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Martin C, Clift S, Leisewitz A. Lung pathology of natural Babesia rossi infection in dogs. J S Afr Vet Assoc 2023; 94:59-69. [PMID: 37358318 DOI: 10.36303/jsava.523] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023] Open
Abstract
A proportion of Babesia rossi infections in dogs are classified as complicated and one of the most lethal complications is acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Most dogs that die succumb within 24 hours of presentation. The pulmonary pathology caused by B. rossi in dogs has not been described. The aim of this study was to provide a thorough macroscopic, histological and immunohistochemical description of the lung changes seen in dogs naturally infected with B. rossi that succumbed to the infection. Death was invariably accompanied by alveolar oedema. Histopathology showed acute interstitial pneumonia characterised by alveolar oedema and haemorrhages, with increased numbers of mononuclear leucocytes in alveolar walls and lumens. Intra-alveolar polymerised fibrin aggregates were observed in just over half the infected cases. Immunohistochemistry showed increased numbers of MAC387- and CD204-reactive monocyte-macrophages in alveolar walls and lumens, and increased CD3-reactive T-lymphocytes in alveolar walls, compared with controls. These histological features overlap to some extent (but far from perfectly) with the histological pattern of lung injury referred to as the exudative stage of diffuse alveolar damage (DAD) as is quite commonly reported in ALI/ARDS.
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Affiliation(s)
- C Martin
- Idexx Laboratories (Pty) Ltd, South Africa
| | - S Clift
- Section of Pathology, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, South Africa
| | - A Leisewitz
- Department of Clinical Sciences, Bailey Small Animal Teaching Hospital, Auburn University College of Veterinary Medicine, United States of America and Section of Small Animal Medicine, Companion Animal Clinical Sciences, Faculty of Veterinary Science, University of Pretoria, South Africa
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2
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Chaturvedi R, Mohan M, Kumar S, Chandele A, Sharma A. Profiles of host immune impairment in Plasmodium and SARS-CoV-2 infections. Heliyon 2022; 8:e11744. [PMID: 36415655 PMCID: PMC9671871 DOI: 10.1016/j.heliyon.2022.e11744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 07/21/2022] [Accepted: 11/11/2022] [Indexed: 11/19/2022] Open
Abstract
Over the past two decades, many countries have reported a steady decline in reported cases of malaria, and a few countries, like China, have been declared malaria-free by the World Health Organization. In 2020 the number of deaths from malaria has declined since 2000. The COVID-19 pandemic has adversely affected overall public health efforts and thus it is feasible that there might be a resurgence of malaria. COVID-19 and malaria share some similarities in the immune responses of the patient and these two diseases also share overlapping early symptoms such as fever, headache, nausea, and muscle pain/fatigue. In the absence of early diagnostics, there can be a misdiagnosis of the infection(s) that can pose additional challenges due to delayed treatment. In both SARS-CoV-2 and Plasmodium infections, there is a rapid release of cytokines/chemokines that play a key role in disease pathophysiology. In this review, we have discussed the cytokine/chemokine storm observed during COVID-19 and malaria. We observed that: (1) the severity in malaria and COVID-19 is likely a consequence primarily of an uncontrolled 'cytokine storm'; (2) five pro-inflammatory cytokines (IL-6, IL-10, TNF-α, type I IFN, and IFN-γ) are significantly increased in severe/critically ill patients in both diseases; (3) Plasmodium and SARS-CoV-2 share some similar clinical manifestations and thus may result in fatal consequences if misdiagnosed during onset.
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Affiliation(s)
- Rini Chaturvedi
- Molecular Medicine Group, International Center for Genetic Engineering and Biotechnology, New Delhi, Delhi, India
| | - Mradul Mohan
- Parasite-Host Biology Group, National Institute of Malaria Research, New Delhi, Delhi, India,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Sanjeev Kumar
- ICGEB-Emory Vaccine Program, International Center for Genetic Engineering and Biotechnology, New Delhi, Delhi, India
| | - Anmol Chandele
- ICGEB-Emory Vaccine Program, International Center for Genetic Engineering and Biotechnology, New Delhi, Delhi, India
| | - Amit Sharma
- Molecular Medicine Group, International Center for Genetic Engineering and Biotechnology, New Delhi, Delhi, India,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India,Corresponding author
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3
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Plasmodium falciparum transcription in different clinical presentations of malaria associates with circulation time of infected erythrocytes. Nat Commun 2021; 12:4711. [PMID: 34330920 PMCID: PMC8324851 DOI: 10.1038/s41467-021-25062-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 07/06/2021] [Indexed: 02/07/2023] Open
Abstract
Following Plasmodium falciparum infection, individuals can remain asymptomatic, present with mild fever in uncomplicated malaria cases, or show one or more severe malaria symptoms. Several studies have investigated associations between parasite transcription and clinical severity, but no broad conclusions have yet been drawn. Here, we apply a series of bioinformatic approaches based on P. falciparum's tightly regulated transcriptional pattern during its ~48-hour intraerythrocytic developmental cycle (IDC) to publicly available transcriptomes of parasites obtained from malaria cases of differing clinical severity across multiple studies. Our analysis shows that within each IDC, the circulation time of infected erythrocytes without sequestering to endothelial cells decreases with increasing parasitaemia or disease severity. Accordingly, we find that the size of circulating infected erythrocytes is inversely related to parasite density and disease severity. We propose that enhanced adhesiveness of infected erythrocytes leads to a rapid increase in parasite burden, promoting higher parasitaemia and increased disease severity.
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4
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Mita-Mendoza NK, Magallon-Tejada A, Parmar P, Furtado R, Aldrich M, Saidi A, Taylor T, Smith J, Seydel K, Daily JP. Dimethyl fumarate reduces TNF and Plasmodium falciparum induced brain endothelium activation in vitro. Malar J 2020; 19:376. [PMID: 33087130 PMCID: PMC7579885 DOI: 10.1186/s12936-020-03447-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 10/16/2020] [Indexed: 11/10/2022] Open
Abstract
Background Cerebral malaria (CM) is associated with morbidity and mortality despite the use of potent anti-malarial agents. Brain endothelial cell activation and dysfunction from oxidative and inflammatory host responses and products released by Plasmodium falciparum-infected erythrocytes (IE), are likely the major contributors to the encephalopathy, seizures, and brain swelling that are associated with CM. The development of adjunctive therapy to reduce the pathological consequences of host response pathways could improve outcomes. A potentially protective role of the nuclear factor E2-related factor 2 (NRF2) pathway, which serves as a therapeutic target in brain microvascular diseases and central nervous system (CNS) inflammatory diseases such as multiple sclerosis was tested to protect endothelial cells in an in vitro culture system subjected to tumour necrosis factor (TNF) or infected red blood cell exposure. NRF2 is a transcription factor that mediates anti-oxidant and anti-inflammatory responses. Methods To accurately reflect clinically relevant parasite biology a unique panel of parasite isolates derived from patients with stringently defined CM was developed. The effect of TNF and these parasite lines on primary human brain microvascular endothelial cell (HBMVEC) activation in an in vitro co-culture model was tested. HBMVEC activation was measured by cellular release of IL6 and nuclear translocation of NFκB. The transcriptional and functional effects of dimethyl fumarate (DMF), an FDA approved drug which induces the NRF2 pathway, on host and parasite induced HBMVEC activation was characterized. In addition, the effect of DMF on parasite binding to TNF stimulated HBMVEC in a semi-static binding assay was examined. Results Transcriptional profiling demonstrates that DMF upregulates the NRF2-Mediated Oxidative Stress Response, ErbB4 Signaling Pathway, Peroxisome Proliferator-activated Receptor (PPAR) Signaling and downregulates iNOS Signaling and the Neuroinflammation Signaling Pathway on TNF activated HBMVEC. The parasite lines derived from eight paediatric CM patients demonstrated increased binding to TNF activated HBMVEC and varied in their binding and activation of HBMVEC. Overall DMF reduced both TNF and CM derived parasite activation of HBMVEC. Conclusions These findings provide evidence that targeting the NRF2 pathway in TNF and parasite activated HBMVEC mediates multiple protective pathways and may represent a novel adjunctive therapy to improve infection outcomes in CM.
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Affiliation(s)
- Neida K Mita-Mendoza
- Department of Microbiology & Immunology and Infectious Diseases, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Ariel Magallon-Tejada
- Seattle Biomedical Research Institute, Seattle, WA, USA.,Department of Research in Parasitology, Gorgas Memorial Research Institute for Health Studies, Panama City, Panama
| | - Priyanka Parmar
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Raquel Furtado
- Department of Microbiology & Immunology and Infectious Diseases, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Margaret Aldrich
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Alex Saidi
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre 3, Malawi
| | - Terrie Taylor
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre 3, Malawi.,Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA
| | - Joe Smith
- Seattle Children's Research Institute, Seattle, WA, USA.,Department of Global Health, University of Washington, Seattle, WA, USA
| | - Karl Seydel
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre 3, Malawi.,Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA
| | - Johanna P Daily
- Department of Microbiology & Immunology and Infectious Diseases, Albert Einstein College of Medicine, Bronx, NY, USA. .,Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA.
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5
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de Azevedo-Quintanilha IG, Vieira-de-Abreu A, Ferreira AC, Reis PA, Silva TI, Nascimento DDO, Campbell RA, Estato V, Weyrich AS, Bozza PT, Zimmerman GA, Castro-Faria-Neto HC. Integrin αDβ2 influences cerebral edema, leukocyte accumulation and neurologic outcomes in experimental severe malaria. PLoS One 2019; 14:e0224610. [PMID: 31869339 PMCID: PMC6927624 DOI: 10.1371/journal.pone.0224610] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 10/17/2019] [Indexed: 12/30/2022] Open
Abstract
Malaria is an infectious disease of major worldwide clinical importance that causes a variety of severe, or complicated, syndromes including cerebral malaria, which is often fatal. Leukocyte integrins are essential for host defense but also mediate physiologic responses of the innate and adaptive immune systems. We previously showed that targeted deletion of the αD subunit (αD-/-) of the αDβ2 integrin, which is expressed on key leukocyte subsets in mice and humans, leads to absent expression of the integrin heterodimer on murine macrophages and reduces mortality in mice infected with Plasmodium berghei ANKA (P. berghei ANKA). To further identify mechanisms involved in the protective effect of αD deletion in this model of severe malaria we examined wild type C57BL/6 (WT) and αD-/- mice after P. berghei ANKA infection and found that vessel plugging and leukocyte infiltration were significantly decreased in the brains of αD-/- animals. Intravital microscopy demonstrated decreased rolling and adhesion of leukocytes in cerebral vessels of αD-/- mice. Flow cytometry analysis showed decreased T-lymphocyte accumulation in the brains of infected αD-/- animals. Evans blue dye exclusion assays demonstrated significantly less dye extravasation in the brains of αD-/- mice, indicating preserved blood-brain barrier integrity. WT mice that were salvaged from P. berghei ANKA infection by treatment with chloroquine had impaired aversive memory, which was not observed in αD-/- mice. We conclude that deletion of integrin αDβ2 alters the natural course of experimental severe malaria, demonstrating previously unrecognized activities of a key leukocyte integrin in immune-inflammatory responses that mediate cerebral involvement.
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Affiliation(s)
| | - Adriana Vieira-de-Abreu
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - André C. Ferreira
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Patricia A. Reis
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Tathiany I. Silva
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Danielle de O. Nascimento
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Robert A. Campbell
- Department of Internal Medicine and Program in Molecular Medicine, University of Utah, Salt Lake City, Utah, United States of America
| | - Vanessa Estato
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Andrew S. Weyrich
- Department of Internal Medicine and Program in Molecular Medicine, University of Utah, Salt Lake City, Utah, United States of America
| | - Patrícia T. Bozza
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Guy A. Zimmerman
- Department of Internal Medicine and Program in Molecular Medicine, University of Utah, Salt Lake City, Utah, United States of America
| | - Hugo C. Castro-Faria-Neto
- Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brazil
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6
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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: 73] [Impact Index Per Article: 14.6] [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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7
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Épidémiologie et cycle parasitaire d’un fléau mondial, le paludisme. ACTUALITES PHARMACEUTIQUES 2018. [DOI: 10.1016/j.actpha.2018.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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8
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Exploring experimental cerebral malaria pathogenesis through the characterisation of host-derived plasma microparticle protein content. Sci Rep 2016; 6:37871. [PMID: 27917875 PMCID: PMC5137300 DOI: 10.1038/srep37871] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 10/28/2016] [Indexed: 01/09/2023] Open
Abstract
Cerebral malaria (CM) is a severe complication of Plasmodium falciparum infection responsible for thousands of deaths in children in sub-Saharan Africa. CM pathogenesis remains incompletely understood but a number of effectors have been proposed, including plasma microparticles (MP). MP numbers are increased in CM patients’ circulation and, in the mouse model, they can be localised within inflamed vessels, suggesting their involvement in vascular damage. In the present work we define, for the first time, the protein cargo of MP during experimental cerebral malaria (ECM) with the overarching hypothesis that this characterisation could help understand CM pathogenesis. Using qualitative and quantitative high-throughput proteomics we compared MP proteins from non-infected and P. berghei ANKA-infected mice. More than 360 proteins were identified, 60 of which were differentially abundant, as determined by quantitative comparison using TMTTM isobaric labelling. Network analyses showed that ECM MP carry proteins implicated in molecular mechanisms relevant to CM pathogenesis, including endothelial activation. Among these proteins, the strict association of carbonic anhydrase I and S100A8 with ECM was verified by western blot on MP from DBA/1 and C57BL/6 mice. These results demonstrate that MP protein cargo represents a novel ECM pathogenic trait to consider in the understanding of CM pathogenesis.
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9
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Vásquez AM, Blair S, García LF, Segura C. Plasmodium falciparum isolates from patients with uncomplicated malaria promote endothelial inflammation. Microbes Infect 2016; 19:132-141. [PMID: 27717894 DOI: 10.1016/j.micinf.2016.09.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 09/21/2016] [Accepted: 09/27/2016] [Indexed: 12/23/2022]
Abstract
The ability of Plasmodium falciparum infected erythrocytes (Pf-IEs) to activate endothelial cells has been described; however, the interaction of the endothelium with Pf-IEs field isolates from patients has been less characterized. Previous reports have shown that isolates alter the endothelial permeability and apoptosis. In this study, the adhesion of 19 uncomplicated malaria isolates to Human Dermal Microvascular Endothelial Cells (HDMEC), and their effect on the expression of ICAM-1 and proinflammatory molecules (sICAM-1, IL-6, IL-8, and MCP-1) was evaluated. P. falciparum isolates adhered to resting and TNFα-activated HDEMC cells at different levels. All isolates increased the ICAM-1 expression on the membrane (mICAM-1) of HDMEC and increased the release of its soluble form (sICAM-1), as well the production of IL-6, IL-8 and MCP-1 by HDMEC with no signs of cell apoptosis. No correlation between parasite adhesion and production of cytokines was observed. In conclusion, isolates from uncomplicated malaria can induce a proinflammatory response in endothelial cells that may play a role during the initial inflammatory response to parasite infection; however, a continuous activation of the endothelium can contribute to pathogenesis.
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Affiliation(s)
- Ana María Vásquez
- Grupo Malaria, Universidad de Antioquia, Carrera 53 No. 61 - 30, Lab 610, Medellín, Colombia.
| | - Silvia Blair
- Grupo Malaria, Universidad de Antioquia, Carrera 53 No. 61 - 30, Lab 610, Medellín, Colombia
| | - Luis F García
- Grupo de Inmunología Celular e Inmunogenética (GICIG), Sede de Investigación Universitaria, Universidad de Antioquia, Carrera 53 No. 61 - 30, Lab 410, Medellín, Colombia
| | - Cesar Segura
- Grupo Malaria, Universidad de Antioquia, Carrera 53 No. 61 - 30, Lab 610, Medellín, Colombia
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10
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de Azevedo-Quintanilha IG, Vieira-de-Abreu A, Ferreira AC, Nascimento DO, Siqueira AM, Campbell RA, Teixeira Ferreira TP, Gutierrez TM, Ribeiro GM, E Silva PMR, Carvalho AR, Bozza PT, Zimmerman GA, Castro-Faria-Neto HC. Integrin αDβ2 (CD11d/CD18) mediates experimental malaria-associated acute respiratory distress syndrome (MA-ARDS). Malar J 2016; 15:393. [PMID: 27473068 PMCID: PMC4967320 DOI: 10.1186/s12936-016-1447-7] [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: 09/19/2015] [Accepted: 07/20/2016] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Malaria-associated acute respiratory distress syndrome (MA-ARDS) is a potentially lethal complication of clinical malaria. Acute lung injury in MA-ARDS shares features with ARDS triggered by other causes, including alveolar inflammation and increased alveolar-capillary permeability, leading to leak of protein-rich pulmonary oedema fluid. Mechanisms and physiologic alterations in MA-ARDS can be examined in murine models of this syndrome. Integrin αDβ2 is a member of the leukocyte, or β2 (CD18), sub-family of integrins, and emerging observations indicate that it has important activities in leukocyte adhesion, accumulation and signalling. The goal was to perform analysis of the lungs of mice wild type C57Bl/6 (a D (+/+) ) and Knockout C57Bl/6 (a D (-/-) ) with malaria-associated acute lung injury to better determine the relevancy of the murine models and investigate the mechanism of disease. METHODS C57BL/6 wild type (a D (+/+) ) and deficient for CD11d sub-unit (a D (-/-) ) mice were monitored after infection with 10(5) Plasmodium berghei ANKA. CD11d subunit expression RNA was measured by real-time polymerase chain reaction, vascular barrier integrity by Evans blue dye (EBD) exclusion and cytokines by ELISA. Protein and leukocytes were measured in bronchoalveolar lavage fluid (BALF) samples. Tissue cellularity was measured by the point-counting technique, F4/80 and VCAM-1 expression by immunohistochemistry. Respiratory function was analysed by non-invasive BUXCO and mechanical ventilation. RESULTS Alveolar inflammation, vascular and interstitial accumulation of monocytes and macrophages, and disrupted alveolar-capillary barrier function with exudation of protein-rich pulmonary oedema fluid were present in P. berghei-infected wild type mice and were improved in αDβ2-deficient animals. Key pro-inflammatory cytokines were also decreased in lung tissue from α D (-/-) mice, providing a mechanistic explanation for reduced alveolar-capillary inflammation and leak. CONCLUSIONS The results indicate that αDβ2 is an important inflammatory effector molecule in P. berghei-induced MA-ARDS, and that leukocyte integrins regulate critical inflammatory and pathophysiologic events in this model of complicated malaria. Genetic deletion of integrin subunit αD in mice, leading to deficiency of integrin αDβ2, alters lung inflammation and acute lung injury in a mouse model of MA-ARDS caused by P. berghei.
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Affiliation(s)
- Isaclaudia G de Azevedo-Quintanilha
- Laboratório de Immunofarmacologia, Instituto Oswaldo Cruz, Fiocruz, Pavilhão Ozório de Almeida, Av. Brasil 4365, Manguinhos, Rio de Janeiro, RJ, CEP 21045-900, Brazil.
| | - Adriana Vieira-de-Abreu
- Program in Molecular Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA.
| | - André Costa Ferreira
- Laboratório de Immunofarmacologia, Instituto Oswaldo Cruz, Fiocruz, Pavilhão Ozório de Almeida, Av. Brasil 4365, Manguinhos, Rio de Janeiro, RJ, CEP 21045-900, Brazil
| | - Daniele O Nascimento
- Laboratório de Immunofarmacologia, Instituto Oswaldo Cruz, Fiocruz, Pavilhão Ozório de Almeida, Av. Brasil 4365, Manguinhos, Rio de Janeiro, RJ, CEP 21045-900, Brazil
| | - Alessandra M Siqueira
- Laboratório de Immunofarmacologia, Instituto Oswaldo Cruz, Fiocruz, Pavilhão Ozório de Almeida, Av. Brasil 4365, Manguinhos, Rio de Janeiro, RJ, CEP 21045-900, Brazil
| | - Robert A Campbell
- Program in Molecular Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - Tatiana P Teixeira Ferreira
- Laboratório de Inflamação, Instituto Oswaldo Cruz, Fiocruz, Pavilhão Ozório de Almeida, Rio de Janeiro, Brazil
| | - Tatiana M Gutierrez
- Laboratório de Immunofarmacologia, Instituto Oswaldo Cruz, Fiocruz, Pavilhão Ozório de Almeida, Av. Brasil 4365, Manguinhos, Rio de Janeiro, RJ, CEP 21045-900, Brazil
| | - Gabriel M Ribeiro
- Laboratório de Engenharia Pulmonar no Programa de Engenharia Biomédica, Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa de Engenharia-COPPE/Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Patricia M R E Silva
- Laboratório de Inflamação, Instituto Oswaldo Cruz, Fiocruz, Pavilhão Ozório de Almeida, Rio de Janeiro, Brazil
| | - Alysson R Carvalho
- Laboratório de Fisiologia da Respiração, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Patricia T Bozza
- Laboratório de Immunofarmacologia, Instituto Oswaldo Cruz, Fiocruz, Pavilhão Ozório de Almeida, Av. Brasil 4365, Manguinhos, Rio de Janeiro, RJ, CEP 21045-900, Brazil
| | - Guy A Zimmerman
- Program in Molecular Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - Hugo C Castro-Faria-Neto
- Laboratório de Immunofarmacologia, Instituto Oswaldo Cruz, Fiocruz, Pavilhão Ozório de Almeida, Av. Brasil 4365, Manguinhos, Rio de Janeiro, RJ, CEP 21045-900, Brazil.,Programa de Produtividade Científica, Universidade Estácio de Sá, Rio de Janeiro, RJ, Brazil
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11
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Cruz LN, Wu Y, Ulrich H, Craig AG, Garcia CRS. Tumor necrosis factor reduces Plasmodium falciparum growth and activates calcium signaling in human malaria parasites. Biochim Biophys Acta Gen Subj 2016; 1860:1489-97. [PMID: 27080559 PMCID: PMC4876768 DOI: 10.1016/j.bbagen.2016.04.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 03/08/2016] [Accepted: 04/04/2016] [Indexed: 12/29/2022]
Abstract
Background Plasmodium has a complex biology including the ability to interact with host signals modulating their function through cellular machinery. Tumor necrosis factor (TNF) elicits diverse cellular responses including effects in malarial pathology and increased infected erythrocyte cytoadherence. As TNF levels are raised during Plasmodium falciparum infection we have investigated whether it has an effect on the parasite asexual stage. Methods Flow cytometry, spectrofluorimetric determinations, confocal microscopy and PCR real time quantifications were employed for characterizing TNF induced effects and membrane integrity verified by wheat germ agglutinin staining. Results TNF is able to decrease intracellular parasitemia, involving calcium as a second messenger of the pathway. Parasites incubated for 48 h with TNF showed reduced erythrocyte invasion. Thus, TNF induced rises in intracellular calcium concentration, which were blocked by prior addition of the purinergic receptor agonists KN62 and A438079, or interfering with intra- or extracellular calcium release by thapsigargin or EGTA (ethylene glycol tetraacetic acid). Importantly, expression of PfPCNA1 which encodes the Plasmodium falciparum Proliferating-Cell Nuclear Antigen 1, decreased after P. falciparum treatment of TNF (tumor necrosis factor) or 6-Bnz cAMP (N6-benzoyladenosine-3′,5′-cyclic monophosphate sodium salt). Conclusions This is potentially interesting data showing the relevance of calcium in downregulating a gene involved in cellular proliferation, triggered by TNF. General significance The data show that Plasmodium may subvert the immunological system and use TNF for the control of its proliferation within the vertebrate host. TNF is able to decrease parasitemia in P. falciparum‐infected RBCs. TNF induced rises in intracellular calcium concentration, which were blocked by the purinergic receptor agonists KN62 and A438079. Interfering with intra‐ or extracellular calcium release by thapsigargin or EGTA also block TNF‐induce calcium release in P. falciparum. Expression of the P. falciparum Proliferating‐Cell Nuclear Antigen 1 (PfPCNA1) decreased after P. falciparum treatment with TNF or 6‐Bnz cAMP. The data show that Plasmodium may subvert the immunological system and use TNF for the control of its proliferation within the vertebrate host.
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Affiliation(s)
- Laura N Cruz
- Department of Physiology, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, travessa 14, n321, CEP 05508-900 São Paulo, SP, Brazil
| | - Yang Wu
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Henning Ulrich
- Department of Biochemistry, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Alister G Craig
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Célia R S Garcia
- Department of Physiology, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, travessa 14, n321, CEP 05508-900 São Paulo, SP, Brazil.
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Wu Y, Cruz LN, Szestak T, Laing G, Molyneux GR, Garcia CRS, Craig AG. An external sensing system in Plasmodium falciparum-infected erythrocytes. Malar J 2016; 15:103. [PMID: 26893139 PMCID: PMC4759932 DOI: 10.1186/s12936-016-1144-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 02/04/2016] [Indexed: 11/17/2022] Open
Abstract
Background A number of experiments have previously indicated that Plasmodium falciparum-infected erythrocytes (pRBC) were able to sense host environment. The basis of this ability to detect external cues is not known but in screening signalling molecules from pRBC using commercial antibodies, a 34 kDa phosphorylated molecule that possesses such ability was identified. Methods The pRBC were exposed to different culture conditions and proteins were extracted for 1D or 2D gel electrophoresis followed by Western blot. The localization of 34 kDa protein was examined by biochemical fractionation followed by Western blot. High-resolution mass spectrometric analysis of immune precipitants was used to identify this protein and real-time quantitative reverse transcriptase polymerase chain reaction was used for detecting mRNA expression level. Results The 34 kDa protein was called PfAB4 has immediate responses (dephosphorylation and rapid turnover) to host environmental stimuli such as serum depletion, osmolality change and cytokine addition. PfAB4 is expressed constitutively throughout the erythrocytic lifecycle with dominant expression in trophozoites 30 h post-infection. Tumour necrosis factor (TNF) treatment induced a transient detectable dephosphorylation of PfAB4 in the ItG strain (2 min after addition) and the level of expression and phosphorylation returned to normal within 1–2 h. PfAB4 localized dominantly in pRBC cytoplasm, with a transient shift to the nucleus under TNF stimulation as shown by biochemical fractionation. High-resolution mass spectrometric analysis of immune precipitants of AB4 antibodies revealed a 34 kDa PfAB4 component as a mixture of proliferating cellular nuclear antigen-1 (PCNA1) and exported protein-2 (EXP2), along with a small number of other inconsistently identified peptides. Different parasite strains have different PfAB4 expression levels, but no significant association between mRNA and PfAB4 levels was seen, indicating that the differences may be at the post-transcriptional, presumably phosphorylation, level. A triple serine phosphorylated PCNA1 peptide was identified from the PfAB4 high expression strain only, providing further evidence that the identity of PfAB4 is PCNA1 in P.falciparum. Conclusion A protein element in the human malaria parasite that responds to external cues, including the pro-inflammatory cytokine TNF have been discovered. Treatment results in a transient change in phosphorylation status of the response element, which also migrates from the parasite cytoplasm to the nucleus. The response element has been identified as PfPCNA1. This sensing response could be regulated by a parasite checkpoint system and be analogous to bacterial two-component signal transduction systems. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1144-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yang Wu
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Laura N Cruz
- Department of Physiology, Instituto de Biociências, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
| | - Tadge Szestak
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Gavin Laing
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Gemma R Molyneux
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Celia R S Garcia
- Department of Physiology, Instituto de Biociências, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
| | - Alister G Craig
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK.
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13
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Church JA, Nyamako L, Olupot-Olupot P, Maitland K, Urban BC. Increased adhesion of Plasmodium falciparum infected erythrocytes to ICAM-1 in children with acute intestinal injury. Malar J 2016; 15:54. [PMID: 26830671 PMCID: PMC4736236 DOI: 10.1186/s12936-016-1110-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 01/18/2016] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Children with severe malaria are at increased risk of invasive bacterial disease particularly infection with enteric gram-negative organisms. These organisms are likely to originate from the gut, however, how and why they breach the intestinal interface in the context of malaria infection remains unclear. One explanation is that accumulation of infected red blood cells (iRBCs) in the intestinal microvasculature contributes to tissue damage and subsequent microbial translocation which can be addressed through investigation of the impact of cytoadhesion in patients with malaria and intestinal damage. METHODS Using a static adhesion assay, cytoadhesion of iRBCs was quantified in 48 children with malaria to recombinant proteins constitutively expressed on endothelial cell surfaces. Cytoadhesive phenotypes between children with and without biochemical evidence of intestinal damage [defined as endotoxemia or elevated plasma intestinal fatty acid binding protein (I-FABP)] was compared. RESULTS The majority of parasites demonstrated binding to the endothelial receptors CD36 and to a lesser extent to ICAM-1. Reduced adhesion to CD36 but not adhesion to ICAM-1 or rosetting was associated with malarial anaemia (p = 0.004). Increased adhesion of iRBCs to ICAM-1 in children who had evidence of elevated I-FABP (p = 0.022), a marker of intestinal ischaemia was observed. There was no correlation between the presence of endotoxemia and increased adhesion to any of the recombinant proteins. CONCLUSION Increased parasite adhesion to ICAM-1 in children with evidence of intestinal ischaemia lends further evidence to a link between the cytoadherence of iRBCs in gut microvasculature and intestinal damage.
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Affiliation(s)
- James A Church
- Centre for Paediatrics, Blizard Institute, Queen Mary University of London, London, UK. .,KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.
| | - Lydia Nyamako
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.
| | - Peter Olupot-Olupot
- Mbale Regional Referral Hospital Clinical Research Unit (MCRU), Mbale, Uganda. .,Busitema University Faculty of Health Sciences, Mbale Campus, Mbale, Uganda.
| | - Kathryn Maitland
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya. .,Wellcome Centre for Clinical Tropical Medicine, Imperial College, London, UK.
| | - Britta C Urban
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya. .,Parasitology Department, Liverpool School of Tropical Medicine, Liverpool, UK.
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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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15
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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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16
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Khaw LT, Ball HJ, Mitchell AJ, Grau GE, Stocker R, Golenser J, Hunt NH. Brain endothelial cells increase the proliferation of Plasmodium falciparum through production of soluble factors. Exp Parasitol 2014; 145:34-41. [PMID: 25045850 DOI: 10.1016/j.exppara.2014.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 05/06/2014] [Accepted: 07/08/2014] [Indexed: 01/01/2023]
Abstract
We here describe the novel finding that brain endothelial cells in vitro can stimulate the growth of Plasmodium falciparum through the production of low molecular weight growth factors. By using a conditioned medium approach, we show that the brain endothelial cells continued to release these factors over time. If this mirrors the in vivo situation, these growth factors potentially would provide an advantage, in terms of enhanced growth, for sequestered parasitised red blood cells in the brain microvasculature. We observed this phenomenon with brain endothelial cells from several sources as well as a second P. falciparum strain. The characteristics of the growth factors included: <3 kDa molecular weight, heat stable, and in part chloroform soluble. Future efforts should be directed at identifying these growth factors, since blocking their production or actions might be of benefit for reducing parasite load and, hence, malaria pathology.
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Affiliation(s)
- L T Khaw
- Molecular Immunopathology Unit, School of Medical Sciences and Bosch Institute, Sydney Medical School, University of Sydney, NSW 2006, Australia; Department of Parasitology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - H J Ball
- Molecular Immunopathology Unit, School of Medical Sciences and Bosch Institute, Sydney Medical School, University of Sydney, NSW 2006, Australia
| | - A J Mitchell
- Molecular Immunopathology Unit, School of Medical Sciences and Bosch Institute, Sydney Medical School, University of Sydney, NSW 2006, Australia; Immune Imaging Program, Centenary Institute, Sydney, NSW 2050, Australia
| | - G E Grau
- Vascular Immunology Unit, School of Medical Sciences and Bosch Institute, Sydney Medical School, University of Sydney, NSW 2006, Australia
| | - R Stocker
- Vascular Biology Division, Victor Chang Cardiac Research Institute, Lowy Packer Building, 405 Liverpool Street, Darlinghurst, NSW 2010, Australia
| | - J Golenser
- Department of Microbiology and Molecular Genetics, Kuvin Centre for the Study of Tropical and Infectious Diseases, Hebrew University of Jerusalem, Jerusalem, Israel
| | - N H Hunt
- Molecular Immunopathology Unit, School of Medical Sciences and Bosch Institute, Sydney Medical School, University of Sydney, NSW 2006, Australia.
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Cytoadherence of Plasmodium berghei-infected red blood cells to murine brain and lung microvascular endothelial cells in vitro. Infect Immun 2013; 81:3984-91. [PMID: 23940206 DOI: 10.1128/iai.00428-13] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sequestration of infected red blood cells (iRBC) within the cerebral and pulmonary microvasculature is a hallmark of human cerebral malaria (hCM). The interaction between iRBC and the endothelium in hCM has been studied extensively and is linked to the severity of malaria. Experimental CM (eCM) caused by Plasmodium berghei ANKA reproduces most features of hCM, although the sequestration of RBC infected by P. berghei ANKA (PbA-iRBC) has not been completely delineated. The role of PbA-iRBC sequestration in the severity of eCM is not well characterized. Using static and flow cytoadherence assays, we provide the first direct in vitro evidence for the binding of PbA-iRBC to murine brain and lung microvascular endothelial cells (MVEC). We found that basal PbA-iRBC cytoadherence to MVECs was significantly higher than that of normal red blood cells (NRBC) and of RBC infected with P. berghei K173 (PbK173-iRBC), a strain that causes noncerebral malaria (NCM). MVEC prestimulation with tumor necrosis factor (TNF) failed to promote any further significant increase in mixed-stage iRBC adherence. Interestingly, enrichment of the blood for mature parasites significantly increased PbA-iRBC binding to the MVECs prestimulated with TNF, while blockade of VCAM-1 reduced this adhesion. Our study provides evidence for the firm, flow-resistant binding to endothelial cells of iRBC from strain ANKA-infected mice, which develop CM, and for less binding of iRBC from strain K173-infected mice, which develop NCM. An understanding of P. berghei cytoadherence may help elucidate the importance of sequestration in the development of CM and aid the development of antibinding therapies to help reduce the burden of this syndrome.
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18
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Abstract
Plasmodium falciparum malaria kills over 500,000 children every year and has been a scourge of humans for millennia. Owing to the co-evolution of humans and P. falciparum parasites, the human genome is imprinted with polymorphisms that not only confer innate resistance to falciparum malaria, but also cause hemoglobinopathies. These genetic traits—including hemoglobin S (HbS), hemoglobin C (HbC), and α-thalassemia—are the most common monogenic human disorders and can confer remarkable degrees of protection from severe, life-threatening falciparum malaria in African children: the risk is reduced 70% by homozygous HbC and 90% by heterozygous HbS (sickle-cell trait). Importantly, this protection is principally present for severe disease and largely absent for P. falciparum infection, suggesting that these hemoglobinopathies specifically neutralize the parasite's in vivo mechanisms of pathogenesis. These hemoglobin variants thus represent a “natural experiment” to identify the cellular and molecular mechanisms by which P. falciparum produces clinical morbidity, which remain partially obscured due to the complexity of interactions between this parasite and its human host. Multiple lines of evidence support a restriction of parasite growth by various hemoglobinopathies, and recent data suggest this phenomenon may result from host microRNA interference with parasite metabolism. Multiple hemoglobinopathies mitigate the pathogenic potential of parasites by interfering with the export of P. falciparum erythrocyte membrane protein 1 (PfEMP1) to the surface of the host red blood cell. Few studies have investigated their effects upon the activation of the innate and adaptive immune systems, although recent murine studies suggest a role for heme oxygenase-1 in protection. Ultimately, the identification of mechanisms of protection and pathogenesis can inform future therapeutics and preventive measures. Hemoglobinopathies slice the “Gordian knot” of host and parasite interactions to confer malaria protection, and offer a translational model to identify the most critical mechanisms of P. falciparum pathogenesis.
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Tibúrcio M, Silvestrini F, Bertuccini L, Sander AF, Turner L, Lavstsen T, Alano P. Early gametocytes of the malaria parasite Plasmodium falciparum specifically remodel the adhesive properties of infected erythrocyte surface. Cell Microbiol 2012; 15:647-59. [PMID: 23114006 DOI: 10.1111/cmi.12062] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 10/11/2012] [Accepted: 10/24/2012] [Indexed: 11/27/2022]
Abstract
In Plasmodium falciparum infections the parasite transmission stages, the gametocytes, mature in 10 days sequestered in internal organs. Recent studies suggest that cell mechanical properties rather than adhesive interactions play a role in sequestration during gametocyte maturation. It remains instead obscure how sequestration is established, and how the earliest sexual stages, morphologically similar to asexual trophozoites, modify the infected erythrocytes and their cytoadhesive properties at the onset of gametocytogenesis. Here, purified P. falciparum early gametocytes were used to ultrastructurally and biochemically analyse parasite-induced modifications on the red blood cell surface and to measure their functional consequences on adhesion to human endothelial cells. This work revealed that stage I gametocytes are able to deform the infected erythrocytes like asexual parasites, but do not modify its surface with adhesive 'knob' structures and associated proteins. Reduced levels of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) adhesins are exposed on the red blood cell surface by these parasites, and the expression of the var gene family, which encodes 50-60 variants of PfEMP1, is dramatically downregulated in the transition from asexual development to gametocytogenesis. Cytoadhesion assays show that such gene expression changes and host cell surface modifications functionally result in the inability of stage I gametocytes to bind the host ligands used by the asexual parasite to bind endothelial cells. In conclusion, these results identify specific differences in molecular and cellular mechanisms of host cell remodelling and in adhesive properties, leading to clearly distinct host parasite interplays in the establishment of sequestration of stage I gametocytes and of asexual trophozoites.
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Affiliation(s)
- Marta Tibúrcio
- Dipartimento di Malattie Infettive, Parassitarie ed Immunomediate, Istituto Superiore di Sanità, viale Regina Elena 299, 00161, Rome, Italy
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Differential adhesive properties of sequestered asexual and sexual stages of Plasmodium falciparum on human endothelial cells are tissue independent. PLoS One 2012; 7:e31567. [PMID: 22363675 PMCID: PMC3283655 DOI: 10.1371/journal.pone.0031567] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Accepted: 01/13/2012] [Indexed: 01/14/2023] Open
Abstract
The protozoan parasite Plasmodium falciparum, responsible for the most severe form of malaria, is able to sequester from peripheral circulation during infection. The asexual stage parasites sequester by binding to endothelial cell receptors in the microvasculature of various organs. P. falciparum gametocytes, the developmental stages responsible for parasite transmission from humans to Anopheles mosquitoes, also spend the almost ten days necessary for their maturation sequestered away from the peripheral circulation before they are released in blood mainstream. In contrast to those of asexual parasites, the mechanisms and cellular interactions responsible for immature gametocyte sequestration are largely unexplored, and controversial evidence has been produced so far on this matter. Here we present a systematic comparison of cell binding properties of asexual stages and immature and mature gametocytes from the reference P. falciparum clone 3D7 and from a patient parasite isolate on a panel of human endothelial cells from different tissues. This analysis includes assays on human bone marrow derived endothelial cell lines (HBMEC), as this tissue has been proposed as a major site of gametocyte maturation. Our results clearly demonstrate that cell adhesion of asexual stage parasites is consistently more efficient than that, virtually undetectable of immature gametocytes, irrespectively of the endothelial cell lines used and of parasite genotypes. Importantly, immature gametocytes of both lines tested here do not show a higher binding efficiency compared to asexual stages on bone marrow derived endothelial cells, unlike previously reported in the only study on this issue. This indicates that gametocyte-host interactions in this tissue are unlikely to be mediated by the same adhesion processes to specific endothelial receptors as seen with asexual forms.
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Fatih FA, Siner A, Ahmed A, Woon LC, Craig AG, Singh B, Krishna S, Cox-Singh J. Cytoadherence and virulence - the case of Plasmodium knowlesi malaria. Malar J 2012; 11:33. [PMID: 22305466 PMCID: PMC3330018 DOI: 10.1186/1475-2875-11-33] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Accepted: 02/03/2012] [Indexed: 12/02/2022] Open
Abstract
Background Cytoadherence of infected red blood cells to brain endothelium is causally implicated in malarial coma, one of the severe manifestations of falciparum malaria. Cytoadherence is mediated by specific binding of variant parasite antigens, expressed on the surface of infected erythrocytes, to endothelial receptors including, ICAM-1, VCAM and CD36. In fatal cases of severe falciparum malaria with coma, blood vessels in the brain are characteristically congested with infected erythrocytes. Brain sections from a fatal case of knowlesi malaria, but without coma, were similarly congested with infected erythrocytes. The objective of this study was to determine the binding phenotype of Plasmodium knowlesi infected human erythrocytes to recombinant human ICAM-1, VCAM and CD36. Methods Five patients with PCR-confirmed P. knowlesi malaria were recruited into the study with consent between April and August 2010. Pre-treatment venous blood was washed and cultured ex vivo to increase the proportion of schizont-infected erythrocytes. Cultured blood was seeded into Petri dishes with triplicate areas coated with ICAM-1, VCAM and CD36. Following incubation at 37°C for one hour the dishes were washed and the number of infected erythrocytes bound/mm2 to PBS control areas and to recombinant human ICAM-1 VCAM and CD36 coated areas were recorded. Each assay was performed in duplicate. Assay performance was monitored with the Plasmodium falciparum clone HB3. Results Blood samples were cultured ex vivo for up to 14.5 h (mean 11.3 ± 1.9 h) to increase the relative proportion of mature trophozoite and schizont-infected red blood cells to at least 50% (mean 65.8 ± 17.51%). Three (60%) isolates bound significantly to ICAM-1 and VCAM, one (20%) isolate bound to VCAM and none of the five bound significantly to CD36. Conclusions Plasmodium knowlesi infected erythrocytes from human subjects bind in a specific but variable manner to the inducible endothelial receptors ICAM-1 and VCAM. Binding to the constitutively-expressed endothelial receptor CD36 was not detected. Further work will be required to define the pathological consequences of these interactions.
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Affiliation(s)
- Farrah A Fatih
- Centre for Infection and Immunity, St George's University of London, London SW17 0RE, UK
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