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Sharma I, Kataria P, Das J. Cerebral malaria pathogenesis: Dissecting the role of CD4 + and CD8 + T-cells as major effectors in disease pathology. Int Rev Immunol 2024:1-18. [PMID: 38618863 DOI: 10.1080/08830185.2024.2336539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 03/24/2024] [Indexed: 04/16/2024]
Abstract
Cerebral malaria (CM) is a severe complication of Plasmodium falciparum (P. falciparum) infection, with complex pathogenesis involving multiple factors, including the host's immunological response. T lymphocytes, specifically CD4+ T helper cells and CD8+ cytotoxic T cells, are crucial in controlling parasite growth and activating cells for parasite clearance via cytokine secretion. Contrary to this, reports also suggest the pathogenic nature of T lymphocytes as they are often involved in disease progression and severity. CD8+ cytotoxic T cells migrate to the host's brain vasculature, disrupting the blood-brain barrier and causing neurological manifestations. CD4+ T helper cells on the other hand play a variety of functions as they differentiate into different subtypes which may function as pro-inflammatory or anti-inflammatory. The excessive pro-inflammatory response in CM can lead to multi-organ failure, necessitating a check mechanism to maintain immune homeostasis. This is achieved by regulatory T cells and their characteristic cytokines, which counterbalance the pro-inflammatory immune response. Maintaining a critical balance between pro and anti-inflammatory responses is crucial for determining disease outcomes in CM. A slight change in this balance may contribute to a disease severity owing to an extreme inflammatory response or unrestricted parasite growth, a potential target for designing immunotherapeutic treatment approaches. The review briefly discusses the pathogenesis of CM and various mechanisms responsible for the disruption of the blood-brain barrier. It also highlights the role of different T cell subsets during infection and emphasizes the importance of balance between pro and anti-inflammatory T cells that ultimately decides the outcome of the disease.
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Affiliation(s)
- Indu Sharma
- Academy of Scientific and Innovative Research (AcSIR), Noida, India
- Division of Immunology, National Institute of Malaria Research, Dwarka, New Delhi, India
| | - Poonam Kataria
- Academy of Scientific and Innovative Research (AcSIR), Noida, India
- Division of Immunology, National Institute of Malaria Research, Dwarka, New Delhi, India
| | - Jyoti Das
- Academy of Scientific and Innovative Research (AcSIR), Noida, India
- Division of Immunology, National Institute of Malaria Research, Dwarka, New Delhi, India
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2
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Oelschlegel AM, Bhattacharjee R, Wenk P, Harit K, Rothkötter HJ, Koch SP, Boehm-Sturm P, Matuschewski K, Budinger E, Schlüter D, Goldschmidt J, Nishanth G. Beyond the microcirculation: sequestration of infected red blood cells and reduced flow in large draining veins in experimental cerebral malaria. Nat Commun 2024; 15:2396. [PMID: 38493187 PMCID: PMC10944460 DOI: 10.1038/s41467-024-46617-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 02/29/2024] [Indexed: 03/18/2024] Open
Abstract
Sequestration of infected red blood cells (iRBCs) in the microcirculation is a hallmark of cerebral malaria (CM) in post-mortem human brains. It remains controversial how this might be linked to the different disease manifestations, in particular brain swelling leading to brain herniation and death. The main hypotheses focus on iRBC-triggered inflammation and mechanical obstruction of blood flow. Here, we test these hypotheses using murine models of experimental CM (ECM), SPECT-imaging of radiolabeled iRBCs and cerebral perfusion, MR-angiography, q-PCR, and immunohistochemistry. We show that iRBC accumulation and reduced flow precede inflammation. Unexpectedly, we find that iRBCs accumulate not only in the microcirculation but also in large draining veins and sinuses, particularly at the rostral confluence. We identify two parallel venous streams from the superior sagittal sinus that open into the rostral rhinal veins and are partially connected to infected skull bone marrow. The flow in these vessels is reduced early, and the spatial patterns of pathology correspond to venous drainage territories. Our data suggest that venous efflux reductions downstream of the microcirculation are causally linked to ECM pathology, and that the different spatiotemporal patterns of edema development in mice and humans could be related to anatomical differences in venous anatomy.
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Affiliation(s)
- A M Oelschlegel
- Combinatorial NeuroImaging Core Facility, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany
- Research group Neuroplasticity, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany
| | - R Bhattacharjee
- Combinatorial NeuroImaging Core Facility, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, 30625, Hannover, Germany
| | - P Wenk
- Combinatorial NeuroImaging Core Facility, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany
| | - K Harit
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, 30625, Hannover, Germany
| | - H-J Rothkötter
- Institute of Anatomy, Medical Faculty, Otto-von-Guericke-University Magdeburg, Leipziger Strasse 44, 39120, Magdeburg, Germany
| | - S P Koch
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Experimental Neurology and Center for Stroke Research, Charitéplatz 1, 10117, Berlin, Germany
- Charité-Universitätsmedizin Berlin, NeuroCure Cluster of Excellence and Charité Core Facility 7T Experimental MRIs, 10117, Berlin, Germany
- Charité-Universitätsmedizin Berlin, Charité 3R | Replace, Reduce, Refine, Charitéplatz 1, 10117, Berlin, Germany
| | - P Boehm-Sturm
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Experimental Neurology and Center for Stroke Research, Charitéplatz 1, 10117, Berlin, Germany
- Charité-Universitätsmedizin Berlin, NeuroCure Cluster of Excellence and Charité Core Facility 7T Experimental MRIs, 10117, Berlin, Germany
- Charité-Universitätsmedizin Berlin, Charité 3R | Replace, Reduce, Refine, Charitéplatz 1, 10117, Berlin, Germany
| | - K Matuschewski
- Department of Molecular Parasitology, Institute of Biology, Humboldt University, 10115, Berlin, Germany
| | - E Budinger
- Combinatorial NeuroImaging Core Facility, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany
- Center of Behavioural Brain Sciences, Universitätsplatz 2, 39106, Magdeburg, Germany
| | - D Schlüter
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, 30625, Hannover, Germany
| | - J Goldschmidt
- Combinatorial NeuroImaging Core Facility, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany.
- Center of Behavioural Brain Sciences, Universitätsplatz 2, 39106, Magdeburg, Germany.
| | - G Nishanth
- Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, 30625, Hannover, Germany.
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3
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Bensalel J, Gallego-Delgado J. Exploring adjunctive therapies for cerebral malaria. Front Cell Infect Microbiol 2024; 14:1347486. [PMID: 38410724 PMCID: PMC10895034 DOI: 10.3389/fcimb.2024.1347486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 01/17/2024] [Indexed: 02/28/2024] Open
Abstract
Cerebral malaria (CM) is one of the most severe complications of malaria infection characterized by coma and neurological effects. Despite standardized treatment of malaria infection with artemisinin-based combination therapies (ACT), the mortality rate is still high, and it primarily affects pediatric patients. ACT reduces parasitemia but fails to adequately target the pathogenic mechanisms underlying CM, including blood-brain-barrier (BBB) disruption, endothelial activation/dysfunction, and hyperinflammation. The need for adjunctive therapies to specifically treat this form of severe malaria is critical as hundreds of thousands of people continue to die each year from this disease. Here we present a summary of some potential promising therapeutic targets and treatments for CM, as well as some that have been tested and deemed ineffective or, in some cases, even deleterious. Further exploration into these therapeutic agents is warranted to assess the effectiveness of these potential treatments for CM patients.
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Affiliation(s)
- Johanna Bensalel
- Ph.D. Program in Biology, The Graduate Center, The City University of New York, New York, NY, United States
- Department of Biological Sciences, Lehman College, City University of New York, New York, NY, United States
| | - Julio Gallego-Delgado
- Ph.D. Program in Biology, The Graduate Center, The City University of New York, New York, NY, United States
- Department of Biological Sciences, Lehman College, City University of New York, New York, NY, United States
- Ph.D. Program in Biochemistry, The Graduate Center, The City University of New York, New York, NY, United States
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4
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Albrecht-Schgoer K, Lackner P, Schmutzhard E, Baier G. Cerebral Malaria: Current Clinical and Immunological Aspects. Front Immunol 2022; 13:863568. [PMID: 35514965 PMCID: PMC9067128 DOI: 10.3389/fimmu.2022.863568] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/21/2022] [Indexed: 11/23/2022] Open
Abstract
This review focuses on current clinical and immunological aspects of cerebral malaria induced by Plasmodium falciparum infection. Albeit many issues concerning the inflammatory responses remain unresolved and need further investigations, current knowledge of the underlying molecular mechanisms is highlighted. Furthermore, and in the light of significant limitations in preventative diagnosis and treatment of cerebral malaria, this review mainly discusses our understanding of immune mechanisms in the light of the most recent research findings. Remarkably, the newly proposed CD8+ T cell-driven pathophysiological aspects within the central nervous system are summarized, giving first rational insights into encouraging studies with immune-modulating adjunctive therapies that protect from symptomatic cerebral participation of Plasmodium falciparum infection.
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Affiliation(s)
- Karin Albrecht-Schgoer
- Division of Translational Cell Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - Peter Lackner
- Department of Neurology, Klinik Floridsdorf, Wien, Austria
| | - Erich Schmutzhard
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Gottfried Baier
- Division of Translational Cell Genetics, Medical University of Innsbruck, Innsbruck, Austria
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Abstract
PURPOSE OF REVIEW This article reviews how parasites affect the human nervous system, with a focus on four parasitic infections of major public health importance worldwide, two caused by protozoa (malaria and toxoplasmosis) and two by helminths (neurocysticercosis and schistosomiasis). RECENT FINDINGS Parasitic infections in humans are common, and many can affect the central nervous system where they may survive unnoticed or may cause significant pathology that can even lead to the death of the host. Neuroparasitoses should be considered in the differential diagnosis of neurologic lesions, particularly in individuals from endemic regions or those with a history of travel to endemic regions. SUMMARY Cerebral malaria is a significant cause of mortality, particularly in African children, in whom infected red blood cells affect the cerebral vessels, causing severe encephalopathy. Neurocysticercosis is the most common cause of acquired epilepsy worldwide and has varied clinical presentations, depending on the number, size, and location of the parasites in the nervous system as well as on the host's inflammatory response. Toxoplasmosis is distributed worldwide, affecting a significant proportion of the population, and may reactivate in patients who are immunosuppressed, causing encephalitis and focal abscesses. Schistosomiasis causes granulomatous lesions in the brain or the spinal cord.
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Affiliation(s)
- Geoffrey Guenther
- Department of Pediatrics, Children's National Hospital, Washington, DC, USA
| | - Daniel Muller
- The George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - Dominic Moyo
- Department of Paediatric and Child Health, University of Malawi College of Medicine, Blantyre, Malawi
| | - Douglas Postels
- Department of Pediatric Neurology, George Washington University/ Children's National Medical Center; Washington DC, USA; Blantyre Malaria Project; Blantyre, Malawi, Street Address: Department of Neurology; 111 Michigan Avenue NW; Washington DC; 20010; USA
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7
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Patel H, Dunican C, Cunnington AJ. Predictors of outcome in childhood Plasmodium falciparum malaria. Virulence 2020; 11:199-221. [PMID: 32063099 PMCID: PMC7051137 DOI: 10.1080/21505594.2020.1726570] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 01/16/2020] [Accepted: 01/20/2020] [Indexed: 12/16/2022] Open
Abstract
Plasmodium falciparum malaria is classified as either uncomplicated or severe, determining clinical management and providing a framework for understanding pathogenesis. Severe malaria in children is defined by the presence of one or more features associated with adverse outcome, but there is wide variation in the predictive value of these features. Here we review the evidence for the usefulness of these features, alone and in combination, to predict death and other adverse outcomes, and we consider the role that molecular biomarkers may play in augmenting this prediction. We also examine whether a more personalized approach to predicting outcome for specific presenting syndromes of severe malaria, particularly cerebral malaria, has the potential to be more accurate. We note a general need for better external validation in studies of outcome predictors and for the demonstration that predictors can be used to guide clinical management in a way that improves survival and long-term health.
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Affiliation(s)
- Harsita Patel
- Section of Paediatric Infectious Disease, Department of Infectious Disease, Imperial College London, London, UK
| | - Claire Dunican
- Section of Paediatric Infectious Disease, Department of Infectious Disease, Imperial College London, London, UK
| | - Aubrey J. Cunnington
- Section of Paediatric Infectious Disease, Department of Infectious Disease, Imperial College London, London, UK
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8
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Postels DG, Osei-Tutu L, Seydel KB, Xu Q, Li C, Taylor TE, John CC, Mallewa M, Solomon T, Agbenyega T, Ansong D, Opoka RO, Khan LM, Ramachandran PS, Leon KE, DeRisi JL, Langelier C, Wilson MR. Central Nervous System Virus Infection in African Children with Cerebral Malaria. Am J Trop Med Hyg 2020; 103:200-205. [PMID: 32342847 PMCID: PMC7356427 DOI: 10.4269/ajtmh.19-0962] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/30/2020] [Indexed: 11/07/2022] Open
Abstract
We aimed to identify the contribution of central nervous system (CNS) viral coinfection to illness in African children with retinopathy-negative or retinopathy-positive cerebral malaria (CM). We collected cerebrospinal fluid (CSF) from 272 children with retinopathy-negative or retinopathy-positive CM and selected CSF from 111 of these children (38 retinopathy positive, 71 retinopathy negative, 2 retinopathy unknown) for analysis by metagenomic next-generation sequencing. We found CSF viral coinfections in 7/38 (18.4%) retinopathy-positive children and in 18/71 (25.4%) retinopathy-negative children. Excluding HIV-1, human herpesviruses (HHV) represented 61% of viruses identified. Excluding HIV-1, CNS viral coinfection was equally likely in children who were retinopathy positive and retinopathy negative (P = 0.1431). Neither mortality nor neurological morbidity was associated with the presence of virus (odds ratio [OR] = 0.276, 95% CI: 0.056-1.363). Retinopathy-negative children with a higher temperature, lower white blood cell count, or being dehydrated were more likely to have viral coinfection. Level of consciousness at admission was not associated with CNS viral coinfection in retinopathy-negative children. Viral CNS coinfection is unlikely to contribute to coma in children with CM. The herpesviruses other than herpes simplex virus may represent incidental bystanders in CM, reactivating during acute malaria infection.
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Affiliation(s)
- Douglas G. Postels
- Address correspondence to Douglas G. Postels, Department of Neurology, Children’s National Medical Center, George Washington University, 111 Michigan Ave. NW, Washington, DC 20010. E-mail:
| | | | | | - Qian Xu
- Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, Michigan
| | - Chenxi Li
- Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, Michigan
| | | | - Chandy C. John
- Ryan White Center for Pediatric Infectious Diseases and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana
| | | | - Tom Solomon
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Tsiri Agbenyega
- Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Daniel Ansong
- Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Robert O. Opoka
- Department of Paediatrics and Child Health, Makerere University School of Medicine, Kampala, Uganda
| | - Lillian M. Khan
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California
| | - Prashanth S. Ramachandran
- Weill Institute for Neurosciences, Department of Neurology, University of California San Francisco, San Francisco, California
| | - Kristoffer E. Leon
- UCSF School of Medicine, University of California San Francisco, San Francisco, California
| | | | - Charles Langelier
- Division of Infectious Diseases, Department of Medicine, University of California San Francisco, San Francisco, California
| | - Michael R. Wilson
- Weill Institute for Neurosciences, Department of Neurology, University of California San Francisco, San Francisco, California
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Lang SS, Paden W, Steenhoff AP, Hines K, Storm PB, Huh J. Intracranial Pressure and Brain Tissue Oxygen Neuromonitoring in Pediatric Cerebral Malaria. World Neurosurg 2020; 141:115-118. [PMID: 32526359 DOI: 10.1016/j.wneu.2020.06.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/03/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND Pediatric cerebral malaria (CM) is a severe complication of Plasmodium falciparum that often leaves survivors with severe neurologic impairment. Increased intracranial pressure (ICP) as a result of cerebral edema has been identified as a major predictor of morbidity and mortality in CM. Past studies have demonstrated that survivors are more likely to have resolution of elevated ICP and that efficient management of ICP crises may lead to better outcomes. However, data on invasive brain tissue oxygen monitoring are unknown. CASE DESCRIPTION We report a case of a pediatric patient with cerebral malaria who developed encephalopathy and cerebral edema and describe the pathophysiology of this disease process with invasive ICP and brain tissue oxygen multimodality neuromonitoring. The utilization of both ICP and brain tissue oxygen monitoring allowed prompt diagnosis and successful treatment of severe intracranial hypertension and low brain tissue oxygenation crisis. The patient was discharged to home in good neurologic condition. CONCLUSIONS Multimodality neuromonitoring may be considered in pediatric patients who have cerebral edema and encephalopathy from CM.
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Affiliation(s)
- Shih-Shan Lang
- Division of Neurosurgery, Department of Neurosurgery, Children's Hospital of Philadelphia, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA.
| | - William Paden
- Drexel University, College of Medicine, Philadelphia, Pennsylvania, USA
| | - Andrew P Steenhoff
- Division of Infectious Diseases, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Kevin Hines
- Department of Neurosurgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, USA
| | - Phillip B Storm
- Division of Neurosurgery, Department of Neurosurgery, Children's Hospital of Philadelphia, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Jimmy Huh
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
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Mensah BA, Aydemir O, Myers-Hansen JL, Opoku M, Hathaway NJ, Marsh PW, Anto F, Bailey J, Abuaku B, Ghansah A. Antimalarial Drug Resistance Profiling of Plasmodium falciparum Infections in Ghana Using Molecular Inversion Probes and Next-Generation Sequencing. Antimicrob Agents Chemother 2020; 64:e01423-19. [PMID: 31932374 PMCID: PMC7179265 DOI: 10.1128/aac.01423-19] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 12/19/2019] [Indexed: 01/24/2023] Open
Abstract
A key drawback to monitoring the emergence and spread of antimalarial drug resistance in sub-Saharan Africa is early detection and containment. Next-generation sequencing methods offer the resolution, sensitivity, and scale required to fill this gap by surveilling for molecular markers of drug resistance. We performed targeted sequencing using molecular inversion probes to interrogate five Plasmodium falciparum genes (pfcrt, pfmdr1, pfdhps, pfdhfr, and pfk13) implicated in chloroquine, sulfadoxine-pyrimethamine (SP), and artemisinin resistance in two sites in Ghana. A total of 803 dried blood spots from children aged between 6 months and 14 years presenting with uncomplicated P. falciparum malaria at the Begoro District Hospital in Begoro and the Ewim Polyclinic in Cape Coast, Ghana, from 2014 to 2017 were prepared on filter paper. Thirteen years after the removal of drug pressure, chloroquine-sensitive parasite strains with pfcrt K76 have increased nearly to fixation in Begoro, in the forest area (prevalence = 95%), but at a lower rate in Cape Coast, in the coastal region (prevalence = 71%, Z = -3.5, P < 0.001). In addition, pfmdr1 184F-bearing parasites are under strong selection. The pfdhfr/pfdhps quadruple genotype ( IRNG K), associated with SP resistance, is near saturation. Our study identified at a 2 to 10% prevalence pfdhps 581G, which is a sulfadoxine resistance marker that correlates with the failure of SP prophylaxis in pregnancy and which has not been observed in Ghana. The differences in the reexpansion of chloroquine-sensitive strains observed at the two study sites, the stronger SP resistance, and the high prevalence of pfmdr1 184F should be further monitored to inform malaria control strategies in Ghana.
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Affiliation(s)
- Benedicta A Mensah
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
- School of Public Health, University of Ghana, Accra, Ghana
| | - Ozkan Aydemir
- Program in Bioinformatics and Integrative Biology, University of Massachusetts, Worcester, Massachusetts, USA
| | - James L Myers-Hansen
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Millicent Opoku
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Nicholas J Hathaway
- Program in Bioinformatics and Integrative Biology, University of Massachusetts, Worcester, Massachusetts, USA
| | - Patrick W Marsh
- Program in Bioinformatics and Integrative Biology, University of Massachusetts, Worcester, Massachusetts, USA
| | - Francis Anto
- School of Public Health, University of Ghana, Accra, Ghana
| | - Jeffrey Bailey
- Program in Bioinformatics and Integrative Biology, University of Massachusetts, Worcester, Massachusetts, USA
- Division of Transfusion Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Benjamin Abuaku
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Anita Ghansah
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
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Brown A, Dike N, Derkyi-Kwarteng L, Abaidoo C. The effect of recurrent malaria infections on bone and cartilage at the distal femoral epiphysis of rats: A histological study. JOURNAL OF CURRENT RESEARCH IN SCIENTIFIC MEDICINE 2020. [DOI: 10.4103/jcrsm.jcrsm_11_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Villabona-Rueda A, Erice C, Pardo CA, Stins MF. The Evolving Concept of the Blood Brain Barrier (BBB): From a Single Static Barrier to a Heterogeneous and Dynamic Relay Center. Front Cell Neurosci 2019; 13:405. [PMID: 31616251 PMCID: PMC6763697 DOI: 10.3389/fncel.2019.00405] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Accepted: 08/23/2019] [Indexed: 12/27/2022] Open
Abstract
The blood–brain barrier (BBB) helps maintain a tightly regulated microenvironment for optimal central nervous system (CNS) homeostasis and facilitates communications with the peripheral circulation. The brain endothelial cells, lining the brain’s vasculature, maintain close interactions with surrounding brain cells, e.g., astrocytes, pericytes and perivascular macrophages. This function facilitates critical intercellular crosstalk, giving rise to the concept of the neurovascular unit (NVU). The steady and appropriate communication between all components of the NVU is essential for normal CNS homeostasis and function, and dysregulation of one of its constituents can result in disease. Among the different brain regions, and along the vascular tree, the cellular composition of the NVU varies. Therefore, differential cues from the immediate vascular environment can affect BBB phenotype. To support the fluctuating metabolic and functional needs of the underlying neuropil, a specialized vascular heterogeneity is required. This is achieved by variances in barrier function, expression of transporters, receptors, and adhesion molecules. This mini-review will take you on a journey through evolving concepts surrounding the BBB, the NVU and beyond. Exploring classical experiments leading to new approaches will allow us to understand that the BBB is not merely a static separation between the brain and periphery but a closely regulated and interactive entity. We will discuss shifting paradigms, and ultimately aim to address the importance of BBB endothelial heterogeneity with regard to the function of the BBB within the NVU, and touch on its implications for different neuropathologies.
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Affiliation(s)
- Andres Villabona-Rueda
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Clara Erice
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Carlos A Pardo
- Department of Neurology, Division of Neuroimmunology and Neuroinfectious Disorders, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Monique F Stins
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
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13
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Moghaddam SM, Birbeck GL, Taylor TE, Seydel KB, Kampondeni SD, Potchen MJ. Diffusion-Weighted MR Imaging in a Prospective Cohort of Children with Cerebral Malaria Offers Insights into Pathophysiology and Prognosis. AJNR Am J Neuroradiol 2019; 40:1575-1580. [PMID: 31439630 PMCID: PMC7048462 DOI: 10.3174/ajnr.a6159] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 06/28/2019] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Validation of diffusion-weighted images obtained on 0.35T MR imaging in Malawi has facilitated meaningful review of previously unreported findings in cerebral malaria. Malawian children with acute cerebral malaria demonstrated restricted diffusion on brain MR imaging, including an unusual pattern of restriction isolated to the subcortical white matter. We describe the patterns of diffusion restriction in cerebral malaria and further evaluate risk factors for and outcomes associated with an isolated subcortical white matter diffusion restriction. MATERIALS AND METHODS Between 2009 and 2014, comatose Malawian children admitted to the hospital with cerebral malaria underwent admission brain MR imaging. Imaging data were compiled via NeuroInterp, a RedCap data base. Clinical information obtained included coma score, serum studies, and coma duration. Electroencephalograms were obtained between 2009 and 2011. Outcomes captured included death, neurologic sequelae, or full recovery. RESULTS One hundred ninety-four/269 (72.1%) children with cerebral malaria demonstrated at least 1 area of diffusion restriction. The most common pattern was bilateral subcortical white matter involvement (41.6%), followed by corpus callosum (37.5%), deep gray matter (36.8%), cortical gray matter (17.8%), and posterior fossa (8.9%) involvement. Sixty-one (22.7%) demonstrated isolated subcortical white matter diffusion restriction. These children had lower whole-blood lactate levels (OR, 0.9; 95% CI, 0.85-0.98), were less likely to require anticonvulsants (OR, 0.6; 95% CI, 0.30-0.98), had higher average electroencephalogram voltage (OR, 1.01; 95% CI, 1.00-1.02), were less likely to die (OR, 0.09; 95% CI, 0.01-0.67), and were more likely to recover without neurologic sequelae (OR, 3.7; 95% CI, 1.5-9.1). CONCLUSIONS Restricted diffusion is common in pediatric cerebral malaria. Isolated subcortical white matter diffusion restriction is a unique imaging pattern associated with less severe disease and a good prognosis for full recovery. The underlying pathophysiology may be related to selective white matter vulnerability.
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Affiliation(s)
- S M Moghaddam
- From the Department of Imaging Sciences (S.M.M., M.J.P.)
| | - G L Birbeck
- Department of Neurology, Department of Public Health, Center for Experimental Therapeutics (G.L.B.), University of Rochester, Rochester, New York
| | - T E Taylor
- Department of Osteopathic Medical Specialties (T.E.T., K.B.S.), Michigan State University, East Lansing, Michigan
| | - K B Seydel
- Department of Osteopathic Medical Specialties (T.E.T., K.B.S.), Michigan State University, East Lansing, Michigan
| | - S D Kampondeni
- Queen Elizabeth Central Hospital (S.D.K.), University of Malawi College of Medicine, Blantyre, Malawi
| | - M J Potchen
- From the Department of Imaging Sciences (S.M.M., M.J.P.)
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14
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Deigendesch N, Schlüter D, Siebert E, Stenzel W. [Infections of the central nervous system by protozoa, helminths and fungi]. DER NERVENARZT 2019; 90:623-641. [PMID: 31073673 DOI: 10.1007/s00115-019-0719-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A plethora of different parasites and fungi can lead to infections of the central nervous system (CNS) and cause different clinical symptoms and outcomes depending on the pathogen and the anatomic location of the infection. The diagnosis and treatment of these eukaryotic infections is challenging. The prevalence of CNS infections depends on many factors, including geographical location, living conditions, genetic background and the immune status of the individual. In Germany, infections of the CNS by fungi and parasites are rare but can lead to considerable morbidity. Some parasitic and fungal CNS infections are becoming increasingly more prevalent and clinically relevant due to the increasing number of immunocompromised people. Case fatality rates of these infections, which are difficult to diagnose and to treat, are high. This article provides an overview of a subjective selection of parasitic and fungal infections of the CNS relevant to clinical practice in Germany and presents the diagnostic and therapeutic options.
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Affiliation(s)
- Nikolaus Deigendesch
- Institut für Medizinische Genetik und Pathologie, Universitätsspital Basel, Schönbeinstraße 40, 4031, Basel, Schweiz.
| | - Dirk Schlüter
- Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Otto-von-Guericke-Universität Magdeburg, Leipziger Str. 44, 39120, Magdeburg, Deutschland
| | - Eberhard Siebert
- Institut für Neuroradiologie, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Deutschland
| | - Werner Stenzel
- Institut für Neuropathologie, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Deutschland
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15
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Abstract
Following unsuccessful eradication attempts there was a resurgence of malaria towards the end of the 20th century. Renewed control efforts using a range of improved tools, such as long-lasting insecticide-treated bednets and artemisinin-based combination therapies, have more than halved the global burden of disease, but it remains high with 445 000 deaths and more than 200 million cases in 2016. Pitfalls in individual patient management are delayed diagnosis and overzealous fluid resuscitation in severe malaria. Even in the absence of drug resistance, parasite recurrence can occur, owing to high parasite densities, low host immunity, or suboptimal drug concentrations. Malaria elimination is firmly back as a mainstream policy but resistance to the artemisinin derivatives, their partner drugs, and insecticides present major challenges. Vaccine development continues on several fronts but none of the candidates developed to date have been shown to provide long-lasting benefits at a population level. Increased resources and unprecedented levels of regional cooperation and societal commitment will be needed if further substantial inroads into the malaria burden are to be made.
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Affiliation(s)
- Elizabeth A Ashley
- Myanmar-Oxford Clinical Research Unit, Yangon, Myanmar; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Aung Pyae Phyo
- Shoklo Malaria Research Unit, Mae Sot, Thailand; Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Charles J Woodrow
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK; Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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16
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Abstract
Cerebral malaria is one of the most severe complications of human infection by the Plasmodium falciparum parasite. In this issue of Cell Host & Microbe, Kessler et al. (2017) provide valuable insights into the diagnosis and pathogenesis of this poorly understood manifestation of malaria.
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Affiliation(s)
- Jeffrey D Dvorin
- Division of Infectious Diseases, Boston Children's Hospital and Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA.
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17
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Infected erythrocytes expressing DC13 PfEMP1 differ from recombinant proteins in EPCR-binding function. Proc Natl Acad Sci U S A 2018; 115:1063-1068. [PMID: 29339517 PMCID: PMC5798336 DOI: 10.1073/pnas.1712879115] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Sequestration of Plasmodium falciparum-infected erythrocytes (IEs) in the brain microvasculature underlies the pathology of cerebral malaria. Parasites that express P. falciparum erythrocyte membrane protein 1 of domain cassette (DC) 8 and DC13 types bind to brain endothelial cells. Recent studies, largely based on recombinant proteins, have identified endothelial protein C receptor (EPCR) as the key receptor for endothelial cell binding. Using DC8- and DC13-expressing IEs, we show that binding of DC13 IEs to brain endothelial cells is not EPCR-dependent and that cytoadhesion of EPCR-binding DC8 IEs to brain endothelial cells is blocked by human serum. This study highlights differences between recombinant protein and native protein in EPCR-binding properties and suggests that other receptors are also required for sequestration in cerebral malaria. Recent advances have identified a new paradigm for cerebral malaria pathogenesis in which endothelial protein C receptor (EPCR) is a major host receptor for sequestration of Plasmodium falciparum-infected erythrocytes (IEs) in the brain and other vital organs. The parasite adhesins that bind EPCR are members of the IE variant surface antigen family Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) containing specific adhesion domains called domain cassette (DC) 8 and DC13. The binding interaction site between PfEMP1 and EPCR has been mapped by biophysical and crystallography studies using recombinant proteins. However, studies examining the interaction of native PfEMP1 on the IE surface with EPCR are few. We aimed to study binding to EPCR by IEs expressing DC8 and DC13 PfEMP1 variants whose recombinant proteins have been used in key prior functional and structural studies. IE binding to EPCR immobilized on plastic and on human brain endothelial cells was examined in static and flow adhesion assays. Unexpectedly, we found that IEs expressing the DC13 PfEMP1 variant HB3var03 or IT4var07 did not bind to EPCR on plastic and the binding of these variants to brain endothelial cells was not dependent on EPCR. IEs expressing the DC8 variant IT4var19 did bind to EPCR, but this interaction was inhibited if normal human serum or plasma was present, raising the possibility that IE–EPCR interaction may be prevented by plasma components under physiological conditions. These data highlight a discrepancy in EPCR-binding activity between PfEMP1 recombinant proteins and IEs, and indicate the critical need for further research to understand the pathophysiological significance of the PfEMP1–EPCR interaction.
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18
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Pádua TA, Torres ND, Candéa ALP, Costa MFS, Silva JD, Silva‐Filho JL, Costa FTM, Rocco PRM, Souza MC, Henriques MG. Therapeutic effect of Lipoxin A
4
in malaria‐induced acute lung injury. J Leukoc Biol 2018; 103:657-670. [DOI: 10.1002/jlb.3a1016-435rrr] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 05/29/2017] [Accepted: 10/23/2017] [Indexed: 01/04/2023] Open
Affiliation(s)
- Tatiana A. Pádua
- Laboratory of Applied PharmacologyFarmanguinhos, Oswaldo Cruz Foundation Rio de Janeiro Brazil
- National Institute of Science and Technology of Innovation on Diseases of Neglected Populations (INCT‐IDPN) FIOCRUZ Rio de Janeiro Brazil
| | - Natalia D. Torres
- Laboratory of Applied PharmacologyFarmanguinhos, Oswaldo Cruz Foundation Rio de Janeiro Brazil
- National Institute of Science and Technology of Innovation on Diseases of Neglected Populations (INCT‐IDPN) FIOCRUZ Rio de Janeiro Brazil
| | - André L. P. Candéa
- Laboratory of Applied PharmacologyFarmanguinhos, Oswaldo Cruz Foundation Rio de Janeiro Brazil
- National Institute of Science and Technology of Innovation on Diseases of Neglected Populations (INCT‐IDPN) FIOCRUZ Rio de Janeiro Brazil
| | - Maria Fernanda Souza Costa
- Laboratory of Applied PharmacologyFarmanguinhos, Oswaldo Cruz Foundation Rio de Janeiro Brazil
- National Institute of Science and Technology of Innovation on Diseases of Neglected Populations (INCT‐IDPN) FIOCRUZ Rio de Janeiro Brazil
| | - Johnatas D. Silva
- Laboratory of Pulmonary InvestigationCarlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro Rio de Janeiro Brazil
| | - João Luiz Silva‐Filho
- Laboratory of Tropical Diseases – Prof. Dr. Luiz Jacintho da Silva, Department of Genetics, Evolution and Bioagents, Institute of Biology (IB)University of Campinas (UNICAMP) Campinas Brazil
| | - Fabio T. M. Costa
- Laboratory of Tropical Diseases – Prof. Dr. Luiz Jacintho da Silva, Department of Genetics, Evolution and Bioagents, Institute of Biology (IB)University of Campinas (UNICAMP) Campinas Brazil
| | - Patricia R. M. Rocco
- Laboratory of Pulmonary InvestigationCarlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro Rio de Janeiro Brazil
| | - Mariana C. Souza
- Laboratory of Applied PharmacologyFarmanguinhos, Oswaldo Cruz Foundation Rio de Janeiro Brazil
- National Institute of Science and Technology of Innovation on Diseases of Neglected Populations (INCT‐IDPN) FIOCRUZ Rio de Janeiro Brazil
| | - Maria G. Henriques
- Laboratory of Applied PharmacologyFarmanguinhos, Oswaldo Cruz Foundation Rio de Janeiro Brazil
- National Institute of Science and Technology of Innovation on Diseases of Neglected Populations (INCT‐IDPN) FIOCRUZ Rio de Janeiro Brazil
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19
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Deigendesch N, Costa Nunez J, Stenzel W. Parasitic and fungal infections. HANDBOOK OF CLINICAL NEUROLOGY 2018; 145:245-262. [PMID: 28987173 DOI: 10.1016/b978-0-12-802395-2.00018-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Parasitic infections of the central nervous system (CNS) comprise a plethora of infectious agents leading to a multitude of different disease courses and thus diagnostic and therapeutic challenges. The prevalence of different pathogens is basically dependent on geographic and ethnic backgrounds, its infectious route frequently involving a third party, such as flies or domestic animals. The present review focuses on cerebral malaria due to Plasmodium falciparum infection, and Toxoplasma gondii encephalitis. Fungi produce a large variety of inflammatory conditions of the CNS with a variegated spectrum of signs and symptoms, which may involve the meninges and the brain parenchyma, where they produce cerebritis or abscesses and granulomatous lesions, respectively. Fungal CNS lesions are increasingly prevalent and diagnostically relevant due to increasing numbers of human immunodeficiency virus-positive patients, increasing numbers of patients reaching old age suffering from malignant tumors or decreased immunity, and finally the increasing use of established and new immunosuppressive treatments, which increase the susceptibility of patients to develop invasive mycoses. Fungi appear with characteristic morphotypes comprising hyphae, yeasts, and pseudohyphae. The mode by which fungi penetrate into the CNS, and the host/immune requirements are incompletely understood and remain a challenge for research.
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Affiliation(s)
- Nikolaus Deigendesch
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jean Costa Nunez
- Department of Pathology, Universidade Federal de Santa Catarina, Florianopolis, Brazil
| | - Werner Stenzel
- Department of Neuropathology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
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20
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Swamy L, Beare NAV, Okonkwo O, Mahmoud TH. Funduscopy in Cerebral Malaria Diagnosis: An International Survey of Practice Patterns. Am J Trop Med Hyg 2017; 98:516-519. [PMID: 29280430 DOI: 10.4269/ajtmh.17-0506] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Cerebral malaria (CM) is a significant cause of mortality and morbidity in sub-Saharan Africa, particularly among young children. Malarial retinopathy is the most specific clinical finding in CM, and fundus examination could help clinicians distinguish CM from other causes of encephalopathy in resource-poor areas. To assess clinician knowledge, practice patterns, and barriers to the use of funduscopy in the diagnosis of CM, we designed a descriptive multinational survey of clinicians in malaria endemic areas. Results of this survey showed that 19% of respondents were not aware of the utility of eye examinations for malarial retinopathy, and almost half (49%) never or almost never examine the eyes in cases of suspected CM. Educating clinicians about malarial retinopathy could be important in improving diagnostic specificity for CM.
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Affiliation(s)
- Lakshmi Swamy
- Asheville Eye Associates, Pediatric Ophthalmology, Asheville, North Carolina
| | - Nicholas A V Beare
- Department of Eye and Vision Science, St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, United Kingdom
| | - Ogugua Okonkwo
- Eye Foundation Center for the Prevention of Blindness, Retina Institute, Lagos, Nigeria
| | - Tamer H Mahmoud
- Duke University Eye Center, Durham, North Carolina.,Oakland University William Beaumont School of Medicine, Associated Retinal Consultants, Royal Oak, Michigan
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21
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Burrows JN, Duparc S, Gutteridge WE, Hooft van Huijsduijnen R, Kaszubska W, Macintyre F, Mazzuri S, Möhrle JJ, Wells TNC. New developments in anti-malarial target candidate and product profiles. Malar J 2017; 16:26. [PMID: 28086874 PMCID: PMC5237200 DOI: 10.1186/s12936-016-1675-x] [Citation(s) in RCA: 309] [Impact Index Per Article: 44.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 12/30/2016] [Indexed: 11/10/2022] Open
Abstract
A decade of discovery and development of new anti-malarial medicines has led to a renewed focus on malaria elimination and eradication. Changes in the way new anti-malarial drugs are discovered and developed have led to a dramatic increase in the number and diversity of new molecules presently in pre-clinical and early clinical development. The twin challenges faced can be summarized by multi-drug resistant malaria from the Greater Mekong Sub-region, and the need to provide simplified medicines. This review lists changes in anti-malarial target candidate and target product profiles over the last 4 years. As well as new medicines to treat disease and prevent transmission, there has been increased focus on the longer term goal of finding new medicines for chemoprotection, potentially with long-acting molecules, or parenteral formulations. Other gaps in the malaria armamentarium, such as drugs to treat severe malaria and endectocides (that kill mosquitoes which feed on people who have taken the drug), are defined here. Ultimately the elimination of malaria requires medicines that are safe and well-tolerated to be used in vulnerable populations: in pregnancy, especially the first trimester, and in those suffering from malnutrition or co-infection with other pathogens. These updates reflect the maturing of an understanding of the key challenges in producing the next generation of medicines to control, eliminate and ultimately eradicate malaria.
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Affiliation(s)
- Jeremy N Burrows
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | - Stephan Duparc
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | | | | | - Wiweka Kaszubska
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | - Fiona Macintyre
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | | | - Jörg J Möhrle
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland
| | - Timothy N C Wells
- Medicines for Malaria Venture, Route de Pré Bois 20, 1215, Geneva 15, Switzerland.
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22
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Malaria: Biology and Disease. Cell 2016; 167:610-624. [PMID: 27768886 DOI: 10.1016/j.cell.2016.07.055] [Citation(s) in RCA: 449] [Impact Index Per Article: 56.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/17/2016] [Accepted: 07/29/2016] [Indexed: 11/22/2022]
Abstract
Malaria has been a major global health problem of humans through history and is a leading cause of death and disease across many tropical and subtropical countries. Over the last fifteen years renewed efforts at control have reduced the prevalence of malaria by over half, raising the prospect that elimination and perhaps eradication may be a long-term possibility. Achievement of this goal requires the development of new tools including novel antimalarial drugs and more efficacious vaccines as well as an increased understanding of the disease and biology of the parasite. This has catalyzed a major effort resulting in development and regulatory approval of the first vaccine against malaria (RTS,S/AS01) as well as identification of novel drug targets and antimalarial compounds, some of which are in human clinical trials.
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23
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Bernabeu M, Smith JD. EPCR and Malaria Severity: The Center of a Perfect Storm. Trends Parasitol 2016; 33:295-308. [PMID: 27939609 DOI: 10.1016/j.pt.2016.11.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 11/07/2016] [Accepted: 11/10/2016] [Indexed: 12/20/2022]
Abstract
Severe malaria due to Plasmodium falciparum infection causes nearly half a million deaths per year. The different symptomatology and disease manifestations among patients have hampered understanding of severe malaria pathology and complicated efforts to develop targeted disease interventions. Infected erythrocyte sequestration in the microvasculature plays a critical role in the development of severe disease, and there is increasing evidence that cytoadherent parasites interact with host factors to enhance the damage caused by the parasite. The recent discovery that parasite binding to endothelial protein C receptor (EPCR) is associated with severe disease has suggested new mechanisms of pathology and provided new avenues for severe malaria adjunctive therapy research.
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Affiliation(s)
- Maria Bernabeu
- Center for Infectious Disease Research, Seattle, WA 98109, USA
| | - Joseph D Smith
- Center for Infectious Disease Research, Seattle, WA 98109, USA; Department of Global Health, University of Washington, Seattle, WA 98195, USA.
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24
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Swanson PA, Hart GT, Russo MV, Nayak D, Yazew T, Peña M, Khan SM, Janse CJ, Pierce SK, McGavern DB. CD8+ T Cells Induce Fatal Brainstem Pathology during Cerebral Malaria via Luminal Antigen-Specific Engagement of Brain Vasculature. PLoS Pathog 2016; 12:e1006022. [PMID: 27907215 PMCID: PMC5131904 DOI: 10.1371/journal.ppat.1006022] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 10/25/2016] [Indexed: 01/01/2023] Open
Abstract
Cerebral malaria (CM) is a severe complication of Plasmodium falciparum infection that results in thousands of deaths each year, mostly in African children. The in vivo mechanisms underlying this fatal condition are not entirely understood. Using the animal model of experimental cerebral malaria (ECM), we sought mechanistic insights into the pathogenesis of CM. Fatal disease was associated with alterations in tight junction proteins, vascular breakdown in the meninges / parenchyma, edema, and ultimately neuronal cell death in the brainstem, which is consistent with cerebral herniation as a cause of death. At the peak of ECM, we revealed using intravital two-photon microscopy that myelomonocytic cells and parasite-specific CD8+ T cells associated primarily with the luminal surface of CNS blood vessels. Myelomonocytic cells participated in the removal of parasitized red blood cells (pRBCs) from cerebral blood vessels, but were not required for the disease. Interestingly, the majority of disease-inducing parasite-specific CD8+ T cells interacted with the lumen of brain vascular endothelial cells (ECs), where they were observed surveying, dividing, and arresting in a cognate peptide-MHC I dependent manner. These activities were critically dependent on IFN-γ, which was responsible for activating cerebrovascular ECs to upregulate adhesion and antigen-presenting molecules. Importantly, parasite-specific CD8+ T cell interactions with cerebral vessels were impaired in chimeric mice rendered unable to present EC antigens on MHC I, and these mice were in turn resistant to fatal brainstem pathology. Moreover, anti-adhesion molecule (LFA-1 / VLA-4) therapy prevented fatal disease by rapidly displacing luminal CD8+ T cells from cerebrovascular ECs without affecting extravascular T cells. These in vivo data demonstrate that parasite-specific CD8+ T cell-induced fatal vascular breakdown and subsequent neuronal death during ECM is associated with luminal, antigen-dependent interactions with cerebrovasculature. Cerebral malaria (CM) is a severe and potentially fatal complication of malaria in humans that results in swelling and bleeding within the brain. The mechanisms that cause this fatal disease in humans are not completely understood. We studied an animal model known as experimental cerebral malaria to learn more about the factors that drive this disease process. Using a technique referred to as intravital microscopy, we captured movies of immune cells operating in the living brain as the disease developed. At the peak of disease, we observed evidence of immune cells interacting with and aggregating along blood vessels throughout the brain. These interactions were directly associated vascular leakage. This caused the brain to swell, which gave rise to an unsustainable pressure that ultimately killed neurons responsible for heart and lung function. The fatal swelling was induced by immune cells (referred to as T cells) interacting with bits of parasite presented by blood vessels in the brain. Removal of this parasite presentation protected the mice from fatal disease. We also evaluated a straightforward therapy that involved intravenous administration of antibodies that interfered with T cell sticking to blood vessels. Our movies revealed that this therapeutic approach rapidly displaced T cells from the blood vessels in the brain and prevented fatal disease.
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Affiliation(s)
- Phillip A. Swanson
- Viral Immunology & Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Geoffrey T. Hart
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Matthew V. Russo
- Viral Immunology & Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Debasis Nayak
- Center for Bioscience and Biomedical Engineering, Indian Institute of Technology Indore, Madhya Pradesh, India
| | - Takele Yazew
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Mirna Peña
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Shahid M. Khan
- Leiden Malaria Research Group, Department of Parasitology, Center of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands
| | - Chris J. Janse
- Leiden Malaria Research Group, Department of Parasitology, Center of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands
| | - Susan K. Pierce
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Dorian B. McGavern
- Viral Immunology & Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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25
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Rubio M, Bassat Q, Estivill X, Mayor A. Tying malaria and microRNAs: from the biology to future diagnostic perspectives. Malar J 2016; 15:167. [PMID: 26979504 PMCID: PMC4793504 DOI: 10.1186/s12936-016-1222-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 03/09/2016] [Indexed: 12/21/2022] Open
Abstract
Symptoms caused by bacterial, viral and malarial infections usually overlap and aetiologic diagnosis is difficult. Patient management in low-resource countries with limited laboratory services has been based predominantly on clinical evaluation and syndromic approaches. However, such clinical assessment has limited accuracy both for identifying the likely aetiological cause and for the early recognition of patients who will progress to serious or fatal disease. Plasma-detectable biomarkers that rapidly and accurately diagnose severe infectious diseases could reduce morbidity and decrease the unnecessary use of usually scarce therapeutic drugs. The discovery of microRNAs (miRNAs) has opened exciting new avenues to identify blood biomarkers of organ-specific injury. This review assesses current knowledge on the relationship between malaria disease and miRNAs, and evaluates how future research might lead to the use of these small molecules for identifying patients with severe malaria disease and facilitate treatment decisions.
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Affiliation(s)
- Mercedes Rubio
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK building), 08036, Barcelona, Spain
| | - Quique Bassat
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK building), 08036, Barcelona, Spain.,Centro de Investigação em Saúde da Manhiça (CISM), Maputo, Mozambique
| | - Xavier Estivill
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology; CIBER in Epidemiology and Public Health (CIBERESP), Universitat Pompeu Fabra (UPF), Barcelona, Spain.,Experimental Genetics, Sidra Medical and Research Centre, Doha, Qatar
| | - Alfredo Mayor
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK building), 08036, Barcelona, Spain. .,Centro de Investigação em Saúde da Manhiça (CISM), Maputo, Mozambique.
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26
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Deroost K, Pham TT, Opdenakker G, Van den Steen PE. The immunological balance between host and parasite in malaria. FEMS Microbiol Rev 2015; 40:208-57. [PMID: 26657789 DOI: 10.1093/femsre/fuv046] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2015] [Indexed: 12/16/2022] Open
Abstract
Coevolution of humans and malaria parasites has generated an intricate balance between the immune system of the host and virulence factors of the parasite, equilibrating maximal parasite transmission with limited host damage. Focusing on the blood stage of the disease, we discuss how the balance between anti-parasite immunity versus immunomodulatory and evasion mechanisms of the parasite may result in parasite clearance or chronic infection without major symptoms, whereas imbalances characterized by excessive parasite growth, exaggerated immune reactions or a combination of both cause severe pathology and death, which is detrimental for both parasite and host. A thorough understanding of the immunological balance of malaria and its relation to other physiological balances in the body is of crucial importance for developing effective interventions to reduce malaria-related morbidity and to diminish fatal outcomes due to severe complications. Therefore, we discuss in this review the detailed mechanisms of anti-malarial immunity, parasite virulence factors including immune evasion mechanisms and pathogenesis. Furthermore, we propose a comprehensive classification of malaria complications according to the different types of imbalances.
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Affiliation(s)
- Katrien Deroost
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium The Francis Crick Institute, Mill Hill Laboratory, London, NW71AA, UK
| | - Thao-Thy Pham
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium
| | - Ghislain Opdenakker
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium
| | - Philippe E Van den Steen
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium
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27
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Endothelial-Leukocyte Interaction in Severe Malaria: Beyond the Brain. Mediators Inflamm 2015; 2015:168937. [PMID: 26491221 PMCID: PMC4605361 DOI: 10.1155/2015/168937] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 08/25/2015] [Accepted: 09/01/2015] [Indexed: 01/23/2023] Open
Abstract
Malaria is the most important parasitic disease worldwide, accounting for 1 million deaths each year. Severe malaria is a systemic illness characterized by dysfunction of brain tissue and of one or more peripheral organs as lungs and kidney. The most severe and most studied form of malaria is associated with cerebral complications due to capillary congestion and the adhesion of infected erythrocytes, platelets, and leukocytes to brain vasculature. Thus, leukocyte rolling and adhesion in the brain vascular bed during severe malaria is singular and distinct from other models of inflammation. The leukocyte/endothelium interaction and neutrophil accumulation are also observed in the lungs. However, lung interactions differ from brain interactions, likely due to differences in the blood-brain barrier and blood-air barrier tight junction composition of the brain and lung endothelium. Here, we review the importance of endothelial dysfunction and the mechanism of leukocyte/endothelium interaction during severe malaria. Furthermore, we hypothesize a possible use of adjunctive therapies to antimalarial drugs that target the interaction between the leukocytes and the endothelium.
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