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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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52
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Kariuki SN, Williams TN. Human genetics and malaria resistance. Hum Genet 2020; 139:801-811. [PMID: 32130487 PMCID: PMC7271956 DOI: 10.1007/s00439-020-02142-6] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 02/18/2020] [Indexed: 12/18/2022]
Abstract
Malaria has been the pre-eminent cause of early mortality in many parts of the world throughout much of the last five thousand years and, as a result, it is the strongest force for selective pressure on the human genome yet described. Around one third of the variability in the risk of severe and complicated malaria is now explained by additive host genetic effects. Many individual variants have been identified that are associated with malaria protection, but the most important all relate to the structure or function of red blood cells. They include the classical polymorphisms that cause sickle cell trait, α-thalassaemia, G6PD deficiency, and the major red cell blood group variants. More recently however, with improving technology and experimental design, others have been identified that include the Dantu blood group variant, polymorphisms in the red cell membrane protein ATP2B4, and several variants related to the immune response. Characterising how these genes confer their effects could eventually inform novel therapeutic approaches to combat malaria. Nevertheless, all together, only a small proportion of the heritable component of malaria resistance can be explained by the variants described so far, underscoring its complex genetic architecture and the need for continued research.
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Affiliation(s)
- Silvia N Kariuki
- Department of Epidemiology, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.
| | - Thomas N Williams
- Department of Epidemiology, KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya. .,Department of Medicine, Imperial College of Science and Technology, London, UK.
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53
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Old and Recent Advances in Life Cycle, Pathogenesis, Diagnosis, Prevention, and Treatment of Malaria Including Perspectives in Ethiopia. ScientificWorldJournal 2020. [DOI: 10.1155/2020/1295381] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Malaria, caused by apicomplexan parasite, is an old disease and continues to be a major public health threat in many countries. This article aims to present different aspects of malaria including causes, pathogenesis, prevention, and treatment in an articulate and comprehensive manner. Six Plasmodium species are recognized as the etiology of human malaria, of which Plasmodium falciparum is popular in East and Southern Africa. Malaria is transmitted mainly through Anopheles gambiae and Anopheles funestus, the two most effective malaria vectors in the world. Half of the world’s population is at risk for malaria infection. Globally, the morbidity and mortality rates of malaria have become decreased even though few reports in Ethiopia showed high prevalence of malaria. The malaria parasite has a complex life cycle that takes place both inside the mosquito and human beings. Generally, diagnosis of malaria is classified into clinical and parasitological diagnoses. Lack of clear understanding on the overall biology of Plasmodium has created a challenge in an effort to develop new drugs, vaccines, and preventive methods against malaria. However, three types of vaccines and a lot of novel compounds are under perclinical and clinical studies that are triggered by the occurrence of resistance among commonly used drugs and insecticides. Antiadhesion adjunctive therapies are also under investigation in the laboratory. In addition to previously known targets for diagnostic tool, vaccine and drug discovery scientists from all corner of the world are in search of new targets and chemical entities.
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54
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Vanka R, Nakka VP, Kumar SP, Baruah UK, Babu PP. Molecular targets in cerebral malaria for developing novel therapeutic strategies. Brain Res Bull 2020; 157:100-107. [PMID: 32006570 DOI: 10.1016/j.brainresbull.2020.01.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 01/27/2020] [Indexed: 10/25/2022]
Abstract
Cerebral malaria (CM) is the severe neurological complication associated with Plasmodium falciparum infection. In clinical settings CM is predominantly characterized by fever, epileptic seizures, and asexual forms of parasite on blood smears, coma and even death. Cognitive impairment in the children and adults even after survival is one of the striking consequences of CM. Poor diagnosis often leads to inappropriate malaria therapy which in turn progress into a severe form of disease. Activation of multiple cell death pathways such as Inflammation, oxidative stress, apoptosis and disruption of blood brain barrier (BBB) plays critical role in the pathogenesis of CM and secondary brain damage. Thus, understanding such mechanisms of neuronal cell death might help to identify potential molecular targets for CM. Mitigation strategies for mortality rate and long-term cognitive deficits caused by existing anti-malarial drugs still remains a valid research question to ask. In this review, we discuss in detail about critical neuronal cell death mechanisms and the overall significance of adjunctive therapy with recent trends, which provides better insight towards establishing newer therapeutic strategies for CM.
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Affiliation(s)
- Ravisankar Vanka
- Department of Pharmaceutics, Aditya Pharmacy College, Suramaplem, Gandepalli Mandal, East Godavari, Andhra Pradesh, 533437, India
| | - Venkata Prasuja Nakka
- Department of Biochemistry, Acharya Nagarjuna University, Nagarjuna Nagar, Guntur, Andhra Pradesh, 522510, India
| | - Simhadri Praveen Kumar
- Department of Biotechnology and Bioinformatics, School of life Sciences, University of Hyderabad, Hyderabad, Telangana, 500046, India
| | - Uday Krishna Baruah
- Department of Pharmaceutics, JSS College of Pharmacy, Ooty, Tamil Nadu 643001, India
| | - Phanithi Prakash Babu
- Department of Biotechnology and Bioinformatics, School of life Sciences, University of Hyderabad, Hyderabad, 500046, Telangana, India.
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55
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Stringent Selection of Knobby Plasmodium falciparum-Infected Erythrocytes during Cytoadhesion at Febrile Temperature. Microorganisms 2020; 8:microorganisms8020174. [PMID: 31991814 PMCID: PMC7074740 DOI: 10.3390/microorganisms8020174] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 11/17/2022] Open
Abstract
Changes in the erythrocyte membrane induced by Plasmodium falciparum invasion allow cytoadhesion of infected erythrocytes (IEs) to the host endothelium, which can lead to severe complications. Binding to endothelial cell receptors (ECRs) is mainly mediated by members of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family, encoded by var genes. Malaria infection causes several common symptoms, with fever being the most apparent. In this study, the effects of febrile conditions on cytoadhesion of predominately knobless erythrocytes infected with the laboratory isolate IT4 to chondroitin-4-sulfate A (CSA), intercellular adhesion molecule 1 (ICAM-1), and CD36 were investigated. IEs enriched for binding to CSA at 40 °C exhibited significantly increased binding capacity relative to parasites enriched at 37 °C. This interaction was due to increased var2csa expression and trafficking of the corresponding PfEMP1 to the IE surface as well as to a selection of knobby IEs. Furthermore, the enrichment of IEs to ICAM-1 at 40 °C also led to selection of knobby IEs over knobless IEs, whereas enrichment on CD36 did not lead to a selection. In summary, these findings demonstrate that knobs are crucial for parasitic survival in the host, especially during fever episodes, and thus, that selection pressure on the formation of knobs could be controlled by the host.
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56
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Riggle BA, Miller LH, Pierce SK. Desperately Seeking Therapies for Cerebral Malaria. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2020; 204:327-334. [PMID: 31907275 PMCID: PMC6951433 DOI: 10.4049/jimmunol.1900829] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 09/10/2019] [Indexed: 02/07/2023]
Abstract
Malaria is a deadly infectious disease caused by parasites of the Plasmodium spp. that takes an estimated 435,000 lives each year, primarily among young African children. For most children, malaria is a febrile illness that resolves with time, but in ∼1% of cases, for reasons we do not understand, malaria becomes severe and life threatening. Cerebral malaria (CM) is the most common form of severe malaria, accounting for the vast majority of childhood deaths from malaria despite highly effective antiparasite chemotherapy. Thus, CM is one of the most prevalent lethal brain diseases, and one for which we have no effective therapy. CM is, in part, an immune-mediated disease, and to fully understand CM, it is essential to appreciate the complex relationship between the malarial parasite and the human immune system. In this study, we provide a primer on malaria for immunologists and, in this context, review progress identifying targets for therapeutic intervention.
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Affiliation(s)
- Brittany A Riggle
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852; and
| | - Louis H Miller
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852
| | - Susan K Pierce
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852; and
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57
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Investigating a Plasmodium falciparum erythrocyte invasion phenotype switch at the whole transcriptome level. Sci Rep 2020; 10:245. [PMID: 31937828 PMCID: PMC6959351 DOI: 10.1038/s41598-019-56386-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 12/11/2019] [Indexed: 12/14/2022] Open
Abstract
The central role that erythrocyte invasion plays in Plasmodium falciparum survival and reproduction makes this process an attractive target for therapeutic or vaccine development. However, multiple invasion-related genes with complementary and overlapping functions afford the parasite the plasticity to vary ligands used for invasion, leading to phenotypic variation and immune evasion. Overcoming the challenge posed by redundant ligands requires a deeper understanding of conditions that select for variant phenotypes and the molecular mediators. While host factors including receptor heterogeneity and acquired immune responses may drive parasite phenotypic variation, we have previously shown that host-independent changes in invasion phenotype can be achieved by continuous culturing of the W2mef and Dd2 P. falciparum strains in moving suspension as opposed to static conditions. Here, we have used a highly biologically replicated whole transcriptome sequencing approach to identify the molecular signatures of variation associated with the phenotype switch. The data show increased expression of particular invasion-related genes in switched parasites, as well as a large number of genes encoding proteins that are either exported or form part of the export machinery. The genes with most markedly increased expression included members of the erythrocyte binding antigens (EBA), reticulocyte binding homologues (RH), surface associated interspersed proteins (SURFIN), exported protein family 1 (EPF1) and Plasmodium Helical Interspersed Sub-Telomeric (PHIST) gene families. The data indicate changes in expression of a repertoire of genes not previously associated with erythrocyte invasion phenotypes, suggesting the possibility that moving suspension culture may also select for other traits.
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58
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Lim YB, Thingna J, Kong F, Dao M, Cao J, Lim CT. Temperature-Induced Catch-Slip to Slip Bond Transit in Plasmodium falciparum-Infected Erythrocytes. Biophys J 2019; 118:105-116. [PMID: 31813540 DOI: 10.1016/j.bpj.2019.11.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 10/26/2019] [Accepted: 11/12/2019] [Indexed: 11/28/2022] Open
Abstract
Plasmodium falciparum malaria-infected red blood cells (IRBCs), or erythrocytes, avoid splenic clearance by adhering to host endothelium. Upregulation of endothelial receptors intercellular adhesion molecule-1 (ICAM-1) and cluster of differentiation 36 (CD36) are associated with severe disease pathology. Most in vitro studies of IRBCs interacting with these molecules were conducted at room temperature. However, as IRBCs are exposed to temperature variations between 37°C (body temperature) and 41°C (febrile temperature) in the host, it is important to understand IRBC-receptor interactions at these physiologically relevant temperatures. Here, we probe IRBC interactions against ICAM-1 and CD36 at 37 and 41°C. Single bond force-clamp spectroscopy is used to determine the bond dissociation rates and hence, unravel the nature of the IRBC-receptor interaction. The association rates are also extracted from a multiple bond flow assay using a cellular stochastic model. Surprisingly, IRBC-ICAM-1 bond transits from a catch-slip bond at 37°C toward a slip bond at 41°C. Moreover, binding affinities of both IRBC-ICAM-1 and IRBC-CD36 decrease as the temperature rises from 37 to 41°C. This study highlights the significance of examining receptor-ligand interactions at physiologically relevant temperatures and reveals biophysical insight into the temperature dependence of P. falciparum malaria cytoadherent bonds.
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Affiliation(s)
- Ying Bena Lim
- Department of Biomedical Engineering, National University of Singapore, Singapore; Singapore-Massachusetts Institute of Technology Alliance for Research and Technology Centre, Infectious Diseases IRG, Singapore
| | - Juzar Thingna
- Singapore-Massachusetts Institute of Technology Alliance for Research and Technology Centre, Infectious Diseases IRG, Singapore; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts; Center for Theoretical Physics of Complex Systems, Institute for Basic Science, Daejeon, Republic of Korea
| | - Fang Kong
- Singapore-Massachusetts Institute of Technology Alliance for Research and Technology Centre, Infectious Diseases IRG, Singapore; School of Biological Science, Nanyang Technological University, Singapore
| | - Ming Dao
- Singapore-Massachusetts Institute of Technology Alliance for Research and Technology Centre, Infectious Diseases IRG, Singapore; School of Biological Science, Nanyang Technological University, Singapore; Department of Material Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Jianshu Cao
- Singapore-Massachusetts Institute of Technology Alliance for Research and Technology Centre, Infectious Diseases IRG, Singapore; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts.
| | - Chwee Teck Lim
- Department of Biomedical Engineering, National University of Singapore, Singapore; Singapore-Massachusetts Institute of Technology Alliance for Research and Technology Centre, Infectious Diseases IRG, Singapore; Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore.
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59
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Rosetting revisited: a critical look at the evidence for host erythrocyte receptors in Plasmodium falciparum rosetting. Parasitology 2019; 147:1-11. [PMID: 31455446 PMCID: PMC7050047 DOI: 10.1017/s0031182019001288] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Malaria remains a major cause of mortality in African children, with no adjunctive treatments currently available to ameliorate the severe clinical forms of the disease. Rosetting, the adhesion of infected erythrocytes (IEs) to uninfected erythrocytes, is a parasite phenotype strongly associated with severe malaria, and hence is a potential therapeutic target. However, the molecular mechanisms of rosetting are complex and involve multiple distinct receptor–ligand interactions, with some similarities to the diverse pathways involved in P. falciparum erythrocyte invasion. This review summarizes the current understanding of the molecular interactions that lead to rosette formation, with a particular focus on host uninfected erythrocyte receptors including the A and B blood group trisaccharides, complement receptor one, heparan sulphate, glycophorin A and glycophorin C. There is strong evidence supporting blood group A trisaccharides as rosetting receptors, but evidence for other molecules is incomplete and requires further study. It is likely that additional host erythrocyte rosetting receptors remain to be discovered. A rosette-disrupting low anti-coagulant heparin derivative is being investigated as an adjunctive therapy for severe malaria, and further research into the receptor–ligand interactions underlying rosetting may reveal additional therapeutic approaches to reduce the unacceptably high mortality rate of severe malaria.
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60
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Kumar V, Behl A, Sharma R, Sharma A, Hora R. Plasmodium helical interspersed subtelomeric family-an enigmatic piece of the Plasmodium biology puzzle. Parasitol Res 2019; 118:2753-2766. [PMID: 31418110 DOI: 10.1007/s00436-019-06420-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 08/02/2019] [Indexed: 11/27/2022]
Abstract
Plasmodium falciparum (Pf) refurbishes the infected erythrocytes by exporting a myriad of parasite proteins to the host cell. A novel exported protein family 'Plasmodium Helical Interspersed Subtelomeric' (PHIST) has gained attention for its significant roles in parasite biology. Here, we have collected and analysed available information on PHIST members to enhance understanding of their functions, varied localization and structure-function correlation. Functional diversity of PHIST proteins is highlighted by their involvement in PfEMP1 (Pf erythrocyte membrane protein 1) expression, trafficking and switching. This family also contributes to cytoadherence, gametocytogenesis, host cell modification and generation of extracellular vesicles. While the PHIST domain forms the hallmark of this family, existence and functions of additional domains (LyMP, TIGR01639) and the MEC motif underscores its diversity further. Since specific PHIST proteins seem to form pairs with PfEMP1 members, we have used in silico tools to predict such potential partners in Pf. This information and our analysis of structural data on a PHIST member provide important insights into their functioning. This review overall enables readers to view the PHIST family comprehensively, while highlighting key knowledge gaps in the field.
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Affiliation(s)
- Vikash Kumar
- Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Ankita Behl
- Department of Biotechnology, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Rachana Sharma
- Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Aanchal Sharma
- Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Rachna Hora
- Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, Punjab, India.
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61
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Storm J, Jespersen JS, Seydel KB, Szestak T, Mbewe M, Chisala NV, Phula P, Wang CW, Taylor TE, Moxon CA, Lavstsen T, Craig AG. Cerebral malaria is associated with differential cytoadherence to brain endothelial cells. EMBO Mol Med 2019; 11:emmm.201809164. [PMID: 30610112 PMCID: PMC6365927 DOI: 10.15252/emmm.201809164] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Sequestration of Plasmodium falciparum‐infected erythrocytes (IE) within the brain microvasculature is a hallmark of cerebral malaria (CM). Using a microchannel flow adhesion assay with TNF‐activated primary human microvascular endothelial cells, we demonstrate that IE isolated from Malawian paediatric CM cases showed increased binding to brain microvascular endothelial cells compared to IE from uncomplicated malaria (UM) cases. Further, UM isolates showed significantly greater adhesion to dermal than to brain microvascular endothelial cells. The major mediator of parasite adhesion is P. falciparum erythrocyte membrane protein 1, encoded by var genes. Higher levels of var gene transcripts predicted to bind host endothelial protein C receptor (EPCR) and ICAM‐1 were detected in CM isolates. These data provide further evidence for differential tissue binding in severe and uncomplicated malaria syndromes, and give additional support to the hypothesis that CM pathology is based on increased cytoadherence of IE in the brain microvasculature.
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Affiliation(s)
- Janet Storm
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK .,Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,College of Medicine, University of Malawi, Blantyre, Malawi
| | - Jakob S Jespersen
- Department of International Health, Immunology & Microbiology, Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Karl B Seydel
- College of Medicine, University of Malawi, Blantyre, Malawi.,Blantyre Malaria Project, College of Medicine, University of Malawi, Blantyre, Malawi.,Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA
| | - Tadge Szestak
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Maurice Mbewe
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Ngawina V Chisala
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Patricia Phula
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Christian W Wang
- Department of International Health, Immunology & Microbiology, Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Terrie E Taylor
- Blantyre Malaria Project, College of Medicine, University of Malawi, Blantyre, Malawi.,Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA
| | - Christopher A Moxon
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.,Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical Veterinary & Life Sciences, University of Glasgow, Glasgow, UK
| | - Thomas Lavstsen
- Department of International Health, Immunology & Microbiology, Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Alister G Craig
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
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62
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Penha-Gonçalves C. Genetics of Malaria Inflammatory Responses: A Pathogenesis Perspective. Front Immunol 2019; 10:1771. [PMID: 31417551 PMCID: PMC6682681 DOI: 10.3389/fimmu.2019.01771] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 07/15/2019] [Indexed: 12/27/2022] Open
Abstract
Despite significant progress in combating malaria in recent years the burden of severe disease and death due to Plasmodium infections remains a global public health concern. Only a fraction of infected people develops severe clinical syndromes motivating a longstanding search for genetic determinants of malaria severity. Strong genetic effects have been repeatedly ascribed to mutations and allelic variants of proteins expressed in red blood cells but the role of inflammatory response genes in disease pathogenesis has been difficult to discern. We revisited genetic evidence provided by inflammatory response genes that have been repeatedly associated to malaria, namely TNF, NOS2, IFNAR1, HMOX1, TLRs, CD36, and CD40LG. This highlighted specific genetic variants having opposing roles in the development of distinct malaria clinical outcomes and unveiled diverse levels of genetic heterogeneity that shaped the complex association landscape of inflammatory response genes with malaria. However, scrutinizing genetic effects of individual variants corroborates a pathogenesis model where pro-inflammatory genetic variants acting in early infection stages contribute to resolve infection but at later stages confer increased vulnerability to severe organ dysfunction driven by tissue inflammation. Human genetics studies are an invaluable tool to find genes and molecular pathways involved in the inflammatory response to malaria but their precise roles in disease pathogenesis are still unexploited. Genome editing in malaria experimental models and novel genotyping-by-sequencing techniques are promising approaches to delineate the relevance of inflammatory response gene variants in the natural history of infection thereby will offer new rational angles on adjuvant therapeutics for prevention and clinical management of severe malaria.
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63
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Wichers JS, Scholz JAM, Strauss J, Witt S, Lill A, Ehnold LI, Neupert N, Liffner B, Lühken R, Petter M, Lorenzen S, Wilson DW, Löw C, Lavazec C, Bruchhaus I, Tannich E, Gilberger TW, Bachmann A. Dissecting the Gene Expression, Localization, Membrane Topology, and Function of the Plasmodium falciparum STEVOR Protein Family. mBio 2019; 10:e01500-19. [PMID: 31363031 PMCID: PMC6667621 DOI: 10.1128/mbio.01500-19] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 07/02/2019] [Indexed: 01/22/2023] Open
Abstract
During its intraerythrocytic development, the malaria parasite Plasmodium falciparum exposes variant surface antigens (VSAs) on infected erythrocytes to establish and maintain an infection. One family of small VSAs is the polymorphic STEVOR proteins, which are marked for export to the host cell surface through their PEXEL signal peptide. Interestingly, some STEVORs have also been reported to localize to the parasite plasma membrane and apical organelles, pointing toward a putative function in host cell egress or invasion. Using deep RNA sequencing analysis, we characterized P. falciparumstevor gene expression across the intraerythrocytic development cycle, including free merozoites, in detail and used the resulting stevor expression profiles for hierarchical clustering. We found that most stevor genes show biphasic expression oscillation, with maximum expression during trophozoite stages and a second peak in late schizonts. We selected four STEVOR variants, confirmed the expected export of these proteins to the host cell membrane, and tracked them to a secondary location, either to the parasite plasma membrane or the secretory organelles of merozoites in late schizont stages. We investigated the function of a particular STEVOR that showed rhoptry localization and demonstrated its role at the parasite-host interface during host cell invasion by specific antisera and targeted gene disruption. Experimentally determined membrane topology of this STEVOR revealed a single transmembrane domain exposing the semiconserved as well as variable protein regions to the cell surface.IMPORTANCE Malaria claims about half a million lives each year. Plasmodium falciparum, the causative agent of the most severe form of the disease, uses proteins that are translocated to the surface of infected erythrocytes for immune evasion. To circumvent the detection of these gene products by the immune system, the parasite evolved a complex strategy that includes gene duplications and elaborate sequence polymorphism. STEVORs are one family of these variant surface antigens and are encoded by about 40 genes. Using deep RNA sequencing of blood-stage parasites, including free merozoites, we first established stevor expression of the cultured isolate and compared it with published transcriptomes. We reveal a biphasic expression of most stevor genes and confirm this for individual STEVORs at the protein level. The membrane topology of a rhoptry-associated variant was experimentally elucidated and linked to host cell invasion, underlining the importance of this multifunctional protein family for parasite proliferation.
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Affiliation(s)
- J Stephan Wichers
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
| | | | - Jan Strauss
- Centre for Structural Systems Biology (CSSB), DESY, and European Molecular Biology Laboratory Hamburg, Hamburg, Germany
| | - Susanne Witt
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Andrés Lill
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
| | | | | | - Benjamin Liffner
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Renke Lühken
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Michaela Petter
- Institute of Microbiology, University Hospital Erlangen, Erlangen, Germany
| | - Stephan Lorenzen
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Danny W Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
- Burnet Institute, Melbourne, Victoria, Australia
| | - Christian Löw
- Centre for Structural Systems Biology (CSSB), DESY, and European Molecular Biology Laboratory Hamburg, Hamburg, Germany
| | | | - Iris Bruchhaus
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Egbert Tannich
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Tim W Gilberger
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
| | - Anna Bachmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
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CX3CL1 binding protein-2 (CBP2) of Plasmodium falciparum binds nucleic acids. Int J Biol Macromol 2019; 138:996-1005. [PMID: 31356937 DOI: 10.1016/j.ijbiomac.2019.07.178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 07/25/2019] [Accepted: 07/25/2019] [Indexed: 12/21/2022]
Abstract
Several exported Plasmodium falciparum (Pf) proteins contribute to malaria biology through their involvement in cytoadherence, immune evasion and host cell remodelling. Many of these exported proteins and other host molecules are present in iRBC (infected red blood cell) generated extracellular vesicles (EVs), which are responsible for host cell modification and parasite development. CX3CL1 binding proteins (CBPs) present on the surface of iRBCs have been reported to contribute to cytoadhesion by binding with the chemokine 'CX3CL1' via their extracellular domains. Here, we have characterized the cytoplasmic domain of CBP2 to understand its function in parasite biology using biochemical and biophysical methods. Recombinant cytoplasmic CBP2 (cCBP2) binds nucleic acids showing interaction with DNA/RNA. cCBP2 shows dimer formation under non-reducing conditions highlighting the role of disulphide bonds in its oligomerization while ATP binding leads to structural changes in the protein. In vitro interaction studies depict its binding with a Maurer's cleft resident protein 'PfSBP1', which is influenced by ATP binding of cCBP2. Our results suggest CBP2 as a two-transmembrane (2TM) receptor responsible for targeting EVs and delivering cargo to host endothelial cells. We propose CBP2 as an important molecule having roles in cytoadherence and immune modulation through its extracellular and cytoplasmic domains respectively.
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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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Lee WC, Russell B, Rénia L. Sticking for a Cause: The Falciparum Malaria Parasites Cytoadherence Paradigm. Front Immunol 2019; 10:1444. [PMID: 31316507 PMCID: PMC6610498 DOI: 10.3389/fimmu.2019.01444] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 06/10/2019] [Indexed: 12/26/2022] Open
Abstract
After a successful invasion, malaria parasite Plasmodium falciparum extensively remodels the infected erythrocyte cellular architecture, conferring cytoadhesive properties to the infected erythrocytes. Cytoadherence plays a central role in the parasite's immune-escape mechanism, at the same time contributing to the pathogenesis of severe falciparum malaria. In this review, we discuss the cytoadhesive interactions between P. falciparum infected erythrocytes and various host cell types, and how these events are linked to malaria pathogenesis. We also highlight the limitations faced by studies attempting to correlate diversity in parasite ligands and host receptors with the development of severe malaria.
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Affiliation(s)
- Wenn-Chyau Lee
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (ASTAR), Singapore, Singapore
| | - Bruce Russell
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Laurent Rénia
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (ASTAR), Singapore, Singapore
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Blood-Brain Barrier in Cerebral Malaria: Pathogenesis and Therapeutic Intervention. Trends Parasitol 2019; 35:516-528. [PMID: 31147271 DOI: 10.1016/j.pt.2019.04.010] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/25/2019] [Accepted: 04/25/2019] [Indexed: 02/06/2023]
Abstract
Cerebral malaria is a life-threatening complication of malaria caused by the parasite Plasmodium falciparum. The growing problem of drug resistance and the dearth of new antiparasitic drugs are a serious threat to the antimalaria treatment regimes. Studies on humans and the murine model have implicated the disruption of the blood-brain barrier (BBB) in the lethal course of the disease. Therefore, efforts to alleviate the BBB dysfunction could serve as an adjunct therapy. Here, we review the mechanisms associated with the disruption of the BBB. In addition, we discuss the current, still limited, knowledge on the contribution of different cell types, microparticles, and the kynurenine pathway in the regulation of BBB dysfunction, and how these molecules could be used as potential new therapeutic targets.
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Leopold SJ, Ghose A, Allman EL, Kingston HWF, Hossain A, Dutta AK, Plewes K, Chotivanich K, Day NPJ, Tarning J, Winterberg M, White NJ, Llinás M, Dondorp AM. Identifying the Components of Acidosis in Patients With Severe Plasmodium falciparum Malaria Using Metabolomics. J Infect Dis 2019; 219:1766-1776. [PMID: 30566600 PMCID: PMC6500555 DOI: 10.1093/infdis/jiy727] [Citation(s) in RCA: 26] [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] [Received: 09/19/2018] [Accepted: 12/15/2018] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Acidosis in severe Plasmodium falciparum malaria is associated with high mortality, yet the pathogenesis remains incompletely understood. The aim of this study was to determine the nature and source of metabolic acids contributing to acidosis in patients with severe falciparum malaria. METHODS A prospective observational study was conducted to characterize circulating acids in adults with P. falciparum malaria (n = 107) and healthy controls (n = 45) from Bangladesh using high-resolution liquid chromatography-mass spectrometry metabolomics. Additional in vitro P. falciparum culture studies were performed to determine if parasites release the acids detected in plasma from patients with severe malaria acidosis. RESULTS We identified previously unmeasured plasma acids strongly associated with acidosis in severe malaria. Metabolomic analysis of P. falciparum parasites in vitro showed no evidence that these acids are released by the parasite during its life cycle. Instead, 10 of the plasma acids could be mapped to a gut microbial origin. Patients with malaria had low L-citrulline levels, a plasma marker indicating reduced gut barrier integrity. Longitudinal data showed the clearance of these newly identified acids was delayed in fatal cases. CONCLUSIONS These data suggest that a compromise in intestinal barrier function may contribute significantly to the pathogenesis of life-threatening acidosis in severe falciparum malaria. CLINICAL TRIALS REGISTRATION NCT02451904.
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Affiliation(s)
- Stije J Leopold
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Aniruddha Ghose
- Department of Internal Medicine, Chittagong Medical College Hospital, Bangladesh
| | - Erik L Allman
- Department of Biochemistry and Molecular Biology and Huck Center for Malaria Research
| | - Hugh W F Kingston
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Amir Hossain
- Department of Internal Medicine, Chittagong Medical College Hospital, Bangladesh
| | - Asok Kumar Dutta
- Department of Internal Medicine, Chittagong Medical College Hospital, Bangladesh
| | - Katherine Plewes
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Kesinee Chotivanich
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas P J Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Joel Tarning
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Markus Winterberg
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Nicholas J White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
| | - Manuel Llinás
- Department of Biochemistry and Molecular Biology and Huck Center for Malaria Research
- Department of Chemistry, Pennsylvania State University, State College, PA
| | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, United Kingdom
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Orish V, Amegan Aho K, Ofori-Amoah J, Osei-Yobah J, Jamfaru I, Afeke I, Mac-Ankrah L, Adzaku F. Asymptomatic Plasmodium falciparum infection and poor school performance in primary school children in the Volta Region of Ghana. Ethiop J Health Sci 2019; 28:749-758. [PMID: 30607092 PMCID: PMC6308746 DOI: 10.4314/ejhs.v28i6.10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Background This study aimed to evaluate the association between asymptomatic Plasmodium falciparum infection and poor intellectual development in primary school children in the Volta Region of Ghana. Methods This was a cross-sectional study conducted among children from 5 primary schools in 3 districts in the Volta region of Ghana. Questionnaires were administered, and blood samples collected for malaria investigation using Rapid diagnostic test (RDT) and microscopy. School performance was used to assess intellectual development in the children. Arithmetic was the subject of choice for the standardized test. Pearson chi square test was used to evaluate the association between Plasmodium falciparum and poor school performance. Multivariate analysis was used to identify factors independently associated with risk of poor school performance. Results Out of 550 children, 305(55.45%) tested positive for malaria with RDT and 249(45.27%) positive with microscopy. Children from the Evangelical Presbyterian (EP) primary school in Afegame had the highest prevalence of Plasmodium falciparum infection with both RDT (92, 74.80%) and microscopy (73, 59.35%). Two hundred and fifteen students (39.09%) failed the arithmetic school test. EP primary school in Afegame recorded the highest frequency of poor school performance among the children (53.66%). School performance was significantly associated with RDT malaria diagnosis with failure rate higher among children who were RDT positive (135, 62.79%, p=0.005). Lower mean scores were seen in children with positive RDT result (47.35, [SD 30.85], p=0.021). Plasmodium falciparum infection (RDT) was independently associated with increased risk of poor school performance (AOR, 1.92, p=0.003). Conclusion An urgent scale-up of malaria control program targeting school-going children in this region is needed to mitigate the possible negative impact of Plasmodium falciparum infection on their intellectual development.
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Affiliation(s)
- Verner Orish
- Department of Microbiology and Immunology, School of Medicine, University of Health and Allied Sciences, Ho Volta Region, Ghana, West Africa
| | - Kokou Amegan Aho
- Department of Paediatrics, Schoolof Medicine, University of Health and Allied Sciences, Ho, Ghana
| | - Jones Ofori-Amoah
- Department of Pharmacology, School of Medicine, University of Health and Allied Sciences, Ho, Volta Region, Ghana
| | - James Osei-Yobah
- Department of Medical Laboratory Sciences, School of Allied Health Sciences, University of Health and Allied Sciences, Ho, Ghanaa
| | - Ibrahim Jamfaru
- Department of Microbiology and Immunology, School of Medicine, University of Health and Allied Sciences, Ho Volta Region, Ghana, West Africa
| | - Innocent Afeke
- Department of Medical Laboratory Sciences, School of Allied Health Sciences, University of Health and Allied Sciences, Ho, Ghanaa
| | - Lennox Mac-Ankrah
- Department of Microbiology and Immunology, School of Medicine, University of Health and Allied Sciences, Ho Volta Region, Ghana, West Africa
| | - Festus Adzaku
- School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho, Ghanaa
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Clark RL. Genesis of placental sequestration in malaria and possible targets for drugs for placental malaria. Birth Defects Res 2019; 111:569-583. [PMID: 30919596 PMCID: PMC7432169 DOI: 10.1002/bdr2.1496] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/05/2019] [Accepted: 03/06/2019] [Indexed: 01/11/2023]
Abstract
Malaria during pregnancy results in intrauterine growth restriction, fetal anemia, and infant mortality. Women are more susceptible to malaria during pregnancy due to malaria‐induced inflammation and the sequestration of infected red blood cells in the placenta, which bind to the chondroitin sulfate portion of syndecan‐1 on the syncytiotrophoblast and in the intervillous space. Syndecan‐1 is a dimeric proteoglycan with an extracellular ectodomain that is cleaved from the transmembrane domain (referred to as “shedding”) by matrix metalloproteinases (MMPs), likely the secreted MMP‐9. The ectodomain includes four binding sites for chondroitin sulfate, which are proximal to the transmembrane domain, and six distal binding sites primarily for heparan sulfate. This “shedding” of syndecan‐1 is inhibited by the presence of the heparan sulfate chains, which can be removed by heparanase. The intervillous space contains fibrin strands and syndecan‐1 ectodomains free of heparan sulfate. The following is proposed as the sequence of events that leads to and is primarily responsible for sequestration in the intervillous space of the placenta. Inflammation associated with malaria triggers increased heparanase activity that degrades the heparan sulfate on the membrane‐bound syndecan‐1. Inflammation also upregulates MMP‐9 and the removal of heparan sulfate gives MMP‐9 access to cleave syndecan‐1, thereby releasing dimeric syndecan‐1 ectodomains with at least four chondroitin sulfate chains attached. These multivalent ectodomains bind infected RBCs together leading to their aggregation and entrapment in intervillous fibrin. This mechanism suggests possible new targets for anti‐placental malaria drugs such as the inhibition of MMP‐9. Doxycycline is an antimalarial drug which inhibits MMP‐9.
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The bacterial protein CNF1 as a new strategy against Plasmodium falciparum cytoadherence. PLoS One 2019; 14:e0213529. [PMID: 30845261 PMCID: PMC6405130 DOI: 10.1371/journal.pone.0213529] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 02/22/2019] [Indexed: 11/19/2022] Open
Abstract
Plasmodium falciparum severe malaria causes more than 400,000 deaths every year. One feature of P. falciparum-parasitized erythrocytes (pRBC) leading to cerebral malaria (CM), the most dangerous form of severe malaria, is cytoadherence to endothelium and blockage of the brain microvasculature. Preventing ligand-receptor interactions involved in this process could inhibit pRBC sequestration and insurgence of severe disease whilst reversing existing cytoadherence could be a saving life adjunct therapy. Increasing evidence indicate the endothelial Rho signaling as a crucial player in malaria parasite cytoadherence. Therefore, we have used the cytotoxic necrotizing factor 1 (CNF1), an Escherichia coli protein able to modulate the activity of Cdc42, Rac, and Rho, three subfamilies of the Rho GTPases family, to study interactions between infected erythrocytes and cerebral endothelium in co-culture models. The main results are that CNF1 not only prevents cytoadherence but, more importantly, induces the detachment of pRBCs from endothelia monolayers. We first observed that CNF1 does affect neither parasite growth, nor the morphology and concentration of knobs that characterize the parasitized erythrocyte surface, as viewed by scanning electron microscopy. On the other hand, flow cytometry experiments show that cytoadherence reversion induced by CNF1 occurs in parallel with a decreased ICAM-1 receptor expression on the cell surface, suggesting the involvement of a toxin-promoted endocytic activity in such a response. Furthermore, since the endothelial barrier functionality is compromised by P. falciparum, we conducted a permeability assay on endothelial cells, revealing the CNF1 capacity to restore the brain endothelial barrier integrity. Then, using pull-down assays and inhibitory studies, we demonstrated, for the first time, that CNF1 is able not only to prevent but also to cause the parasite detachment by simultaneously activating Rho, Rac and Cdc42 in endothelial cells. All in all our findings indicate that CNF1 may represent a potential novel therapeutic strategy for preventing neurological complications of CM.
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Introini V, Carciati A, Tomaiuolo G, Cicuta P, Guido S. Endothelial glycocalyx regulates cytoadherence in Plasmodium falciparum malaria. J R Soc Interface 2018; 15:20180773. [PMID: 30958233 PMCID: PMC6303788 DOI: 10.1098/rsif.2018.0773] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 11/20/2018] [Indexed: 12/31/2022] Open
Abstract
Malaria is associated with significant microcirculation disorders, especially when the infection reaches its severe stage. This can lead to a range of fatal conditions, from cerebral malaria to multiple organ failure, of not fully understood pathogenesis. It has recently been proposed that a breakdown of the glycocalyx, the carbohydrate-rich layer lining the vascular endothelium, plays a key role in severe malaria, but direct evidence supporting this hypothesis is still lacking. Here, the interactions between Plasmodium falciparum infected red blood cells ( PfRBCs) and endothelial glycocalyx are investigated by developing an in vitro, physiologically relevant model of human microcirculation based on microfluidics. Impairment of the glycocalyx is obtained by enzymatic removal of sialic acid residues, which, due to their terminal location and net negative charge, are implicated in the initial interactions with contacting cells. We show a more than twofold increase of PfRBC adhesion to endothelial cells upon enzymatic treatment, relative to untreated endothelial cells. As a control, no effect of enzymatic treatment on healthy red blood cell adhesion is found. The increased adhesion of PfRBCs is also associated with cell flipping and reduced velocity as compared to the untreated endothelium. Altogether, these results provide a compelling evidence of the increased cytoadherence of PfRBCs to glycocalyx-impaired vascular endothelium, thus supporting the advocated role of glycocalyx disruption in the pathogenesis of this disease.
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Affiliation(s)
- Viola Introini
- Biological and Soft Systems, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, UK
| | - Antonio Carciati
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Napoli, Italy
| | - Giovanna Tomaiuolo
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Napoli, Italy
- CEINGE Biotecnologie avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy
| | - Pietro Cicuta
- Biological and Soft Systems, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, UK
| | - Stefano Guido
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Napoli, Italy
- CEINGE Biotecnologie avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy
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Tan J, Piccoli L, Lanzavecchia A. The Antibody Response to Plasmodium falciparum: Cues for Vaccine Design and the Discovery of Receptor-Based Antibodies. Annu Rev Immunol 2018; 37:225-246. [PMID: 30566366 DOI: 10.1146/annurev-immunol-042617-053301] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Plasmodium falciparum remains a serious public health problem and a continuous challenge for the immune system due to the complexity and diversity of the pathogen. Recent advances from several laboratories in the characterization of the antibody response to the parasite have led to the identification of critical targets for protection and revealed a new mechanism of diversification based on the insertion of host receptors into immunoglobulin genes, leading to the production of receptor-based antibodies. These advances have opened new possibilities for vaccine design and passive antibody therapies to provide sterilizing immunity and control blood-stage parasites.
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Affiliation(s)
- Joshua Tan
- Institute for Research in Biomedicine, Università della Svizzera italiana, 6500 Bellinzona, Switzerland; .,Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, United Kingdom.,Current affiliation: National Institute of Allergy and Infectious Diseases, Rockville, Maryland 20852, USA
| | - Luca Piccoli
- Institute for Research in Biomedicine, Università della Svizzera italiana, 6500 Bellinzona, Switzerland;
| | - Antonio Lanzavecchia
- Institute for Research in Biomedicine, Università della Svizzera italiana, 6500 Bellinzona, Switzerland; .,VIR Biotechnology, San Francisco, California 94158, USA
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75
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Human erythrocyte band 3 is a host receptor for Plasmodium falciparum glutamic acid-rich protein. Blood 2018; 133:470-480. [PMID: 30545833 DOI: 10.1182/blood-2018-07-865451] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 12/10/2018] [Indexed: 12/18/2022] Open
Abstract
Malaria remains a major global threat to human health and economic development. Microvascular lesions caused by Plasmodium falciparum-infected human erythrocytes/red blood cells are hallmarks of severe pathogenesis contributing to high mortality, particularly in children from sub-Saharan Africa. In this study, we used a phage display complementary DNA library screening strategy to identify P falciparum glutamic acid-rich protein (PfGARP) as a secreted ligand that recognizes an ectodomain of human erythrocyte anion-exchanger, band 3/AE1, as a host receptor. Domain mapping of PfGARP revealed distinct nonoverlapping repeats encoding the immune response epitopes and core erythrocyte-binding activity. Synthetic peptides derived from the erythrocyte-binding repeats of PfGARP induced erythrocyte aggregation reminiscent of the rosetting phenomenon. Using peptides derived from the immunogenic repeats, a quantitative immunoassay was developed to detect a selective immune response against PfGARP in human plasma samples obtained from patients in rural Mali, suggesting the feasibility of PfGARP as a potential biomarker of disease progression. Collectively, our results suggest that PfGARP may play a functional role in enhancing the adhesive properties of human erythrocytes by engaging band 3 as a host receptor. We propose that immunological and pharmacological inhibition of PfGARP may unveil new therapeutic options for mitigating lesions in cerebral and pregnancy-associated malaria.
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76
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Cespedes JC, Liu M, Harbuzariu A, Nti A, Onyekaba J, Cespedes HW, Bharti PK, Solomon W, Anyaoha P, Krishna S, Adjei A, Botchway F, Ford B, Stiles JK. Neuregulin in Health and Disease. INTERNATIONAL JOURNAL OF BRAIN DISORDERS AND TREATMENT 2018; 4:024. [PMID: 31032468 PMCID: PMC6483402 DOI: 10.23937/2469-5866/1410024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Juan Carlos Cespedes
- Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, USA
| | - Mingli Liu
- Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, USA
| | - Adriana Harbuzariu
- Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, USA
| | - Annette Nti
- Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, USA
| | - John Onyekaba
- Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, USA
| | - Hanna Watson Cespedes
- Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, USA
| | | | - Wesley Solomon
- Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, USA
| | - Precious Anyaoha
- Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, USA
| | - Sri Krishna
- ICMR-National Institute for Research in Tribal Health, India
| | - Andrew Adjei
- Department of Pathology, Korle-Bu Teaching Hospital, University of Ghana Medical School, Ghana
| | - Felix Botchway
- Department of Pathology, Korle-Bu Teaching Hospital, University of Ghana Medical School, Ghana
| | - Byron Ford
- Division of Biomedical Sciences, University of California-Riverside School of Medicine, USA
| | - Jonathan K Stiles
- Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine, USA
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77
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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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78
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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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79
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Degarege A, Gebrezgi MT, Ibanez G, Wahlgren M, Madhivanan P. Effect of the ABO blood group on susceptibility to severe malaria: A systematic review and meta-analysis. Blood Rev 2018; 33:53-62. [PMID: 30029997 DOI: 10.1016/j.blre.2018.07.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 06/29/2018] [Accepted: 07/12/2018] [Indexed: 12/25/2022]
Abstract
Understanding how ABO blood group interacts with Plasmodium falciparum (P. falciparum) infection may facilitate development of antimalarial treatments and vaccines. This study systematically summarizes information on the relationship of ABO blood group with severe P. falciparum infection, level of parasitemia and haemoglobin. A total of 1923 articles were retrieved from five databases. After removal of duplicates, and two levels of screening, 21 articles were selected for inclusion in the meta-analysis. A meta-analysis of the studies showed an increased odds of severe P. falciparum infection among individuals with blood group A, B, AB or non-O compared with blood group O. However, the difference in the level of P. falciparum parasitemia was not significant among individuals with blood group A or non-O compared with blood group O. The difference in haemoglobin level among P. falciparum infected individuals was also not significant between those with blood group A, B or AB versus those with blood group O.
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Affiliation(s)
- Abraham Degarege
- Department of Epidemiology, Robert Stempel College of Public Health & Social Work, Florida International University, Miami, USA; Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.
| | - Merhawi T Gebrezgi
- Department of Epidemiology, Robert Stempel College of Public Health & Social Work, Florida International University, Miami, USA.
| | - Gladys Ibanez
- Department of Epidemiology, Robert Stempel College of Public Health & Social Work, Florida International University, Miami, USA.
| | - Mats Wahlgren
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institute, Stockholm, Sweden.
| | - Purnima Madhivanan
- Department of Epidemiology, Robert Stempel College of Public Health & Social Work, Florida International University, Miami, USA; Public Health Research Institute of India, Mysore, India.
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80
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Wu X, Gowda NM, Kawasawa YI, Gowda DC. A malaria protein factor induces IL-4 production by dendritic cells via PI3K-Akt-NF-κB signaling independent of MyD88/TRIF and promotes Th2 response. J Biol Chem 2018; 293:10425-10434. [PMID: 29666186 PMCID: PMC6036203 DOI: 10.1074/jbc.ac118.001720] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 04/06/2018] [Indexed: 11/06/2022] Open
Abstract
Dendritic cells (DC) and cytokines produced by DC play crucial roles in inducing and regulating pro-/anti-inflammatory and Th1/Th2 responses. DC are known to produce a Th1-promoting cytokine, interleukin (IL)-12, in response to malaria and other pathogenic infections, but it is thought that DC do not produce Th2-promoting cytokine, IL-4. Here, we show that a protein factor of malaria parasites induces IL-4 responses by CD11chiMHCIIhiCD3ϵ-CD49b-CD19-FcϵRI- DC via PI3K-Akt-NF-κB signaling independent of TLR-MyD88/TRIF. Malaria parasite-activated DC induced IL-4 responses by T cells both in vitro and in vivo, favoring Th2, and il-4-deficient DC were unable to induce IL-4 expression by T cells. Interestingly, lethal parasites, Plasmodium falciparum and Plasmodium berghei ANKA, induced IL-4 response primarily by CD8α- DC, whereas nonlethal Plasmodium yoelii induced IL-4 by both CD8α+ and CD8α- DC. In both P. berghei ANKA- and P. yoelii-infected mice, IL-4-expressing CD8α- DC did not express IL-12, but a distinct CD8α- DC subset expressed IL-12. In P. berghei ANKA infection, CD8α+ DC expressed IL-12 but not IL-4, whereas in P. yoelii infection, CD8α+ DC expressed IL-4 but not IL-12. These differential IL-4 and IL-12 responses by DC subsets may contribute to different Th1/Th2 development and clinical outcomes in lethal and nonlethal malaria. Our results for the first time demonstrate that a malaria protein factor induces IL-4 production by DC via PI3K-Akt-NF-κB signaling, revealing signaling and molecular mechanisms that initiate and promote Th2 development.
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Affiliation(s)
- Xianzhu Wu
- From the Department of Biochemistry and Molecular Biology and
| | - Nagaraj M Gowda
- From the Department of Biochemistry and Molecular Biology and
| | - Yuka I Kawasawa
- From the Department of Biochemistry and Molecular Biology and
- the Department of Pharmacology and the Institute for Personalized Medicine, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033
| | - D Channe Gowda
- From the Department of Biochemistry and Molecular Biology and
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81
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Yam XY, Preiser PR. Host immune evasion strategies of malaria blood stage parasite. MOLECULAR BIOSYSTEMS 2018; 13:2498-2508. [PMID: 29091093 DOI: 10.1039/c7mb00502d] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Host immune evasion is a key strategy for the continual survival of many microbial pathogens including Apicomplexan protozoan: Plasmodium spp., the causative agent of Malaria. The malaria parasite has evolved a variety of mechanisms to evade the host immune responses within its two hosts: the female Anopheles mosquito vector and vertebrate host. In this review, we will focus on the molecular mechanisms of the immune evasion strategies used by the Plasmodium parasite at the blood stage which is responsible for the clinical manifestations of human malaria. We also aim to provide some insights on the potential targets for malaria interventions through the recent advancement in understanding the molecular biology of the parasite.
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Affiliation(s)
- Xue Yan Yam
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore.
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82
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Ramirez SH, Andrews AM, Paul D, Pachter JS. Extracellular vesicles: mediators and biomarkers of pathology along CNS barriers. Fluids Barriers CNS 2018; 15:19. [PMID: 29960602 PMCID: PMC6026502 DOI: 10.1186/s12987-018-0104-7] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 05/28/2018] [Indexed: 02/07/2023] Open
Abstract
Extracellular vesicles (EVs) are heterogeneous, nano-sized vesicles that are shed into the blood and other body fluids, which disperse a variety of bioactive molecules (e.g., protein, mRNA, miRNA, DNA and lipids) to cellular targets over long and short distances. EVs are thought to be produced by nearly every cell type, however this review will focus specifically on EVs that originate from cells at the interface of CNS barriers. Highlighted topics include, EV biogenesis, the production of EVs in response to neuroinflammation, role in intercellular communication and their utility as a therapeutic platform. In this review, novel concepts regarding the use of EVs as biomarkers for BBB status and as facilitators for immune neuroinvasion are also discussed. Future directions and prospective are covered along with important unanswered questions in the field of CNS endothelial EV biology.
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Affiliation(s)
- Servio H Ramirez
- Department of Pathology and Laboratory Medicine, The Lewis Katz School of Medicine at Temple University, 3500 N Broad St, Philadelphia, PA, 19140, USA. .,Shriners Hospital Pediatric Research Center, Philadelphia, PA, 19140, USA. .,Center for Substance Abuse Research, The Lewis Katz School of Medicine at Temple University, Philadelphia, PA, 19140, USA.
| | - Allison M Andrews
- Department of Pathology and Laboratory Medicine, The Lewis Katz School of Medicine at Temple University, 3500 N Broad St, Philadelphia, PA, 19140, USA.,Center for Substance Abuse Research, The Lewis Katz School of Medicine at Temple University, Philadelphia, PA, 19140, USA
| | - Debayon Paul
- Department of Immunology, Blood-Brain Barrier Laboratory & Laser Capture Microdissection Core, UConn Health, 263 Farmington Ave., Farmington, CT, 06070, USA
| | - Joel S Pachter
- Department of Immunology, Blood-Brain Barrier Laboratory & Laser Capture Microdissection Core, UConn Health, 263 Farmington Ave., Farmington, CT, 06070, USA.
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83
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Opi DH, Swann O, Macharia A, Uyoga S, Band G, Ndila CM, Harrison EM, Thera MA, Kone AK, Diallo DA, Doumbo OK, Lyke KE, Plowe CV, Moulds JM, Shebbe M, Mturi N, Peshu N, Maitland K, Raza A, Kwiatkowski DP, Rockett KA, Williams TN, Rowe JA. Two complement receptor one alleles have opposing associations with cerebral malaria and interact with α +thalassaemia. eLife 2018; 7:e31579. [PMID: 29690995 PMCID: PMC5953541 DOI: 10.7554/elife.31579] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 04/01/2018] [Indexed: 12/13/2022] Open
Abstract
Malaria has been a major driving force in the evolution of the human genome. In sub-Saharan African populations, two neighbouring polymorphisms in the Complement Receptor One (CR1) gene, named Sl2 and McCb, occur at high frequencies, consistent with selection by malaria. Previous studies have been inconclusive. Using a large case-control study of severe malaria in Kenyan children and statistical models adjusted for confounders, we estimate the relationship between Sl2 and McCb and malaria phenotypes, and find they have opposing associations. The Sl2 polymorphism is associated with markedly reduced odds of cerebral malaria and death, while the McCb polymorphism is associated with increased odds of cerebral malaria. We also identify an apparent interaction between Sl2 and α+thalassaemia, with the protective association of Sl2 greatest in children with normal α-globin. The complex relationship between these three mutations may explain previous conflicting findings, highlighting the importance of considering genetic interactions in disease-association studies.
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Affiliation(s)
- D Herbert Opi
- Kenya Medical Research Institute-Wellcome Trust Research ProgrammeKilifiKenya
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological SciencesUniversity of EdinburghEdinburghUnited Kingdom
| | - Olivia Swann
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological SciencesUniversity of EdinburghEdinburghUnited Kingdom
| | - Alexander Macharia
- Kenya Medical Research Institute-Wellcome Trust Research ProgrammeKilifiKenya
| | - Sophie Uyoga
- Kenya Medical Research Institute-Wellcome Trust Research ProgrammeKilifiKenya
| | - Gavin Band
- Wellcome Trust Centre for Human GeneticsUniversity of OxfordOxfordUnited Kingdom
| | - Carolyne M Ndila
- Kenya Medical Research Institute-Wellcome Trust Research ProgrammeKilifiKenya
| | - Ewen M Harrison
- Centre for Medical InfomaticsUsher Insitute of Population Health Sciences and Informatics, University of EdinburghEdinburghUnited Kingdom
| | - Mahamadou A Thera
- Malaria Research and Training Centre, Faculty of Medicine, Pharmacy, and DentistryUniversity of BamakoBamakoMali
| | - Abdoulaye K Kone
- Malaria Research and Training Centre, Faculty of Medicine, Pharmacy, and DentistryUniversity of BamakoBamakoMali
| | - Dapa A Diallo
- Malaria Research and Training Centre, Faculty of Medicine, Pharmacy, and DentistryUniversity of BamakoBamakoMali
| | - Ogobara K Doumbo
- Malaria Research and Training Centre, Faculty of Medicine, Pharmacy, and DentistryUniversity of BamakoBamakoMali
| | - Kirsten E Lyke
- Division of Malaria Research, Institute for Global HealthUniversity of Maryland School of MedicineBaltimoreUnited States
| | - Christopher V Plowe
- Division of Malaria Research, Institute for Global HealthUniversity of Maryland School of MedicineBaltimoreUnited States
| | | | - Mohammed Shebbe
- Kenya Medical Research Institute-Wellcome Trust Research ProgrammeKilifiKenya
| | - Neema Mturi
- Kenya Medical Research Institute-Wellcome Trust Research ProgrammeKilifiKenya
| | - Norbert Peshu
- Kenya Medical Research Institute-Wellcome Trust Research ProgrammeKilifiKenya
| | - Kathryn Maitland
- Kenya Medical Research Institute-Wellcome Trust Research ProgrammeKilifiKenya
- Department of MedicineImperial CollegeLondonUnited Kingdom
| | - Ahmed Raza
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological SciencesUniversity of EdinburghEdinburghUnited Kingdom
| | - Dominic P Kwiatkowski
- Wellcome Trust Centre for Human GeneticsUniversity of OxfordOxfordUnited Kingdom
- Wellcome Trust Sanger InstituteCambridgeUnited Kingdom
| | - Kirk A Rockett
- Wellcome Trust Centre for Human GeneticsUniversity of OxfordOxfordUnited Kingdom
| | - Thomas N Williams
- Kenya Medical Research Institute-Wellcome Trust Research ProgrammeKilifiKenya
- Department of MedicineImperial CollegeLondonUnited Kingdom
| | - J Alexandra Rowe
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological SciencesUniversity of EdinburghEdinburghUnited Kingdom
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84
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Leligdowicz A, Richard-Greenblatt M, Wright J, Crowley VM, Kain KC. Endothelial Activation: The Ang/Tie Axis in Sepsis. Front Immunol 2018; 9:838. [PMID: 29740443 PMCID: PMC5928262 DOI: 10.3389/fimmu.2018.00838] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 04/05/2018] [Indexed: 12/21/2022] Open
Abstract
Sepsis, a dysregulated host response to infection that causes life-threatening organ dysfunction, is a highly heterogeneous syndrome with no specific treatment. Although sepsis can be caused by a wide variety of pathogenic organisms, endothelial dysfunction leading to vascular leak is a common mechanism of injury that contributes to the morbidity and mortality associated with the syndrome. Perturbations to the angiopoietin (Ang)/Tie2 axis cause endothelial cell activation and contribute to the pathogenesis of sepsis. In this review, we summarize how the Ang/Tie2 pathway is implicated in sepsis and describe its prognostic as well as therapeutic utility in life-threatening infections.
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Affiliation(s)
- Aleksandra Leligdowicz
- Sandra Rotman Centre for Global Health, University Health Network and University of Toronto, Toronto, ON, Canada
| | - Melissa Richard-Greenblatt
- Sandra Rotman Centre for Global Health, University Health Network and University of Toronto, Toronto, ON, Canada
| | - Julie Wright
- Sandra Rotman Centre for Global Health, University Health Network and University of Toronto, Toronto, ON, Canada
| | - Valerie M Crowley
- Sandra Rotman Centre for Global Health, University Health Network and University of Toronto, Toronto, ON, Canada
| | - Kevin C Kain
- Sandra Rotman Centre for Global Health, University Health Network and University of Toronto, Toronto, ON, Canada
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85
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Minkah NK, Schafer C, Kappe SHI. Humanized Mouse Models for the Study of Human Malaria Parasite Biology, Pathogenesis, and Immunity. Front Immunol 2018; 9:807. [PMID: 29725334 PMCID: PMC5917005 DOI: 10.3389/fimmu.2018.00807] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 04/03/2018] [Indexed: 12/25/2022] Open
Abstract
Malaria parasite infection continues to inflict extensive morbidity and mortality in resource-poor countries. The insufficiently understood parasite biology, continuously evolving drug resistance and the lack of an effective vaccine necessitate intensive research on human malaria parasites that can inform the development of new intervention tools. Humanized mouse models have been greatly improved over the last decade and enable the direct study of human malaria parasites in vivo in the laboratory. Nevertheless, no small animal model developed so far is capable of maintaining the complete life cycle of Plasmodium parasites that infect humans. The ultimate goal is to develop humanized mouse systems in which a Plasmodium infection closely reproduces all stages of a parasite infection in humans, including pre-erythrocytic infection, blood stage infection and its associated pathology, transmission as well as the human immune response to infection. Here, we discuss current humanized mouse models and the future directions that should be taken to develop next-generation models for human malaria parasite research.
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Affiliation(s)
- Nana K Minkah
- Center for Infectious Disease Research, Seattle, WA, United States
| | - Carola Schafer
- Center for Infectious Disease Research, Seattle, WA, United States
| | - Stefan H I Kappe
- Center for Infectious Disease Research, Seattle, WA, United States.,Department of Global Health, University of Washington, Seattle, WA, United States
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86
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Messina V, Valtieri M, Rubio M, Falchi M, Mancini F, Mayor A, Alano P, Silvestrini F. Gametocytes of the Malaria Parasite Plasmodium falciparum Interact With and Stimulate Bone Marrow Mesenchymal Cells to Secrete Angiogenetic Factors. Front Cell Infect Microbiol 2018; 8:50. [PMID: 29546035 PMCID: PMC5838020 DOI: 10.3389/fcimb.2018.00050] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 02/09/2018] [Indexed: 12/31/2022] Open
Abstract
The gametocytes of Plasmodium falciparum, responsible for the transmission of this malaria parasite from humans to mosquitoes, accumulate and mature preferentially in the human bone marrow. In the 10 day long sexual development of P. falciparum, the immature gametocytes reach and localize in the extravascular compartment of this organ, in contact with several bone marrow stroma cell types, prior to traversing the endothelial lining and re-entering in circulation at maturity. To investigate the host parasite interplay underlying this still obscure process, we developed an in vitro tridimensional co-culture system in a Matrigel scaffold with P. falciparum gametocytes and self-assembling spheroids of human bone marrow mesenchymal cells (hBM-MSCs). Here we show that this co-culture system sustains the full maturation of the gametocytes and that the immature, but not the mature, gametocytes adhere to hBM-MSCs via trypsin-sensitive parasite ligands exposed on the erythrocyte surface. Analysis of a time course of gametocytogenesis in the co-culture system revealed that gametocyte maturation is accompanied by the parasite induced stimulation of hBM-MSCs to secrete a panel of 14 cytokines and growth factors, 13 of which have been described to play a role in angiogenesis. Functional in vitro assays on human bone marrow endothelial cells showed that supernatants from the gametocyte mesenchymal cell co-culture system enhance ability of endothelial cells to form vascular tubes. These results altogether suggest that the interplay between immature gametocytes and hBM-MSCs may induce functional and structural alterations in the endothelial lining of the human bone marrow hosting the P. falciparum transmission stages.
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Affiliation(s)
- Valeria Messina
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy
| | - Mauro Valtieri
- Dipartimento di Oncologia e Medicina Molecolare, Istituto Superiore di Sanità, Rome, Italy
| | - Mercedes Rubio
- ISGlobal, Barcelona Ctr. Int. Health Res, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Mario Falchi
- AIDS National Center, Istituto Superiore di Sanità, Rome, Italy
| | - Francesca Mancini
- Dipartimento di Biotecnologie Cellulari ed Ematologia, Umberto I - Policlinico di Roma, Rome, Italy
| | - Alfredo Mayor
- ISGlobal, Barcelona Ctr. Int. Health Res, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.,Centro de Investigação em Saúde da Manhiça, Maputo, Mozambique
| | - Pietro Alano
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy
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87
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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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88
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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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89
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Kumar K, Srinivasan P, Nold MJ, Moch JK, Reiter K, Sturdevant D, Otto TD, Squires RB, Herrera R, Nagarajan V, Rayner JC, Porcella SF, Geromanos SJ, Haynes JD, Narum DL. Profiling invasive Plasmodium falciparum merozoites using an integrated omics approach. Sci Rep 2017; 7:17146. [PMID: 29215067 PMCID: PMC5719419 DOI: 10.1038/s41598-017-17505-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/22/2017] [Indexed: 02/06/2023] Open
Abstract
The symptoms of malaria are brought about by blood-stage parasites, which are established when merozoites invade human erythrocytes. Our understanding of the molecular events that underpin erythrocyte invasion remains hampered by the short-period of time that merozoites are invasive. To address this challenge, a Plasmodium falciparum gamma-irradiated long-lived merozoite (LLM) line was developed and investigated. Purified LLMs invaded erythrocytes by an increase of 10-300 fold compared to wild-type (WT) merozoites. Using an integrated omics approach, we investigated the basis for the phenotypic difference. Only a few single nucleotide polymorphisms within the P. falciparum genome were identified and only marginal differences were observed in the merozoite transcriptomes. By contrast, using label-free quantitative mass-spectrometry, a significant change in protein abundance was noted, of which 200 were proteins of unknown function. We determined the relative molar abundance of over 1100 proteins in LLMs and further characterized the major merozoite surface protein complex. A unique processed MSP1 intermediate was identified in LLM but not observed in WT suggesting that delayed processing may be important for the observed phenotype. This integrated approach has demonstrated the significant role of the merozoite proteome during erythrocyte invasion, while identifying numerous unknown proteins likely to be involved in invasion.
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Affiliation(s)
- Krishan Kumar
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA
| | - Prakash Srinivasan
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, MD, USA.
- Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| | | | - J Kathleen Moch
- Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Karine Reiter
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA
| | - Dan Sturdevant
- Genomics Unit, Research Technologies Section, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT, USA
| | - Thomas D Otto
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - R Burke Squires
- Computational Biology Section, Bioinformatics and Computational Biosciences Branch, NIAID, NIH, Bethesda, MD, USA
| | - Raul Herrera
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA
| | - Vijayaraj Nagarajan
- Computational Biology Section, Bioinformatics and Computational Biosciences Branch, NIAID, NIH, Bethesda, MD, USA
| | - Julian C Rayner
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - Stephen F Porcella
- Genomics Unit, Research Technologies Section, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, MT, USA
| | | | - J David Haynes
- Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - David L Narum
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Rockville, MD, USA.
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90
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Priya SP, Sakinah S, Sharmilah K, Hamat RA, Sekawi Z, Higuchi A, Ling MP, Nordin SA, Benelli G, Kumar SS. Leptospirosis: Molecular trial path and immunopathogenesis correlated with dengue, malaria and mimetic hemorrhagic infections. Acta Trop 2017; 176:206-223. [PMID: 28823908 DOI: 10.1016/j.actatropica.2017.08.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 08/03/2017] [Accepted: 08/04/2017] [Indexed: 12/12/2022]
Abstract
Immuno-pathogenesis of leptospirosis can be recounted well by following its trail path from entry to exit, while inducing disastrous damages in various tissues of the host. Dysregulated, inappropriate and excessive immune responses are unanimously blamed in fatal leptospirosis. The inherent abilities of the pathogen and inabilities of the host were debated targeting the severity of the disease. Hemorrhagic manifestation through various mechanisms leading to a fatal end is observed when this disease is unattended. The similar vascular destructions and hemorrhage manifestations are noted in infections with different microbes in endemic areas. The simultaneous infection in a host with more than one pathogen or parasite is referred as the coinfection. Notably, common endemic infections such as leptospirosis, dengue, chikungunya, and malaria, harbor favorable environments to flourish in similar climates, which is aggregated with stagnated water and aggravated with the poor personal and environmental hygiene of the inhabitants. These factors aid the spread of pathogens and parasites to humans and potential vectors, eventually leading to outbreaks of public health relevance. Malaria, dengue and chikungunya need mosquitoes as vectors, in contrast with leptospirosis, which directly invades human, although the environmental bacterial load is maintained through other mammals, such as rodents. The more complicating issue is that infections by different pathogens exhibiting similar symptoms but require different treatment management. The current review explores different pathogens expressing specific surface proteins and their ability to bind with array of host proteins with or without immune response to enter into the host tissues and their ability to evade the host immune responses to invade and their affinity to certain tissues leading to the common squeal of hemorrhage. Furthermore, at the host level, the increased susceptibility and inability of the host to arrest the pathogens' and parasites' spread in different tissues, various cytokines accumulated to eradicate the microorganisms and their cellular interactions, the antibody dependent defense and the susceptibility of individual organs bringing the manifestation of the diseases were explored. Lastly, we provided a discussion on the immune trail path of pathogenesis from entry to exit to narrate the similarities and dissimilarities among various hemorrhagic fevers mentioned above, in order to outline future possibilities of prevention, diagnosis, and treatment of coinfections, with special reference to endemic areas.
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91
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Riggle BA, Miller LH, Pierce SK. Do we know enough to find an adjunctive therapy for cerebral malaria in African children? F1000Res 2017; 6:2039. [PMID: 29250318 PMCID: PMC5701444 DOI: 10.12688/f1000research.12401.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/23/2017] [Indexed: 01/27/2023] Open
Abstract
Cerebral malaria is the deadliest complication of malaria, a febrile infectious disease caused by Plasmodium parasite. Any of the five human Plasmodium species can cause disease, but, for unknown reasons, in approximately 2 million cases each year P. falciparum progresses to severe disease, ultimately resulting in half a million deaths. The majority of these deaths are in children under the age of five. Currently, there is no way to predict which child will progress to severe disease and there are no adjunctive therapies to halt the symptoms after onset. Herein, we discuss what is known about the disease mechanism of one form of severe malaria, cerebral malaria, and how we might exploit this understanding to rescue children in the throes of cerebral disease.
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Affiliation(s)
- Brittany A Riggle
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, USA
| | - Louis H Miller
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, USA
| | - Susan K Pierce
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, USA
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92
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Nilsson Bark SK, Ahmad R, Dantzler K, Lukens AK, De Niz M, Szucs MJ, Jin X, Cotton J, Hoffmann D, Bric-Furlong E, Oomen R, Parrington M, Milner D, Neafsey DE, Carr SA, Wirth DF, Marti M. Quantitative Proteomic Profiling Reveals Novel Plasmodium falciparum Surface Antigens and Possible Vaccine Candidates. Mol Cell Proteomics 2017; 17:43-60. [PMID: 29162636 DOI: 10.1074/mcp.ra117.000076] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 09/20/2017] [Indexed: 12/30/2022] Open
Abstract
Despite recent efforts toward control and elimination, malaria remains a major public health problem worldwide. Plasmodium falciparum resistance against artemisinin, used in front line combination drugs, is on the rise, and the only approved vaccine shows limited efficacy. Combinations of novel and tailored drug and vaccine interventions are required to maintain the momentum of the current malaria elimination program. Current evidence suggests that strain-transcendent protection against malaria infection can be achieved using whole organism vaccination or with a polyvalent vaccine covering multiple antigens or epitopes. These approaches have been successfully applied to the human-infective sporozoite stage. Both systemic and tissue-specific pathology during infection with the human malaria parasite P. falciparum is caused by asexual blood stages. Tissue tropism and vascular sequestration are the result of specific binding interactions between antigens on the parasite-infected red blood cell (pRBC) surface and endothelial receptors. The major surface antigen and parasite ligand binding to endothelial receptors, PfEMP1 is encoded by about 60 variants per genome and shows high sequence diversity across strains. Apart from PfEMP1 and three additional variant surface antigen families RIFIN, STEVOR, and SURFIN, systematic analysis of the infected red blood cell surface is lacking. Here we present the most comprehensive proteomic investigation of the parasitized red blood cell surface so far. Apart from the known variant surface antigens, we identified a set of putative single copy surface antigens with low sequence diversity, several of which are validated in a series of complementary experiments. Further functional and immunological investigation is underway to test these novel P. falciparum blood stage proteins as possible vaccine candidates.
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Affiliation(s)
- Sandra K Nilsson Bark
- From the ‡Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115
| | - Rushdy Ahmad
- §The Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142
| | - Kathleen Dantzler
- From the ‡Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115.,¶Wellcome Centre for Molecular Parasitology, University of Glasgow, Glasgow G12 8TA, UK
| | - Amanda K Lukens
- From the ‡Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115.,§The Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142
| | - Mariana De Niz
- ¶Wellcome Centre for Molecular Parasitology, University of Glasgow, Glasgow G12 8TA, UK
| | - Matthew J Szucs
- §The Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142
| | - Xiaoying Jin
- ‖Sanofi Biopharmaceutics Development, Framingham, Massachusetts 02142
| | - Joanne Cotton
- ‖Sanofi Biopharmaceutics Development, Framingham, Massachusetts 02142
| | | | | | - Ray Oomen
- **Sanofi Pasteur Biologics, Cambridge, Massachusetts 02139
| | | | - Dan Milner
- From the ‡Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115.,‡‡Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts 02115
| | - Daniel E Neafsey
- §The Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142
| | - Steven A Carr
- §The Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142
| | - Dyann F Wirth
- From the ‡Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115.,§The Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142
| | - Matthias Marti
- From the ‡Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115; .,¶Wellcome Centre for Molecular Parasitology, University of Glasgow, Glasgow G12 8TA, UK
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93
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Cunha JA, Carvalho LJM, Bianco-Junior C, Andrade MCR, Pratt-Riccio LR, Riccio EKP, Pelajo-Machado M, da Silva IJ, Druilhe P, Daniel-Ribeiro CT. Increased Plasmodium falciparum Parasitemia in Non-splenectomized Saimiri sciureus Monkeys Treated with Clodronate Liposomes. Front Cell Infect Microbiol 2017; 7:408. [PMID: 28983468 PMCID: PMC5613086 DOI: 10.3389/fcimb.2017.00408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 09/04/2017] [Indexed: 11/25/2022] Open
Abstract
A major constraint in the study of Plasmodium falciparum malaria, including vaccine development, lies on the parasite's strict human host specificity and therefore the shortage of animal experimental models able to harbor human plasmodia. The best experimental models are neo-tropical primates of the genus Saimiri and Aotus, but they require splenectomy to reduce innate defenses for achieving high and consistent parasitemias, an important limitation. Clodronate-liposomes (CL) have been successfully used to deplete monocytes/macrophages in several experimental models. We investigated whether a reduction in the numbers of phagocytic cells by CL would improve the development of P. falciparum parasitemia in non-splenectomized Saimiri sciureus monkeys. Depletion of S. sciureus splenocytes after in vitro incubation with CL was quantified using anti-CD14 antibodies and flow cytometry. Non-infected and P. falciparum-infected S. sciureus were injected intravenously twice a week with either CL at either 0.5 or 1 mL (5 mg/mL) or phosphate buffered saline (PBS). Animals were monitored during infection and treated with mefloquine. After treatment and euthanasia, spleen and liver were collected for histological analysis. In vitro CL depleted S. sciureus splenic monocyte/macrophage population in a dose- and time-dependent manner. In vivo, half of P. falciparum-infected S. sciureus treated with CL 0.5 mL, and two-thirds of those treated with CL 1 mL developed high parasitemias requiring mefloquine treatment, whereas all control animals were able to self-control parasitemia without the need for antimalarial treatment. CL-treated infected S. sciureus showed a marked decrease in the degree of splenomegaly despite higher parasitemias, compared to PBS-treated animals. Histological evidence of partial monocyte/macrophage depletion, decreased hemozoin phagocytosis and decreased iron recycling was observed in both the spleen and liver of CL-treated infected S. sciureus. CL is capable of promoting higher parasitemia in P. falciparum-infected S. sciureus, associated with evidence of partial macrophage depletion in the spleen and liver. Macrophage depletion by CL is therefore a practical and viable alternative to surgical splenectomy in this experimental model.
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Affiliation(s)
- Janaiara A Cunha
- Laboratório de Pesquisa em Malária, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz)Rio de Janeiro, Brazil
| | - Leonardo J M Carvalho
- Laboratório de Pesquisa em Malária, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz)Rio de Janeiro, Brazil
| | - Cesare Bianco-Junior
- Laboratório de Pesquisa em Malária, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz)Rio de Janeiro, Brazil
| | - Márcia C R Andrade
- Instituto de Ciência e Tecnologia em Biomodelos, FiocruzRio de Janeiro, Brazil
| | - Lilian R Pratt-Riccio
- Laboratório de Pesquisa em Malária, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz)Rio de Janeiro, Brazil
| | - Evelyn K P Riccio
- Laboratório de Pesquisa em Malária, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz)Rio de Janeiro, Brazil
| | | | - Igor J da Silva
- Laboratório de Patologia, Instituto Oswaldo Cruz, FiocruzRio de Janeiro, Brazil
| | - Pierre Druilhe
- Vac4All Initiative, Pepinière Paris Biotech SantéParis, France
| | - Cláudio Tadeu Daniel-Ribeiro
- Laboratório de Pesquisa em Malária, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (Fiocruz)Rio de Janeiro, Brazil
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94
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Goheen MM, Campino S, Cerami C. The role of the red blood cell in host defence against falciparum malaria: an expanding repertoire of evolutionary alterations. Br J Haematol 2017; 179:543-556. [PMID: 28832963 DOI: 10.1111/bjh.14886] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The malaria parasite has co-evolved with its human host as each organism struggles for resources and survival. The scars of this war are carried in the human genome in the form of polymorphisms that confer innate resistance to malaria. Clinical, epidemiological and genome-wide association studies have identified multiple polymorphisms in red blood cell (RBC) proteins that attenuate malaria pathogenesis. These include well-known polymorphisms in haemoglobin, intracellular enzymes, RBC channels, RBC surface markers, and proteins impacting the RBC cytoskeleton and RBC morphology. A better understanding of how changes in RBC physiology impact malaria pathogenesis may uncover new strategies to combat the disease.
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Affiliation(s)
- Morgan M Goheen
- Department of Microbiology and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Susana Campino
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, The London School of Hygiene & Tropical Medicine, London, UK
| | - Carla Cerami
- MRC International Nutrition Group at Keneba, MRC Unit The Gambia, Banjul, The Gambia
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95
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Abdi AI, Hodgson SH, Muthui MK, Kivisi CA, Kamuyu G, Kimani D, Hoffman SL, Juma E, Ogutu B, Draper SJ, Osier F, Bejon P, Marsh K, Bull PC. Plasmodium falciparum malaria parasite var gene expression is modified by host antibodies: longitudinal evidence from controlled infections of Kenyan adults with varying natural exposure. BMC Infect Dis 2017; 17:585. [PMID: 28835215 PMCID: PMC5569527 DOI: 10.1186/s12879-017-2686-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Accepted: 08/15/2017] [Indexed: 11/10/2022] Open
Abstract
Background The PfEMP1 family of Plasmodium falciparum antigens play a key role in pathogenesis of severe malaria through their insertion into the surface of parasite infected erythrocytes, and adhesion to host cells. Previous studies have suggested that parasites expressing PfEMP1 subclasses group A and DC8, associated with severe malaria, may have a growth advantage in immunologically naïve individuals. However, this idea has not been tested in longitudinal studies. Methods Here we assessed expression of the var genes encoding PfEMP1, in parasites sampled from volunteers with varying prior exposure to malaria, following experimental infection by sporozoites (PfSPZ). Using qPCR, we tested for associations between the expression of various var subgroups in surviving parasite populations from each volunteer and 1) the levels of participants’ antibodies to infected erythrocytes before challenge infection and 2) the apparent in vivo parasite multiplication rate. Results We show that 1) expression of var genes encoding for group A and DC8-like PfEMP1 were associated with low levels of antibodies to infected erythrocytes (αIE) before challenge, and 2) expression of a DC8-like CIDRα1.1 domain was associated with higher apparent parasite multiplication rate in a manner that was independent of levels of prior antibodies to infected erythrocytes. Conclusions This study provides insight into the role of antibodies to infected erythrocytes surface antigens in the development of naturally acquired immunity and may help explain why specific PfEMP1 variants may be associated with severe malaria. Trial registration Pan African Clinical Trial Registry: PACTR201211000433272. Date of registration: 10th October 2012.
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Affiliation(s)
- Abdirahman I Abdi
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya. .,Pwani University, P. O. Box 195-80108, Kilifi, Kenya.
| | | | - Michelle K Muthui
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya
| | - Cheryl A Kivisi
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya.,Pwani University, P. O. Box 195-80108, Kilifi, Kenya
| | - Gathoni Kamuyu
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya
| | - Domtila Kimani
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya
| | | | - Elizabeth Juma
- Centre for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya.,Centre for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya
| | - Bernhards Ogutu
- Centre for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya.,Centre for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya
| | | | - Faith Osier
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya
| | - Philip Bejon
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya
| | - Kevin Marsh
- KEMRI-Wellcome Trust Research Programme, CGMRC, P.O. Box 230-80108, Kilifi County, Kenya
| | - Peter C Bull
- Department of Pathology, University of Cambridge, 17 Tennis Court Road, Cambridge, CB2 1QP, UK.
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96
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Dara A, Travassos MA, Adams M, Schaffer DeRoo S, Drábek EF, Agrawal S, Laufer MK, Plowe CV, Silva JC. A new method for sequencing the hypervariable Plasmodium falciparum gene var2csa from clinical samples. Malar J 2017; 16:343. [PMID: 28818101 PMCID: PMC5561619 DOI: 10.1186/s12936-017-1976-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Accepted: 08/04/2017] [Indexed: 11/14/2022] Open
Abstract
Background VAR2CSA, a member of the Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family, mediates the binding of P. falciparum-infected erythrocytes to chondroitin sulfate A, a surface-associated molecule expressed in placental cells, and plays a central role in the pathogenesis of placental malaria. VAR2CSA is a target of naturally acquired immunity and, as such, is a leading vaccine candidate against placental malaria. This protein is very polymorphic and technically challenging to sequence. Published var2csa sequences, mostly limited to specific domains, have been generated through the sequencing of cloned PCR amplicons using capillary electrophoresis, a method that is both time consuming and costly, and that performs poorly when applied to clinical samples that are commonly polyclonal. A next-generation sequencing platform, Pacific Biosciences (PacBio), offers an alternative approach to overcome these issues. Methods PCR primers were designed that target a 5 kb segment in the 5′ end of var2csa and the resulting amplicons were sequenced using PacBio sequencing. The primers were optimized using two laboratory strains and were validated on DNA from 43 clinical samples, extracted from dried blood spots on filter paper or from cryopreserved P. falciparum-infected erythrocytes. Sequence reads were assembled using the SMRT-analysis ConsensusTools module. Results Here, a PacBio sequencing-based approach for recovering a segment encoding the majority of VAR2CSA’s extracellular region is described; this segment includes the totality of the first four domains in the 5′ end of var2csa (~5 kb), from clinical malaria samples. The feasibility of the method is demonstrated, showing a high success rate from cryopreserved samples and more limited success from dried blood spots stored at room temperature, and characterized the genetic variation of the var2csa locus. Conclusions This method will facilitate a detailed analysis of var2csa genetic variation and can be adapted to sequence other hypervariable P. falciparum genes. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1976-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Antoine Dara
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mark A Travassos
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Matthew Adams
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Sarah Schaffer DeRoo
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Elliott F Drábek
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Sonia Agrawal
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Miriam K Laufer
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Christopher V Plowe
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Joana C Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA. .,Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA.
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97
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Hou N, Jiang N, Zou Y, Piao X, Liu S, Li S, Chen Q. Down-Regulation of Tim-3 in Monocytes and Macrophages in Plasmodium Infection and Its Association with Parasite Clearance. Front Microbiol 2017; 8:1431. [PMID: 28824565 PMCID: PMC5539084 DOI: 10.3389/fmicb.2017.01431] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 07/14/2017] [Indexed: 01/08/2023] Open
Abstract
T-cell immunoglobulin and mucin-domain-containing molecule 3 (Tim-3) has complicated roles in regulating monocytes and macrophages in various diseases and it tends to be an inhibitory molecule to facilitate the immune escape of parasites in malaria. However, the mechanisms of Tim-3 mediated responses in monocytes and macrophages in malaria have not been clear. In this study, we found that Plasmodium infection down-regulated Tim-3 expression in peripheral monocytes of patients suffering from Plasmodium falciparum malaria and in splenic macrophages of Plasmodium berghei ANKA-infected mice. Tim-3 signal blockade with anti-Tim-3 antibodies enhanced phagocytosis and parasitical mediator production of murine splenic macrophages during Plasmodium infection. In conclusion, Tim-3 constricts monocytes/macrophages activity, and anti-Tim-3 treatment facilitates parasite clearance, especially in the early stage of Plasmodium infection.
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Affiliation(s)
- Nan Hou
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing, China
| | - Ning Jiang
- Key Laboratory of Zoonosis, Shenyang Agriculture UniversityShenyang, China
| | - Yang Zou
- Beijing Key Laboratory for Research on Prevention and Treatment of Tropical Diseases, Beijing Tropical Medicine Research Institute, Beijing Friendship Hospital, Capital Medical UniversityBeijing, China
| | - Xianyu Piao
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing, China
| | - Shuai Liu
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing, China
| | - Shanshan Li
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing, China
| | - Qijun Chen
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing, China.,Key Laboratory of Zoonosis, Shenyang Agriculture UniversityShenyang, China
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98
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Dunst J, Kamena F, Matuschewski K. Cytokines and Chemokines in Cerebral Malaria Pathogenesis. Front Cell Infect Microbiol 2017; 7:324. [PMID: 28775960 PMCID: PMC5517394 DOI: 10.3389/fcimb.2017.00324] [Citation(s) in RCA: 142] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 07/03/2017] [Indexed: 12/18/2022] Open
Abstract
Cerebral malaria is among the major causes of malaria-associated mortality and effective adjunctive therapeutic strategies are currently lacking. Central pathophysiological processes involved in the development of cerebral malaria include an imbalance of pro- and anti-inflammatory responses to Plasmodium infection, endothelial cell activation, and loss of blood-brain barrier integrity. However, the sequence of events, which initiates these pathophysiological processes as well as the contribution of their complex interplay to the development of cerebral malaria remain incompletely understood. Several cytokines and chemokines have repeatedly been associated with cerebral malaria severity. Increased levels of these inflammatory mediators could account for the sequestration of leukocytes in the cerebral microvasculature present during cerebral malaria, thereby contributing to an amplification of local inflammation and promoting cerebral malaria pathogenesis. Herein, we highlight the current knowledge on the contribution of cytokines and chemokines to the pathogenesis of cerebral malaria with particular emphasis on their roles in endothelial activation and leukocyte recruitment, as well as their implication in the progression to blood-brain barrier permeability and neuroinflammation, in both human cerebral malaria and in the murine experimental cerebral malaria model. A better molecular understanding of these processes could provide the basis for evidence-based development of adjunct therapies and the definition of diagnostic markers of disease progression.
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Affiliation(s)
- Josefine Dunst
- Parasitology Unit, Max Planck Institute for Infection BiologyBerlin, Germany.,Institute of Chemistry and Biochemistry, Free UniversityBerlin, Germany.,Molecular Parasitology, Institute of Biology, Humboldt UniversityBerlin, Germany
| | - Faustin Kamena
- Parasitology Unit, Max Planck Institute for Infection BiologyBerlin, Germany.,Institute of Chemistry and Biochemistry, Free UniversityBerlin, Germany.,Molecular Parasitology, Institute of Biology, Humboldt UniversityBerlin, Germany
| | - Kai Matuschewski
- Parasitology Unit, Max Planck Institute for Infection BiologyBerlin, Germany.,Institute of Chemistry and Biochemistry, Free UniversityBerlin, Germany
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99
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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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100
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Wu X, Dayanand KK, Thylur RP, Norbury CC, Gowda DC. Small molecule-based inhibition of MEK1/2 proteins dampens inflammatory responses to malaria, reduces parasite load, and mitigates pathogenic outcomes. J Biol Chem 2017; 292:13615-13634. [PMID: 28679535 DOI: 10.1074/jbc.m116.770313] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 06/23/2017] [Indexed: 12/16/2022] Open
Abstract
Malaria infections cause several systemic and severe single- or multi-organ pathologies, killing hundreds of thousands of people annually. Considering the existing widespread resistance of malaria parasites to anti-parasitic drugs and their high propensity to develop drug resistance, alternative strategies are required to manage malaria infections. Because malaria is a host immune response-driven disease, one approach is based on gaining a detailed understanding of the molecular and cellular processes that modulate malaria-induced innate and adaptive immune responses. Here, using a mouse cerebral malaria model and small-molecule inhibitors, we demonstrate that inhibiting MEK1/2, the upstream kinases of ERK1/2 signaling, alters multifactorial components of the innate and adaptive immune responses, controls parasitemia, and blocks pathogenesis. Specifically, MEK1/2 inhibitor treatment up-regulated B1 cell expansion, IgM production, phagocytic receptor expression, and phagocytic activity, enhancing parasite clearance by macrophages and neutrophils. Further, the MEK1/2 inhibitor treatment down-regulated pathogenic pro-inflammatory and helper T cell 1 (Th1) responses and up-regulated beneficial anti-inflammatory cytokine responses and Th2 responses. These inhibitor effects resulted in reduced granzyme B expression by T cells, chemokine and intracellular cell adhesion molecule 1 (ICAM-1) expression in the brain, and chemokine receptor expression by both myeloid and T cells. These bimodal effects of the MEK1/2 inhibitor treatment on immune responses contributed to decreased parasite biomass, organ inflammation, and immune cell recruitment, preventing tissue damage and death. In summary, we have identified several previously unrecognized immune regulatory processes through which a MEK1/2 inhibitor approach controls malaria parasitemia and mitigates pathogenic effects on host organs.
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Affiliation(s)
- Xianzhu Wu
- From the Departments of Biochemistry and Molecular Biology and
| | | | - Ramesh P Thylur
- From the Departments of Biochemistry and Molecular Biology and
| | - Christopher C Norbury
- Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033
| | - D Channe Gowda
- From the Departments of Biochemistry and Molecular Biology and
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