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Nielsen MA, Køster D, Greisen S, Troldborg A, Stengaard-Pedersen K, Junker P, Hørslev-Petersen K, Hetland ML, Østergaard M, Hvid M, Leffler H, Kragstrup TW, Deleuran B. Increased synovial galectin-3 induce inflammatory fibroblast activation and osteoclastogenesis in patients with rheumatoid arthritis. Scand J Rheumatol 2023; 52:33-41. [PMID: 35023445 DOI: 10.1080/03009742.2021.1992860] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Galectin-3 (Gal-3) has been suggested as a proinflammatory mediator in rheumatoid arthritis (RA). We aimed to study clinical and pathogenic aspects of Gal-3 in RA. METHOD Plasma samples from healthy controls (n = 48) and patients with newly diagnosed, early RA were assayed for soluble Gal-3. In patients with chronic RA (n = 18), Gal-3 was measured in both plasma and synovial fluid. Synovial fluid mononuclear cells were used to purify fibroblast-like synoviocytes (FLSs) and osteoclasts. Monocultures of FLSs and autologous co-cultures of FLSs and peripheral blood mononuclear cells were established and co-incubated with a Gal-3 inhibitor. RESULTS Patients with early and chronic RA had persistently increased plasma levels of Gal-3 compared with controls. However, changes in plasma Gal-3 at the level of individuals were associated with long-term disease activity. In seropositive early RA patients, all patients with decreasing plasma Gal-3 from 0 to 3 months had low disease activity after 2 years (p < 0.05). Gal-3 levels in synovial fluid were markedly elevated. In vitro, co-incubation with a Gal-3 inhibitor (GB1107, 10 µM) led to a significant reduction in both interleukin-1β and tumour necrosis factor-α secretion from FLS monocultures (both p < 0.05) and decreased monocyte-derived osteoclastogenesis compared with controls (both p < 0.05). CONCLUSIONS Our findings underscore the role of Gal-3 regarding disease activity and tissue destruction in RA. An initial decrease in plasma Gal-3 levels predicted decreased long-term disease activity. Correspondingly, a Gal-3 inhibitor decreased the activity of inflammatory FLSs and osteoclastogenesis in patients with RA.
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Affiliation(s)
- M A Nielsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.,Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark
| | - D Køster
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - S Greisen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.,Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark
| | - A Troldborg
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.,Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark
| | | | - P Junker
- Department of Rheumatology, Odense University Hospital, Odense, Denmark
| | - K Hørslev-Petersen
- Danish Hospital for Rheumatic Diseases, University of Southern Denmark, Odense, Denmark
| | - M L Hetland
- Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Glostrup, Denmark
| | - M Østergaard
- Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Glostrup, Denmark
| | - M Hvid
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - H Leffler
- Immunology and Glycobiology (MIG), Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - T W Kragstrup
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.,Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark
| | - B Deleuran
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.,Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark
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Raghavan SSR, Dagil R, Lopez-Perez M, Conrad J, Bassi MR, Quintana MDP, Choudhary S, Gustavsson T, Wang Y, Gourdon P, Ofori MF, Christensen SB, Minja DTR, Schmiegelow C, Nielsen MA, Barfod L, Hviid L, Salanti A, Lavstsen T, Wang K. Cryo-EM reveals the conformational epitope of human monoclonal antibody PAM1.4 broadly reacting with polymorphic malarial protein VAR2CSA. PLoS Pathog 2022; 18:e1010924. [PMCID: PMC9668162 DOI: 10.1371/journal.ppat.1010924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 10/10/2022] [Indexed: 11/17/2022] Open
Abstract
Malaria during pregnancy is a major global health problem caused by infection with Plasmodium falciparum parasites. Severe effects arise from the accumulation of infected erythrocytes in the placenta. Here, erythrocytes infected by late blood-stage parasites adhere to placental chondroitin sulphate A (CS) via VAR2CSA-type P. falciparum erythrocyte membrane protein 1 (PfEMP1) adhesion proteins. Immunity to placental malaria is acquired through exposure and mediated through antibodies to VAR2CSA. Through evolution, the VAR2CSA proteins have diversified in sequence to escape immune recognition but retained their overall macromolecular structure to maintain CS binding affinity. This structural conservation may also have allowed development of broadly reactive antibodies to VAR2CSA in immune women. Here we show the negative stain and cryo-EM structure of the only known broadly reactive human monoclonal antibody, PAM1.4, in complex with VAR2CSA. The data shows how PAM1.4’s broad VAR2CSA reactivity is achieved through interactions with multiple conserved residues of different sub-domains forming conformational epitope distant from the CS binding site on the VAR2CSA core structure. Thus, while PAM1.4 may represent a class of antibodies mediating placental malaria immunity by inducing phagocytosis or NK cell-mediated cytotoxicity, it is likely that broadly CS binding-inhibitory antibodies target other epitopes at the CS binding site. Insights on both types of broadly reactive monoclonal antibodies may aid the development of a vaccine against placental malaria.
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Affiliation(s)
- Sai Sundar Rajan Raghavan
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Robert Dagil
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Mary Lopez-Perez
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Julian Conrad
- Swedish National Cryo-EM Facility, Science for Life Laboratories, Solna, Sweden
| | - Maria Rosaria Bassi
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Maria del Pilar Quintana
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Swati Choudhary
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Tobias Gustavsson
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Yong Wang
- Joint Research Centre for Engineering Biology, Zhejiang University-University of Edinburgh Institute, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Pontus Gourdon
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Michael Fokuo Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Sebastian Boje Christensen
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | | | - Christentze Schmiegelow
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Morten Agertoug Nielsen
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Lea Barfod
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Lars Hviid
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Ali Salanti
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Thomas Lavstsen
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
- * E-mail: (TL); (KW)
| | - Kaituo Wang
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail: (TL); (KW)
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Farzadfard A, Pedersen JN, Meisl G, Somavarapu AK, Alam P, Goksøyr L, Nielsen MA, Sander AF, Knowles TPJ, Pedersen JS, Otzen DE. The C-terminal tail of α-synuclein protects against aggregate replication but is critical for oligomerization. Commun Biol 2022; 5:123. [PMID: 35145226 PMCID: PMC8831632 DOI: 10.1038/s42003-022-03059-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 01/18/2022] [Indexed: 12/16/2022] Open
Abstract
Aggregation of the 140-residue protein α-synuclein (αSN) is a key factor in the etiology of Parkinson’s disease. Although the intensely anionic C-terminal domain (CTD) of αSN does not form part of the amyloid core region or affect membrane binding ability, truncation or reduction of charges in the CTD promotes fibrillation through as yet unknown mechanisms. Here, we study stepwise truncated CTDs and identify a threshold region around residue 121; constructs shorter than this dramatically increase their fibrillation tendency. Remarkably, these effects persist even when as little as 10% of the truncated variant is mixed with the full-length protein. Increased fibrillation can be explained by a substantial increase in self-replication, most likely via fragmentation. Paradoxically, truncation also suppresses toxic oligomer formation, and oligomers that can be formed by chemical modification show reduced membrane affinity and cytotoxicity. These remarkable changes correlate to the loss of negative electrostatic potential in the CTD and highlight a double-edged electrostatic safety guard. Farzadfard et al. present a comprehensive analysis of a range of C-terminal truncations of aSN, linking the importance of high C-terminus charge for decreased fibrillation rates. The ability to formation oligomers, to disrupt synthetic vesicles and cell toxicity was reduced with truncated aSN, aiding in understanding of the intramolecular interactions of aSN which promote/inhibit aggregation.
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Affiliation(s)
- Azad Farzadfard
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark.,School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Jannik Nedergaard Pedersen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark
| | - Georg Meisl
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Arun Kumar Somavarapu
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark
| | - Parvez Alam
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark.,Department of Biomedicine, Aarhus University, 8000, Aarhus C, Denmark
| | - Louise Goksøyr
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - Morten Agertoug Nielsen
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - Adam Frederik Sander
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - Tuomas P J Knowles
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.,Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Jan Skov Pedersen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark.,Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark
| | - Daniel Erik Otzen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark. .,Department of Molecular Biology and Genetics, Gustav Wieds Vej 10C, 8000, Aarhus C, Denmark.
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Larsen MD, Lopez-Perez M, Dickson EK, Ampomah P, Tuikue Ndam N, Nouta J, Koeleman CAM, Ederveen ALH, Mordmüller B, Salanti A, Nielsen MA, Massougbodji A, van der Schoot CE, Ofori MF, Wuhrer M, Hviid L, Vidarsson G. Afucosylated Plasmodium falciparum-specific IgG is induced by infection but not by subunit vaccination. Nat Commun 2021. [PMID: 34611164 DOI: 10.1101/2021.04.23.441082v1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family members mediate receptor- and tissue-specific sequestration of infected erythrocytes (IEs) in malaria. Antibody responses are a central component of naturally acquired malaria immunity. PfEMP1-specific IgG likely protects by inhibiting IE sequestration and through IgG-Fc Receptor (FcγR) mediated phagocytosis and killing of antibody-opsonized IEs. The affinity of afucosylated IgG to FcγRIIIa is up to 40-fold higher than fucosylated IgG, resulting in enhanced antibody-dependent cellular cytotoxicity. Most IgG in plasma is fully fucosylated, but afucosylated IgG is elicited in response to enveloped viruses and to paternal alloantigens during pregnancy. Here we show that naturally acquired PfEMP1-specific IgG is strongly afucosylated in a stable and exposure-dependent manner, and efficiently induces FcγRIIIa-dependent natural killer (NK) cell degranulation. In contrast, immunization with a subunit PfEMP1 (VAR2CSA) vaccine results in fully fucosylated specific IgG. These results have implications for understanding protective natural- and vaccine-induced immunity to malaria.
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Affiliation(s)
- Mads Delbo Larsen
- Department of Experimental Immunohematology, Sanquin Research, Amsterdam, The Netherlands.,Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Mary Lopez-Perez
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emmanuel Kakra Dickson
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Paulina Ampomah
- Department of Biomedical Sciences, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana
| | | | - Jan Nouta
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, The Netherlands
| | - Carolien A M Koeleman
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Benjamin Mordmüller
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.,Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
| | - Ali Salanti
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten Agertoug Nielsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Achille Massougbodji
- Centre d'Etude et de Recherche sur le Paludisme Associé à la Grossesse et à l'Enfance (CERPAGE), Faculté des Sciences de la Santé, Université d'Abomey-Calavi, Godomey, Benin
| | - C Ellen van der Schoot
- Department of Experimental Immunohematology, Sanquin Research, Amsterdam, The Netherlands.,Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Michael F Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Manfred Wuhrer
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, The Netherlands
| | - Lars Hviid
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. .,Centre for Medical Parasitology, Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark.
| | - Gestur Vidarsson
- Department of Experimental Immunohematology, Sanquin Research, Amsterdam, The Netherlands. .,Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
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5
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Gruca M, Yu W, Amoateng P, Nielsen MA, Poulsen TB, Balslev H. Ethnomedicinal survey and in vitro anti-plasmodial activity of the palm Borassus aethiopum Mart. J Ethnopharmacol 2015; 175:356-369. [PMID: 26384000 DOI: 10.1016/j.jep.2015.09.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 09/08/2015] [Indexed: 06/05/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Malaria remains a major global health threat, with the heaviest burden of disease in sub-Saharan Africa. Effective treatment is not available in many affected areas, and the Plasmodium falciparum parasite is becoming resistant to existing drugs. Alternative therapies are necessary to overcome these challenges. Borassus aethiopum is the third most used palm species in traditional medicines in Africa. Yet, there is only limited information substantiating medicinal properties of the palm. The objective of this study was to document medicinal uses of B. aethiopum and investigate anti-plasmodial activity of the palm extracts used in traditional medicine to treat malaria. MATERIALS AND METHODS The fieldwork and collection of samples was done in Ghana in the Greater Accra, Brong Ahafo, and Volta regions. Our ethnomedicinal survey did not specifically focus on medicinal uses against malaria; any medicinal application of B. aethiopum was of interest. Data collection employed a structured questionnaire, open-ended questions, and group discussion. The experimental extraction of samples was carried out using three common solvents: distilled water, absolute ethanol, and dichloromethane (CH2Cl2). Anti-plasmodial activity of compounds was determined against erythrocytic stages of the FCR3 strain of P. falciparum by a [3H]-hypoxanthine incorporation assay. RESULTS A total of 37 use records were documented regarding the medicinal uses of B. aethiopum for the management of 24 different disorders. The highest medicinal use value was recorded for the use of B. aethiopum against malaria, and a subsequent laboratory investigation focused on evaluating anti-plasmodial activity of the palm. Several root and leaf extracts displayed anti-plasmodial activity, with the highest (78% at 50 μg/mL) elicited by one of the dichloromethane root extracts. CONCLUSION Our results demonstrate the value of integrating ethnobotanical and pharmacological research in the study of beneficial effects of palm products on human health. While the high inhibitory activity found in dichloromethane extracts cannot validate the ethnomedicinal use, the anti-plasmodial effect observed cannot be nullified. We brought preliminary evidence that this palm is a promising source of alternative medicines that could contribute to improving health conditions in malaria endemic areas of sub-Saharan Africa.
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Affiliation(s)
- Marta Gruca
- Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Ny Munkegade 114, Aarhus C DK 8000, Denmark
| | - Wanwan Yu
- Chemical Biology Laboratory, Department of Chemistry, Aarhus University, Langelandsgade 140, Aarhus C DK 8000, Denmark
| | - Patrick Amoateng
- Department of Pharmacology & Toxicology, University of Ghana, School of Pharmacy, P.O. Box LG 43, Legon, Accra, Ghana
| | - Morten Agertoug Nielsen
- Department of International Health, Immunology and Microbiology, Centre for Medical Parasitology, University of Copenhagen, Øster Farimagsgade 5, 1014 Copenhagen K, Denmark
| | - Thomas B Poulsen
- Chemical Biology Laboratory, Department of Chemistry, Aarhus University, Langelandsgade 140, Aarhus C DK 8000, Denmark
| | - Henrik Balslev
- Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, Ny Munkegade 114, Aarhus C DK 8000, Denmark.
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Doritchamou J, Bigey P, Nielsen MA, Gnidehou S, Ezinmegnon S, Burgain A, Massougbodji A, Deloron P, Salanti A, Ndam NT. Differential adhesion-inhibitory patterns of antibodies raised against two major variants of the NTS-DBL2X region of VAR2CSA. Vaccine 2013; 31:4516-22. [PMID: 23933341 DOI: 10.1016/j.vaccine.2013.07.072] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 07/19/2013] [Accepted: 07/29/2013] [Indexed: 11/18/2022]
Abstract
BACKGROUND VAR2CSA is a large polymorphic Plasmodium falciparum protein expressed on infected erythrocytes (IE) that allows their binding in the placenta, thus precipitating placental malaria (PM). The N-terminal part of VAR2CSA that contains the binding site to placental chondroitin sulfate A (CSA) is currently recognized as the most attractive region for vaccine development. An ultimate challenge is to define epitopes in this region that induce a broad cross-reactive adhesion inhibitory antibody response. METHODS Based on phylogenetic data that identified a dimorphic sequence motif in the VAR2CSA DBL2X, we raised antibodies against the NTS-DBL2X constructs containing one sequence or the other (3D7 and FCR3) and tested their functional properties on P. falciparum isolates from pregnant women and on laboratory-adapted strains. RESULTS The CSA binding inhibitory capacity of the antibodies induced varied from one parasite isolate to another (range, 10%–100%), but the combined analysis of individual activity highlighted a broader functionality that increased the total number of isolates inhibited. Interestingly, the differential inhibitory effect of the antibodies observed on field isolates resulted in significant inhibition of all field isolates tested, suggesting that optimal inhibitory spectrum on field isolates from pregnant women might be achieved with antibodies targeting limited variants of the N-terminal VAR2CSA. CONCLUSIONS Our findings indicate that the NTS-DBL2X region of VAR2CSA can elicit strain-transcending anti-adhesion antibodies and suggest that the combination of the two major variants used here could represent the basis for an effective bivalent VAR2CSA-based vaccine.
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Affiliation(s)
- Justin Doritchamou
- PRES Sorbonne Paris Cité, Faculté de Pharmacie, Université Paris Descartes, France; Institut de Recherche pour le Développement, UMR216 Mère et enfant face aux infections tropicales, Paris, France; Centre d'Etude et de Recherche sur le paludisme associé à la Grossesse et à l'Enfance, Université d'Abomey-Calavi, Cotonou, Benin
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Jensen S, Omarsdottir S, Bwalya AG, Nielsen MA, Tasdemir D, Olafsdottir ES. Marchantin A, a macrocyclic bisbibenzyl ether, isolated from the liverwort Marchantia polymorpha, inhibits protozoal growth in vitro. Phytomedicine 2012; 19:1191-1195. [PMID: 22951393 DOI: 10.1016/j.phymed.2012.07.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 05/28/2012] [Accepted: 07/14/2012] [Indexed: 06/01/2023]
Abstract
In vitro anti-plasmodial activity-guided fractionation of a diethyl ether extract of the liverwort species Marchantia polymorpha, collected in Iceland, led to isolation of the bisbibenzyl ether, marchantin A. The structure of marchantin A (1) was confirmed by NMR and HREIMS. Marchantin A inhibited proliferation of the Plasmodium falciparum strains, NF54 (IC(50)=3.41μM) and K1 (IC(50)=2.02μM) and showed activity against other protozoan species Trypanosoma brucei rhodesiense, T. cruzi and Leishmania donovani with IC(50) values 2.09, 14.90 and 1.59μM, respectively. Marchantin A was tested against three recombinant enzymes (PfFabI, PfFabG and PfFabZ) of the PfFAS-II pathway of P. falciparum for malaria prophylactic potential and showed moderate inhibitory activity against PfFabZ (IC(50)=18.18μM). In addition the cytotoxic effect of marchantin A was evaluated. This is the first report describing the inhibitory effects of the liverwort metabolite marchantin A against these parasites in vitro.
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Affiliation(s)
- Sophie Jensen
- School of Health Sciences, University of Iceland, Reykjavik, Iceland
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Pinto VV, Salanti A, Joergensen LM, Dahlbäck M, Resende M, Ditlev SB, Agger EM, Arnot DE, Theander TG, Nielsen MA. The effect of adjuvants on the immune response induced by a DBL4ɛ-ID4 VAR2CSA based Plasmodium falciparum vaccine against placental malaria. Vaccine 2011; 30:572-9. [PMID: 22122859 DOI: 10.1016/j.vaccine.2011.11.068] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Revised: 10/15/2011] [Accepted: 11/16/2011] [Indexed: 10/15/2022]
Abstract
A vaccine protecting women against placental malaria could be based on the sub-domains of the VAR2CSA antigen, since antibodies against the DBL4ɛ-ID4 subunit of the VAR2CSA protein can inhibit parasite binding to the placental ligand chondroitin sulphate A (CSA). Here we tested the ability of DBL4ɛ-ID4 to induce binding-inhibitory antibodies when formulated with adjuvants approved for human use. We have characterized the immune response of DBL4ɛ-ID4 in combination with Freund's complete and incomplete adjuvant and with three adjuvants currently being used in clinical trials: Montanide(®) ISA 720, Alhydrogel(®) and CAF01. Antibodies induced against DBL4ɛ-ID4 in combination with these adjuvants inhibited parasite binding to CSA from 82% to 99%. Although, different epitope recognition patterns were obtained for the different formulations, all adjuvant combinations induced strong Th1 and Th2 type responses, resulting in IgG with similar binding strength, with to the DBL4ɛ-ID4 antigen. These results demonstrate that the DBL4ɛ-ID4 antigen is highly immunogenic and that binding inhibitory antibodies are induced when formulated with any of the tested adjuvants.
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Affiliation(s)
- V V Pinto
- Centre for Medical Parasitology, Department of International Health, University of Copenhagen, CSS, Øster Farimagsgade 5 A, DK-1014 Copenhagen K, Denmark.
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9
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A-Elgadir TME, Theander TG, Elghazali G, Nielsen MA, A-Elbasit IE, Adam I, Troye-Blomberg M, Elbashir MI, Giha HA. Determinants of Variant Surface Antigen Antibody Response in Severe Plasmodium falciparum Malaria in an Area of Low and Unstable Malaria Transmission. Scand J Immunol 2006; 63:232-40. [PMID: 16499577 DOI: 10.1111/j.1365-3083.2006.01732.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The variant surface antigens (VSA) of infected erythrocytes are important pathogenic markers, a set of variants (VSA(SM)), were assumed to be associated with severe malaria (SM), while SM constitutes clinically diverse forms, such as, severe malarial anemia (SMA) and cerebral malaria (CM). This study was conducted in Eastern Sudan, an area of seasonal and unstable malaria transmission. Parasites and plasma were obtained from patients with different clinical grades of malaria, and flow cytometry was used for analysis of VSA antibody (Ab) response. We found that individuals recognized a broader range of isolates had a higher level of VSA Ab against the recognized isolates (correlation coefficient, 0.727, P<0.001). Unexpectedly, at the time of malaria diagnosis, plasma from patients with CM recognized a significantly larger number of isolates than did the plasma from patients with SMA (P<0.001). Parasites obtained from patients with SMA or from children were better recognized than isolates obtained from patients with uncomplicated malaria or from adults, P<0.001, P=0.021, respectively. Taken together, the above findings suggest that the limitations in the VSA immunoglobulin G repertoire were most probably contributing to the pathogenesis of SMA but not to that of CM.
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Affiliation(s)
- T M E A-Elgadir
- Malaria Research Centre (MalRC), Department of Biochemistry; Faculty of Medicine, University of Khartoum, Khartoum, Sudan
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Altepeter JB, Branning D, Jeffrey E, Wei TC, Kwiat PG, Thew RT, O'Brien JL, Nielsen MA, White AG. Ancilla-assisted quantum process tomography. Phys Rev Lett 2003; 90:193601. [PMID: 12785945 DOI: 10.1103/physrevlett.90.193601] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2002] [Indexed: 05/24/2023]
Abstract
Complete and precise characterization of a quantum dynamical process can be achieved via the method of quantum process tomography. Using a source of correlated photons, we have implemented several methods, each investigating a wide range of processes, e.g., unitary, decohering, and polarizing. One of these methods, ancilla-assisted process tomography (AAPT), makes use of an additional "ancilla system," and we have theoretically determined the conditions when AAPT is possible. Surprisingly, entanglement is not required. We present data obtained using both separable and entangled input states. The use of entanglement yields superior results, however.
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Affiliation(s)
- J B Altepeter
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana Illinois 61801-3080, USA
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Abstract
A remarkable feature of quantum entanglement is that an entangled state of two parties, Alice ( A) and Bob ( B), may be more disordered locally than globally. That is, S(A)>S(A,B), where S(*) is the von Neumann entropy. It is known that satisfaction of this inequality implies that a state is nonseparable. In this paper we prove the stronger result that for separable states the vector of eigenvalues of the density matrix of system AB is majorized by the vector of eigenvalues of the density matrix of system A alone. This gives a strong sense in which a separable state is more disordered globally than locally and a new necessary condition for separability of bipartite states in arbitrary dimensions.
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Affiliation(s)
- M A Nielsen
- Centre for Quantum Computer Technology, University of Queensland, Queensland 4072, Australia.
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Hindsbo O, Nielsen CV, Andreassen J, Willingham AL, Bendixen M, Nielsen MA, Nielsen NO. Age-dependent occurrence of the intestinal ciliate Balantidium coli in pigs at a Danish research farm. Acta Vet Scand 2000; 41:79-83. [PMID: 10920478 PMCID: PMC7996444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
A cross sectional study of the prevalence and intensity of Balantidium coli in pigs was carried out on a Danish research farm. The prevalence of B. coli infection increased from 57% in suckling piglets to 100% in most pig groups > or = 4 weeks old. The mean number of cysts per gram faeces (CPG) of pigs aged 12 weeks and younger were < or = 206, whereas pigs aged 28 weeks and > 52 weeks had significantly higher counts of > or = 865 CPG. Although some lactating sows had very high CPG's, no significant differences in CPG could be detected between the intensities of pregnant sows, lactating sows and empty and dry sows. No human cases of B. coli infection have been published in Denmark though it is zoonotic.
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Affiliation(s)
- O Hindsbo
- Department of Population Ecology, University of Copenhagen, Denmark.
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Abstract
Thirty-two patients underwent free, full thickness skin (patch) graft urethroplasties between September, 1974, and May, 1978. Sixty-five per cent of the 23 patients available for five-year follow-up had good results from grafts ranging from 3 to 14 cm in length. In patients with good one-year results strictures did not develop during the review period, suggesting the need for only short-term follow-up in this group.
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Abstract
Neural projections from nucleus accumbens to subpallidal region, which contains a major GABAergic component, have been demonstrated with anatomical and electrophysiological techniques. The possible contribution of this GABA projection to the initiation of locomotor activity was investigated using neuropharmacological techniques. Injecting picrotoxin, a GABA antagonist, into the ventral globus pallidus increased locomotor activity measured in an open-field test, confirming findings. Locomotor activity was also increased when picrotoxin was injected into the lateral preoptic area, the sublenticular part of the substantia innominata and bed nucleus of the stria terminalis. In another series of experiments locomotor activity initiated by injecting dopamine into the nucleus accumbens was attenuated by pretreating the lateral preoptic area, the substantia innominata and ventral globus pallidus with GABA. These observations provide evidence that GABAergic projections from accumbens to subpallidal region contribute to locomotor activity and raise the possibility that they have a role in exploratory locomotion and in certain goal-directed behaviors.
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Nielsen MA. Intra-arterial monitoring of blood pressure. Am J Nurs 1974; 74:48-53. [PMID: 4491937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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