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Pádua TA, Souza MC. Heme on Pulmonary Malaria: Friend or Foe? Front Immunol 2020; 11:1835. [PMID: 32983096 PMCID: PMC7477073 DOI: 10.3389/fimmu.2020.01835] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 07/08/2020] [Indexed: 12/19/2022] Open
Abstract
Malaria is a hemolytic disease that, in severe cases, can compromise multiple organs. Pulmonary distress is a common symptom observed in severe malaria caused by Plasmodium vivax or Plasmodium falciparum. However, biological components involved in the development of lung malaria are poorly studied. In experimental models of pulmonary malaria, it was observed that parasitized red blood cell-congested pulmonary capillaries are related to intra-alveolar hemorrhages and inflammatory cell infiltration. Thus, it is very likely that hemolysis participates in malaria-induced acute lung injury. During malaria, heme assumes different biochemical structures such as hemin and hemozoin (biocrystallized structure of heme inside Plasmodium sp.). Each heme-derived structure triggers a different biological effect: on the one hand, hemozoin found in lung tissue is responsible for the infiltration of inflammatory cells and consequent tissue injury; on the other hand, heme stimulates heme oxygenase-1 (HO-1) expression and CO production, which protect mice from severe malaria. In this review, we discuss the biological mechanism involved in the dual role of heme response in experimental malaria-induced acute lung injury.
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Affiliation(s)
- Tatiana Almeida Pádua
- Laboratory of Applied Pharmacology, Institute of Drug Technology (Farmanguinhos), Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Mariana Conceição Souza
- Laboratory of Applied Pharmacology, Institute of Drug Technology (Farmanguinhos), Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
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Skorokhod OA, Barrera V, Heller R, Carta F, Turrini F, Arese P, Schwarzer E. Malarial pigment hemozoin impairs chemotactic motility and transendothelial migration of monocytes via 4-hydroxynonenal. Free Radic Biol Med 2014; 75:210-21. [PMID: 25017964 DOI: 10.1016/j.freeradbiomed.2014.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 06/25/2014] [Accepted: 07/03/2014] [Indexed: 12/24/2022]
Abstract
Natural hemozoin, nHZ, is avidly phagocytosed in vivo and in vitro by human monocytes. The persistence of the undigested β-hematin core of nHZ in the phagocyte lysosome for long periods of time modifies several cellular immune functions. Here we show that nHZ phagocytosis by human primary monocytes severely impaired their chemotactic motility toward MCP-1, TNF, and FMLP, by approximately 80% each, and their diapedesis across a confluent human umbilical vein endothelial cell layer toward MCP-1 by 45±5%. No inhibition was observed with latex-fed or unfed monocytes. Microscopic inspection revealed polarization defects in nHZ-fed monocytes due to irregular actin polymerization. Phagocytosed nHZ catalyzes the peroxidation of polyunsaturated fatty acids and generation of the highly reactive derivative 4-hydroxynonenal (4-HNE). Similar to nHZ phagocytosis, the exposure of monocytes to in vivo-compatible 4-HNE concentrations inhibited cell motility in both the presence and the absence of chemotactic stimuli, suggesting severe impairment of cytoskeleton dynamics. Consequently, 4-HNE conjugates with the cytoskeleton proteins β-actin and coronin-1A were immunochemically identified in nHZ-fed monocytes and mass spectrometrically localized in domains of protein-protein interactions involved in cytoskeleton reorganization and cell motility. The molecular and functional modifications of actin and coronin by nHZ/4-HNE may also explain impaired phagocytosis, another motility-dependent process previously described in nHZ-fed monocytes. Further studies will show whether impaired monocyte motility may contribute to the immunodepression and the frequent occurrence of secondary infections observed in malaria patients.
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Affiliation(s)
| | | | - Regine Heller
- Institute for Molecular Cell Biology, Center for Molecular Biomedicine, Friedrich Schiller University of Jena, 07745 Jena, Germany
| | | | - Franco Turrini
- Department of Oncology, University of Torino, 10126 Torino, Italy
| | - Paolo Arese
- Department of Oncology, University of Torino, 10126 Torino, Italy
| | - Evelin Schwarzer
- Department of Oncology, University of Torino, 10126 Torino, Italy.
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3
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Phagocytic uptake of oxidized heme polymer is highly cytotoxic to macrophages. PLoS One 2014; 9:e103706. [PMID: 25078090 PMCID: PMC4117526 DOI: 10.1371/journal.pone.0103706] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 07/06/2014] [Indexed: 11/26/2022] Open
Abstract
Apoptosis in macrophages is responsible for immune-depression and pathological effects during malaria. Phagocytosis of PRBC causes induction of apoptosis in macrophages through release of cytosolic factors from infected cells. Heme polymer or β-hematin causes dose-dependent death of macrophages with LC50 of 132 µg/ml and 182 µg/ml respectively. The toxicity of hemin or heme polymer was amplified several folds in the presence of non-toxic concentration of methemoglobin. β-hematin uptake in macrophage through phagocytosis is crucial for enhanced toxicological effects in the presence of methemoglobin. Higher accumulation of β-hematin is observed in macrophages treated with β-hematin along with methemoglobin. Light and scanning electron microscopic observations further confirm accumulation of β-hematin with cellular toxicity. Toxicological potentiation of pro-oxidant molecules toward macrophages depends on generation of H2O2 and independent to release of free iron from pro-oxidant molecules. Methemoglobin oxidizes β-hematin to form oxidized β-hematin (βH*) through single electron transfer mechanism. Pre-treatment of reaction mixture with spin-trap Phenyl-N-t-butyl-nitrone dose-dependently reverses the β-hematin toxicity, indicates crucial role of βH* generation with the toxicological potentiation. Acridine orange/ethidium bromide staining and DNA fragmentation analysis indicate that macrophage follows an oxidative stress dependent apoptotic pathway to cause death. In summary, current work highlights mutual co-operation between methemoglobin and different pro-oxidant molecules to enhance toxicity towards macrophages. Hence, methemoglobin peroxidase activity can be probed for subduing cellular toxicity of pro-oxidant molecules and it may in-turn make up for host immune response against the malaria parasite.
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Olivier M, Van Den Ham K, Shio MT, Kassa FA, Fougeray S. Malarial pigment hemozoin and the innate inflammatory response. Front Immunol 2014; 5:25. [PMID: 24550911 PMCID: PMC3913902 DOI: 10.3389/fimmu.2014.00025] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 01/16/2014] [Indexed: 12/28/2022] Open
Abstract
Malaria is a deadly infectious disease caused by the intraerythrocytic protozoan parasite Plasmodium. The four species of Plasmodium known to affect humans all produce an inorganic crystal called hemozoin (HZ) during the heme detoxification process. HZ is released from the food vacuole into circulation during erythrocyte lysis, while the released parasites further infect additional naive red blood cells. Once in circulation, HZ is rapidly taken up by circulating monocytes and tissue macrophages, inducing the production of pro-inflammatory mediators, such as interleukin-1β (IL-1β). Over the last few years, it has been reported that HZ, similar to uric acid crystals, asbestos, and silica, is able to trigger IL-1β production via the activation of the NOD-like receptor containing pyrin domain 3 (NLRP3) inflammasome complex. Additionally, recent findings have shown that host factors, such as fibrinogen, have the ability to adhere to free HZ and modify its capacity to activate host immune cells. Although much has been discovered regarding NLRP3 inflammasome induction, the mechanism through which this intracellular multimolecular complex is activated remains unclear. In the present review, the most recent discoveries regarding the capacity of HZ to trigger this innate immune complex as well as the impact of HZ on several other inflammatory signaling pathways will be discussed.
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Affiliation(s)
- Martin Olivier
- Department of Medicine, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada ; Department of Microbiology and Immunology, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada
| | - Kristin Van Den Ham
- Department of Medicine, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada ; Department of Microbiology and Immunology, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada
| | - Marina Tiemi Shio
- Department of Medicine, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada ; Department of Microbiology and Immunology, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada
| | - Fikregabrail Aberra Kassa
- Department of Medicine, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada ; Department of Microbiology and Immunology, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada
| | - Sophie Fougeray
- Department of Medicine, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada ; Department of Microbiology and Immunology, McGill TB International Centre, Research Institute of the McGill University Health Centre, McGill University , Montréal, QC , Canada
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Ghosh D, Stumhofer JS. Do you see what I see: Recognition of protozoan parasites by Toll-like receptors. ACTA ACUST UNITED AC 2014; 9:129-140. [PMID: 25383072 DOI: 10.2174/1573395509666131203225929] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Toll-like receptors (TLRs) are important for recognizing a variety of pathogens, including protozoan parasites, and initiating innate immune responses against them. TLRs are localized on the cell surface as well as in the endosome, and are implicated in innate sensing of these parasites. In this review, we will discuss recent findings on the identification of parasite-derived pathogen associated molecular patterns and the TLRs that bind them. The role of these TLRs in initiating the immune response against protozoan parasitic infections in vivo will be presented in the context of murine models of infection utilizing TLR-deficient mice. Additionally, we will explore evidence that TLRs and genetic variants of TLRs may impact the outcome of these parasitic infections in humans.
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Affiliation(s)
- Debopam Ghosh
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205
| | - Jason S Stumhofer
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205
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Trapani S, Canessa C, Fedi A, Giusti G, Barni S, Montagnani C, Galli L, Resti M, De Martino M. Macrophage Activation Syndrome in a Child Affected by Malaria: The Choice of Steroid. Int J Immunopathol Pharmacol 2013; 26:535-9. [DOI: 10.1177/039463201302600229] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Macrophage activation syndrome is a potentially fatal clinical syndrome caused by an excessive activation and proliferation of macrophages and T cells, leading to an exaggerated inflammatory reaction. It is well known that it can complicate the course of different conditions, especially autoimmune, lympho-proliferative, infectious diseases and drugs. Many infective pathogens can trigger the syndrome but the association with malaria has rarely been described, especially in children. We report a child with severe malaria complicated by MAS, in whom the clinical appearance of this syndrome could be considered as worsening of malaria itself. Furthermore, the use of steroids as first choice drugs in this complication, but arguable in malaria, has been highlighted. Clinicians should be aware of this syndrome when malaria does not respond to conventional therapy, since early diagnosis and prompt treatment may dramatically reduce the mortality associated with this condition.
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Affiliation(s)
- S. Trapani
- Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, Florence, Italy
| | - C. Canessa
- Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, Florence, Italy
| | - A. Fedi
- Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, Florence, Italy
| | - G. Giusti
- Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, Florence, Italy
| | - S. Barni
- Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, Florence, Italy
| | - C. Montagnani
- Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, Florence, Italy
| | - L. Galli
- Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, Florence, Italy
| | - M. Resti
- Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, Florence, Italy
| | - M. De Martino
- Department of Health Sciences, University of Florence, Anna Meyer Children's University Hospital, Florence, Italy
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Leoratti FMDS, Trevelin SC, Cunha FQ, Rocha BC, Costa PAC, Gravina HD, Tada MS, Pereira DB, Golenbock DT, do Valle Antonelli LR, Gazzinelli RT. Neutrophil paralysis in Plasmodium vivax malaria. PLoS Negl Trop Dis 2012; 6:e1710. [PMID: 22745844 PMCID: PMC3383745 DOI: 10.1371/journal.pntd.0001710] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 05/13/2012] [Indexed: 12/03/2022] Open
Abstract
Background The activation of innate immune responses by Plasmodium vivax results in activation of effector cells and an excessive production of pro-inflammatory cytokines that may culminate in deleterious effects. Here, we examined the activation and function of neutrophils during acute episodes of malaria. Materials and Methods Blood samples were collected from P. vivax-infected patients at admission (day 0) and 30–45 days after treatment with chloroquine and primaquine. Expression of activation markers and cytokine levels produced by highly purified monocytes and neutrophils were measured by the Cytometric Bead Assay. Phagocytic activity, superoxide production, chemotaxis and the presence of G protein-coupled receptor (GRK2) were also evaluated in neutrophils from malaria patients. Principal Findings Both monocytes and neutrophils from P. vivax-infected patients were highly activated. While monocytes were found to be the main source of cytokines in response to TLR ligands, neutrophils showed enhanced phagocytic activity and superoxide production. Interestingly, neutrophils from the malaria patients expressed high levels of GRK2, low levels of CXCR2, and displayed impaired chemotaxis towards IL-8 (CXCL8). Conclusion Activated neutrophils from malaria patients are a poor source of pro-inflammatory cytokines and display reduced chemotactic activity, suggesting a possible mechanism for an enhanced susceptibility to secondary bacterial infection during malaria. Plasmodium vivax is responsible for approximately 60–80% of the malaria cases in the world, and contributes to significant social and economic instability in the developing countries of Latin America and Asia. The pathogenesis of P. vivax malaria is a consequence of host derived inflammatory mediators. Hence, a better understanding of the mechanisms involved in induction of systemic inflammation during P. vivax malaria is critical for the clinical management and prevention of severe disease. The innate immune receptors recognize Plasmodium sp. and initiate a broad spectrum of host defense mechanisms that mediate resistance to infection. However, the innate immune response is the classic “two-edged sword”, and clinical malaria is associated with high levels of circulating pro-inflammatory cytokines. Our findings show that both monocytes and neutrophils are highly activated during malaria. Monocytes produced high levels of IL-1β, IL-6 and TNF-α during acute malaria. On the other hand, neutrophils were a poor source of cytokines, but displayed an enhanced phagocytic activity and superoxide production. Unexpectedly, we noticed an impaired chemotaxis of neutrophils towards an IL-8 (CXCL8) gradient. We proposed that neutrophil paralysis is in part responsible for the enhanced susceptibility to bacterial infection observed in malaria patients.
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Affiliation(s)
| | - Silvia Cellone Trevelin
- Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Fernando Queiroz Cunha
- Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Bruno Coelho Rocha
- Laboratório de Imunopatologia, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Pedro Augusto Carvalho Costa
- Laboratório de Imunopatologia, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Humberto Doriguêtto Gravina
- Laboratório de Imunopatologia, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Mauro Shugiro Tada
- Centro de Pesquisas em Medicina Tropical de Rondônia, Porto Velho, Rondônia, Brazil
| | | | - Douglas Taylor Golenbock
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Lis Ribeiro do Valle Antonelli
- Laboratório de Imunopatologia, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Ricardo T. Gazzinelli
- Laboratório de Imunopatologia, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail:
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Hochman S, Kim K. The Impact of HIV Coinfection on Cerebral Malaria Pathogenesis. JOURNAL OF NEUROPARASITOLOGY 2012; 3:235547. [PMID: 22545215 PMCID: PMC3336366 DOI: 10.4303/jnp/235547] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
HIV infection is widespread throughout the world and is especially prevalent in sub-Saharan Africa and Asia. Similarly, Plasmodium falciparum, the most common cause of severe malaria, affects large areas of sub-Saharan Africa, the Indian subcontinent, and Southeast Asia. Although initial studies suggested that HIV and malaria had independent impact upon patient outcomes, recent studies have indicated a more significant interaction. Clinical studies have shown that people infected with HIV have more frequent and severe episodes of malaria, and parameters of HIV disease progression worsen in individuals during acute malaria episodes. However, the effect of HIV on development of cerebral malaria, a manifestation of P. falciparum infection that is frequently fatal, has not been characterized. We review clinical and basic science studies pertaining to HIV and malaria coinfection and cerebral malaria in particular in order to highlight the likely role HIV plays in exacerbating cerebral malaria pathogenesis.
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Affiliation(s)
- Sarah Hochman
- Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY 10461, USA
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Geurts N, Opdenakker G, Van den Steen PE. Matrix metalloproteinases as therapeutic targets in protozoan parasitic infections. Pharmacol Ther 2011; 133:257-79. [PMID: 22138604 DOI: 10.1016/j.pharmthera.2011.11.008] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 10/28/2011] [Indexed: 12/11/2022]
Abstract
Matrix metalloproteinases (MMPs) are associated with processes of tissue remodeling and are expressed in all infections with protozoan parasites. We here report the status of MMP research in malaria, trypanosomiasis, leishmaniasis and toxoplasmosis. In all these infections, the balances between MMPs and endogenous MMP inhibitors are disturbed, mostly in favor of active proteolysis. When the infection is associated with leukocyte influx into specific organs, immunopathology and collateral tissue damage may occur. These pathologies include cerebral malaria, sleeping sickness (human African trypanosomiasis), Chagas disease (human American trypanosomiasis), leishmaniasis and toxoplasmic encephalitis in immunocompromised hosts. Destruction of the integrity of the blood-brain barrier (BBB) is a common denominator that may be executed by leukocytic MMPs under the control of host cytokines and chemokines as well as influenced by parasite products. Mechanisms by which parasite-derived products alter host expression of MMP and endogenous MMP inhibitors, have only been described for hemozoin (Hz) in malaria. Hence, understanding these interactions in other parasitic infections remains an important challenge. Furthermore, the involved parasites are also known to produce their own metalloproteinases, and this forms an extra stimulus to investigate MMP inhibitory drugs as therapeutics. MMP inhibitors (MMPIs) may dampen collateral tissue damage, as is anecdotically reported for tetracyclines as MMP regulators in parasite infections.
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Affiliation(s)
- Nathalie Geurts
- Laboratory of Immunobiology, Rega Institute for Medical Research, University of Leuven, Leuven, Minderbroedersstraat 10, B3000 Leuven, Belgium
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Schrimpe AC, Wright DW. Comparative analysis of gene expression changes mediated by individual constituents of hemozoin. Chem Res Toxicol 2010; 22:433-45. [PMID: 19191707 DOI: 10.1021/tx8002752] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Plasmodium protozoa, the source of malarial infections, catabolize large quantities of hemoglobin during an intraerythrocytic phase. During this process, free heme is detoxified through biomineralization into an insoluble heme aggregate, hemozoin (Hz). In its native state, Hz is associated with a variety of lipid peroxidation products including 4-hydroxy-2-nonenal (HNE). In the present study, gene expression profiles were used to compare responses to two of the individual components of Hz in a model macrophage cell line. LPS-stimulated RAW 264.7 cells were exposed to HNE and the synthetic form of Hz, beta-hematin (BH), for 6 or 24 h. Microarray analysis identified alterations in gene expression induced by exposure to HNE and opsonized BH (fold change, > or = 1.8; p value, < or = 0.01). Patterns of gene expression were compared to changes induced by an opsonized control latex bead challenge in LPS-stimulated cells and revealed that the BH response was predominantly phagocytic. Ingenuity Pathway Analysis demonstrated that HNE mediated a short-term oxidative stress response and had a prolonged effect on the expression of genes associated with categories of "Cell Cycle", "Cellular Assembly and Organization", "DNA Replication, Recombination, and Repair", and "Cellular Development". Comparisons of expression changes caused by BH and HNE with those observed during malarial infection suggest that BH and HNE are involved in inflammatory response modulation, altered NF-kappaB signal transduction, extracellular matrix (ECM) degradation, and dyserythropoiesis. HNE exposure led to several significant steady-state expression changes including repressed chemokine (C-C motif) ligand 5 (Ccl5), indicative of dyserythropoiesis, and a severe matrix metalloproteinase 9 (Mmp9)/tissue inhibitor of metalloproteinase 1 (Timp1) imbalance in favor of ECM proteolysis.
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11
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Shio MT, Kassa FA, Bellemare MJ, Olivier M. Innate inflammatory response to the malarial pigment hemozoin. Microbes Infect 2010; 12:889-99. [PMID: 20637890 DOI: 10.1016/j.micinf.2010.07.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 07/01/2010] [Accepted: 07/02/2010] [Indexed: 11/19/2022]
Abstract
Malaria is an infectious disease caused by parasites of the genus Plasmodium. This intraerythrocytic protozoan produces hemozoin (HZ), an insoluble crystalline metabolite resulting from the heme detoxification mechanism. This review will focus on HZ biosynthesis and synthetic preparation, but in particular on its effect on host's innate inflammatory responses.
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Affiliation(s)
- Marina T Shio
- Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada
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12
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Evaluation of a loop-mediated isothermal amplification method using fecal specimens for differential detection of Taenia species from humans. J Clin Microbiol 2010; 48:3350-2. [PMID: 20631114 DOI: 10.1128/jcm.00697-10] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We compared the performance of loop-mediated isothermal amplification (LAMP) with that of a multiplex PCR method for differential detection of human Taenia parasites in fecal specimens from taeniasis patients. The LAMP method, with no false positives, showed a higher sensitivity (88.4%) than the multiplex PCR (37.2%). Thus, it is expected that the LAMP method has a high value for molecular diagnosis of taeniasis.
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13
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Arnold L, Tyagi RK, Mejia P, Van Rooijen N, Pérignon JL, Druilhe P. Analysis of innate defences against Plasmodium falciparum in immunodeficient mice. Malar J 2010; 9:197. [PMID: 20618960 PMCID: PMC2914061 DOI: 10.1186/1475-2875-9-197] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 07/09/2010] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Mice with genetic deficiencies in adaptive immunity are used for the grafting of human cells or pathogens, to study human diseases, however, the innate immune responses to xenografts in these mice has received little attention. Using the NOD/SCID Plasmodium falciparum mouse model an analysis of innate defences responsible for the substantial control of P. falciparum which remains in such mice, was performed. METHODS NOD/SCID mice undergoing an immunomodulatory protocol that includes, clodronate-loaded liposomes to deplete macrophages and an anti-polymorphonuclear leukocytes antibody, were grafted with human red blood cells and P. falciparum. The systematic and kinetic analysis of the remaining innate immune responses included the number and phenotype of peripheral blood leukocytes as well as inflammatory cytokines/chemokines released in periphery. The innate responses towards the murine parasite Plasmodium yoelii were used as a control. RESULTS Results show that 1) P. falciparum induces a strong inflammation characterized by an increase in circulating leukocytes and the release of inflammatory cytokines; 2) in contrast, the rodent parasite P. yoelii, induces a far more moderate inflammation; 3) human red blood cells and the anti-inflammatory agents employed induce low-grade inflammation; and 4) macrophages seem to bear the most critical function in controlling P. falciparum survival in those mice, whereas polymorphonuclear and NK cells have only a minor role. CONCLUSIONS Despite the use of an immunomodulatory treatment, immunodeficient NOD/SCID mice are still able to mount substantial innate responses that seem to be correlated with parasite clearance. Those results bring new insights on the ability of innate immunity from immunodeficient mice to control xenografts of cells of human origin and human pathogens.
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Affiliation(s)
- Ludovic Arnold
- Laboratoire de Parasitologie Bio-Médicale, Institut Pasteur, 28, rue du Dr Roux, 75015 Paris, France
| | - Rajeev Kumar Tyagi
- Laboratoire de Parasitologie Bio-Médicale, Institut Pasteur, 28, rue du Dr Roux, 75015 Paris, France
| | - Pedro Mejia
- Laboratoire de Parasitologie Bio-Médicale, Institut Pasteur, 28, rue du Dr Roux, 75015 Paris, France
- Current Address; James Mitchell Laboratory, Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, MA, USA
| | - Nico Van Rooijen
- Department of Molecular Cell Biology, VU University Medical Center, 1007 MB Amsterdam, the Netherlands
| | - Jean-Louis Pérignon
- Laboratoire de Parasitologie Bio-Médicale, Institut Pasteur, 28, rue du Dr Roux, 75015 Paris, France
| | - Pierre Druilhe
- Laboratoire de Parasitologie Bio-Médicale, Institut Pasteur, 28, rue du Dr Roux, 75015 Paris, France
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Diou J, Tardif MR, Barat C, Tremblay MJ. Dendritic cells derived from hemozoin-loaded monocytes display a partial maturation phenotype that promotes HIV-1 trans-infection of CD4+ T cells and virus replication. THE JOURNAL OF IMMUNOLOGY 2010; 184:2899-907. [PMID: 20147629 DOI: 10.4049/jimmunol.0901513] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Coinfection of HIV-1 patients with Plasmodium falciparum, the etiological agent of malaria, results in a raise of viral load and an acceleration of disease progression. The primary objective of this study was to investigate whether the malarial pigment hemozoin (HZ), a heme by-product of hemoglobin digestion by malaria parasites, can affect HIV-1 transmission by monocytes-derived dendritic cells (DCs) to CD4(+) T cells when HZ is initially internalized in monocytes before their differentiation in DCs. We demonstrate in this study that HZ treatment during the differentiation process induces an intermediate maturation phenotype when compared with immature and fully mature DCs. Furthermore, the DC-mediated transfer of HIV-1 is enhanced in presence of HZ, a phenomenon that may be linked with the capacity of HZ-loaded cells to interact and activate CD4(+) T cells. Altogether our findings suggest a new mechanism that could partially explain the increased HIV-1 virus production during a coinfection with P. falciparum. Understanding the multifaceted interactions between P. falciparum and HIV-1 is an important challenge that could lead to the development of new treatment strategies.
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Affiliation(s)
- Juliette Diou
- Centre de Recherche en Infectiologie, Centre Hospitalier de l'Université Laval and Faculté de Médecine, Université Laval, Québec City, Québec, Canada
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Ingestion of the malaria pigment hemozoin renders human macrophages less permissive to HIV-1 infection. Virology 2009; 395:56-66. [DOI: 10.1016/j.virol.2009.09.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Revised: 07/02/2009] [Accepted: 09/05/2009] [Indexed: 11/18/2022]
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Griffith JW, Sun T, McIntosh MT, Bucala R. Pure Hemozoin is inflammatory in vivo and activates the NALP3 inflammasome via release of uric acid. THE JOURNAL OF IMMUNOLOGY 2009; 183:5208-20. [PMID: 19783673 DOI: 10.4049/jimmunol.0713552] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The role of proinflammatory cytokine production in the pathogenesis of malaria is well established, but the identification of the parasite products that initiate inflammation is not complete. Hemozoin is a crystalline metabolite of hemoglobin digestion that is released during malaria infection. In the present study, we characterized the immunostimulatory activity of pure synthetic hemozoin (sHz) in vitro and in vivo. Stimulation of naive murine macrophages with sHz results in the MyD88-independent activation of NF-kappaB and ERK, as well as the release of the chemokine MCP-1; these responses are augmented by IFN-gamma. In macrophages prestimulated with IFN-gamma, sHz also results in a MyD88-dependent release of TNF-alpha. Endothelial cells, which encounter hemozoin after schizont rupture, respond to sHz by releasing IL-6 and the chemokines MCP-1 and IL-8. In vivo, the introduction of sHz into the peritoneal cavity produces an inflammatory response characterized by neutrophil recruitment and the production of MCP-1, KC, IL-6, IL-1alpha, and IL-1beta. MCP-1 and KC are produced independently of MyD88, TLR2/4 and TLR9, and components of the inflammasome; however, neutrophil recruitment, the localized production of IL-1beta, and the increase in circulating IL-6 require MyD88 signaling, the IL-1R pathway, and the inflammasome components ICE (IL-1beta-converting enzyme), ASC (apoptosis-associated, speck-like protein containing CARD), and NALP3. Of note, inflammasome activation by sHz is reduced by allopurinol, which is an inhibitor of uric acid synthesis. These data suggest that uric acid is released during malaria infection and may serve to augment the initial host response to hemozoin via activation of the NALP3 inflammasome.
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Affiliation(s)
- Jason W Griffith
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06511, USA
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Kulkarni H, Marconi VC, He W, Landrum ML, Okulicz JF, Delmar J, Kazandjian D, Castiblanco J, Ahuja SS, Wright EJ, Weiss RA, Clark RA, Dolan MJ, Ahuja SK. The Duffy-null state is associated with a survival advantage in leukopenic HIV-infected persons of African ancestry. Blood 2009; 114:2783-92. [PMID: 19620399 PMCID: PMC2927046 DOI: 10.1182/blood-2009-04-215186] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Accepted: 05/18/2009] [Indexed: 12/22/2022] Open
Abstract
Persons of African ancestry, on average, have lower white blood cell (WBC) counts than those of European descent (ethnic leukopenia), but whether this impacts negatively on HIV-1 disease course remains unknown. Here, in a large natural history cohort of HIV-infected subjects, we show that, although leukopenia (< 4000 WBC/mm(3) during infection) was associated with an accelerated HIV disease course, this effect was more prominent in leukopenic subjects of European than African ancestry. The African-specific -46C/C genotype of Duffy Antigen Receptor for Chemokines (DARC) confers the malaria-resisting, Duffy-null phenotype, and we found that the recently described association of this genotype with ethnic leukopenia extends to HIV-infected African Americans (AAs). The association of Duffy-null status with HIV disease course differed according to WBC but not CD4(+) T-cell counts, such that leukopenic but not nonleukopenic HIV(+) AAs with DARC -46C/C had a survival advantage compared with all Duffy-positive subjects. This survival advantage became increasingly pronounced in those with progressively lower WBC counts. These data highlight that the interaction between DARC genotype and the cellular milieu defined by WBC counts may influence HIV disease course, and this may provide a partial explanation of why ethnic leukopenia remains benign in HIV-infected AAs, despite immunodeficiency.
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Affiliation(s)
- Hemant Kulkarni
- Veterans Administration Research Center for AIDS and HIV-1 Infection, South Texas Veterans Health Care System, San Antonio, USA
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18
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Apoptosis of endothelial cells in bacterial sepsis and severe Plasmodium falciparum malaria: do we know enough to consider clinical trials? Crit Care Med 2008; 36:2690-2. [PMID: 18728485 DOI: 10.1097/ccm.0b013e3181833c6f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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19
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Hänscheid T, Längin M, Lell B, Pötschke M, Oyakhirome S, Kremsner PG, Grobusch MP. Full blood count and haemozoin-containing leukocytes in children with malaria: diagnostic value and association with disease severity. Malar J 2008; 7:109. [PMID: 18549498 PMCID: PMC2435542 DOI: 10.1186/1475-2875-7-109] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Accepted: 06/12/2008] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Diligent and correct laboratory diagnosis and up-front identification of risk factors for progression to severe disease are the basis for optimal management of malaria. METHODS Febrile children presenting to the Medical Research Unit at the Albert Schweitzer Hospital (HAS) in Lambaréné, Gabon, were assessed for malaria. Giemsa-stained thick films for qualitative and quantitative diagnosis and enumeration of malaria pigment, or haemozoin (Hz)-containing leukocytes (PCL) were performed, and full blood counts (FBC) were generated with a Cell Dyn 3000 instrument. RESULTS Compared to standard light microscopy of Giemsa-stained thick films, diagnosis by platelet count only, by malaria pigment-containing monocytes (PCM) only, or by pigment-containing granulocytes (PCN) only yielded sensitivities/specificities of 92%/93%; 96%/96%; and 85%/96%, respectively. The platelet count was significantly lower in children with malaria compared to those without (p < 0.001), and values showed little overlap between groups. Compared to microscopy, scatter flow cytometry as applied in the Cell-Dyn 3000(R) instrument detected significantly more patients with PCL (p < 0.01). Both PCM and PCN numbers were higher in severe versus non-severe malaria yet reached statistical significance only for PCN (p < 0.0001; PCM: p = 0.14). Of note was the presence of another, so far ill-defined pigment-containing group of phagocytic cells, identified by laser-flow cytometry as lymphocyte-like gated events, and predominantly found in children with malaria-associated anaemia. CONCLUSION In the age group examined in the Lambaréné area, platelets are an excellent adjuvant tool to diagnose malaria. Pigment-containing leukocytes (PCL) are more readily detected by automated scatter flow cytometry than by microscopy. Automated Hz detection by an instrument as used here is a reliable diagnostic tool and correlates with disease severity. However, clinical usefulness as a prognostic tool is limited due to an overlap of PCL numbers recorded in severe versus non-severe malaria. However, this is possibly because of the instrument detection algorithm was not geared towards this task, and data lost during processing; and thus adjusting the instrument's algorithm may allow to establish a meaningful cut-off value.
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Affiliation(s)
- Thomas Hänscheid
- Medical Research Unit, Albert Schweitzer Hospital, Lambaréné, Gabon
- Institute of Molecular Medicine, Lisbon Medical College, Lisbon, Portugal
| | - Matthias Längin
- Medical Research Unit, Albert Schweitzer Hospital, Lambaréné, Gabon
- Department of Parasitology, Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Bertrand Lell
- Medical Research Unit, Albert Schweitzer Hospital, Lambaréné, Gabon
- Department of Parasitology, Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Marc Pötschke
- Medical Research Unit, Albert Schweitzer Hospital, Lambaréné, Gabon
- Department of Parasitology, Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Sunny Oyakhirome
- Medical Research Unit, Albert Schweitzer Hospital, Lambaréné, Gabon
- Department of Parasitology, Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Peter G Kremsner
- Medical Research Unit, Albert Schweitzer Hospital, Lambaréné, Gabon
- Department of Parasitology, Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Martin P Grobusch
- Medical Research Unit, Albert Schweitzer Hospital, Lambaréné, Gabon
- Infectious Diseases Unit, Infectious Diseases Unit, Division of Clinical Microbiology and Infectious Diseases, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, 7 York Road, Parktown, South Africa
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Lagan AL, Melley DD, Evans TW, Quinlan GJ. Pathogenesis of the systemic inflammatory syndrome and acute lung injury: role of iron mobilization and decompartmentalization. Am J Physiol Lung Cell Mol Physiol 2008; 294:L161-74. [DOI: 10.1152/ajplung.00169.2007] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Changes in iron homeostatic responses routinely accompany infectious or proinflammatory insults. The systemic inflammatory response syndrome (SIRS) and the development of acute lung injury (ALI) feature pronounced systemic and lung-specific alterations in iron/heme mobilization and decompartmentalization; such responses may be of pathological significance for both the onset and progression of acute inflammation. The potential for excessive iron-catalyzed oxidative stress, altered proinflammatory redox signaling, and provision of iron as a microbial growth factor represent obvious adverse aspects of altered in vivo iron handling. The release of hemoglobin during hemolytic disease or surgical procedures such as those utilizing cardiopulmonary bypass procedures further impacts on iron mobilization, turnover, and storage with associated implications. Genetic predisposition may ultimately determine the extent to which SIRS and related syndromes develop in response to such changes. The design of specific therapeutic interventions based on endogenous stratagems to limit adverse aspects of altered iron handling may prove of therapeutic benefit for the treatment of SIRS and ALI.
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Role of TLRs/MyD88 in host resistance and pathogenesis during protozoan infection: lessons from malaria. Semin Immunopathol 2007; 30:41-51. [PMID: 18071705 DOI: 10.1007/s00281-007-0103-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Accepted: 11/07/2007] [Indexed: 01/23/2023]
Abstract
Toll-like receptors (TLRs) are important to initiate the innate immune response to a wide variety of pathogens. The protective role of TLRs during infection with protozoan parasites has been established. In this regard, malaria represents an exception where activation of TLRs seems to be deleterious to the host. In this article, we review the recent findings indicating the contrasting role of Myeloid Differentiation Primary-Response gene 88 (MyD88) and TLRs during malaria and infection with other protozoa. These findings suggest that MyD88 may represent an Achilles' heel during Plasmodium infection.
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Hänscheid T, Egan TJ, Grobusch MP. Haemozoin: from melatonin pigment to drug target, diagnostic tool, and immune modulator. THE LANCET. INFECTIOUS DISEASES 2007; 7:675-85. [PMID: 17897610 DOI: 10.1016/s1473-3099(07)70238-4] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Plasmodium spp produce a pigment (haemozoin) to detoxify the free haem that is generated by haemoglobin degradation. Haemozoin was originally thought to be an inert waste byproduct of the parasite. However, recent research has led to the recognition that haemozoin is possibly of great importance in various aspects of malaria. Haemozoin is the target of many antimalarial drugs, and the unravelling of the exact modes of action may allow the design of novel antimalarial compounds. The detection of haemozoin in erythrocytes or leucocytes facilitates the diagnosis of malaria. The number of haemozoin-containing monocytes and granulocytes has been shown to correlate well with disease severity and may hold the potential for becoming a novel, automated laboratory marker in the assessment of patients. Finally, haemozoin has a substantial effect on the immune system. Further research is needed to clarify these aspects, many of which are important in clinical practice.
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Affiliation(s)
- Thomas Hänscheid
- Institute of Molecular Medicine, Lisbon Medical College, Lisbon, Portugal
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Coban C, Ishii KJ, Horii T, Akira S. Manipulation of host innate immune responses by the malaria parasite. Trends Microbiol 2007; 15:271-8. [PMID: 17466521 DOI: 10.1016/j.tim.2007.04.003] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Revised: 03/26/2007] [Accepted: 04/11/2007] [Indexed: 10/23/2022]
Abstract
It has long been known that malaria infection causes host immune modulation by various mechanisms. However, the role of Toll-like receptors (TLRs) in mediating innate immune responses to parasite-derived components during the blood stages of malaria has only recently been described. TLRs might have an important role in pathogenesis during malaria infection, as supported by genetic analyses in mice and humans. Moreover, recent findings revealed that sporozoites can partially differentiate in lymph nodes and that liver stages induce the formation of previously unknown parasite-filled vesicles (merosomes) that could function as immune escape machinery. Elucidation of the mechanisms by which the host innate immune system responds to, and/or is manipulated by, Plasmodium infection will hopefully lead to discoveries of potential targets that will ultimately prevent and/or intervene in malaria infection.
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Affiliation(s)
- Cevayir Coban
- Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, Yamadaoka 3-1, Suita City, Osaka 565-0871, Japan
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Huy NT, Maeda A, Uyen DT, Trang DTX, Sasai M, Shiono T, Oida T, Harada S, Kamei K. Alcohols induce beta-hematin formation via the dissociation of aggregated heme and reduction in interfacial tension of the solution. Acta Trop 2007; 101:130-8. [PMID: 17274939 DOI: 10.1016/j.actatropica.2007.01.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2006] [Revised: 12/01/2006] [Accepted: 01/03/2007] [Indexed: 11/27/2022]
Abstract
The formation of the malarial pigment, a unique hemozoin crystal with unit cells comprised of heme dimers, has been proposed as an ideal target for antimalarial screening. The mechanism of beta-hematin formation (a synthetic crystal structurally identical to hemozoin) has been suggested that a hydrophobic interaction is needed to solubilize heme, but this hypothesis needs further evidence. Direct study of the process of hemozoin formation in the malarial food vacuole has not been performed, due to complicated groups of lipids and proteins. To overcome this difficulty and to explore the environmental conditions for beta-hematin formation, we systematically studied beta-hematin formation induced by a series of small normal alcohols (methanol, ethanol, n-propanol, and n-butanol), which are structurally similar. For the first time, the ability of beta-hematin inducer could be evaluated by its concentration that is required to enhance heme crystallization by 50% (EC(50) values). These values provide a rapid and convenient tool for comparing the ability of initiators in beta-hematin formation. Our results showed that the ability of alcohols to induce beta-hematin formation in the order: n-butanol>n-propanol>ethanol>methanol. The induction of beta-hematin formation by alcohols is related with their degree of hydrophobicity and ability to solubilize heme, suggesting that the dissociation of aggregated heme by alcohols is a major factor in beta-hematin formation. In addition, alcohols can reduce the surface tension of a solution, thus lowering the energy barrier for creating critical nuclei.
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Affiliation(s)
- Nguyen T Huy
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; Venture Laboratory, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
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Huy NT, Uyen DT, Maeda A, Trang DTX, Oida T, Harada S, Kamei K. Simple colorimetric inhibition assay of heme crystallization for high-throughput screening of antimalarial compounds. Antimicrob Agents Chemother 2006; 51:350-3. [PMID: 17088494 PMCID: PMC1797674 DOI: 10.1128/aac.00985-06] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Current assays for screening new antimalarials need initiators of beta-hematin formation that require laborious preparation, special devices, and substrates. In this study, based on reduction of heme absorption in beta-hematin formation, we developed a simple colorimetric assay using Tween 20 as an initiator and a microplate reader for high-throughput screening of inhibitors of beta-hematin formation.
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Affiliation(s)
- Nguyen Tien Huy
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
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