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Huang B, Liu M, Huang S, Wu B, Guo H, Su XZ, Lu F. Expression of Tim-1 and Tim-3 in Plasmodium berghei ANKA infection. Parasitol Res 2013; 112:2713-9. [PMID: 23653017 DOI: 10.1007/s00436-013-3442-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 04/25/2013] [Indexed: 11/30/2022]
Abstract
Cerebral malaria (CM) is a serious and often fatal complication of Plasmodium falciparum infections; however, the precise mechanisms leading to CM is poorly understood. Mouse malaria models have provided insight into the key events in pathogenesis of CM. T-cell immune response is known to play an important role in malaria infection, and members of the T-cell immunoglobulin- and mucin-domain-containing molecule (Tim) family have roles in T-cell-mediated immune responses. Tim-1 and Tim-3 are expressed on terminally differentiated Th2 and Th1 cells, respectively, and participate in the regulation of Th immune response. Until now, the role of Tim family proteins in Plasmodium infection remains unclear. In the present study, the mRNA levels of Tim-1, Tim-3, and some key Th1 and Th2 cytokines in the spleen of Kunming outbred mice infected with Plasmodium berghei ANKA (PbANKA) were determined using real-time polymerase chain reaction (qRT-PCR). Compared with uninfected controls, Tim-1 expression was significantly decreased in infected mice with CM at day 10 postinfection (p.i.) but significantly increased in infected mice with non-CM at day 22 p.i.; in contrast, Tim-3 expression was significantly increased in infected mice both with CM at day 10 p.i. and with non-CM at day 22 p.i. The expressions of IFN-γ, TNF-α, IL-10, and IL-12 were significantly increased but IL-4 was significantly decreased in infected mice with CM at days 10 p.i., whereas the expressions of IFN-γ, TNF-α, IL-4, IL-10, and TGF-β were significantly increased but IL-12 was significantly decreased in infected mice with non-CM at days 22 p.i. Furthermore, the expression of Tim-1 and Tim-3 could reflect Th2 and Th1 immune response in the spleen of PbANKA-infected mice, respectively. Our data suggest that PbANKA infection could inhibit the differentiation of T lymphocytes toward Th2 cells, promote the Th1 cell differentiation, and induce Th1-biased immune response in the early infective stage, whereas the infection could promote Th2 cell differentiation and induce Th2-biased immune response in the late infective stage. Our data indicate that both Tim-1 and Tim-3 may play a role in the process of PbANKA infection, which may represent a potential therapeutic target.
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Affiliation(s)
- Bo Huang
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong Province 510080, China
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Lipoxin A₄ and 15-epi-lipoxin A₄ protect against experimental cerebral malaria by inhibiting IL-12/IFN-γ in the brain. PLoS One 2013; 8:e61882. [PMID: 23613965 PMCID: PMC3628580 DOI: 10.1371/journal.pone.0061882] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 03/17/2013] [Indexed: 12/12/2022] Open
Abstract
Cerebral malaria is caused by infection with Plasmodium falciparum and can lead to severe neurological manifestations and predominantly affects sub-Saharan African children. The pathogenesis of this disease involves unbalanced over-production of pro-inflammatory cytokines. It is clear that signaling though IL-12 receptor is a critical step for development of cerebral malaria, IL-12 genetic deficiency failed to show the same effect, suggesting that there is redundancy among the soluble mediators which leads to immunopathology and death. Consequently, counter-regulatory mediators might protect the host during cerebral malaria. We have previously showed that endogenously produced lipoxins, which are anti-inflammatory mediators generated by 5-lipoxygenase (5-LO)-dependent metabolism of arachidonic acid, limit host damage in a model of mouse toxoplasmosis. We postulated here that lipoxins might also play a counter-regulatory role during cerebral malaria. To test this hypothesis, we infected 5-LO-deficient hosts with P. berghei ANKA strain, which induces a mouse model of cerebral malaria (ECM). Our results show accelerated mortality concomitant with exuberant IL-12 and IFN-γ production in the absence of 5-lipoxygenase. Moreover, in vivo administration of lipoxin to 5-LO-deficient hosts prevented early mortality and reduced the accumulation of CD8+IFN-γ+ cells in the brain. Surprisingly, WT animals treated with lipoxin either at the time of infection or 3 days post-inoculum also showed prolonged survival and diminished brain inflammation, indicating that although protective, endogenous lipoxin production is not sufficient to optimally protect the host from brain damage in cerebral malaria. These observations establish 5-LO/LXA4 as a host protective pathway and suggest a new therapeutic approach against human cerebral malaria (HCM). (255 words).
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Wilson NO, Solomon W, Anderson L, Patrickson J, Pitts S, Bond V, Liu M, Stiles JK. Pharmacologic inhibition of CXCL10 in combination with anti-malarial therapy eliminates mortality associated with murine model of cerebral malaria. PLoS One 2013; 8:e60898. [PMID: 23630573 PMCID: PMC3618178 DOI: 10.1371/journal.pone.0060898] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 03/04/2013] [Indexed: 02/05/2023] Open
Abstract
Despite appropriate anti-malarial treatment, cerebral malaria (CM)-associated mortalities remain as high as 30%. Thus, adjunctive therapies are urgently needed to prevent or reduce such mortalities. Overproduction of CXCL10 in a subset of CM patients has been shown to be tightly associated with fatal human CM. Mice with deleted CXCL10 gene are partially protected against experimental cerebral malaria (ECM) mortality indicating the importance of CXCL10 in the pathogenesis of CM. However, the direct effect of increased CXCL10 production on brain cells is unknown. We assessed apoptotic effects of CXCL10 on human brain microvascular endothelial cells (HBVECs) and neuroglia cells in vitro. We tested the hypothesis that reducing overexpression of CXCL10 with a synthetic drug during CM pathogenesis will increase survival and reduce mortality. We utilized atorvastatin, a widely used synthetic blood cholesterol-lowering drug that specifically targets and reduces plasma CXCL10 levels in humans, to determine the effects of atorvastatin and artemether combination therapy on murine ECM outcome. We assessed effects of atorvastatin treatment on immune determinants of severity, survival, and parasitemia in ECM mice receiving a combination therapy from onset of ECM (day 6 through 9 post-infection) and compared results with controls. The results indicate that CXCL10 induces apoptosis in HBVECs and neuroglia cells in a dose-dependent manner suggesting that increased levels of CXCL10 in CM patients may play a role in vasculopathy, neuropathogenesis, and brain injury during CM pathogenesis. Treatment of ECM in mice with atorvastatin significantly reduced systemic and brain inflammation by reducing the levels of the anti-angiogenic and apoptotic factor (CXCL10) and increasing angiogenic factor (VEGF) production. Treatment with a combination of atorvastatin and artemether improved survival (100%) when compared with artemether monotherapy (70%), p<0.05. Thus, adjunctively reducing CXCL10 levels and inflammation by atorvastatin treatment during anti-malarial therapy may represent a novel approach to treating CM patients.
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Affiliation(s)
- Nana O. Wilson
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - Wesley Solomon
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - Leonard Anderson
- Cardiovascular Research Institute, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - John Patrickson
- Department of Pathology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - Sidney Pitts
- Department of Pathology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - Vincent Bond
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - Mingli Liu
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - Jonathan K. Stiles
- Department of Microbiology, Biochemistry, and Immunology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
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Crandall IE, Wasilewski E, Bello AM, Mohmmed A, Malhotra P, Pai EF, Kain KC, Kotra LP. Antimalarial Activities of 6-Iodouridine and Its Prodrugs and Potential for Combination Therapy. J Med Chem 2013; 56:2348-58. [DOI: 10.1021/jm301678j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ian E. Crandall
- Department of Pharmaceutical
Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, M5S 3M2, Canada
| | - Ewa Wasilewski
- Center for Molecular Design
and Preformulations, Toronto General Research Institute, University Health Network, 5-356 TMDT/MaRS, 101 College
Street, Toronto, Ontario, M5G 1L7, Canada
| | - Angelica M. Bello
- Department of Pharmaceutical
Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, M5S 3M2, Canada
- Center for Molecular Design
and Preformulations, Toronto General Research Institute, University Health Network, 5-356 TMDT/MaRS, 101 College
Street, Toronto, Ontario, M5G 1L7, Canada
| | - Asif Mohmmed
- International Center for Genetic Engineering and Biotechnology, Aruna Asaf
Ali Marg, New Delhi 110 067, India
| | - Pawan Malhotra
- International Center for Genetic Engineering and Biotechnology, Aruna Asaf
Ali Marg, New Delhi 110 067, India
| | - Emil F. Pai
- Ontario Cancer Institute, Campbell Family Cancer Research Institute, Toronto
Medical Discoveries Tower, 101 College Street, Toronto, Ontario, M5G
1L7, Canada
- Departments
of Medical Biophysics,
Biochemistry, and Molecular Genetics, University of Toronto, 1 King’s College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Kevin C. Kain
- McLaughlin Center for Molecular Medicine
and Department of Medicine, University of Toronto, Toronto, Ontario, Canada
- McLaughlin-Rotman Center for Global Health, Toronto General and Western Hospital Foundation, Toronto Medical Discoveries Tower, 101 College Street, Toronto,
Ontario, M5G 1L7, Canada
| | - Lakshmi P. Kotra
- Department of Pharmaceutical
Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, M5S 3M2, Canada
- Center for Molecular Design
and Preformulations, Toronto General Research Institute, University Health Network, 5-356 TMDT/MaRS, 101 College
Street, Toronto, Ontario, M5G 1L7, Canada
- McLaughlin Center for Molecular Medicine
and Department of Medicine, University of Toronto, Toronto, Ontario, Canada
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Miller LH, Ackerman HC, Su XZ, Wellems TE. Malaria biology and disease pathogenesis: insights for new treatments. Nat Med 2013; 19:156-67. [PMID: 23389616 DOI: 10.1038/nm.3073] [Citation(s) in RCA: 380] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 12/17/2012] [Indexed: 12/12/2022]
Abstract
Plasmodium falciparum malaria, an infectious disease caused by a parasitic protozoan, claims the lives of nearly a million children each year in Africa alone and is a top public health concern. Evidence is accumulating that resistance to artemisinin derivatives, the frontline therapy for the asexual blood stage of the infection, is developing in southeast Asia. Renewed initiatives to eliminate malaria will benefit from an expanded repertoire of antimalarials, including new drugs that kill circulating P. falciparum gametocytes, thereby preventing transmission. Our current understanding of the biology of asexual blood-stage parasites and gametocytes and the ability to culture them in vitro lends optimism that high-throughput screenings of large chemical libraries will produce a new generation of antimalarial drugs. There is also a need for new therapies to reduce the high mortality of severe malaria. An understanding of the pathophysiology of severe disease may identify rational targets for drugs that improve survival.
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Affiliation(s)
- Louis H Miller
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Rockville, Maryland, USA.
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Postels DG, Chimalizeni YF, Mallewa M, Boivin MJ, Seydel KB. Pediatric cerebral malaria: a scourge of Africa. FUTURE NEUROLOGY 2013. [DOI: 10.2217/fnl.12.84] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cerebral malaria, defined as an otherwise unexplained coma in a patient with Plasmodium falciparum parasitemia, affects up to 1 million people per year, the vast majority of them being children living in sub-Saharan Africa. Despite optimal treatment, this condition kills 15% of those affected and leaves 30% of survivors with neurologic sequelae. The clinical diagnosis is hampered by its poor specificity, but the presence or absence of a malarial retinopathy in cerebral malaria has proven to be important in the differentiation of underlying coma etiology. Both antimalarials and intense supportive care are necessary for optimal treatment. As of yet, clinical trials of adjunctive therapies have not improved the high rates of mortality and morbidity. Survivors are at high risk of neurologic sequelae including epilepsy, neurodisabilities and cognitive–behavioral problems. The neuroanatomic and functional bases of these sequelae are being elucidated. Although adjunctive therapy trials continue, the best hope for African children may lie in disease prevention. Strategies include bednets, chemoprophylaxis and vaccine development.
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Affiliation(s)
| | - Yamikani F Chimalizeni
- Department of Pediatrics, University of Malawi College of Medicine, Private Bag 360, Blantyre 3, Malawi
| | - Macpherson Mallewa
- Department of Pediatrics, University of Malawi College of Medicine, Private Bag 360, Blantyre 3, Malawi
| | | | - Karl B Seydel
- Michigan State University, East Lansing, MI 48824, USA
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Percário S, Moreira DR, Gomes BAQ, Ferreira MES, Gonçalves ACM, Laurindo PSOC, Vilhena TC, Dolabela MF, Green MD. Oxidative stress in malaria. Int J Mol Sci 2012; 13:16346-72. [PMID: 23208374 PMCID: PMC3546694 DOI: 10.3390/ijms131216346] [Citation(s) in RCA: 184] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 11/08/2012] [Accepted: 11/23/2012] [Indexed: 12/16/2022] Open
Abstract
Malaria is a significant public health problem in more than 100 countries and causes an estimated 200 million new infections every year. Despite the significant effort to eradicate this dangerous disease, lack of complete knowledge of its physiopathology compromises the success in this enterprise. In this paper we review oxidative stress mechanisms involved in the disease and discuss the potential benefits of antioxidant supplementation as an adjuvant antimalarial strategy.
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Affiliation(s)
- Sandro Percário
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Para (LAPEO/ICB/UFPA) Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mails: (D.R.M.); (B.A.Q.G.); (M.E.S.F.); (A.C.M.G.); (P.S.O.C.L.); (T.C.V.)
| | - Danilo R. Moreira
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Para (LAPEO/ICB/UFPA) Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mails: (D.R.M.); (B.A.Q.G.); (M.E.S.F.); (A.C.M.G.); (P.S.O.C.L.); (T.C.V.)
| | - Bruno A. Q. Gomes
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Para (LAPEO/ICB/UFPA) Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mails: (D.R.M.); (B.A.Q.G.); (M.E.S.F.); (A.C.M.G.); (P.S.O.C.L.); (T.C.V.)
| | - Michelli E. S. Ferreira
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Para (LAPEO/ICB/UFPA) Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mails: (D.R.M.); (B.A.Q.G.); (M.E.S.F.); (A.C.M.G.); (P.S.O.C.L.); (T.C.V.)
| | - Ana Carolina M. Gonçalves
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Para (LAPEO/ICB/UFPA) Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mails: (D.R.M.); (B.A.Q.G.); (M.E.S.F.); (A.C.M.G.); (P.S.O.C.L.); (T.C.V.)
| | - Paula S. O. C. Laurindo
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Para (LAPEO/ICB/UFPA) Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mails: (D.R.M.); (B.A.Q.G.); (M.E.S.F.); (A.C.M.G.); (P.S.O.C.L.); (T.C.V.)
| | - Thyago C. Vilhena
- Oxidative Stress Research Laboratory, Institute of Biological Sciences, Federal University of Para (LAPEO/ICB/UFPA) Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mails: (D.R.M.); (B.A.Q.G.); (M.E.S.F.); (A.C.M.G.); (P.S.O.C.L.); (T.C.V.)
| | - Maria F. Dolabela
- Pharmacy Faculty, Institute of Health Sciences, Federal University of Para. Av. Augusto Correa, 1, Guama, Belem, Para 66075-110, Brazil; E-Mail:
| | - Michael D. Green
- US Centers for Disease Control and Prevention, 1600 Clifton Road NE, mailstop G49, Atlanta, GA 30329, USA; E-Mail:
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Inhaled nitric oxide and cerebral malaria: basis of a strategy for buying time for pharmacotherapy. Pediatr Infect Dis J 2012; 31:e250-4. [PMID: 22760538 DOI: 10.1097/inf.0b013e318266c113] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
There are approximately 225-600 million new malaria infections worldwide annually, with severe and cerebral malaria representing major causes of death internationally. The role of nitric oxide (NO) in the host response in cerebral malaria continues to be elucidated, with numerous known functions relating to the cytokine, endovascular and cellular responses to infection with Plasmodium falciparum. Evidence from diverse modes of inquiry suggests NO to be critical in modulating the immune response and promoting survival in patients with cerebral malaria. This line of investigation has culminated in the approval of 2 phase II randomized prospective clinical trials in Uganda studying the use of inhaled NO as adjuvant therapy in children with severe malaria. The strategy underlying both trials is to use the sytemic antiinflammatory properties of inhaled NO to "buy time" for chemical antiparasite therapy to lower the parasite load. This article reviews the nexus of malaria and NO biology with a primary focus on cerebral malaria in humans.
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Monocytes and macrophages in malaria: protection or pathology? Trends Parasitol 2012; 29:26-34. [PMID: 23142189 DOI: 10.1016/j.pt.2012.10.002] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 10/12/2012] [Accepted: 10/16/2012] [Indexed: 02/07/2023]
Abstract
Recruitment and activation of monocytes and macrophages are essential for clearance of malaria infection, but these have also been associated with adverse clinical outcomes. In this review we discuss recent discoveries on how distinct molecular interactions between monocytes, macrophages, and malaria parasites may alter the balance between protection and pathology in malaria-infected individuals. The immunopathology of severe malaria often originates from excessive immune activation by parasites. The involvement of monocytes and macrophages in these events is highlighted, and priorities for future research to clarify the roles of these cells in malaria are proposed. Knowledge of the factors influencing the balance between protection and pathology can assist in the design of therapeutics aimed at modulating monocyte and macrophage functions to improve outcomes.
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