | - Louise Turner
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Denmark
| | - Laurens Manning
- School of Medicine and Pharmacology, University of Western Australia, Harry Perkins Research Institute, Fiona Stanley Hospital, Murdoch
| | - Moses Laman
- Papua New Guinea Institute of Medical Research, Madang
| | - Timothy M E Davis
- School of Medicine and Pharmacology, University of Western Australia, Harry Perkins Research Institute, Fiona Stanley Hospital, Murdoch
| | - James G Beeson
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Australia
| | - Ivo Mueller
- Department of Medical Biology, University of Melbourne, Parkville.,Walter and Eliza Hall Institute of Medical Research, Parkville.,Parasite and Insect Vectors Department, Institut Pasteur, Paris, France
| | | | - Thor G Theander
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Denmark
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Denmark
| | - Stephen J Rogerson
- Department of Medicine, The Peter Doherty Institute for Infection and Immunity, Parkville
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60
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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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Olsen RW, Ecklu-Mensah G, Bengtsson A, Ofori MF, Kusi KA, Koram KA, Hviid L, Adams Y, Jensen ATR. Acquisition of IgG to ICAM-1-Binding DBLβ Domains in the Plasmodium falciparum Erythrocyte Membrane Protein 1 Antigen Family Varies between Groups A, B, and C. Infect Immun 2019; 87:e00224-19. [PMID: 31308082 PMCID: PMC6759304 DOI: 10.1128/iai.00224-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 07/03/2019] [Indexed: 12/31/2022] Open
Abstract
Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is an important malaria virulence factor. The protein family can be divided into clinically relevant subfamilies. ICAM-1-binding group A PfEMP1 proteins also bind endothelial protein C receptor and have been associated with cerebral malaria in children. IgG to these PfEMP1 proteins is acquired later in life than that to group A PfEMP1 not binding ICAM-1. The kinetics of acquisition of IgG to group B and C PfEMP1 proteins binding ICAM-1 is unclear and was studied here. Gene sequences encoding group B and C PfEMP1 with DBLβ domains known to bind ICAM-1 were used to identify additional binders. Levels of IgG specific for DBLβ domains from group A, B, and C PfEMP1 binding or not binding ICAM-1 were measured in plasma from Ghanaian children with or without malaria. Seven new ICAM-1-binding DBLβ domains from group B and C PfEMP1 were identified. Healthy children had higher levels of IgG specific for ICAM-1-binding DBLβ domains from group A than from groups B and C. However, the opposite pattern was found in children with malaria, particularly among young patients. Acquisition of IgG specific for DBLβ domains binding ICAM-1 differs between PfEMP1 groups.
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MESH Headings
- Antibodies, Protozoan/biosynthesis
- Child
- Child, Preschool
- Erythrocytes/immunology
- Erythrocytes/parasitology
- Female
- Gene Expression
- Ghana
- Humans
- Immunoglobulin G/biosynthesis
- Infant
- Intercellular Adhesion Molecule-1/genetics
- Intercellular Adhesion Molecule-1/immunology
- Malaria, Cerebral/genetics
- Malaria, Cerebral/immunology
- Malaria, Cerebral/parasitology
- Malaria, Cerebral/pathology
- Malaria, Falciparum/genetics
- Malaria, Falciparum/immunology
- Malaria, Falciparum/parasitology
- Malaria, Falciparum/pathology
- Male
- Plasmodium falciparum/immunology
- Plasmodium falciparum/pathogenicity
- Polymorphism, Genetic
- Protein Binding
- Protein Domains
- Protozoan Proteins/classification
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Seasons
- Severity of Illness Index
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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
- 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
| | - Kwadwo A Kusi
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Kwadwo A Koram
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - 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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Abstract
PURPOSE OF REVIEW Activated protein C (APC) is a homeostatic coagulation protease with anticoagulant and cytoprotective activities. Focusing on APC's effects in the brain, this review discusses three different scenarios that illustrate how APC functions are intimately affecting the physiology and pathophysiology of the brain. RECENT FINDINGS Cytoprotective APC therapy holds promise for the treatment of ischemic stroke, and a recently completed trial suggested that cytoprotective-selective 3K3A-APC reduced bleeding in ischemic stroke patients. In contrast, APC's anticoagulant activity contributes to brain bleeding as shown by the disproportional upregulation of APC generation in cerebral cavernous malformations lesions in mice. However, too little APC generation also contributes to maladies of the brain, such as in case of cerebral malaria where the binding of infected erythrocytes to the endothelial protein C receptor (EPCR) may interfere with the EPCR-dependent functions of the protein C pathway. Furthermore, discoveries of new activities of APC such as the inhibition of the NLRP3-mediated inflammasome and of new applications of APC therapy such as in Alzheimer's disease and graft-versus-host disease continue to advance our knowledge of this important proteolytic regulatory system. SUMMARY APC's many activities or lack thereof are intimately involved in multiple neuropathologies, providing abundant opportunities for translational research.
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63
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Bachmann A, Bruske E, Krumkamp R, Turner L, Wichers JS, Petter M, Held J, Duffy MF, Sim BKL, Hoffman SL, Kremsner PG, Lell B, Lavstsen T, Frank M, Mordmüller B, Tannich E. Controlled human malaria infection with Plasmodium falciparum demonstrates impact of naturally acquired immunity on virulence gene expression. PLoS Pathog 2019; 15:e1007906. [PMID: 31295334 PMCID: PMC6650087 DOI: 10.1371/journal.ppat.1007906] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 07/23/2019] [Accepted: 06/10/2019] [Indexed: 12/14/2022] Open
Abstract
The pathogenesis of Plasmodium falciparum malaria is linked to the variant surface antigen PfEMP1, which mediates tethering of infected erythrocytes to the host endothelium and is encoded by approximately 60 var genes per parasite genome. Repeated episodes of malaria infection result in the gradual acquisition of protective antibodies against PfEMP1 variants. The antibody repertoire is believed to provide a selective pressure driving the clonal expansion of parasites expressing unrecognized PfEMP1 variants, however, due to the lack of experimental in vivo models there is only limited experimental evidence in support of this concept. To get insight into the impact of naturally acquired immunity on the expressed var gene repertoire early during infection we performed controlled human malaria infections of 20 adult African volunteers with life-long malaria exposure using aseptic, purified, cryopreserved P. falciparum sporozoites (Sanaria PfSPZ Challenge) and correlated serological data with var gene expression patterns from ex vivo parasites. Among the 10 African volunteers who developed patent infections, individuals with low antibody levels showed a steep rise in parasitemia accompanied by broad activation of multiple, predominantly subtelomeric var genes, similar to what we previously observed in naïve volunteers. In contrast, individuals with intermediate antibody levels developed asymptomatic infections and the ex vivo parasite populations expressed only few var gene variants, indicative of clonal selection. Importantly, in contrast to parasites from naïve volunteers, expression of var genes coding for endothelial protein C receptor (EPCR)-binding PfEMP1 that are associated with severe childhood malaria was rarely detected in semi-immune adult African volunteers. Moreover, we followed var gene expression for up to six parasite replication cycles and demonstrated for the first time in vivo a shift in the dominant var gene variant. In conclusion, our data suggest that P. falciparum activates multiple subtelomeric var genes at the onset of blood stage infection facilitating rapid expansion of parasite clones which express PfEMP1 variants unrecognized by the host's immune system, thus promoting overall parasite survival in the face of host immunity.
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Affiliation(s)
- Anna Bachmann
- Department of Molecular Parasitology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck-Riems, Germany
| | - Ellen Bruske
- Institute of Tropical Medicine, University Hospital Tübingen, Tübingen, Germany
| | - Ralf Krumkamp
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck-Riems, Germany
- Infectious Disease Epidemiology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Louise Turner
- Centre for Medical Parasitology, University of Copenhagen, Copenhagen K, Denmark
| | - J. Stephan Wichers
- Department of Molecular Parasitology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Michaela Petter
- Mikrobiologisches Institut–Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Erlangen, Germany
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Jana Held
- Institute of Tropical Medicine, University Hospital Tübingen, Tübingen, Germany
| | - Michael F. Duffy
- School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
| | | | | | - Peter G. Kremsner
- Institute of Tropical Medicine, University Hospital Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Germany
| | - Bertrand Lell
- Institute of Tropical Medicine, University Hospital Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- German Center for Infection Research (DZIF), African partner institution, CERMEL, Gabon
| | - Thomas Lavstsen
- Centre for Medical Parasitology, University of Copenhagen, Copenhagen K, Denmark
| | - Matthias Frank
- Institute of Tropical Medicine, University Hospital Tübingen, Tübingen, Germany
| | - Benjamin Mordmüller
- Institute of Tropical Medicine, University Hospital Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Germany
| | - Egbert Tannich
- Department of Molecular Parasitology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck-Riems, Germany
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64
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Kamaliddin C, Rombaut D, Guillochon E, Royo J, Ezinmegnon S, Agbota G, Huguet S, Guemouri S, Peirera C, Coppée R, Broussard C, Alao JM, Aubouy A, Guillonneau F, Deloron P, Bertin GI. From genomic to LC-MS/MS evidence: Analysis of PfEMP1 in Benin malaria cases. PLoS One 2019; 14:e0218012. [PMID: 31251748 PMCID: PMC6599223 DOI: 10.1371/journal.pone.0218012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 05/23/2019] [Indexed: 11/18/2022] Open
Abstract
Background PfEMP1 is the major protein from parasitic origin involved in the pathophysiology of severe malaria, and PfEMP1 domain subtypes are associated with the infection outcome. In addition, PfEMP1 variability is endless and current publicly available protein repositories do not reflect the high diversity of the sequences of PfEMP1 proteins. The identification of PfEMP1 protein sequences expressed with samples remains challenging. The aim of our study is to identify the different PfEMP1 proteins variants expressed within patient samples, and therefore identify PfEMP1 proteins domains expressed by patients presenting uncomplicated malaria or severe malaria in malaria endemic setting in Cotonou, Benin. Methods We performed a multi-omic approach to decipher PfEMP1 expression at the patient’s level in different clinical settings. Using a combination of whole genome sequencing approach and RNA sequencing, we were able to identify new PfEMP1 sequences and created a new custom protein database. This database was used for protein identification in mass spectrometry analysis. Results The differential expression analysis of RNAsequencing data shows an increased expression of the var domains transcripts DBLα1.7, DBLα1.1, DBLα2 and DBLβ12 in samples from patients suffering from Cerebral Malaria compared to Uncomplicated Malaria. Our approach allowed us to attribute PfEMP1 sequences to each sample and identify new peptides associated to PfEMP1 proteins in mass spectrometry. Conclusion We highlighted the diversity of the PfEMP1 sequences from field sample compared to reference sequences repositories and confirmed the validity of our approach. These findings should contribute to further vaccine development strategies based on PfEMP1 proteins.
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Affiliation(s)
| | - David Rombaut
- 3p5 Proteomic Facility, Université de Paris, Paris, France
| | | | - Jade Royo
- UMR 152 – PHARMADEV, IRD, Paul Sabatier Toulouse III University, Toulouse, France
| | - Sem Ezinmegnon
- UMR 261 – MERIT, IRD, Université de Paris, Paris, France
- Centre pour la Recherche et l’Etude du paludisme associé à la grossesse et à l’enfance, Cotonou, Bénin
| | - Gino Agbota
- UMR 261 – MERIT, IRD, Université de Paris, Paris, France
- Centre pour la Recherche et l’Etude du paludisme associé à la grossesse et à l’enfance, Cotonou, Bénin
| | - Stéphanie Huguet
- Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRA, Université Paris-Sud, Université d’Evry, Université Paris-Saclay, Gif sur Yvette, France
- Institute of Plant Sciences Paris-Saclay (IPS2), CNRS, INRA Université Paris-Diderot, Sorbonne Paris-Cité, Gif sur Yvette, France
| | - Sayeh Guemouri
- UMR 261 – MERIT, IRD, Université de Paris, Paris, France
| | - Céline Peirera
- UMR 261 – MERIT, IRD, Université de Paris, Paris, France
| | - Romain Coppée
- UMR 261 – MERIT, IRD, Université de Paris, Paris, France
| | | | | | - Agnès Aubouy
- UMR 152 – PHARMADEV, IRD, Paul Sabatier Toulouse III University, Toulouse, France
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Binding Heterogeneity of Plasmodium falciparum to Engineered 3D Brain Microvessels Is Mediated by EPCR and ICAM-1. mBio 2019; 10:mBio.00420-19. [PMID: 31138740 PMCID: PMC6538777 DOI: 10.1128/mbio.00420-19] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cerebral malaria research has been hindered by the inaccessibility of the brain. Here, we have developed an engineered 3D human brain microvessel model that mimics the blood flow rates and architecture of small blood vessels to study how P. falciparum-infected human erythrocytes attach to brain endothelial cells. By studying parasite lines with different adhesive properties, we show that the malaria parasite binding rate is heterogeneous and strongly influenced by physiological differences in flow and whether the endothelium has been previously activated by TNF-α, a proinflammatory cytokine that is linked to malaria disease severity. We also show the importance of human EPCR and ICAM-1 in parasite binding. Our model sheds new light on how P. falciparum binds within brain microvessels and provides a powerful method for future investigations of recruitment of human brain pathogens to the blood vessel lining of the brain. Cerebral malaria is a severe neurological complication associated with sequestration of Plasmodium falciparum-infected erythrocytes (IE) in the brain microvasculature, but the specific binding interactions remain under debate. Here, we have generated an engineered three-dimensional (3D) human brain endothelial microvessel model and studied P. falciparum binding under the large range of physiological flow velocities that occur in both health and disease. Perfusion assays on 3D microvessels reveal previously unappreciated phenotypic heterogeneity in parasite binding to tumor necrosis factor alpha (TNF-α)-activated brain endothelial cells. While clonal parasite lines expressing a group B P. falciparum erythrocyte membrane protein 1 (PfEMP1) present an increase in binding to activated 3D microvessels, P. falciparum-IE expressing DC8-PfEMP1 present a decrease in binding. The differential response to endothelium activation is mediated by surface expression changes of endothelial protein C receptor (EPCR) and intercellular adhesion molecule 1 (ICAM-1). These findings demonstrate heterogeneity in parasite binding and provide evidence for a parasite strategy to adapt to a changing microvascular environment during infection. The engineered 3D human brain microvessel model provides new mechanistic insight into parasite binding and opens opportunities for further studies on malaria pathogenesis and parasite-vessel interactions.
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66
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Meta-analysis of Plasmodium falciparum var Signatures Contributing to Severe Malaria in African Children and Indian Adults. mBio 2019; 10:mBio.00217-19. [PMID: 31040236 PMCID: PMC6495371 DOI: 10.1128/mbio.00217-19] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The clinical presentation of severe Plasmodium falciparum malaria differs between children and adults, but the mechanistic basis for this remains unclear. Contributing factors to disease severity include total parasite biomass and the diverse cytoadhesive properties mediated by the polymorphic var gene parasite ligand family displayed on infected erythrocytes. To explore these factors, we performed a multicohort analysis of the contribution of var expression and parasite biomass to severe malaria in two previously published pediatric cohorts in Tanzania and Malawi and an adult cohort in India. Machine learning analysis revealed independent and complementary roles for var adhesion types and parasite biomass in adult and pediatric severe malaria and showed that similar var profiles, including upregulation of group A and DC8 var, predict severe malaria in adults and children. Among adults, patients with multiorgan complications presented infections with significantly higher parasite biomass without significant differences in var adhesion types. Conversely, pediatric patients with specific complications showed distinct var signatures. Cerebral malaria patients showed broadly increased expression of var genes, in particular group A and DC8 var, while children with severe malaria anemia were classified based on high transcription of DC8 var only. This study represents the first large multisite meta-analysis of var expression, and it demonstrates the presence of common var profiles in severe malaria patients of different ages across distant geographical sites, as well as syndrome-specific disease signatures. The complex associations between parasite biomass, var adhesion type, and clinical presentation revealed here represent the most comprehensive picture so far of the relationship between cytoadhesion, parasite load, and clinical syndrome.IMPORTANCE P. falciparum malaria can cause multiple disease complications that differ by patient age. Previous studies have attempted to address the roles of parasite adhesion and biomass in disease severity; however, these studies have been limited to single geographical sites, and there is limited understanding of how parasite adhesion and biomass interact to influence disease manifestations. In this meta-analysis, we compared parasite disease determinants in African children and Indian adults. This study demonstrates that parasite biomass and specific subsets of var genes are independently associated with detrimental outcomes in both childhood and adult malaria. We also explored how parasite var adhesion types and biomass play different roles in the development of specific severe malaria pathologies, including childhood cerebral malaria and multiorgan complications in adults. This work represents the largest study to date of the role of both var adhesion types and biomass in severe malaria.
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67
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Quintana MDP, Ecklu-Mensah G, Tcherniuk SO, Ditlev SB, Oleinikov AV, Hviid L, Lopez-Perez M. Comprehensive analysis of Fc-mediated IgM binding to the Plasmodium falciparum erythrocyte membrane protein 1 family in three parasite clones. Sci Rep 2019; 9:6050. [PMID: 30988351 PMCID: PMC6465264 DOI: 10.1038/s41598-019-42585-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 04/03/2019] [Indexed: 12/14/2022] Open
Abstract
PfEMP1 is a family of adhesive proteins expressed on the surface of Plasmodium falciparum-infected erythrocytes (IEs), where they mediate adhesion of IEs to a range of host receptors. Efficient PfEMP1-dependent IE sequestration often depends on soluble serum proteins, including IgM. Here, we report a comprehensive investigation of which of the about 60 var gene-encoded PfEMP1 variants per parasite genome can bind IgM via the Fc part of the antibody molecule, and which of the constituent domains of those PfEMP1 are involved. We erased the epigenetic memory of var gene expression in three distinct P. falciparum clones, 3D7, HB3, and IT4/FCR3 by promoter titration, and then isolated individual IEs binding IgM from malaria-unexposed individuals by fluorescence-activated single-cell sorting. The var gene transcription profiles of sub-clones measured by real-time qPCR were used to identify potential IgM-binding PfEMP1 variants. Recombinant DBL and CIDR domains corresponding to those variants were tested by ELISA and protein arrays to confirm their IgM-binding capacity. Selected DBL domains were used to raise specific rat anti-sera to select IEs with uniform expression of candidate PfEMP1 proteins. Our data document that IgM-binding PfEMP1 proteins are common in each of the three clones studied, and that the binding epitopes are mainly found in DBLε and DBLζ domains near the C-terminus.
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Affiliation(s)
- Maria Del Pilar Quintana
- 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
| | - Sergey O Tcherniuk
- Charles E Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Sisse Bolm Ditlev
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Andrew V Oleinikov
- Charles E Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - 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, Rigshospitalet, Copenhagen, Denmark.
| | - Mary Lopez-Perez
- 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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68
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Fougeroux C, Turner L, Bojesen AM, Lavstsen T, Holst PJ. Modified MHC Class II-Associated Invariant Chain Induces Increased Antibody Responses against Plasmodium falciparum Antigens after Adenoviral Vaccination. THE JOURNAL OF IMMUNOLOGY 2019; 202:2320-2331. [PMID: 30833346 DOI: 10.4049/jimmunol.1801210] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 02/01/2019] [Indexed: 01/04/2023]
Abstract
Adenoviral vectors can induce T and B cell immune responses to Ags encoded in the recombinant vector. The MHC class II invariant chain (Ii) has been used as an adjuvant to enhance T cell responses to tethered Ag encoded in adenoviral vectors. In this study, we modified the Ii adjuvant by insertion of a furin recognition site (Ii-fur) to obtain a secreted version of the Ii. To test the capacity of this adjuvant to enhance immune responses, we recombined vectors to encode Plasmodium falciparum virulence factors: two cysteine-rich interdomain regions (CIDR) α1 (IT4var19 and PFCLINvar30 var genes), expressed as a dimeric Ag. These domains are members of a highly polymorphic protein family involved in the vascular sequestration and immune evasion of parasites in malaria. The Ii-fur molecule directed secretion of both Ags in African green monkey cells and functioned as an adjuvant for MHC class I and II presentation in T cell hybridomas. In mice, the Ii-fur adjuvant induced a similar T cell response, as previously demonstrated with Ii, accelerated and enhanced the specific Ab response against both CIDR Ags, with an increased binding capacity to the cognate endothelial protein C receptor, and enhanced the breadth of the response toward different CIDRs. We also demonstrate that the endosomal sorting signal, secretion, and the C-terminal part of Ii were needed for the full adjuvant effect for Ab responses. We conclude that engineered secretion of Ii adjuvant-tethered Ags establishes a single adjuvant and delivery vehicle platform for potent T and B cell-dependent immunity.
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Affiliation(s)
- Cyrielle Fougeroux
- Center for Medical Parasitology, Department of International Health, Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark; and
| | - Louise Turner
- Center for Medical Parasitology, Department of International Health, Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark; and
| | - Anders Miki Bojesen
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg, Denmark
| | - Thomas Lavstsen
- Center for Medical Parasitology, Department of International Health, Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark; and
| | - Peter Johannes Holst
- Center for Medical Parasitology, Department of International Health, Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark; and
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69
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Chan JA, Boyle MJ, Moore KA, Reiling L, Lin Z, Hasang W, Avril M, Manning L, Mueller I, Laman M, Davis T, Smith JD, Rogerson SJ, Simpson JA, Fowkes FJI, Beeson JG. Antibody Targets on the Surface of Plasmodium falciparum-Infected Erythrocytes That Are Associated With Immunity to Severe Malaria in Young Children. J Infect Dis 2019; 219:819-828. [PMID: 30365004 PMCID: PMC6376912 DOI: 10.1093/infdis/jiy580] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 10/15/2018] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Sequestration of Plasmodium falciparum-infected erythrocytes (IEs) in the microvasculature contributes to pathogenesis of severe malaria in children. This mechanism is mediated by antigens expressed on the IE surface. However, knowledge of specific targets and functions of antibodies to IE surface antigens that protect against severe malaria is limited. METHODS Antibodies to IE surface antigens were examined in a case-control study of young children in Papua New Guinea presenting with severe or uncomplicated malaria (n = 448), using isolates with a virulent phenotype associated with severe malaria, and functional opsonic phagocytosis assays. We used genetically modified isolates and recombinant P. falciparum erythrocyte membrane protein 1 (PfEMP1) domains to quantify PfEMP1 as a target of antibodies associated with disease severity. RESULTS Antibodies to the IE surface and recombinant PfEMP1 domains were significantly higher in uncomplicated vs severe malaria and were boosted following infection. The use of genetically modified P. falciparum revealed that PfEMP1 was a major target of antibodies and that PfEMP1-specific antibodies were associated with reduced odds of severe malaria. Furthermore, antibodies promoting the opsonic phagocytosis of IEs by monocytes were lower in those with severe malaria. CONCLUSIONS Findings suggest that PfEMP1 is a dominant target of antibodies associated with reduced risk of severe malaria, and function in part by promoting opsonic phagocytosis.
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Affiliation(s)
- Jo-Anne Chan
- Burnet Institute for Medical Research and Public Health, Melbourne
| | - Michelle J Boyle
- Burnet Institute for Medical Research and Public Health, Melbourne
| | - Kerryn A Moore
- Burnet Institute for Medical Research and Public Health, Melbourne
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Parkville
- Murdoch Children’s Research Institute, Royal Children’s Hospital, Melbourne
| | - Linda Reiling
- Burnet Institute for Medical Research and Public Health, Melbourne
| | - Zaw Lin
- Burnet Institute for Medical Research and Public Health, Melbourne
| | - Wina Hasang
- Department of Medicine, Melbourne School of Population and Global Health, University of Melbourne, Parkville, Australia
| | - Marion Avril
- Center for Infectious Diseases Research, Seattle, Washington
| | - Laurens Manning
- Papua New Guinea Institute of Medical Research, Madang
- University of Western Australia, Perth
| | - Ivo Mueller
- Walter and Eliza Hall Institute of Medical Research, Parkville
| | - Moses Laman
- Papua New Guinea Institute of Medical Research, Madang
| | | | - Joseph D Smith
- Center for Infectious Diseases Research, Seattle, Washington
| | - Stephen J Rogerson
- Department of Medicine, Melbourne School of Population and Global Health, University of Melbourne, Parkville, Australia
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Parkville
| | - Freya J I Fowkes
- Burnet Institute for Medical Research and Public Health, Melbourne
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Parkville
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
- Department of Infectious Diseases, Monash University, Melbourne, Victoria, Australia
| | - James G Beeson
- Burnet Institute for Medical Research and Public Health, Melbourne
- Department of Medicine, Melbourne School of Population and Global Health, University of Melbourne, Parkville, Australia
- Department of Microbiology, Monash University, Melbourne, Victoria, Australia
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70
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Abstract
PURPOSE OF REVIEW Endothelial cell protein C receptor (EPCR), a transmembrane glycoprotein present on the surface of endothelial cells and other cell types, is an essential component of the protein C (PC) anticoagulant system. EPCR is also shown to play a critical role in mediating activated protein C (APC)-induced cytoprotective signaling. The purpose of this review is to outline the mechanisms of EPCR-dependent cell signaling and discuss recent findings made in this area. RECENT FINDINGS Recent studies showed that the cleavage of protease-activated receptor (PAR)1 at a noncanonical site by APC-EPCR or the canonical site by thrombin when PC occupies EPCR induces β-arrestin-2-mediated biased cytoprotective signaling. Factor VIIa binding to EPCR is also shown to induce the cytoprotective signaling. EPCR is found to be a reliable surface marker for identifying human hematopoietic stem cells in culture. EPCR, binding to diverse ligands, is thought to play a role in the pathogenesis of severe malaria, immune functions, and cancer by either blocking the APC-mediated signaling or by mechanisms that are yet to be elucidated. SUMMARY Recent studies provide a mechanistic basis to how EPCR contributes to PAR1-mediated biased signaling. EPCR may play a role in influencing a wide array of biological functions by binding to diverse ligands.
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71
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Derkach A, Otim I, Pfeiffer RM, Onabajo OO, Legason ID, Nabalende H, Ogwang MD, Kerchan P, Talisuna AO, Ayers LW, Reynolds SJ, Nkrumah F, Neequaye J, Bhatia K, Theander TG, Prokunina-Olsson L, Turner L, Goedert JJ, Lavstsen T, Mbulaiteye SM. Associations between IgG reactivity to Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) antigens and Burkitt lymphoma in Ghana and Uganda case-control studies. EBioMedicine 2018; 39:358-368. [PMID: 30579868 PMCID: PMC6355394 DOI: 10.1016/j.ebiom.2018.12.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 12/10/2018] [Accepted: 12/12/2018] [Indexed: 01/26/2023] Open
Abstract
Background Endemic Burkitt lymphoma (eBL) is an aggressive childhood B-cell lymphoma linked to Plasmodium falciparum (Pf) malaria in sub-Saharan Africa. We investigated antibody reactivity to several human receptor-binding domains of the Pf erythrocyte membrane protein 1 (PfEMP1) that play a key role in malaria pathogenesis and are targets of acquired immunity to malaria. Methods Serum/plasma IgG antibody reactivity was measured to 22 Pf antigens, including 18 to PfEMP1 CIDR domains between cases and controls from two populations (149 eBL cases and 150 controls from Ghana and 194 eBL cases and 600 controls from Uganda). Adjusted odds ratios (aORs) for case-control associations were estimated by logistic regression. Findings There was stronger reactivity to the severe malaria associated CIDRα1 domains than other CIDR domains both in cases and controls. eBL cases reacted to fewer antigens than controls (Ghana: p = 0·001; Uganda: p = 0·03), with statistically significant lower ORs associated with reactivity to 13+ antigens in Ghana (aOR 0·39, 95% CI 0·24–0·63; pheterogeneity = 0·00011) and Uganda (aOR 0·60, 95% CI 0.41–0·88; pheterogeneity = 0·008). eBL was inversely associated with reactivity, coded as quartiles, to group A variant CIDRδ1 (ptrend = 0·035) in Ghana and group B CD36-binding variants CIDRα2·2 (ptrend = 0·006) and CIDRα2·4 (ptrend = 0·033) in Uganda, and positively associated with reactivity to SERA5 in Ghana (ptrend = 0·017) and Uganda (ptrend = 0·007) and group A CIDRα1·5 variant in Uganda only (ptrend = 0·034). Interpretation eBL cases reacted to fewer antigens than controls using samples from two populations, Ghana and Uganda. Attenuated humoral immunity to Pf EMP1 may contribute to susceptibility to low-grade malaria and eBL risk. Funding Intramural Research Program, National Cancer Institute and National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services.
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Affiliation(s)
- Andriy Derkach
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Isaac Otim
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
| | - Ruth M Pfeiffer
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Olusegun O Onabajo
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ismail D Legason
- EMBLEM Study, African Field Epidemiology Network, Kampala, Uganda
| | | | | | | | - Ambrose O Talisuna
- World Health Organization, Regional Office for Africa, Brazzaville, Congo
| | - Leona W Ayers
- Department of Pathology, The Ohio State University, Columbus, OH, USA
| | - Steven J Reynolds
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | | | - Janet Neequaye
- Department of Child Health, Korle Bu University Teaching Hospital in Accra, Ghana
| | - Kishor Bhatia
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Thor G Theander
- Centre for Medical Parasitology, Department of International Health, Immunology & Microbiology, University of Copenhagen and Department of Infectious Diseases, Rigs Hospitalet, Copenhagen, Denmark
| | - Ludmila Prokunina-Olsson
- Laboratory of Translational Genomics, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Louise Turner
- Centre for Medical Parasitology, Department of International Health, Immunology & Microbiology, University of Copenhagen and Department of Infectious Diseases, Rigs Hospitalet, Copenhagen, Denmark
| | - James J Goedert
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of International Health, Immunology & Microbiology, University of Copenhagen and Department of Infectious Diseases, Rigs Hospitalet, Copenhagen, Denmark
| | - Sam M Mbulaiteye
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
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72
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Immunization with Recombinant Plasmodium falciparum Erythrocyte Membrane Protein 1 CIDRα1 Domains Induces Domain Subtype Inhibitory Antibodies. Infect Immun 2018; 86:IAI.00435-18. [PMID: 30150256 DOI: 10.1128/iai.00435-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 08/22/2018] [Indexed: 12/19/2022] Open
Abstract
Plasmodium falciparum malaria pathogenesis is tied to the sequestration of parasites in the microvasculature. Parasite sequestration leading to severe malaria is mediated by P. falciparum erythrocyte membrane protein 1 (PfEMP1) binding to endothelial protein C receptor (EPCR) via its CIDRα1 domains. CIDRα1 domains are targets of naturally acquired immunity, and a vaccine eliciting antibodies inhibiting the EPCR binding of CIDRα1 could potentially prevent disease and death from malaria. CIDRα1 domains have diversified in sequence to escape immune recognition but preserved structure to maintain EPCR binding. The EPCR-binding CIDRα1 domains separate into six major sequence types predicted to form a conserved structure in which only the amino acids essential for EPCR binding are highly conserved. Here, we investigated whether antibodies elicited by vaccination with single or multiple recombinant CIDRα1 domains are able to bind and inhibit diverse CIDRα1 domains. We found that EPCR binding-inhibitory antibodies to CIDRα1 variants closely related to those used for vaccination are readily elicited, whereas antibodies binding distant CIDRα1 variants are sporadically generated and are rarely inhibitory. Despite this, sequence similarity correlated poorly with the ability of induced antibodies to inhibit across diverse variants, and no continuous sequence regions of importance for cross-inhibitory antibodies could be identified. This suggested that epitopes of cross-variant inhibitory antibodies were predominantly conformational. Vaccination with immunogens engineered to focus immune responses to specific epitopes or an optimal choice of multiple CIDRα1 variants may improve elicitation of broadly reactive and inhibitory antibody responses.
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73
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Bruske E, Otto TD, Frank M. Whole genome sequencing and microsatellite analysis of the Plasmodium falciparum E5 NF54 strain show that the var, rifin and stevor gene families follow Mendelian inheritance. Malar J 2018; 17:376. [PMID: 30348135 PMCID: PMC6198375 DOI: 10.1186/s12936-018-2503-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 10/03/2018] [Indexed: 12/30/2022] Open
Abstract
Background Plasmodium falciparum exhibits a high degree of inter-isolate genetic diversity in its variant surface antigen (VSA) families: P. falciparum erythrocyte membrane protein 1, repetitive interspersed family (RIFIN) and subtelomeric variable open reading frame (STEVOR). The role of recombination for the generation of this diversity is a subject of ongoing research. Here the genome of E5, a sibling of the 3D7 genome strain is presented. Short and long read whole genome sequencing (WGS) techniques (Ilumina, Pacific Bioscience) and a set of 84 microsatellites (MS) were employed to characterize the 3D7 and non-3D7 parts of the E5 genome. This is the first time that VSA genes in sibling parasites were analysed with long read sequencing technology. Results Of the 5733 E5 genes only 278 genes, mostly var and rifin/stevor genes, had no orthologues in the 3D7 genome. WGS and MS analysis revealed that chromosomal crossovers occurred at a rate of 0–3 per chromosome. var, stevor and rifin genes were inherited within the respective non-3D7 or 3D7 chromosomal context. 54 of the 84 MS PCR fragments correctly identified the respective MS as 3D7- or non-3D7 and this correlated with var and rifin/stevor gene inheritance in the adjacent chromosomal regions. E5 had 61 var and 189 rifin/stevor genes. One large non-chromosomal recombination event resulted in a new var gene on chromosome 14. The remainder of the E5 3D7-type subtelomeric and central regions were identical to 3D7. Conclusions The data show that the rifin/stevor and var gene families represent the most diverse compartments of the P. falciparum genome but that the majority of var genes are inherited without alterations within their respective parental chromosomal context. Furthermore, MS genotyping with 54 MS can successfully distinguish between two sibling progeny of a natural P. falciparum cross and thus can be used to investigate identity by descent in field isolates. Electronic supplementary material The online version of this article (10.1186/s12936-018-2503-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ellen Bruske
- Institute of Tropical Medicine, University of Tuebingen, Wilhelmstr. 27, 72074, Tuebingen, Germany
| | - Thomas D Otto
- Malaria Programme, Wellcome Trust Sanger Institute, Hinxton, CB10 1SA, UK. .,Centre of Immunobiology, Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
| | - Matthias Frank
- Institute of Tropical Medicine, University of Tuebingen, Wilhelmstr. 27, 72074, Tuebingen, Germany.
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74
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Uskov AN, Soloviev AI, Kravtsov VY, Gudkov RV, Kolomoets EV, Levkovskiy AE. MOLECULAR-GENETIC MECHANISMS OF PLASMODIUM FALCIPARUM VIRULENCE AND TROPICAL MALARIA PATHOGENESIS. ACTA ACUST UNITED AC 2018. [DOI: 10.22625/2072-6732-2018-10-3-23-29] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
There is introduced the analysis of molecular-genetic mechanisms of tropical malaria pathogenesis and P. falciparum virulence. It is shown, that pathogenesis of tropical malaria is associated with the properties of red blood cells membrane surface (RBCs or erythrocytes) that are infected by P. falciparum. There are «knobs structures» on membrane surface infected RBCs. Knobs structures contains a complex of P. falciparum proteins – PfEMP1 (Plasmodium falciparum erythrocyte membrane protein 1). PfEMP1 is associated with virulence of P. falciparum. Complex PfEMP1 has difficult polymorphous structure. Domains of PfEMP1 are able to associate with different cell receptors. Virulence`s individual components of the main factor are selectively sensitive to different tissues and organs. The severity of the clinical malaria infection course depends on the complex structure PfEMP1 of malaria parasites. Composition of polypeptide PfEMP1 is determined by var-complex. Nowadays there are 60 variants of var-complex. Regulation of gene expression, forming part of the var-complex, is carried out on a molecular-genetic level, cellular level, tissue level. Modern research in this area are aimed to explore genes polymorphism of the virulence`s main factor, to identify mechanism of its differential expression. Search of molecular – genetic markers is relevant to develop methods of gene diagnostic and malaria vaccine.
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Affiliation(s)
- A. N. Uskov
- Pediatric Research and Clinical Center for Infectious Diseases
| | | | | | | | - E. V. Kolomoets
- Medical serves of Compagnie des Bauxites de Kindia (СВК of UC Rusal)
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75
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Glennon EKK, Dankwa S, Smith JD, Kaushansky A. Opportunities for Host-targeted Therapies for Malaria. Trends Parasitol 2018; 34:843-860. [PMID: 30122551 PMCID: PMC6168423 DOI: 10.1016/j.pt.2018.07.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/20/2018] [Accepted: 07/23/2018] [Indexed: 12/19/2022]
Abstract
Despite the recent successes of artemisinin-based antimalarial drugs, many still die from severe malaria, and eradication efforts are hindered by the limited drugs currently available to target transmissible gametocyte parasites and liver-resident dormant Plasmodium vivax hypnozoites. Host-targeted therapy is a new direction for infectious disease drug development and aims to interfere with host molecules, pathways, or networks that are required for infection or that contribute to disease. Recent advances in our understanding of host pathways involved in parasite development and pathogenic mechanisms in severe malaria could facilitate the development of host-targeted interventions against Plasmodium infection and malaria disease. This review discusses new opportunities for host-targeted therapeutics for malaria and the potential to harness drug polypharmacology to simultaneously target multiple host pathways using a single drug intervention.
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Affiliation(s)
- Elizabeth K K Glennon
- Center for Infectious Disease Research, 307 Westlake Ave N Suite 500, Seattle, WA 98109, USA; Department of Global Health, University of Washington, Harris Hydraulics Laboratory, Box 357965, Seattle, WA 98195, USA; These authors made an equal contribution
| | - Selasi Dankwa
- Center for Infectious Disease Research, 307 Westlake Ave N Suite 500, Seattle, WA 98109, USA; These authors made an equal contribution
| | - Joseph D Smith
- Center for Infectious Disease Research, 307 Westlake Ave N Suite 500, Seattle, WA 98109, USA; Department of Global Health, University of Washington, Harris Hydraulics Laboratory, Box 357965, Seattle, WA 98195, USA
| | - Alexis Kaushansky
- Center for Infectious Disease Research, 307 Westlake Ave N Suite 500, Seattle, WA 98109, USA; Department of Global Health, University of Washington, Harris Hydraulics Laboratory, Box 357965, Seattle, WA 98195, USA.
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76
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Bruun TJ, Andersson AMC, Draper SJ, Howarth M. Engineering a Rugged Nanoscaffold To Enhance Plug-and-Display Vaccination. ACS NANO 2018; 12:8855-8866. [PMID: 30028591 PMCID: PMC6158681 DOI: 10.1021/acsnano.8b02805] [Citation(s) in RCA: 159] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 07/20/2018] [Indexed: 05/24/2023]
Abstract
Nanoscale organization is crucial to stimulating an immune response. Using self-assembling proteins as multimerization platforms provides a safe and immunogenic system to vaccinate against otherwise weakly immunogenic antigens. Such multimerization platforms are generally based on icosahedral viruses and have led to vaccines given to millions of people. It is unclear whether synthetic protein nanoassemblies would show similar potency. Here we take the computationally designed porous dodecahedral i301 60-mer and rationally engineer this particle, giving a mutated i301 (mi3) with improved particle uniformity and stability. To simplify the conjugation of this nanoparticle, we employ a SpyCatcher fusion of mi3, such that an antigen of interest linked to the SpyTag peptide can spontaneously couple through isopeptide bond formation (Plug-and-Display). SpyCatcher-mi3 expressed solubly to high yields in Escherichia coli, giving more than 10-fold greater yield than a comparable phage-derived icosahedral nanoparticle, SpyCatcher-AP205. SpyCatcher-mi3 nanoparticles showed high stability to temperature, freeze-thaw, lyophilization, and storage over time. We demonstrate approximately 95% efficiency coupling to different transmission-blocking and blood-stage malaria antigens. Plasmodium falciparum CyRPA was conjugated to SpyCatcher-mi3 nanoparticles and elicited a high avidity antibody response, comparable to phage-derived virus-like particles despite their higher valency and RNA cargo. The simple production, precise derivatization, and exceptional ruggedness of this nanoscaffold should facilitate broad application for nanobiotechnology and vaccine development.
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Affiliation(s)
- Theodora
U. J. Bruun
- Department
of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Anne-Marie C. Andersson
- Department
of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Simon J. Draper
- Jenner
Institute, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Mark Howarth
- Department
of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
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77
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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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78
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Hviid L, Lavstsen T, Jensen AT. A vaccine targeted specifically to prevent cerebral malaria - is there hope? Expert Rev Vaccines 2018; 17:565-567. [PMID: 29898617 DOI: 10.1080/14760584.2018.1488591] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Lars Hviid
- a Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences , University of Copenhagen , Copenhagen , Denmark.,b Department of Infectious Diseases , Copenhagen University Hospital (Rigshospitalet) , Copenhagen , Denmark
| | - Thomas Lavstsen
- a Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences , University of Copenhagen , Copenhagen , Denmark.,b Department of Infectious Diseases , Copenhagen University Hospital (Rigshospitalet) , Copenhagen , Denmark
| | - Anja Tr Jensen
- a Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences , University of Copenhagen , Copenhagen , Denmark.,b Department of Infectious Diseases , Copenhagen University Hospital (Rigshospitalet) , Copenhagen , Denmark
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79
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Rorick MM, Baskerville EB, Rask TS, Day KP, Pascual M. Identifying functional groups among the diverse, recombining antigenic var genes of the malaria parasite Plasmodium falciparum from a local community in Ghana. PLoS Comput Biol 2018; 14:e1006174. [PMID: 29897905 PMCID: PMC6016947 DOI: 10.1371/journal.pcbi.1006174] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 06/25/2018] [Accepted: 05/03/2018] [Indexed: 11/18/2022] Open
Abstract
A challenge in studying diverse multi-copy gene families is deciphering distinct functional types within immense sequence variation. Functional changes can in some cases be tracked through the evolutionary history of a gene family; however phylogenetic approaches are not possible in cases where gene families diversify primarily by recombination. We take a network theoretical approach to functionally classify the highly recombining var antigenic gene family of the malaria parasite Plasmodium falciparum. We sample var DBLα sequence types from a local population in Ghana, and classify 9,276 of these variants into just 48 functional types. Our approach is to first decompose each sequence type into its constituent, recombining parts; we then use a stochastic block model to identify functional groups among the parts; finally, we classify the sequence types based on which functional groups they contain. This method for functional classification does not rely on an inferred phylogenetic history, nor does it rely on inferring function based on conserved sequence features. Instead, it infers functional similarity among recombining parts based on the sharing of similar co-occurrence interactions with other parts. This method can therefore group sequences that have undetectable sequence homology or even distinct origination. Describing these 48 var functional types allows us to simplify the antigenic diversity within our dataset by over two orders of magnitude. We consider how the var functional types are distributed in isolates, and find a nonrandom pattern reflecting that common var functional types are non-randomly distinct from one another in terms of their functional composition. The coarse-graining of var gene diversity into biologically meaningful functional groups has important implications for understanding the disease ecology and evolution of this system, as well as for designing effective epidemiological monitoring and intervention.
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Affiliation(s)
- Mary M. Rorick
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, United States of America
- Department of Biology, University of Utah, Salt Lake City, UT, United States of America
| | - Edward B. Baskerville
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, United States of America
| | - Thomas S. Rask
- School of Biosciences, Bio21 Institute, The University of Melbourne, Melbourne, AU
- Department of Microbiology, New York University, New York, NY, United States of America
| | - Karen P. Day
- School of Biosciences, Bio21 Institute, The University of Melbourne, Melbourne, AU
- Department of Microbiology, New York University, New York, NY, United States of America
| | - Mercedes Pascual
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, United States of America
- The Santa Fe Institute, Santa Fe, NM, United States of America
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80
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Lee HJ, Georgiadou A, Otto TD, Levin M, Coin LJ, Conway DJ, Cunnington AJ. Transcriptomic Studies of Malaria: a Paradigm for Investigation of Systemic Host-Pathogen Interactions. Microbiol Mol Biol Rev 2018; 82:e00071-17. [PMID: 29695497 PMCID: PMC5968457 DOI: 10.1128/mmbr.00071-17] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Transcriptomics, the analysis of genome-wide RNA expression, is a common approach to investigate host and pathogen processes in infectious diseases. Technical and bioinformatic advances have permitted increasingly thorough analyses of the association of RNA expression with fundamental biology, immunity, pathogenesis, diagnosis, and prognosis. Transcriptomic approaches can now be used to realize a previously unattainable goal, the simultaneous study of RNA expression in host and pathogen, in order to better understand their interactions. This exciting prospect is not without challenges, especially as focus moves from interactions in vitro under tightly controlled conditions to tissue- and systems-level interactions in animal models and natural and experimental infections in humans. Here we review the contribution of transcriptomic studies to the understanding of malaria, a parasitic disease which has exerted a major influence on human evolution and continues to cause a huge global burden of disease. We consider malaria a paradigm for the transcriptomic assessment of systemic host-pathogen interactions in humans, because much of the direct host-pathogen interaction occurs within the blood, a readily sampled compartment of the body. We illustrate lessons learned from transcriptomic studies of malaria and how these lessons may guide studies of host-pathogen interactions in other infectious diseases. We propose that the potential of transcriptomic studies to improve the understanding of malaria as a disease remains partly untapped because of limitations in study design rather than as a consequence of technological constraints. Further advances will require the integration of transcriptomic data with analytical approaches from other scientific disciplines, including epidemiology and mathematical modeling.
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Affiliation(s)
- Hyun Jae Lee
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | | | - Thomas D Otto
- Centre of Immunobiology, University of Glasgow, Glasgow, United Kingdom
| | - Michael Levin
- Section of Paediatrics, Imperial College, London, United Kingdom
| | - Lachlan J Coin
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | - David J Conway
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
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81
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Liu X, Wang Y, Liang J, Wang L, Qin N, Zhao Y, Zhao G. In-depth comparative analysis of malaria parasite genomes reveals protein-coding genes linked to human disease in Plasmodium falciparum genome. BMC Genomics 2018; 19:312. [PMID: 29716542 PMCID: PMC5930813 DOI: 10.1186/s12864-018-4654-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 04/10/2018] [Indexed: 11/10/2022] Open
Abstract
Background Plasmodium falciparum is the most virulent malaria parasite capable of parasitizing human erythrocytes. The identification of genes related to this capability can enhance our understanding of the molecular mechanisms underlying human malaria and lead to the development of new therapeutic strategies for malaria control. With the availability of several malaria parasite genome sequences, performing computational analysis is now a practical strategy to identify genes contributing to this disease. Results Here, we developed and used a virtual genome method to assign 33,314 genes from three human malaria parasites, namely, P. falciparum, P. knowlesi and P. vivax, and three rodent malaria parasites, namely, P. berghei, P. chabaudi and P. yoelii, to 4605 clusters. Each cluster consisted of genes whose protein sequences were significantly similar and was considered as a virtual gene. Comparing the enriched values of all clusters in human malaria parasites with those in rodent malaria parasites revealed 115 P. falciparum genes putatively responsible for parasitizing human erythrocytes. These genes are mainly located in the chromosome internal regions and participate in many biological processes, including membrane protein trafficking and thiamine biosynthesis. Meanwhile, 289 P. berghei genes were included in the rodent parasite-enriched clusters. Most are located in subtelomeric regions and encode erythrocyte surface proteins. Comparing cluster values in P. falciparum with those in P. vivax and P. knowlesi revealed 493 candidate genes linked to virulence. Some of them encode proteins present on the erythrocyte surface and participate in cytoadhesion, virulence factor trafficking, or erythrocyte invasion, but many genes with unknown function were also identified. Cerebral malaria is characterized by accumulation of infected erythrocytes at trophozoite stage in brain microvascular. To discover cerebral malaria-related genes, fast Fourier transformation (FFT) was introduced to extract genes highly transcribed at the trophozoite stage. Finally, 55 candidate genes were identified. Considering that parasite-infected erythrocyte surface protein 2 (PIESP2) contains gap-junction-related Neuromodulin_N domain and that anti-PIESP2 might provide protection against malaria, we chose PIESP2 for further experimental study. Conclusions Our analysis revealed a limited number of genes linked to human disease in P. falciparum genome. These genes could be interesting targets for further functional characterization. Electronic supplementary material The online version of this article (10.1186/s12864-018-4654-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xuewu Liu
- Department of Pathogenic Biology, Fourth Military Medical University, Xi'an, 710032, China
| | - Yuanyuan Wang
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Jiao Liang
- Department of Pathogenic Biology, Fourth Military Medical University, Xi'an, 710032, China
| | - Luojun Wang
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Na Qin
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China
| | - Ya Zhao
- Department of Pathogenic Biology, Fourth Military Medical University, Xi'an, 710032, China.
| | - Gang Zhao
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, China.
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82
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The Plasmodium falciparum transcriptome in severe malaria reveals altered expression of genes involved in important processes including surface antigen-encoding var genes. PLoS Biol 2018; 16:e2004328. [PMID: 29529020 PMCID: PMC5864071 DOI: 10.1371/journal.pbio.2004328] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 03/22/2018] [Accepted: 02/16/2018] [Indexed: 01/13/2023] Open
Abstract
Within the human host, the malaria parasite Plasmodium falciparum is exposed to multiple selection pressures. The host environment changes dramatically in severe malaria, but the extent to which the parasite responds to-or is selected by-this environment remains unclear. From previous studies, the parasites that cause severe malaria appear to increase expression of a restricted but poorly defined subset of the PfEMP1 variant, surface antigens. PfEMP1s are major targets of protective immunity. Here, we used RNA sequencing (RNAseq) to analyse gene expression in 44 parasite isolates that caused severe and uncomplicated malaria in Papuan patients. The transcriptomes of 19 parasite isolates associated with severe malaria indicated that these parasites had decreased glycolysis without activation of compensatory pathways; altered chromatin structure and probably transcriptional regulation through decreased histone methylation; reduced surface expression of PfEMP1; and down-regulated expression of multiple chaperone proteins. Our RNAseq also identified novel associations between disease severity and PfEMP1 transcripts, domains, and smaller sequence segments and also confirmed all previously reported associations between expressed PfEMP1 sequences and severe disease. These findings will inform efforts to identify vaccine targets for severe malaria and also indicate how parasites adapt to-or are selected by-the host environment in severe malaria.
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83
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Rorick MM, Artzy-Randrup Y, Ruybal-Pesántez S, Tiedje KE, Rask TS, Oduro A, Ghansah A, Koram K, Day KP, Pascual M. Signatures of competition and strain structure within the major blood-stage antigen of Plasmodium falciparum in a local community in Ghana. Ecol Evol 2018; 8:3574-3588. [PMID: 29686839 PMCID: PMC5901166 DOI: 10.1002/ece3.3803] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 10/31/2017] [Accepted: 12/06/2017] [Indexed: 11/12/2022] Open
Abstract
The concept of niche partitioning has received considerable theoretical attention at the interface of ecology and evolution of infectious diseases. Strain theory postulates that pathogen populations can be structured into distinct nonoverlapping strains by frequency-dependent selection in response to intraspecific competition for host immune space. The malaria parasite Plasmodium falciparum presents an opportunity to investigate this phenomenon in nature, under conditions of high recombination rate and extensive antigenic diversity. The parasite's major blood-stage antigen, Pf EMP1, is encoded by the hyperdiverse var genes. With a dataset that includes thousands of var DBLα sequence types sampled from asymptomatic cases within an area of high endemicity in Ghana, we address how var diversity is distributed within isolates and compare this to the distribution of microsatellite allelic diversity within isolates to test whether antigenic and neutral regions of the genome are structured differently. With respect to var DBLα sequence types, we find that on average isolates exhibit significantly lower overlap than expected randomly, but that there also exists frequent pairs of isolates that are highly related. Furthermore, the linkage network of var DBLα sequence types reveals a pattern of nonrandom modularity unique to these antigenic genes, and we find that modules of highly linked DBLα types are not explainable by neutral forces related to var recombination constraints, microsatellite diversity, sampling location, host age, or multiplicity of infection. These findings of reduced overlap and modularity among the var antigenic genes are consistent with a role for immune selection as proposed by strain theory. Identifying the evolutionary and ecological dynamics that are responsible for the nonrandom structure in P. falciparum antigenic diversity is important for designing effective intervention in endemic areas.
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Affiliation(s)
- Mary M Rorick
- Department of Ecology and Evolution University of Chicago Chicago IL USA.,Department of Biology University of Utah Salt Lake City UT USA
| | - Yael Artzy-Randrup
- Theoretical Ecology Group Institute for Biodiversity and Ecosystem Dynamics University of Amsterdam Amsterdam The Netherlands
| | - Shazia Ruybal-Pesántez
- School of Biosciences Bio21 Institute The University of Melbourne Melbourne Vic. Australia.,Department of Microbiology New York University New York NY USA
| | - Kathryn E Tiedje
- School of Biosciences Bio21 Institute The University of Melbourne Melbourne Vic. Australia.,Department of Microbiology New York University New York NY USA
| | - Thomas S Rask
- School of Biosciences Bio21 Institute The University of Melbourne Melbourne Vic. Australia.,Department of Microbiology New York University New York NY USA
| | | | - Anita Ghansah
- Noguchi Memorial Institute for Medical Research University of Ghana Legon Ghana
| | - Kwadwo Koram
- Noguchi Memorial Institute for Medical Research University of Ghana Legon Ghana
| | - Karen P Day
- School of Biosciences Bio21 Institute The University of Melbourne Melbourne Vic. Australia.,Department of Microbiology New York University New York NY USA
| | - Mercedes Pascual
- Department of Ecology and Evolution University of Chicago Chicago IL USA.,The Santa Fe Institute Santa Fe NM USA
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84
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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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85
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Infected erythrocytes expressing DC13 PfEMP1 differ from recombinant proteins in EPCR-binding function. Proc Natl Acad Sci U S A 2018; 115:1063-1068. [PMID: 29339517 PMCID: PMC5798336 DOI: 10.1073/pnas.1712879115] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Sequestration of Plasmodium falciparum-infected erythrocytes (IEs) in the brain microvasculature underlies the pathology of cerebral malaria. Parasites that express P. falciparum erythrocyte membrane protein 1 of domain cassette (DC) 8 and DC13 types bind to brain endothelial cells. Recent studies, largely based on recombinant proteins, have identified endothelial protein C receptor (EPCR) as the key receptor for endothelial cell binding. Using DC8- and DC13-expressing IEs, we show that binding of DC13 IEs to brain endothelial cells is not EPCR-dependent and that cytoadhesion of EPCR-binding DC8 IEs to brain endothelial cells is blocked by human serum. This study highlights differences between recombinant protein and native protein in EPCR-binding properties and suggests that other receptors are also required for sequestration in cerebral malaria. Recent advances have identified a new paradigm for cerebral malaria pathogenesis in which endothelial protein C receptor (EPCR) is a major host receptor for sequestration of Plasmodium falciparum-infected erythrocytes (IEs) in the brain and other vital organs. The parasite adhesins that bind EPCR are members of the IE variant surface antigen family Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) containing specific adhesion domains called domain cassette (DC) 8 and DC13. The binding interaction site between PfEMP1 and EPCR has been mapped by biophysical and crystallography studies using recombinant proteins. However, studies examining the interaction of native PfEMP1 on the IE surface with EPCR are few. We aimed to study binding to EPCR by IEs expressing DC8 and DC13 PfEMP1 variants whose recombinant proteins have been used in key prior functional and structural studies. IE binding to EPCR immobilized on plastic and on human brain endothelial cells was examined in static and flow adhesion assays. Unexpectedly, we found that IEs expressing the DC13 PfEMP1 variant HB3var03 or IT4var07 did not bind to EPCR on plastic and the binding of these variants to brain endothelial cells was not dependent on EPCR. IEs expressing the DC8 variant IT4var19 did bind to EPCR, but this interaction was inhibited if normal human serum or plasma was present, raising the possibility that IE–EPCR interaction may be prevented by plasma components under physiological conditions. These data highlight a discrepancy in EPCR-binding activity between PfEMP1 recombinant proteins and IEs, and indicate the critical need for further research to understand the pathophysiological significance of the PfEMP1–EPCR interaction.
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86
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Towards an anti-disease malaria vaccine. Emerg Top Life Sci 2017; 1:539-545. [PMID: 33525843 PMCID: PMC7289038 DOI: 10.1042/etls20170091] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 11/01/2017] [Accepted: 11/03/2017] [Indexed: 11/24/2022]
Abstract
Human infective parasites, such as those that cause malaria, are highly adapted to evade clearance by the immune system. In situations where they must maintain prolonged interactions with molecules of their host, they often use parasite surface protein families. These families are highly diverse to prevent immune recognition, and yet, to promote parasite survival, their members must retain the ability to interact with specific human receptors. One of the best understood of the parasite surface protein families is the PfEMP1 proteins of Plasmodium falciparum. These molecules cause infected erythrocytes to adhere to human receptors found on blood vessel and tissue surfaces. This protects the parasite within from clearance by the spleen and also causes symptoms of severe malaria. The PfEMP1 are exposed to the immune system during infection and are therefore excellent vaccine candidates for use in an approach to prevent severe disease. A key question, however, is whether their extensive diversity precludes them from forming components of the malaria vaccines of the future?
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87
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Saito F, Hirayasu K, Satoh T, Wang CW, Lusingu J, Arimori T, Shida K, Palacpac NMQ, Itagaki S, Iwanaga S, Takashima E, Tsuboi T, Kohyama M, Suenaga T, Colonna M, Takagi J, Lavstsen T, Horii T, Arase H. Immune evasion of Plasmodium falciparum by RIFIN via inhibitory receptors. Nature 2017; 552:101-105. [PMID: 29186116 PMCID: PMC5748893 DOI: 10.1038/nature24994] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 11/02/2017] [Indexed: 11/25/2022]
Abstract
Malaria is among the most serious infectious diseases affecting humans, accounting for approximately half a million deaths annually1. Plasmodium falciparum is the causative agent of most life-threatening malaria cases. Acquired immunity to malaria is inefficient, even after repeated exposures to P. falciparum2; immune regulatory mechanisms employed by P. falciparum remain largely unclear. Here, we show that P. falciparum uses immune inhibitory receptors for immune evasion. RIFINs, products of a polymorphic multigene family comprising approximately 150–200 genes per parasite genome3, are expressed on the surface of infected erythrocytes. We found that a subset of RIFINs binds to either leucocyte immunoglobulin-like receptor B1 (LILRB1) or leucocyte-associated immunoglobulin-like receptor 1 (LAIR1). LILRB1-binding RIFINs inhibited activation of LILRB1-expressing B cells and NK cells. Furthermore, interactions between LILRB1 and P. falciparum-infected erythrocytes isolated from malaria patients were associated with severe malaria, although an extended study with larger sample sizes is required to confirm the findings. These results suggest that P. falciparum has acquired multiple RIFINs to evade the host immune system by targeting immune inhibitory receptors.
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Affiliation(s)
- Fumiji Saito
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Kouyuki Hirayasu
- Laboratory of Immunochemistry, WPI Immunology Frontier Research Centre, Osaka University, Suita, Osaka 565-0871, Japan
| | - Takeshi Satoh
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Christian W Wang
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - John Lusingu
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
| | - Takao Arimori
- Laboratory of Protein Synthesis and Expression, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kyoko Shida
- Laboratory of Immunochemistry, WPI Immunology Frontier Research Centre, Osaka University, Suita, Osaka 565-0871, Japan
| | - Nirianne Marie Q Palacpac
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Sawako Itagaki
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Shiroh Iwanaga
- Department of Medical Zoology, School of Medicine, Mie University, Tsu, Mie 514-8507, Japan.,Department of Environmental Parasitology, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Centre, Ehime University, Matsuyama, Ehime, 790-8577, Japan
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Centre, Ehime University, Matsuyama, Ehime, 790-8577, Japan
| | - Masako Kohyama
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan.,Laboratory of Immunochemistry, WPI Immunology Frontier Research Centre, Osaka University, Suita, Osaka 565-0871, Japan
| | - Tadahiro Suenaga
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan.,Laboratory of Immunochemistry, WPI Immunology Frontier Research Centre, Osaka University, Suita, Osaka 565-0871, Japan
| | - Marco Colonna
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Junichi Takagi
- Laboratory of Protein Synthesis and Expression, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Toshihiro Horii
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hisashi Arase
- Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan.,Laboratory of Immunochemistry, WPI Immunology Frontier Research Centre, Osaka University, Suita, Osaka 565-0871, Japan
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88
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Kessler A, Dankwa S, Bernabeu M, Harawa V, Danziger SA, Duffy F, Kampondeni SD, Potchen MJ, Dambrauskas N, Vigdorovich V, Oliver BG, Hochman SE, Mowrey WB, MacCormick IJC, Mandala WL, Rogerson SJ, Sather DN, Aitchison JD, Taylor TE, Seydel KB, Smith JD, Kim K. Linking EPCR-Binding PfEMP1 to Brain Swelling in Pediatric Cerebral Malaria. Cell Host Microbe 2017; 22:601-614.e5. [PMID: 29107642 DOI: 10.1016/j.chom.2017.09.009] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 08/06/2017] [Accepted: 09/22/2017] [Indexed: 11/16/2022]
Abstract
Brain swelling is a major predictor of mortality in pediatric cerebral malaria (CM). However, the mechanisms leading to swelling remain poorly defined. Here, we combined neuroimaging, parasite transcript profiling, and laboratory blood profiles to develop machine-learning models of malarial retinopathy and brain swelling. We found that parasite var transcripts encoding endothelial protein C receptor (EPCR)-binding domains, in combination with high parasite biomass and low platelet levels, are strong indicators of CM cases with malarial retinopathy. Swelling cases presented low platelet levels and increased transcript abundance of parasite PfEMP1 DC8 and group A EPCR-binding domains. Remarkably, the dominant transcript in 50% of swelling cases encoded PfEMP1 group A CIDRα1.7 domains. Furthermore, a recombinant CIDRα1.7 domain from a pediatric CM brain autopsy inhibited the barrier-protective properties of EPCR in human brain endothelial cells in vitro. Together, these findings suggest a detrimental role for EPCR-binding CIDRα1 domains in brain swelling.
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Affiliation(s)
- Anne Kessler
- Department of Medicine, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY 10461, USA
| | - Selasi Dankwa
- Center for Infectious Disease Research, Seattle, WA 98109, USA
| | - Maria Bernabeu
- Center for Infectious Disease Research, Seattle, WA 98109, USA
| | - Visopo Harawa
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre BT3, Malawi; University of Malawi, College of Medicine, Biomedical Department, Blantyre BT3, Malawi
| | | | - Fergal Duffy
- Center for Infectious Disease Research, Seattle, WA 98109, USA
| | | | - Michael J Potchen
- Department of Imaging Sciences, University of Rochester, Rochester, NY 14642, USA
| | | | | | - Brian G Oliver
- Center for Infectious Disease Research, Seattle, WA 98109, USA
| | - Sarah E Hochman
- Department of Medicine, New York University Langone Health, New York, NY 10016, USA
| | - Wenzhu B Mowrey
- Department of Medicine, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY 10461, USA
| | - Ian J C MacCormick
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre BT3, Malawi; Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK; Department of Eye and Vision Sciences, University of Liverpool, Liverpool L69 3BX, UK
| | - Wilson L Mandala
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Blantyre BT3, Malawi; University of Malawi, College of Medicine, Biomedical Department, Blantyre BT3, Malawi; Academy of Medical Sciences, Malawi University of Science and Technology, Thyolo BT3, Malawi
| | - Stephen J Rogerson
- Department of Medicine at the Doherty Institute, The University of Melbourne, Melbourne, VIC 3000, Australia
| | - D Noah Sather
- Center for Infectious Disease Research, Seattle, WA 98109, USA
| | | | - Terrie E Taylor
- Blantyre Malaria Project, Blantyre BT3, Malawi; Department of Osteopathic Medical Specialities, College of Osteopathic Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Karl B Seydel
- Blantyre Malaria Project, Blantyre BT3, Malawi; Department of Osteopathic Medical Specialities, College of Osteopathic Medicine, Michigan State University, East Lansing, MI 48824, USA.
| | - Joseph D Smith
- Center for Infectious Disease Research, Seattle, WA 98109, USA; Department of Global Health, University of Washington, Seattle, WA 98195, USA.
| | - Kami Kim
- Department of Medicine, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY 10461, USA.
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89
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Githinji G, Bull PC. A re-assessment of gene-tag classification approaches for describing var gene expression patterns during human Plasmodium falciparum malaria parasite infections. Wellcome Open Res 2017; 2:86. [PMID: 29062916 PMCID: PMC5635463 DOI: 10.12688/wellcomeopenres.12053.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2017] [Indexed: 11/20/2022] Open
Abstract
PfEMP1 are variant parasite antigens that are inserted on the surface of Plasmodium falciparum infected erythrocytes (IE). Through interactions with various host molecules, PfEMP1 mediate IE sequestration in tissues and play a key role in the pathology of severe malaria. PfEMP1 is encoded by a diverse multi-gene family called var. Previous studies have shown that that expression of specific subsets of var genes are associated with low levels of host immunity and severe malaria. However, in most clinical studies to date, full-length var gene sequences were unavailable and various approaches have been used to make comparisons between var gene expression profiles in different parasite isolates using limited information. Several studies have relied on the classification of a 300 - 500 base-pair "DBLα tag" region in the DBLα domain located at the 5' end of most var genes. We assessed the relationship between various DBLα tag classification methods, and sequence features that are only fully assessable through full-length var gene sequences. We compared these different sequence features in full-length var gene from six fully sequenced laboratory isolates. These comparisons show that despite a long history of recombination, DBLα sequence tag classification can provide functional information on important features of full-length var genes. Notably, a specific subset of DBLα tags previously defined as "group A-like" is associated with CIDRα1 domains proposed to bind to endothelial protein C receptor. This analysis helps to bring together different sources of data that have been used to assess var gene expression in clinical parasite isolates.
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Affiliation(s)
- George Githinji
- Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya
| | - Peter C Bull
- Department of Pathology, University of Cambridge, Cambridge, UK
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90
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Chan JA, Stanisic DI, Duffy MF, Robinson LJ, Lin E, Kazura JW, King CL, Siba PM, Fowkes FJ, Mueller I, Beeson JG. Patterns of protective associations differ for antibodies to P. falciparum-infected erythrocytes and merozoites in immunity against malaria in children. Eur J Immunol 2017; 47:2124-2136. [PMID: 28833064 DOI: 10.1002/eji.201747032] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 07/09/2017] [Accepted: 08/16/2017] [Indexed: 11/10/2022]
Abstract
Acquired antibodies play an important role in immunity to P. falciparum malaria and are typically directed towards surface antigens expressed by merozoites and infected erythrocytes (IEs). The importance of specific IE surface antigens as immune targets remains unclear. We evaluated antibodies and protective associations in two cohorts of children in Papua New Guinea. We used genetically-modified P. falciparum to evaluate the importance of PfEMP1 and a P. falciparum isolate with a virulent phenotype. Our findings suggested that PfEMP1 was the dominant target of antibodies to the IE surface, including functional antibodies that promoted opsonic phagocytosis by monocytes. Antibodies were associated with increasing age and concurrent parasitemia, and were higher among children exposed to a higher force-of-infection as determined using molecular detection. Antibodies to IE surface antigens were consistently associated with reduced risk of malaria in both younger and older children. However, protective associations for antibodies to merozoite surface antigens were only observed in older children. This suggests that antibodies to IE surface antigens, particularly PfEMP1, play an earlier role in acquired immunity to malaria, whereas greater exposure is required for protective antibodies to merozoite antigens. These findings have implications for vaccine design and serosurveillance of malaria transmission and immunity.
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Affiliation(s)
- Jo-Anne Chan
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia.,Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Danielle I Stanisic
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Institute for Glycomics, Griffith University, Southport, Queensland, Australia
| | - Michael F Duffy
- Department of Medicine and Melbourne School of Public Health, University of Melbourne, Parkville, Victoria, Australia
| | - Leanne J Robinson
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia.,Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Enmoore Lin
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - James W Kazura
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Christopher L King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Freya Ji Fowkes
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia.,Melbourne School of Public Health, University of Melbourne, Parkville, Victoria, Australia.,Department of Epidemiology and Preventive Medicine and Department of Infectious Diseases, Monash University, Melbourne, Victoria, Australia
| | - Ivo Mueller
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - James G Beeson
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia.,Department of Medicine and Melbourne School of Public Health, University of Melbourne, Parkville, Victoria, Australia.,Department of Microbiology, Monash University, Melbourne, Victoria, Australia
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91
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Tuikue Ndam N, Moussiliou A, Lavstsen T, Kamaliddin C, Jensen ATR, Mama A, Tahar R, Wang CW, Jespersen JS, Alao JM, Gamain B, Theander TG, Deloron P. Parasites Causing Cerebral Falciparum Malaria Bind Multiple Endothelial Receptors and Express EPCR and ICAM-1-Binding PfEMP1. J Infect Dis 2017; 215:1918-1925. [PMID: 28863469 DOI: 10.1093/infdis/jix230] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 05/10/2017] [Indexed: 11/12/2022] Open
Abstract
Background Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) mediates the binding and accumulation of infected erythrocytes (IE) to blood vessels and tissues. Specific interactions have been described between PfEMP1 and human endothelial proteins CD36, intercellular adhesion molecule-1 (ICAM-1), and endothelial protein C receptor (EPCR); however, cytoadhesion patterns typical for pediatric malaria syndromes and the associated PfEMP1 members are still undefined. Methods In a cohort of 94 hospitalized children with malaria, we characterized the binding properties of IE collected on admission, and var gene transcription using quantitative polymerase chain reaction. Results IE from patients with cerebral malaria were more likely to bind EPCR and ICAM-1 than IE from children with uncomplicated malaria (P = .007). The level of transcripts encoding CIDRα1.4 and CIDRα1.5 domain subclasses was higher in patients with severe disease (P < .05). IE populations exhibiting binding to all 3 receptors had higher levels of transcripts encoding PfEMP1 with CIDRα1.4 and Duffy binding-like (DBL)-β3 domains than parasites, which only bound CD36. Conclusions These results underpin the significance of EPCR binding in pediatric malaria patients that require hospital admission, and support the notion that complementary receptor interactions of EPCR binding PfEMP1with ICAM-1 amplifies development of severe malaria symptoms.
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Affiliation(s)
- Nicaise Tuikue Ndam
- UMR 216, Mère et enfant face aux infections tropicales, Institut de Recherche pour le développement, COMUE Sorbonne Paris Cité, Faculté de pharmacie, Laboratoire d'Excellence GR-Ex, DHU Risques et Grossesse, France
| | - Azizath Moussiliou
- UMR 216, Mère et enfant face aux infections tropicales, Institut de Recherche pour le développement, COMUE Sorbonne Paris Cité, Faculté de pharmacie, Laboratoire d'Excellence GR-Ex, DHU Risques et Grossesse, France
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Denmark
| | - Claire Kamaliddin
- UMR 216, Mère et enfant face aux infections tropicales, Institut de Recherche pour le développement, COMUE Sorbonne Paris Cité, Faculté de pharmacie, Laboratoire d'Excellence GR-Ex, DHU Risques et Grossesse, France
| | - Anja T R Jensen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Denmark
| | - Atikatou Mama
- Centre d'Etude et de Recherche sur le paludisme associé à la Grossesse et à l'Enfance, Université d'Abomey-Calavi
| | - Rachida Tahar
- UMR 216, Mère et enfant face aux infections tropicales, Institut de Recherche pour le développement, COMUE Sorbonne Paris Cité, Faculté de pharmacie, Laboratoire d'Excellence GR-Ex, DHU Risques et Grossesse, France
| | - Christian W Wang
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Denmark
| | - Jakob S Jespersen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Denmark
| | - Jules M Alao
- Département de pédiatrie, Hôpital Mère-enfant de la lagune, Cotonou, Bénin
| | - Benoit Gamain
- Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence GR-Ex, France
| | - Thor G Theander
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Denmark
| | - Philippe Deloron
- UMR 216, Mère et enfant face aux infections tropicales, Institut de Recherche pour le développement, COMUE Sorbonne Paris Cité, Faculté de pharmacie, Laboratoire d'Excellence GR-Ex, DHU Risques et Grossesse, France
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92
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Lennartz F, Adams Y, Bengtsson A, Olsen RW, Turner L, Ndam NT, Ecklu-Mensah G, Moussiliou A, Ofori MF, Gamain B, Lusingu JP, Petersen JEV, Wang CW, Nunes-Silva S, Jespersen JS, Lau CKY, Theander TG, Lavstsen T, Hviid L, Higgins MK, Jensen ATR. Structure-Guided Identification of a Family of Dual Receptor-Binding PfEMP1 that Is Associated with Cerebral Malaria. Cell Host Microbe 2017; 21:403-414. [PMID: 28279348 PMCID: PMC5374107 DOI: 10.1016/j.chom.2017.02.009] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 01/20/2017] [Accepted: 02/10/2017] [Indexed: 11/09/2022]
Abstract
Cerebral malaria is a deadly outcome of infection by Plasmodium falciparum, occurring when parasite-infected erythrocytes accumulate in the brain. These erythrocytes display parasite proteins of the PfEMP1 family that bind various endothelial receptors. Despite the importance of cerebral malaria, a binding phenotype linked to its symptoms has not been identified. Here, we used structural biology to determine how a group of PfEMP1 proteins interacts with intercellular adhesion molecule 1 (ICAM-1), allowing us to predict binders from a specific sequence motif alone. Analysis of multiple Plasmodium falciparum genomes showed that ICAM-1-binding PfEMP1s also interact with endothelial protein C receptor (EPCR), allowing infected erythrocytes to synergistically bind both receptors. Expression of these PfEMP1s, predicted to bind both ICAM-1 and EPCR, is associated with increased risk of developing cerebral malaria. This study therefore reveals an important PfEMP1-binding phenotype that could be targeted as part of a strategy to prevent cerebral malaria. Structural basis for P. falciparum PfEMP1 binding to endothelial receptor ICAM-1defined A sequence motif derived from structure predicts group A PfEMP1 binding to ICAM-1 These ICAM-1-binding PfEMP1s also all bind to endothelial protein C receptor (EPCR) Expression of dual ICAM-1- and EPCR-binding PfEMP1 is associated with cerebral malaria
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Affiliation(s)
- Frank Lennartz
- Department of Biochemistry, University of Oxford, South Parks Road, OX1 3QU Oxford, UK
| | - Yvonne Adams
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Anja Bengtsson
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Rebecca W Olsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Louise Turner
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Nicaise T Ndam
- Faculté de Pharmacie, Institut de Recherche pour le Développement (IRD), COMUE Sorbonne Paris Cité, 75013 Paris, France; Faculté des Sciences de la Santé (FSS), Université d'Aboméy Calavi, 01 BP 526 Cotonou, Benin
| | - Gertrude Ecklu-Mensah
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark; Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Azizath Moussiliou
- Faculté des Sciences de la Santé (FSS), Université d'Aboméy Calavi, 01 BP 526 Cotonou, Benin
| | - Michael F Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Benoit Gamain
- UMR_S1134, Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence GR-Ex, 75013 Paris, France
| | - John P Lusingu
- National Institute for Medical Research, Tanga Centre, 11101 Dar es Salaam, Tanzania
| | - Jens E V Petersen
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Christian W Wang
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Sofia Nunes-Silva
- UMR_S1134, Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence GR-Ex, 75013 Paris, France
| | - Jakob S Jespersen
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Clinton K Y Lau
- Department of Biochemistry, University of Oxford, South Parks Road, OX1 3QU Oxford, UK
| | - Thor G Theander
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Thomas Lavstsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Lars Hviid
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, South Parks Road, OX1 3QU Oxford, UK.
| | - Anja T R Jensen
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen, 1165 Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen, Denmark.
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93
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Mustaffa KMF, Storm J, Whittaker M, Szestak T, Craig AG. In vitro inhibition and reversal of Plasmodium falciparum cytoadherence to endothelium by monoclonal antibodies to ICAM-1 and CD36. Malar J 2017; 16:279. [PMID: 28679447 PMCID: PMC5499065 DOI: 10.1186/s12936-017-1930-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Accepted: 07/01/2017] [Indexed: 12/04/2022] Open
Abstract
Background Sequestration of parasitized red blood cells from the peripheral circulation during an infection with Plasmodium falciparum is caused by an interaction between the parasite protein PfEMP1 and receptors on the surface of host endothelial cells, known as cytoadherence. Several lines of evidence point to a link between the pathology of severe malaria and cytoadherence, therefore blocking adhesion receptors involved in this process could be a good target to inhibit pRBC sequestration and prevent disease. In a malaria endemic setting this is likely to be used as an adjunct therapy by reversing existing cytoadherence. Two well-characterized parasite lines plus three recently derived patient isolates were tested for their cytoadherence to purified receptors (CD36 and ICAM-1) as well as endothelial cells. Monoclonal antibodies against human CD36 and ICAM-1 were used to inhibit and reverse infected erythrocyte binding in static and flow-based adhesion assays. Results Anti-ICAM-1 and CD36 monoclonal antibodies were able to inhibit and reverse P. falciparum binding of lab and recently adapted patient isolates in vitro. However, reversal of binding was incomplete and varied in its efficiency between parasite isolates. Conclusions The results show that, as a proof of concept, disturbing existing ligand–receptor interactions is possible and could have potential therapeutic value for severe malaria. The variation seen in the degree of reversing existing binding with different parasite isolates and the incomplete nature of reversal, despite the use of high affinity inhibitors, suggest that anti-adhesion approaches as adjunct therapies for severe malaria may not be effective, and the focus may need to be on inhibitory approaches such as vaccines.
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Affiliation(s)
- Khairul M F Mustaffa
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 16150, Kubang Kerian, Kelantan, Malaysia.,Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Janet Storm
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Megan Whittaker
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.,School of Medicine, University of Liverpool, Cedar House, Ashton Street, Liverpool, L69 3GE, UK
| | - Tadge Szestak
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Alister G Craig
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
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94
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Metwally NG, Tilly AK, Lubiana P, Roth LK, Dörpinghaus M, Lorenzen S, Schuldt K, Witt S, Bachmann A, Tidow H, Gutsmann T, Burmester T, Roeder T, Tannich E, Bruchhaus I. Characterisation of Plasmodium falciparum populations selected on the human endothelial receptors P-selectin, E-selectin, CD9 and CD151. Sci Rep 2017. [PMID: 28642573 PMCID: PMC5481354 DOI: 10.1038/s41598-017-04241-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The ability of the parasite Plasmodium falciparum to evade the immune system and be sequestered within human small blood vessels is responsible for severe forms of malaria. The sequestration depends on the interaction between human endothelial receptors and P. falciparum erythrocyte membrane protein 1 (PfEMP1) exposed on the surface of the infected erythrocytes (IEs). In this study, the transcriptomes of parasite populations enriched for parasites that bind to human P-selectin, E-selectin, CD9 and CD151 receptors were analysed. IT4_var02 and IT4_var07 were specifically expressed in IT4 parasite populations enriched for P-selectin-binding parasites; eight var genes (IT4_var02/07/09/13/17/41/44/64) were specifically expressed in isolate populations enriched for CD9-binding parasites. Interestingly, IT4 parasite populations enriched for E-selectin- and CD151-binding parasites showed identical expression profiles to those of a parasite population exposed to wild-type CHO-745 cells. The same phenomenon was observed for the 3D7 isolate population enriched for binding to P-selectin, E-selectin, CD9 and CD151. This implies that the corresponding ligands for these receptors have either weak binding capacity or do not exist on the IE surface. Conclusively, this work expanded our understanding of P. falciparum adhesive interactions, through the identification of var transcripts that are enriched within the selected parasite populations.
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Affiliation(s)
- Nahla Galal Metwally
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,Medical Parasitology Department, Faculty of Medicine-Suez Canal University, Ismailia, Egypt
| | | | - Pedro Lubiana
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Lisa K Roth
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | | | - Stephan Lorenzen
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Kathrin Schuldt
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Susanne Witt
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Anna Bachmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Henning Tidow
- Department of Chemistry, Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | - Thomas Gutsmann
- Division of Biophysics, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Borstel, Germany
| | - Thorsten Burmester
- Institute of Zoology, Biocenter Grindel, University of Hamburg, Hamburg, Germany
| | - Thomas Roeder
- Zoological Institute, Department of Molecular Physiology, Christian-Albrechts University Kiel, Kiel, Germany
| | - Egbert Tannich
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Iris Bruchhaus
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
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95
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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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96
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Day KP, Artzy-Randrup Y, Tiedje KE, Rougeron V, Chen DS, Rask TS, Rorick MM, Migot-Nabias F, Deloron P, Luty AJF, Pascual M. Evidence of strain structure in Plasmodium falciparum var gene repertoires in children from Gabon, West Africa. Proc Natl Acad Sci U S A 2017; 114:E4103-E4111. [PMID: 28461509 PMCID: PMC5441825 DOI: 10.1073/pnas.1613018114] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Existing theory on competition for hosts between pathogen strains has proposed that immune selection can lead to the maintenance of strain structure consisting of discrete, weakly overlapping antigenic repertoires. This prediction of strain theory has conceptual overlap with fundamental ideas in ecology on niche partitioning and limiting similarity between coexisting species in an ecosystem, which oppose the hypothesis of neutral coexistence. For Plasmodium falciparum, strain theory has been specifically proposed in relation to the major surface antigen of the blood stage, known as PfEMP1 and encoded by the multicopy multigene family known as the var genes. Deep sampling of the DBLα domain of var genes in the local population of Bakoumba, West Africa, was completed to define whether patterns of repertoire overlap support a role of immune selection under the opposing force of high outcrossing, a characteristic of areas of intense malaria transmission. Using a 454 high-throughput sequencing protocol, we report extremely high diversity of the DBLα domain and a large parasite population with DBLα repertoires structured into nonrandom patterns of overlap. Such population structure, significant for the high diversity of var genes that compose it at a local level, supports the existence of "strains" characterized by distinct var gene repertoires. Nonneutral, frequency-dependent competition would be at play and could underlie these patterns. With a computational experiment that simulates an intervention similar to mass drug administration, we argue that the observed repertoire structure matters for the antigenic var diversity of the parasite population remaining after intervention.
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Affiliation(s)
- Karen P Day
- School of Biosciences, The University of Melbourne, Parkville, VIC 3052, Australia;
- Department of Microbiology, New York University, New York, NY 10016
| | - Yael Artzy-Randrup
- Theoretical Ecology Group, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, 1090 GE Amsterdam, The Netherlands
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109
| | - Kathryn E Tiedje
- School of Biosciences, The University of Melbourne, Parkville, VIC 3052, Australia
- Department of Microbiology, New York University, New York, NY 10016
| | - Virginie Rougeron
- Department of Microbiology, New York University, New York, NY 10016
- Laboratoire Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle, UMR 224-5290 CNRS, Institut de Recherche pour le Développement-Université de Montpellier, Centre Institut de Recherche pour le Développement de Montpellier, 34394 Montpellier, France
| | - Donald S Chen
- Department of Microbiology, New York University, New York, NY 10016
- Department of Medicine, New York Medical College, Valhalla, NY 10595
| | - Thomas S Rask
- School of Biosciences, The University of Melbourne, Parkville, VIC 3052, Australia
- Department of Microbiology, New York University, New York, NY 10016
| | - Mary M Rorick
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109
- Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637
| | - Florence Migot-Nabias
- Institut de Recherche pour le Développement, UMR 216 Mère et Enfant Face aux Infections Tropicales, 75006 Paris, France
- Communautés d'Universités et Établissements, Sorbonne Paris Cité, Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, 75006 Paris, France
| | - Philippe Deloron
- Institut de Recherche pour le Développement, UMR 216 Mère et Enfant Face aux Infections Tropicales, 75006 Paris, France
- Communautés d'Universités et Établissements, Sorbonne Paris Cité, Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, 75006 Paris, France
| | - Adrian J F Luty
- Institut de Recherche pour le Développement, UMR 216 Mère et Enfant Face aux Infections Tropicales, 75006 Paris, France
- Communautés d'Universités et Établissements, Sorbonne Paris Cité, Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, 75006 Paris, France
| | - Mercedes Pascual
- Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637
- Santa Fe Institute, Santa Fe, NM 87501
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97
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Cunningham DA, Lin JW, Brugat T, Jarra W, Tumwine I, Kushinga G, Ramesar J, Franke-Fayard B, Langhorne J. ICAM-1 is a key receptor mediating cytoadherence and pathology in the Plasmodium chabaudi malaria model. Malar J 2017; 16:185. [PMID: 28468674 PMCID: PMC5415785 DOI: 10.1186/s12936-017-1834-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 04/25/2017] [Indexed: 02/07/2023] Open
Abstract
Background Parasite cytoadherence within the microvasculature of tissues and organs of infected individuals is implicated in the pathogenesis of several malaria syndromes. Multiple host receptors may mediate sequestration. The identity of the host receptor(s), or the parasite ligand(s) responsible for sequestration of Plasmodium species other than Plasmodium falciparum is largely unknown. The rodent malaria parasites may be useful to model interactions of parasite species, which lack the var genes with their respective hosts, as other multigene families are shared between the species. The role of the endothelial receptors ICAM-1 and CD36 in cytoadherence and in the development of pathology was investigated in a Plasmodium chabaudi infection in C57BL/6 mice lacking these receptors. The schizont membrane-associated cytoadherence (SMAC) protein of Plasmodium berghei has been shown to exhibit reduced CD36-associated cytoadherence in P. berghei ANKA-infected mice. Methods Parasite tissue sequestration and the development of acute stage pathology in P. chabaudi infections of mice lacking CD36 or ICAM-1, their respective wild type controls, and in infections with mutant P. chabaudi parasites lacking the smac gene were compared. Peripheral blood parasitaemia, red blood cell numbers and weight change were monitored throughout the courses of infection. Imaging of bioluminescent parasites in isolated tissues (spleen, lungs, liver, kidney and gut) was used to measure tissue parasite load. Results This study shows that neither the lack of CD36 nor the deletion of the smac gene from P. chabaudi significantly impacted on acute-stage pathology or parasite sequestration. By contrast, in the absence of ICAM-1, infected animals experience less anaemia and weight loss, reduced parasite accumulation in both spleen and liver and higher peripheral blood parasitaemia during acute stage malaria. The reduction in parasite tissue sequestration in infections of ICAM-1 null mice is maintained after mosquito transmission. Conclusions These results indicate that ICAM-1-mediated cytoadherence is important in the P. chabaudi model of malaria and suggest that for rodent malarias, as for P. falciparum, there may be multiple host and parasite molecules involved in sequestration. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1834-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Jing-Wen Lin
- The Francis Crick Institute, London, NW1 1AT, UK
| | | | | | | | | | - Jai Ramesar
- Leiden Malaria Research Group, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands
| | - Blandine Franke-Fayard
- Leiden Malaria Research Group, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands
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98
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Abstract
Of the five Plasmodium species that infect humans, infection with P. falciparum is the most lethal, causing severe malaria syndromes, that result in over half a million annual deaths. With parasites becoming increasingly resistant to artemisinin there is an urgent need for new preventative and therapeutic options, for which understanding of the mechanisms that cause death and disability in malaria is essential. The recent discoveries that certain variants of P. falciparum erythrocyte membrane protein 1 (PfEMP1) expressed on infected erythrocytes are intimately linked to the precipitation of severe malaria syndromes and that these PfEMP1 variants contain EPCR binding domains provides new opportunities to improve our understanding of the molecular mechanisms responsible for the pathogenesis of severe malaria. EPCR is known for its essential role in the protein C (PC) system and for its ability to support the cytoprotective effects of activated protein C (APC) that result in vascular and tissue protective effects in many organ systems of the body, including the brain, lung, kidney, and liver. Observations that binding of PfEMP1 to EPCR results in an acquired functional PC system deficiency support the new paradigm that EPCR plays a central role in the pathogenesis of severe malaria. Thus, targeting of the PfEMP1-EPCR interaction and restoring the functionality of the PC system may provide new strategies for the development of novel adjuvant therapies for severe malaria.
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99
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The Severity of Plasmodium falciparum Infection Is Associated with Transcript Levels of var Genes Encoding Endothelial Protein C Receptor-Binding P. falciparum Erythrocyte Membrane Protein 1. Infect Immun 2017; 85:IAI.00841-16. [PMID: 28138022 DOI: 10.1128/iai.00841-16] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 01/23/2017] [Indexed: 11/20/2022] Open
Abstract
By attaching infected erythrocytes to the vascular lining, Plasmodium falciparum parasites leave blood circulation and avoid splenic clearance. This sequestration is central to pathogenesis. Severe malaria is associated with parasites expressing an antigenically distinct P. falciparum erythrocyte membrane protein 1 (PfEMP1) subset mediating binding to endothelial receptors. Previous studies indicate that PfEMP1 adhesins with so-called CIDRα1 domains capable of binding endothelial protein C receptor (EPCR) constitute the PfEMP1 subset associated with severe pediatric malaria. To analyze the relative importance of different subtypes of CIDRα1 domains, we compared Pfemp1 transcript levels in children with severe malaria (including 9 fatal and 114 surviving cases), children hospitalized with uncomplicated malaria (n = 42), children with mild malaria not requiring hospitalization (n = 10), and children with parasitemia and no ongoing fever (n = 12). High levels of transcripts encoding EPCR-binding PfEMP1 were found in patients with symptomatic infections, and the abundance of these transcripts increased with disease severity. The compositions of CIDRα1 subtype transcripts varied markedly between patients, and none of the subtypes were dominant. Transcript-level analyses targeting other domain types indicated that subtypes of DBLβ or DBLζ domains might mediate binding phenomena that, in conjunction with EPCR binding, could contribute to pathogenesis. These observations strengthen the rationale for targeting the PfEMP1-EPCR interaction by vaccines and adjunctive therapies. Interventions should target EPCR binding of all CIDRα1 subtypes.
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100
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Mkumbaye SI, Minja DTR, Jespersen JS, Alifrangis M, Kavishe RA, Mwakalinga SB, Lusingu JP, Theander TG, Lavstsen T, Wang CW. Cellulose filtration of blood from malaria patients for improving ex vivo growth of Plasmodium falciparum parasites. Malar J 2017; 16:69. [PMID: 28183301 PMCID: PMC5301330 DOI: 10.1186/s12936-017-1714-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 01/26/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Establishing in vitro Plasmodium falciparum culture lines from patient parasite isolates can offer deeper understanding of geographic variations of drug sensitivity and mechanisms of malaria pathogenesis and immunity. Cellulose column filtration of blood is an inexpensive, rapid and effective method for the removal of host factors, such as leucocytes and platelets, significantly improving the purification of parasite DNA in a blood sample. METHODS In this study, the effect of cellulose column filtration of venous blood on the initial in vitro growth of P. falciparum parasite isolates from Tanzanian children admitted to hospital was tested. The parasites were allowed to expand in culture without subcultivation until 5 days after admission or the appearance of dead parasites and parasitaemia was determined daily. To investigate whether the filtration had an effect on clonality, P. falciparum merozoite surface protein 2 genotyping was performed using nested PCR on extracted genomic DNA, and the var gene transcript levels were investigated, using quantitative PCR on extracted RNA, at admission and 4 days of culture. RESULTS The cellulose-filtered parasites grew to higher parasitaemia faster than non-filtered parasites seemingly due to a higher development ratio of ring stage parasites progressing into the late stages. Cellulose filtration had no apparent effect on clonality or var gene expression; however, evident differences were observed after only 4 days of culture in both the number of clones and transcript levels of var genes compared to the time of admission. CONCLUSIONS Cellulose column filtration of parasitized blood is a cheap, applicable method for improving cultivation of P. falciparum field isolates for ex vivo based assays; however, when assessing phenotype and genotype of cultured parasites, in general, assumed to represent the in vivo infection, caution is advised.
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Affiliation(s)
- Sixbert I Mkumbaye
- Kilimanjaro Clinical Research Institute, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Daniel T R Minja
- Korogwe Research Station, Tanga Centre, National Institute for Medical Research, Tanga, Tanzania
| | - Jakob S Jespersen
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Centre for Medical Parasitology, University of Copenhagen, CSS Building 22-23, Øster Farimagsgade 5, PO Box 2099, 1014, Copenhagen K, Denmark.,Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Michael Alifrangis
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Centre for Medical Parasitology, University of Copenhagen, CSS Building 22-23, Øster Farimagsgade 5, PO Box 2099, 1014, Copenhagen K, Denmark.,Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Reginald A Kavishe
- Kilimanjaro Clinical Research Institute, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Steven B Mwakalinga
- Kilimanjaro Clinical Research Institute, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - John P Lusingu
- Korogwe Research Station, Tanga Centre, National Institute for Medical Research, Tanga, Tanzania
| | - Thor G Theander
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Centre for Medical Parasitology, University of Copenhagen, CSS Building 22-23, Øster Farimagsgade 5, PO Box 2099, 1014, Copenhagen K, Denmark.,Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Thomas Lavstsen
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Centre for Medical Parasitology, University of Copenhagen, CSS Building 22-23, Øster Farimagsgade 5, PO Box 2099, 1014, Copenhagen K, Denmark.,Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Christian W Wang
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Centre for Medical Parasitology, University of Copenhagen, CSS Building 22-23, Øster Farimagsgade 5, PO Box 2099, 1014, Copenhagen K, Denmark. .,Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark.
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