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Tembo DL, Nyoni B, Murikoli RV, Mukaka M, Milner DA, Berriman M, Rogerson SJ, Taylor TE, Molyneux ME, Mandala WL, Craig AG, Montgomery J. Differential PfEMP1 expression is associated with cerebral malaria pathology. PLoS Pathog 2014; 10:e1004537. [PMID: 25473835 PMCID: PMC4256257 DOI: 10.1371/journal.ppat.1004537] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 10/23/2014] [Indexed: 11/23/2022] Open
Abstract
Plasmodium falciparum is unique among human malarias in its ability to sequester in post-capillary venules of host organs. The main variant antigens implicated are the P. falciparum erythrocyte membrane protein 1 (PfEMP1), which can be divided into three major groups (A–C). Our study was a unique examination of sequestered populations of parasites for genetic background and expression of PfEMP1 groups. We collected post-mortem tissue from twenty paediatric hosts with pathologically different forms of cerebral malaria (CM1 and CM2) and parasitaemic controls (PC) to directly examine sequestered populations of parasites in the brain, heart and gut. Use of two different techniques to investigate this question produced divergent results. By quantitative PCR, group A var genes were upregulated in all three organs of CM2 and PC cases. In contrast, in CM1 infections displaying high levels of sequestration but negligible vascular pathology, there was high expression of group B var. Cloning and sequencing of var transcript tags from the same samples indicated a uniformly low expression of group A-like var. Generally, within an organ sample, 1–2 sequences were expressed at dominant levels. 23% of var tags were detected in multiple patients despite the P. falciparum infections being genetically distinct, and two tags were observed in up to seven hosts each with high expression in the brains of 3–4 patients. This study is a novel examination of the sequestered parasites responsible for fatal cerebral malaria and describes expression patterns of the major cytoadherence ligand in three organ-derived populations and three pathological states. One of the most severe forms of malarial disease is cerebral malaria, which disproportionally affects young children. In this disease, the parasite places proteins on the red blood cell surface, providing a “smokescreen” by which they evade host immunity and hide in organ blood vessels, blocking them and causing tissue damage. It is impossible to study parasites in the organs during life and autopsy studies on children with malaria are exceedingly rare. In Malawi, we examined parasites from the brain, heart and intestine of twenty cases of fatal malaria including controls with low numbers of malaria parasites but another identified cause of death. We found little difference in the category of proteins the parasites used in controls and cerebral malaria, although a small number of specific proteins were detected in multiple infections. In an alternative form of malaria in which the brain is heavily infected but shows no evidence of damage, we found a different set of proteins at high proportion. However, as these children were typically older and most were infected with HIV, we could not determine which of these factors was most important. Interactions between host and parasite have the potential to influence disease outcomes.
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Guiguemde WA, Hunt NH, Guo J, Marciano A, Haynes RK, Clark J, Guy RK, Golenser J. Treatment of murine cerebral malaria by artemisone in combination with conventional antimalarial drugs: antiplasmodial effects and immune responses. Antimicrob Agents Chemother 2014; 58:4745-54. [PMID: 24913162 PMCID: PMC4135990 DOI: 10.1128/aac.01553-13] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 05/27/2014] [Indexed: 01/10/2023] Open
Abstract
The decreasing effectiveness of antimalarial therapy due to drug resistance necessitates constant efforts to develop new drugs. Artemisinin derivatives are the most recent drugs that have been introduced and are considered the first line of treatment, but there are already indications of Plasmodium falciparum resistance to artemisinins. Consequently, drug combinations are recommended for prevention of the induction of resistance. The research here demonstrates the effects of novel combinations of the new artemisinin derivative, artemisone, a recently described 10-alkylamino artemisinin derivative with improved antimalarial activity and reduced neurotoxicity. We here investigate its ability to kill P. falciparum in a high-throughput in vitro assay and to protect mice against lethal cerebral malaria caused by Plasmodium berghei ANKA when used alone or in combination with established antimalarial drugs. Artemisone effects against P. falciparum in vitro were synergistic with halofantrine and mefloquine, and additive with 25 other drugs, including chloroquine and doxycycline. The concentrations of artemisone combinations that were toxic against THP-1 cells in vitro were much higher than their effective antimalarial concentration. Artemisone, mefloquine, chloroquine, or piperaquine given individually mostly protected mice against cerebral malaria caused by P. berghei ANKA but did not prevent parasite recrudescence. Combinations of artemisone with any of the other three drugs did completely cure most mice of malaria. The combination of artemisone and chloroquine decreased the ratio of proinflammatory (gamma interferon, tumor necrosis factor) to anti-inflammatory (interleukin 10 [IL-10], IL-4) cytokines in the plasma of P. berghei-infected mice. Thus, artemisone in combinations with other antimalarial drugs might have a dual action, both killing parasites and limiting the potentially deleterious host inflammatory response.
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Ampawong S, Chaisri U, Viriyavejakul P, Nontprasert A, Grau GE, Pongponratn E. Electron microscopic features of brain edema in rodent cerebral malaria in relation to glial fibrillary acidic protein expression. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2014; 7:2056-2067. [PMID: 24966914 PMCID: PMC4069908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 04/04/2014] [Indexed: 06/03/2023]
Abstract
The mechanisms leading to cerebral malaria (CM) are not completely understood. Brain edema has been suggested as having an important role in experimental CM. In this study, CBA/CaH mice were infected with Plasmodium berghei ANKA blood-stage and when typical symptoms of CM developed on day 7, brain tissues were processed for electron-microscopic and immunohistochemical studies. The study demonstrated ultrastructural hallmarks of cerebral edema by perivascular edema and astroglial dilatation confirming existing evidence of vasogenic and cytogenic edema. This correlates closely with the clinical features of CM. An adaptive response of astrocytic activity, represented by increasing glial fibrillary acidic protein (GFAP) expression in the perivascular area and increasing numbers of large astrocyte clusters were predominately found in the CM mice. The presence of multivesicular and lamellar bodies indicates the severity of cerebral damage in experimental CM. Congestion of the microvessels with occluded white blood cells (WBCs), parasitized red blood cells (PRBCs) and platelets is also a crucial covariate role for CM pathogenesis.
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Hansen DS, Ryg-Cornejo V, Ioannidis LJ, Chiu CY, Ly A, Nie CQ, Scalzo AA, Schofield L. The contribution of natural killer complex loci to the development of experimental cerebral malaria. PLoS One 2014; 9:e93268. [PMID: 24691125 PMCID: PMC3972225 DOI: 10.1371/journal.pone.0093268] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Accepted: 03/01/2014] [Indexed: 11/27/2022] Open
Abstract
Background The Natural Killer Complex (NKC) is a genetic region of highly linked genes encoding several receptors involved in the control of NK cell function. The NKC is highly polymorphic and allelic variability of various NKC loci has been demonstrated in inbred mice, providing evidence for NKC haplotypes. Using BALB.B6-Cmv1r congenic mice, in which NKC genes from C57BL/6 mice were introduced into the BALB/c background, we have previously shown that the NKC is a genetic determinant of malarial pathogenesis. C57BL/6 alleles are associated with increased disease-susceptibility as BALB.B6-Cmv1r congenic mice had increased cerebral pathology and death rates during P. berghei ANKA infection than cerebral malaria-resistant BALB/c controls. Methods To investigate which regions of the NKC are involved in susceptibility to experimental cerebral malaria (ECM), intra-NKC congenic mice generated by backcrossing recombinant F2 progeny from a (BALB/c x BALB.B6-Cmv1r) F1 intercross to BALB/c mice were infected with P. berghei ANKA. Results Our results revealed that C57BL/6 alleles at two locations in the NKC contribute to the development of ECM. The increased severity to severe disease in intra-NKC congenic mice was not associated with higher parasite burdens but correlated with a significantly enhanced systemic IFN-γ response to infection and an increased recruitment of CD8+ T cells to the brain of infected animals. Conclusions Polymorphisms within the NKC modulate malarial pathogenesis and acquired immune responses to infection.
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Milner D, Factor R, Whitten R, Carr RA, Kamiza S, Pinkus G, Molyneux M, Taylor T. Pulmonary pathology in pediatric cerebral malaria. Hum Pathol 2013; 44:2719-26. [PMID: 24074535 DOI: 10.1016/j.humpath.2013.07.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Revised: 07/09/2013] [Accepted: 07/10/2013] [Indexed: 11/18/2022]
Abstract
Respiratory signs are common in African children where malaria is highly endemic, and thus, parsing the role of pulmonary pathology in illness is challenging. We examined the lungs of 100 children from an autopsy series in Blantyre, Malawi, many of whom death was attributed to Plasmodium falciparum malaria. Our aim was to describe the pathologic manifestations of fatal malaria; to understand the role of parasites, pigment, and macrophages; and to catalog comorbidities. From available patients, which included 55 patients with cerebral malaria and 45 controls, we obtained 4 cores of lung tissue for immunohistochemistry and morphological evaluation. We found that, in patients with cerebral malaria, large numbers of malaria parasites were present in pulmonary alveolar capillaries, together with extensive deposits of malaria pigment (hemozoin). The number of pulmonary macrophages in this vascular bed did not differ between patients with cerebral malaria, noncerebral malaria, and nonmalarial diagnoses. Comorbidities found in some cerebral malaria patients included pneumonia, pulmonary edema, hemorrhage, and systemic activation of coagulation. We conclude that the respiratory distress seen in patients with cerebral malaria does not appear to be anatomic in origin but that increasing malaria pigment is strongly associated with cerebral malaria at autopsy.
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Waknine-Grinberg JH, Even-Chen S, Avichzer J, Turjeman K, Bentura-Marciano A, Haynes RK, Weiss L, Allon N, Ovadia H, Golenser J, Barenholz Y. Glucocorticosteroids in nano-sterically stabilized liposomes are efficacious for elimination of the acute symptoms of experimental cerebral malaria. PLoS One 2013; 8:e72722. [PMID: 23991146 PMCID: PMC3753236 DOI: 10.1371/journal.pone.0072722] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 07/12/2013] [Indexed: 01/07/2023] Open
Abstract
Cerebral malaria is the most severe complication of Plasmodium falciparum infection, and a leading cause of death in children under the age of five in malaria-endemic areas. We report high therapeutic efficacy of a novel formulation of liposome-encapsulated water-soluble glucocorticoid prodrugs, and in particular β-methasone hemisuccinate (BMS), for treatment of experimental cerebral malaria (ECM), using the murine P. berghei ANKA model. BMS is a novel derivative of the potent steroid β-methasone, and was specially synthesized to enable remote loading into nano-sterically stabilized liposomes (nSSL), to form nSSL-BMS. The novel nano-drug, composed of nSSL remote loaded with BMS, dramatically improves drug efficacy and abolishes the high toxicity seen upon administration of free BMS. nSSL-BMS reduces ECM rates in a dose-dependent manner and creates a survival time-window, enabling administration of an antiplasmodial drug, such as artemisone. Administration of artemisone after treatment with the nSSL-BMS results in complete cure. Treatment with BMS leads to lower levels of cerebral inflammation, demonstrated by changes in cytokines, chemokines, and cell markers, as well as diminished hemorrhage and edema, correlating with reduced clinical score. Administration of the liposomal formulation results in accumulation of BMS in the brains of sick mice but not of healthy mice. This steroidal nano-drug effectively eliminates the adverse effects of the cerebral syndrome even when the treatment is started at late stages of disease, in which disruption of the blood-brain barrier has occurred and mice show clear signs of neurological impairment. Overall, sequential treatment with nSSL-BMS and artemisone may be an efficacious and well-tolerated therapy for prevention of CM, elimination of parasites, and prevention of long-term cognitive damage.
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57
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Bertin GI, Lavstsen T, Guillonneau F, Doritchamou J, Wang CW, Jespersen JS, Ezimegnon S, Fievet N, Alao MJ, Lalya F, Massougbodji A, Ndam NT, Theander TG, Deloron P. Expression of the domain cassette 8 Plasmodium falciparum erythrocyte membrane protein 1 is associated with cerebral malaria in Benin. PLoS One 2013; 8:e68368. [PMID: 23922654 PMCID: PMC3726661 DOI: 10.1371/journal.pone.0068368] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 05/29/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP-1) is a highly polymorphic adherence receptor expressed on the surface of infected erythrocytes. Based on sequence homology PfEMP-1 variants have been grouped into three major groups A-C, the highly conserved VAR2CSA variants, and semi-conserved types defined by tandem runs of specific domains ("domain cassettes" (DC)). The PfEMP-1 type expressed determines the adherence phenotype, and is associated with clinical outcome of infection. METHODS Parasite isolates from Beninese children or women presenting with, respectively, CM or PAM were collected along with samples from patients with uncomplicated malaria (UM). We assessed the transcript level of var genes by RT-qPCR and the expression of PfEMP-1 proteins by LC-MS/MS. RESULTS Var genes encoding DC8 and Group A PfEMP-1 were transcribed more often and at higher levels in cerebral malaria vs. uncomplicated malaria patients. LC-MS/MS identified peptides from group A, DC8 PfEMP-1 more frequently in cerebral malaria than in uncomplicated malaria and pregnancy-associated malaria samples. CONCLUSION This is the first study to show association between PfEMP-1 subtype and disease outcome by direct analysis of parasites proteome. The results corroborate that group A and specifically the PfEMP-1 types DC8 are universally associated with cerebral malaria. This is a crucial observation for promoting studies on malaria pathogenesis.
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MESH Headings
- Adolescent
- Adult
- Benin
- Child
- Child, Preschool
- Chromatography, Liquid
- Female
- Gene Expression Regulation
- Genes, Protozoan
- Humans
- Malaria, Cerebral/genetics
- Malaria, Cerebral/parasitology
- Mass Spectrometry
- Plasmodium falciparum/genetics
- Plasmodium falciparum/physiology
- Pregnancy
- Pregnancy Complications, Parasitic/genetics
- Pregnancy Complications, Parasitic/parasitology
- Protein Structure, Tertiary
- Proteomics
- Protozoan Proteins/chemistry
- Protozoan Proteins/genetics
- Protozoan Proteins/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
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Khaw LT, Ball HJ, Golenser J, Combes V, Grau GE, Wheway J, Mitchell AJ, Hunt NH. Endothelial cells potentiate interferon-γ production in a novel tripartite culture model of human cerebral malaria. PLoS One 2013; 8:e69521. [PMID: 23874969 PMCID: PMC3709908 DOI: 10.1371/journal.pone.0069521] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 06/12/2013] [Indexed: 01/13/2023] Open
Abstract
We have established a novel in vitro co-culture system of human brain endothelial cells (HBEC), Plasmodium falciparum parasitised red blood cells (iRBC) and peripheral blood mononuclear cells (PBMC), in order to simulate the chief pathophysiological lesion in cerebral malaria (CM). This approach has revealed a previously unsuspected pro-inflammatory role of the endothelial cell through potentiating the production of interferon (IFN)-γ by PBMC and concurrent reduction of interleukin (IL)-10. The IFN-γ increased the expression of CXCL10 and intercellular adhesion molecule (ICAM)-1, both of which have been shown to be crucial in the pathogenesis of CM. There was a shift in the ratio of IL-10:IFN-γ protein from >1 to <1 in the presence of HBEC, associated with the pro-inflammatory process in this model. For this to occur, a direct contact between PBMC and HBEC, but not PBMC and iRBC, was necessary. These results support HBEC playing an active role in the pathogenesis of CM. Thus, if these findings reflect the pathogenesis of CM, inhibition of HBEC and PBMC interactions might reduce the occurrence, or improve the prognosis, of the condition.
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Berghout J, Langlais D, Radovanovic I, Tam M, MacMicking JD, Stevenson MM, Gros P. Irf8-regulated genomic responses drive pathological inflammation during cerebral malaria. PLoS Pathog 2013; 9:e1003491. [PMID: 23853600 PMCID: PMC3708918 DOI: 10.1371/journal.ppat.1003491] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 05/28/2013] [Indexed: 02/07/2023] Open
Abstract
Interferon Regulatory Factor 8 (IRF8) is required for development, maturation and expression of anti-microbial defenses of myeloid cells. BXH2 mice harbor a severely hypomorphic allele at Irf8 (Irf8R294C) that causes susceptibility to infection with intracellular pathogens including Mycobacterium tuberculosis. We report that BXH2 are completely resistant to the development of cerebral malaria (ECM) following Plasmodium berghei ANKA infection. Comparative transcriptional profiling of brain RNA as well as chromatin immunoprecipitation and high-throughput sequencing (ChIP-seq) was used to identify IRF8-regulated genes whose expression is associated with pathological acute neuroinflammation. Genes increased by infection were strongly enriched for IRF8 binding sites, suggesting that IRF8 acts as a transcriptional activator in inflammatory programs. These lists were enriched for myeloid-specific pathways, including interferon responses, antigen presentation and Th1 polarizing cytokines. We show that inactivation of several of these downstream target genes (including the Irf8 transcription partner Irf1) confers protection against ECM. ECM-resistance in Irf8 and Irf1 mutants is associated with impaired myeloid and lymphoid cells function, including production of IL12p40 and IFNγ. We note strong overlap between genes bound and regulated by IRF8 during ECM and genes regulated in the lungs of M. tuberculosis infected mice. This IRF8-dependent network contains several genes recently identified as risk factors in acute and chronic human inflammatory conditions. We report a common core of IRF8-bound genes forming a critical inflammatory host-response network. Cerebral malaria is a severe and often lethal complication from infection with Plasmodium falciparum which is driven in part by pathological host inflammatory response to parasitized red cells′ adherence in the brain microvasculature. However, the pathways that initiate and amplify this pathological neuroinflammation are not well understood. As susceptibility to cerebral malaria is variable and has been shown to be partially heritable, we have studied this from a genetic perspective using a mouse model of infection with P. berghei which induces experimental cerebral malaria (ECM). Here we show that mice bearing mutations in the myeloid transcription factor IRF8 and its heterodimerization partner IRF1 are completely resistant to ECM. We have identified the genes and associated networks that are activated by IRF8 during ECM. Loss-of-function mutations of several IRF8 targets are also shown to be protective. Parallel analysis of lungs infected with Mycobacterium tuberculosis show that IRF8-associated core pathways are also engaged during tuberculosis where they play a protective role. This contrast illustrates the balancing act required by the immune system to respond to pathogens and highlights a lynchpin role for IRF8 in both. Finally, several genes in these networks have been individually associated with chronic or acute inflammatory conditions in humans.
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60
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Desmond NA, Nyirenda D, Dube Q, Mallewa M, Molyneux E, Lalloo DG, Heyderman RS. Recognising and treatment seeking for acute bacterial meningitis in adults and children in resource-poor settings: a qualitative study. PLoS One 2013; 8:e68163. [PMID: 23861864 PMCID: PMC3701660 DOI: 10.1371/journal.pone.0068163] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 05/28/2013] [Indexed: 11/26/2022] Open
Abstract
Objective High mortality burden from Acute Bacterial Meningitis (ABM) in resource-poor settings has been frequently blamed on delays in treatment seeking. We explored treatment-seeking pathways from household to primary health care and referral for ABM in Malawi. Design A cross-sectional qualitative study using narrative in-depth interviews, semi-structured interviews and focus group discussions. Participants Adults and children with proven and probable acute bacterial meningitis and/or their carers; adults from urban and peri-urban communities; and primary health care workers (HCW). Setting Queen Elizabeth Central Hospital (QECH), urban and peri-urban private and government primary health centres and communities in Blantyre District, Malawi. Results Whilst communities associated meningitis with a stiff neck, in practice responses focused on ability to recognise severe illness. Misdiagnosis of meningitis as malaria was common. Subsequent action by families depended on the extent to which normal social life was disrupted by the illness and depended on the age and social position of the sufferer. Seizures and convulsions were considered severe symptoms but were often thought to be malaria. Presumptive malaria treatment at home often delayed formal treatment seeking. Further delays in treatment seeking were caused by economic barriers and perceptions of inefficient or inadequate primary health services. Conclusions Given the difficulties in diagnosis of meningitis where malaria is common, any intervention for ABM at primary level must focus on recognising severe illness, and encouraging action at the household, community and primary health levels. Overcoming barriers to recognition and social constraints at community level require broad community-based strategies and may provide a route to addressing poor clinical outcomes.
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MESH Headings
- Acute Disease
- Adolescent
- Adult
- Carrier State/diagnosis
- Carrier State/epidemiology
- Carrier State/microbiology
- Carrier State/psychology
- Child
- Child, Preschool
- Cross-Sectional Studies
- Developing Countries
- Diagnosis, Differential
- Family Characteristics
- Female
- Humans
- Infant
- Infant, Newborn
- Malaria, Cerebral/diagnosis
- Malaria, Cerebral/epidemiology
- Malaria, Cerebral/parasitology
- Malawi/epidemiology
- Male
- Meningitis, Bacterial/diagnosis
- Meningitis, Bacterial/epidemiology
- Meningitis, Bacterial/microbiology
- Meningitis, Bacterial/psychology
- Patient Acceptance of Health Care/psychology
- Qualitative Research
- Referral and Consultation
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61
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Baranova AM, Guzeeva TM, Morozova LF. [Death cases from topical malaria in Russia (2009-2012)]. MEDITSINSKAIA PARAZITOLOGIIA I PARAZITARNYE BOLEZNI 2013:50-52. [PMID: 25924289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
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62
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Khodzhaeva NM, Baranova AM. [Tropical malaria in children in the Republic of Tajikistan]. MEDITSINSKAIA PARAZITOLOGIIA I PARAZITARNYE BOLEZNI 2013:23-26. [PMID: 25924279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The complications of tropical malaria were noted in 25 (9.4%) of 196 pediatric patients followed up. These included cerebral malaria in 8 (3%), severe hemolytic anemia in 15 (5.7%), hemoglobinuric fever in 1 (0.37%), and malarial hepatitis in 1 (0.37%). The occurrence of complications was associated with the late referral of patients to a health care facility and untimely treatment, as well as with preliminary misdiagnoses (acute respiratory viral infection, typhoid-parathyphoid fever, meningitis, acute enteric infection, viral hepatitis, sepsis). The main reasons for late diagnosis were the absence of malarial paroxysm at the onset of disease in infants and the wrong type of a temperature curve.
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MESH Headings
- Acute Disease
- Adolescent
- Anemia, Hemolytic/diagnosis
- Anemia, Hemolytic/epidemiology
- Anemia, Hemolytic/parasitology
- Anemia, Hemolytic/physiopathology
- Child, Preschool
- Delayed Diagnosis
- Diagnostic Errors
- Female
- Hemoglobinuria/diagnosis
- Hemoglobinuria/epidemiology
- Hemoglobinuria/parasitology
- Hemoglobinuria/physiopathology
- Hepatitis/diagnosis
- Hepatitis/epidemiology
- Hepatitis/parasitology
- Hepatitis/physiopathology
- Humans
- Infant
- Malaria, Cerebral/diagnosis
- Malaria, Cerebral/epidemiology
- Malaria, Cerebral/parasitology
- Malaria, Cerebral/physiopathology
- Malaria, Falciparum/diagnosis
- Malaria, Falciparum/epidemiology
- Malaria, Falciparum/parasitology
- Malaria, Falciparum/physiopathology
- Male
- Plasmodium falciparum/pathogenicity
- Plasmodium falciparum/physiology
- Tajikistan/epidemiology
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63
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Ong PK, Melchior B, Martins YC, Hofer A, Orjuela-Sánchez P, Cabrales P, Zanini GM, Frangos JA, Carvalho LJM. Nitric oxide synthase dysfunction contributes to impaired cerebroarteriolar reactivity in experimental cerebral malaria. PLoS Pathog 2013; 9:e1003444. [PMID: 23818850 PMCID: PMC3688552 DOI: 10.1371/journal.ppat.1003444] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 05/07/2013] [Indexed: 12/02/2022] Open
Abstract
Cerebrovascular dysfunction plays a key role in the pathogenesis of cerebral malaria. In experimental cerebral malaria (ECM) induced by Plasmodium berghei ANKA, cerebrovascular dysfunction characterized by vascular constriction, occlusion and damage results in impaired perfusion and reduced cerebral blood flow and oxygenation, and has been linked to low nitric oxide (NO) bioavailability. Here, we directly assessed cerebrovascular function in ECM using a novel cranial window method for intravital microscopy of the pial microcirculation and probed the role of NOS isoforms and phosphorylation patterns in the impaired vascular responses. We show that pial arteriolar responses to endothelial NOS (eNOS) and neuronal NOS (nNOS) agonists (Acetylcholine (ACh) and N-Methyl-D-Aspartate (NMDA)) were blunted in mice with ECM, and could be partially recovered by exogenous supplementation of tetrahydrobiopterin (BH4). Pial arterioles in non-ECM mice infected by Plasmodium berghei NK65 remained relatively responsive to the agonists and were not significantly affected by BH4 treatment. These findings, together with the observed blunting of NO production upon stimulation by the agonists, decrease in total NOS activity, augmentation of lipid peroxidation levels, upregulation of eNOS protein expression, and increase in eNOS and nNOS monomerization in the brain during ECM development strongly indicate a state of eNOS/nNOS uncoupling likely mediated by oxidative stress. Furthermore, the downregulation of Serine 1176 (S1176) phosphorylation of eNOS, which correlated with a decrease in cerebrovascular wall shear stress, implicates hemorheological disturbances in eNOS dysfunction in ECM. Finally, pial arterioles responded to superfusion with the NO donor, S-Nitroso-L-glutathione (GSNO), but with decreased intensity, indicating that not only NO production but also signaling is perturbed during ECM. Therefore, the pathological impairment of eNOS and nNOS functions contribute importantly to cerebrovascular dysfunction in ECM and the recovery of intrinsic functionality of NOS to increase NO bioavailability and restore vascular health represents a target for ECM treatment.
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64
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Milner DA, Valim C, Carr RA, Chandak PB, Fosiko NG, Whitten R, Playforth KB, Seydel KB, Kamiza S, Molyneux ME, Taylor TE. A histological method for quantifying Plasmodium falciparum in the brain in fatal paediatric cerebral malaria. Malar J 2013; 12:191. [PMID: 23758807 PMCID: PMC3701562 DOI: 10.1186/1475-2875-12-191] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 06/03/2013] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND The sequestration of Plasmodium falciparum-infected erythrocytes in brain microvasculature through cytoadherence to endothelium, is the hallmark of the definitive diagnosis of cerebral malaria and plays a critical role in malaria pathogenesis. The complex pathophysiology, which leads each patient to the final outcome of cerebral malaria, is multifaceted and thus, metrics to delineate specific patterns within cerebral malaria are needed to further parse patients. METHODS A method was developed for quantification utilizing counts of capillary contents (early-stage parasites, late-stage parasites and fibrin) from histological preparations of brain tissue after death, and compared it to the standard approach, in which the percentage of parasitized vessels in cross-section is determined. RESULTS Within the initial cohort of 50 patients, two different observers agreed closely on the percentage of vessels parasitized, pigmented parasites and pigment globules (ICC = 0.795-0.970). Correlations between observers for correct diagnostic classification were high (Kendall's tau-b = 0.8779, Kappa = 0.8413). When these methods were applied prospectively to a second set of 50 autopsy samples, they revealed a heterogeneous distribution of sequestered parasites in the brain with pigmented parasites and pigment globules present in the cerebellum > cortex > brainstem. There was no difference in the distribution of early stages of parasites or in the percentage of vessels parasitized across the same sites. The second cohort of cases was also used to test a previously published classification and regression tree (CART) analysis; the quantitative data alone were able to accurately classify and distinguish cerebral malaria from non-cerebral malaria. Classification errors occurred within a subclassification of cerebral malaria (CM1 vs CM2). A repeat CART analysis for the second cohort generated slightly different classification rules with more accurate subclassification, although misclassification still occurred. CONCLUSIONS The traditional measure of parasite sequestration in falciparum malaria, the percentage of vessels parasitized, is the most reliable and consistent for the general diagnosis of cerebral malaria. Methods that involve quantitative measures of different life cycle stages are useful for distinguishing patterns within the cerebral malaria population; these subclassifications may be important for studies of disease pathogenesis and ancillary treatment.
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Bao LQ, Huy NT, Kikuchi M, Yanagi T, Senba M, Shuaibu MN, Honma K, Yui K, Hirayama K. CD19(+) B cells confer protection against experimental cerebral malaria in semi-immune rodent model. PLoS One 2013; 8:e64836. [PMID: 23724100 PMCID: PMC3665539 DOI: 10.1371/journal.pone.0064836] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 04/19/2013] [Indexed: 12/31/2022] Open
Abstract
In African endemic area, adults are less vulnerable to cerebral malaria than children probably because of acquired partial immunity or semi-immune status. Here, we developed an experimental cerebral malaria (ECM) model for semi-immune mice. C57BL/6 (B6) mice underwent one, two and three cycles of infection and radical treatment (1-cure, 2-cure and 3-cure, respectively) before being finally challenged with 104Plasmodium berghei ANKA without treatment. Our results showed that 100% of naïve (0-cure), 67% of 1-cure, 37% of 2-cure and none of 3-cure mice succumbed to ECM within 10 days post challenge infection. In the protected 3-cure mice, significantly higher levels of plasma IL-10 and lower levels of IFN-γ than the others on day 7 post challenge infection were observed. Major increased lymphocyte subset of IL-10 positive cells in 3-cure mice was CD5(−)CD19(+) B cells. Passive transfer of splenic CD19(+) cells from 3-cure mice protected naïve mice from ECM. Additionally, aged 3-cure mice were also protected from ECM 12 and 20 months after the last challenge infection. In conclusion, mice became completely resistant to ECM after three exposures to malaria. CD19(+) B cells are determinants in protective mechanism of semi-immune mice against ECM possibly via modulatory IL-10 for pathogenic IFN-γ production.
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DellaValle B, Staalsoe T, Kurtzhals JAL, Hempel C. Investigation of hydrogen sulfide gas as a treatment against P. falciparum, murine cerebral malaria, and the importance of thiolation state in the development of cerebral malaria. PLoS One 2013; 8:e59271. [PMID: 23555646 PMCID: PMC3608628 DOI: 10.1371/journal.pone.0059271] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 02/12/2013] [Indexed: 01/16/2023] Open
Abstract
Introduction Cerebral malaria (CM) is a potentially fatal cerebrovascular disease of complex pathogenesis caused by Plasmodium falciparum. Hydrogen sulfide (HS) is a physiological gas, similar to nitric oxide and carbon monoxide, involved in cellular metabolism, vascular tension, inflammation, and cell death. HS treatment has shown promising results as a therapy for cardio- and neuro- pathology. This study investigates the effects of fast (NaHS) and slow (GYY4137) HS-releasing drugs on the growth and metabolism of P. falciparum and the development of P. berghei ANKA CM. Moreover, we investigate the role of free plasma thiols and cell surface thiols in the pathogenesis of CM. Methods P. falciparum was cultured in vitro with varying doses of HS releasing drugs compared with artesunate. Growth and metabolism were quantified. C57Bl/6 mice were infected with P. berghei ANKA and were treated with varying doses and regimes of HS-releasing drugs. Free plasma thiols and cell surface thiols were quantified in CM mice and age-matched healthy controls. Results HS-releasing drugs significantly and dose-dependently inhibited P. falciparum growth and metabolism. Treatment of CM did not affect P. berghei growth, or development of CM. Interestingly, CM was associated with lower free plasma thiols, reduced leukocyte+erythrocyte cell surface thiols (infection day 3), and markedly (5-fold) increased platelet cell surface thiols (infection day 7). Conclusions HS inhibits P. falciparum growth and metabolism in vitro. Reduction in free plasma thiols, cell surface thiols and a marked increase in platelet cell surface thiols are associated with development of CM. HS drugs were not effective in vivo against murine CM.
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Hansen DS. Inflammatory responses associated with the induction of cerebral malaria: lessons from experimental murine models. PLoS Pathog 2012; 8:e1003045. [PMID: 23300435 PMCID: PMC3531491 DOI: 10.1371/journal.ppat.1003045] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Mohapatra MK, Dash PC, Mohapatro SC, Mishra RN. Delayed gastric emptying time in adult cerebral Falciparum malaria. J Vector Borne Dis 2012; 49:230-233. [PMID: 23428522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023] Open
Abstract
OBJECTIVE We hypothesize that upper gastrointestinal symptoms in cerebral malaria are due to gastric motor dysfunction. But gastric motility studies in cerebral malaria are scarce. METHODS We determined gastric emptying half-time (GET½) of liquid meals quantitatively by radio isotope scintigraphy in 25 patients of cerebral malaria and 10 healthy controls. RESULTS GET½ was prolonged (46.5 ± 4.8 min) significantly (p <0.001) in patients of cerebral malaria compared to healthy controls (27.6 ± 5.3 min). CONCLUSION Cerebral malaria can cause prolongation of gastric emptying time of liquid foods.
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Dai M, Freeman B, Shikani HJ, Bruno FP, Collado JE, Macias R, Reznik SE, Davies P, Spray DC, Tanowitz HB, Weiss LM, Desruisseaux MS. Altered regulation of Akt signaling with murine cerebral malaria, effects on long-term neuro-cognitive function, restoration with lithium treatment. PLoS One 2012; 7:e44117. [PMID: 23082110 PMCID: PMC3474787 DOI: 10.1371/journal.pone.0044117] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 07/31/2012] [Indexed: 01/29/2023] Open
Abstract
Neurological and cognitive impairment persist in more than 20% of cerebral malaria (CM) patients long after successful anti-parasitic treatment. We recently reported that long term memory and motor coordination deficits are also present in our experimental cerebral malaria model (ECM). We also documented, in a murine model, a lack of obvious pathology or inflammation after parasite elimination, suggesting that the long-term negative neurological outcomes result from potentially reversible biochemical and physiological changes in brains of ECM mice, subsequent to acute ischemic and inflammatory processes. Here, we demonstrate for the first time that acute ECM results in significantly reduced activation of protein kinase B (PKB or Akt) leading to decreased Akt phosphorylation and inhibition of the glycogen kinase synthase (GSK3β) in the brains of mice infected with Plasmodium berghei ANKA (PbA) compared to uninfected controls and to mice infected with the non-neurotrophic P. berghei NK65 (PbN). Though Akt activation improved to control levels after chloroquine treatment in PbA-infected mice, the addition of lithium chloride, a compound which inhibits GSK3β activity and stimulates Akt activation, induced a modest, but significant activation of Akt in the brains of infected mice when compared to uninfected controls treated with chloroquine with and without lithium. In addition, lithium significantly reversed the long-term spatial and visual memory impairment as well as the motor coordination deficits which persisted after successful anti-parasitic treatment. GSK3β inhibition was significantly increased after chloroquine treatment, both in lithium and non-lithium treated PbA-infected mice. These data indicate that acute ECM is associated with abnormalities in cell survival pathways that result in neuronal damage. Regulation of Akt/GSK3β with lithium reduces neuronal degeneration and may have neuroprotective effects in ECM. Aberrant regulation of Akt/GSK3β signaling likely underlies long-term neurological sequelae observed in ECM and may yield adjunctive therapeutic targets for the management of CM.
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Karlsson M, Hempel C, Sjövall F, Hansson MJ, Kurtzhals JAL, Elmér E. Brain mitochondrial function in a murine model of cerebral malaria and the therapeutic effects of rhEPO. Int J Biochem Cell Biol 2012; 45:151-5. [PMID: 22903021 DOI: 10.1016/j.biocel.2012.08.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 07/23/2012] [Accepted: 08/04/2012] [Indexed: 11/18/2022]
Abstract
Cerebral malaria (CM) is a life-threatening complication of Plasmodium falciparum infection. The pathogenesis of CM is complex. Cerebral metabolic dysfunction is implicated in CM, which may be caused by both an impaired cerebral microcirculation and a dysregulated inflammatory response affecting cellular respiration of mitochondria. Recombinant human erythropoietin (rhEPO) is a promising new therapy that has been shown to reduce mortality in a mouse model of CM. In order to further elucidate the metabolic dysfunction in CM the objective of the present study was to assess brain mitochondrial respiratory function in CM with and without rhEPO treatment. The P. berghei ANKA - C57BL/6 murine model of CM was used. Mitochondrial respiration was analyzed in brain homogenates using high-resolution respirometry and a multiple substrate and inhibitor protocol. The animals were divided into four groups; infected injected with saline or with rhEPO, non-infected injected with saline or with rhEPO. Infected mice developed CM and treatment with rhEPO attenuated clinical signs of disease. There were no differences in respiratory parameters of brain mitochondria between infected and non-infected mice and no connection between disease severity and mitochondrial respiratory function. Treatment with rhEPO similarly had no effect on respiratory function. Thus cerebral metabolic dysfunction in CM does not seem to be directly linked to altered mitochondrial respiratory capacity as analyzed in brain homogenates ex vivo. This article is part of a Directed Issue entitled: Bioenergetic dysfunction, adaptation and therapy.
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Martins YC, Zanini GM, Frangos JA, Carvalho LJM. Efficacy of different nitric oxide-based strategies in preventing experimental cerebral malaria by Plasmodium berghei ANKA. PLoS One 2012; 7:e32048. [PMID: 22348145 PMCID: PMC3278462 DOI: 10.1371/journal.pone.0032048] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 01/21/2012] [Indexed: 12/14/2022] Open
Abstract
Background Low nitric oxide (NO) bioavailability plays a role in the pathogenesis of human as well as of experimental cerebral malaria (ECM) caused by Plasmodium berghei ANKA (PbA). ECM is partially prevented by administration of the NO-donor dipropylenetriamine NONOate (DPTA-NO) at high concentration (1 mg/mouse), which also induces major side effects such as a sharp drop in blood pressure. We asked whether alternative strategies to improve NO bioavailability with minor side effects would also be effective in preventing ECM. Methodology/Principal Findings Mice were infected with PbA and prophylactically treated twice a day with bolus injections of L-arginine, Nω-hydroxy-nor-Arginine (nor-NOHA), tetrahydrobiopterin (BH4), separately or combined, sodium nitrite, sildenafil or sildenafil plus DPTA-NO starting on day 0 of infection. L-arginine and BH4 supplementation, with or without arginase inhibition by nor-NOHA, increased plasma nitrite levels but failed to protect against ECM development. Accordingly, prophylactic treatment with continuous delivery of L-arginine using osmotic pumps also did not improve survival. Similar outcomes were observed with sodium nitrite sildenafil (aimed at inhibiting phosphodiesterase-5) or with DPTA-NO. However, sildenafil (0.1 mg/mouse) in combination with a lower dose (0.1 mg/mouse) of DPTA-NO decreased ECM incidence (82±7.4% mortality in the saline group and 38±10.6% in the treated group; p<0.05). The combined prophylactic therapy did not aggravate anemia, had delayed effects in systolic, diastolic and mean arterial blood pressure and induced lower effects in pulse pressure when compared to DPTA-NO 1 mg/mouse. Conclusions/Significance These data show that sildenafil lowers the amount of NO-donor needed to prevent ECM, resulting also in lesser side effects. Prophylactic L-arginine when given in bolus or continuous delivery and bolus BH4 supplementation, with or without arginase inhibition, were able to increase NO bioavailability in PbA-infected mice but failed to decrease ECM incidence in the doses and protocol used.
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Milner DA, Vareta J, Valim C, Montgomery J, Daniels RF, Volkman SK, Neafsey DE, Park DJ, Schaffner SF, Mahesh NC, Barnes KG, Rosen DM, Lukens AK, Van-Tyne D, Wiegand RC, Sabeti PC, Seydel KB, Glover SJ, Kamiza S, Molyneux ME, Taylor TE, Wirth DF. Human cerebral malaria and Plasmodium falciparum genotypes in Malawi. Malar J 2012; 11:35. [PMID: 22314206 PMCID: PMC3295736 DOI: 10.1186/1475-2875-11-35] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 02/07/2012] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Cerebral malaria, a severe form of Plasmodium falciparum infection, is an important cause of mortality in sub-Saharan African children. A Taqman 24 Single Nucleotide Polymorphisms (SNP) molecular barcode assay was developed for use in laboratory parasites which estimates genotype number and identifies the predominant genotype. METHODS The 24 SNP assay was used to determine predominant genotypes in blood and tissues from autopsy and clinical patients with cerebral malaria. RESULTS Single genotypes were shared between the peripheral blood, the brain, and other tissues of cerebral malaria patients, while malaria-infected patients who died of non-malarial causes had mixed genetic signatures in tissues examined. Children with retinopathy-positive cerebral malaria had significantly less complex infections than those without retinopathy (OR = 3.7, 95% CI [1.51-9.10]).The complexity of infections significantly decreased over the malaria season in retinopathy-positive patients compared to retinopathy-negative patients. CONCLUSIONS Cerebral malaria patients harbour a single or small set of predominant parasites; patients with incidental parasitaemia sustain infections involving diverse genotypes. Limited diversity in the peripheral blood of cerebral malaria patients and correlation with tissues supports peripheral blood samples as appropriate for genome-wide association studies of parasite determinants of pathogenicity.
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Waisberg M, Vickers BK, Yager SB, Lin CK, Pierce SK. Testing in mice the hypothesis that melanin is protective in malaria infections. PLoS One 2012; 7:e29493. [PMID: 22242171 PMCID: PMC3252320 DOI: 10.1371/journal.pone.0029493] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Accepted: 11/29/2011] [Indexed: 01/22/2023] Open
Abstract
Malaria has had the largest impact of any infectious disease on shaping the human genome, exerting enormous selective pressure on genes that improve survival in severe malaria infections. Modern humans originated in Africa and lost skin melanization as they migrated to temperate regions of the globe. Although it is well documented that loss of melanization improved cutaneous Vitamin D synthesis, melanin plays an evolutionary ancient role in insect immunity to malaria and in some instances melanin has been implicated to play an immunoregulatory role in vertebrates. Thus, we tested the hypothesis that melanization may be protective in malaria infections using mouse models. Congenic C57BL/6 mice that differed only in the gene encoding tyrosinase, a key enzyme in the synthesis of melanin, showed no difference in the clinical course of infection by Plasmodium yoelii 17XL, that causes severe anemia, Plasmodium berghei ANKA, that causes severe cerebral malaria or Plasmodium chabaudi AS that causes uncomplicated chronic disease. Moreover, neither genetic deficiencies in vitamin D synthesis nor vitamin D supplementation had an effect on survival in cerebral malaria. Taken together, these results indicate that neither melanin nor vitamin D production improve survival in severe malaria.
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Wiwanitkit V. Blood exchange and malaria. J Clin Apher 2011; 26:366; author reply 367. [PMID: 22076791 DOI: 10.1002/jca.20320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Accepted: 10/11/2011] [Indexed: 11/07/2022]
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Ghosh S, Sengupta A, Sharma S, Sonawat HM. Multivariate modelling with (1)H NMR of pleural effusion in murine cerebral malaria. Malar J 2011; 10:330. [PMID: 22047045 PMCID: PMC3228806 DOI: 10.1186/1475-2875-10-330] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 11/02/2011] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Cerebral malaria is a clinical manifestation of Plasmodium falciparum infection. Although brain damage is the predominant pathophysiological complication of cerebral malaria (CM), respiratory distress, acute lung injury, hydrothorax/pleural effusion are also observed in several cases. Immunological parameters have been assessed in pleural fluid in murine models; however there are no reports of characterization of metabolites present in pleural effusion. METHODS 1H NMR of the sera and the pleural effusion of cerebral malaria infected mice were analyzed using principal component analysis, orthogonal partial least square analysis, multiway principal component analysis, and multivariate curve resolution. RESULTS It has been observed that there was 100% occurrence of pleural effusion (PE) in the mice affected with CM, as opposed to those are non-cerebral and succumbing to hyperparasitaemia (NCM/HP). An analysis of 1H NMR and SDS-PAGE profile of PE and serum samples of each of the CM mice exhibited a similar profile in terms of constituents. Multivariate analysis on these two classes of biofluids was performed and significant differences were detected in concentrations of metabolites. Glucose, creatine and glutamine contents were high in the PE and lipids being high in the sera. Multivariate curve resolution between sera and pleural effusion showed that changes in PE co-varied with that of serum in CM mice. The increase of glucose in PE is negatively correlated to the glucose in serum in CM as obtained from the result of multiway principal component analysis. CONCLUSIONS This study reports for the first time, the characterization of metabolites in pleural effusion formed during murine cerebral malaria. The study indicates that the origin of PE metabolites in murine CM may be the serum. The loss of the components like glucose, glutamine and creatine into the PE may worsen the situation of patients, in conjunction with the enhanced glycolysis, glutaminolysis and increased activity of creatine phophokinase which are already reported characteristic pathophysiological features of malaria.
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Gerald NJ, Majam V, Mahajan B, Kozakai Y, Kumar S. Protection from experimental cerebral malaria with a single dose of radiation-attenuated, blood-stage Plasmodium berghei parasites. PLoS One 2011; 6:e24398. [PMID: 21935405 PMCID: PMC3174172 DOI: 10.1371/journal.pone.0024398] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 08/08/2011] [Indexed: 12/31/2022] Open
Abstract
Background Whole malaria parasites are highly effective in inducing immunity against malaria. Due to the limited success of subunit based vaccines in clinical studies, there has been a renewed interest in whole parasite-based malaria vaccines. Apart from attenuated sporozoites, there have also been efforts to use live asexual stage parasites as vaccine immunogens. Methodology and Results We used radiation exposure to attenuate the highly virulent asexual blood stages of the murine malaria parasite P. berghei to a non-replicable, avirulent form. We tested the ability of the attenuated blood stage parasites to induce immunity to parasitemia and the symptoms of severe malaria disease. Depending on the mouse genetic background, a single high dose immunization without adjuvant protected mice from parasitemia and severe disease (CD1 mice) or from experimental cerebral malaria (ECM) (C57BL/6 mice). A low dose immunization did not protect against parasitemia or severe disease in either model after one or two immunizations. The protection from ECM was associated with a parasite specific antibody response and also with a lower level of splenic parasite-specific IFN-γ production, which is a mediator of ECM pathology in C57BL/6 mice. Surprisingly, there was no difference in the sequestration of CD8+ T cells and CD45+ CD11b+ macrophages in the brains of immunized, ECM-protected mice. Conclusions This report further demonstrates the effectiveness of a whole parasite blood-stage vaccine in inducing immunity to malaria and explicitly demonstrates its effectiveness against ECM, the most pathogenic consequence of malaria infection. This experimental model will be important to explore the formulation of whole parasite blood-stage vaccines against malaria and to investigate the immune mechanisms that mediate protection against parasitemia and cerebral malaria.
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Shahar AM, Ngiu CS, Hashim HZ, Tan HJ, Periyasamy P. No coma, but expressive dysphasia with cerebellar signs: an unique presentation of cerebral malaria. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2011; 40:382-383. [PMID: 22065006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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Claser C, Malleret B, Gun SY, Wong AYW, Chang ZW, Teo P, See PCE, Howland SW, Ginhoux F, Rénia L. CD8+ T cells and IFN-γ mediate the time-dependent accumulation of infected red blood cells in deep organs during experimental cerebral malaria. PLoS One 2011; 6:e18720. [PMID: 21494565 PMCID: PMC3073989 DOI: 10.1371/journal.pone.0018720] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 03/08/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Infection with Plasmodium berghei ANKA (PbA) in susceptible mice induces a syndrome called experimental cerebral malaria (ECM) with severe pathologies occurring in various mouse organs. Immune mediators such as T cells or cytokines have been implicated in the pathogenesis of ECM. Red blood cells infected with PbA parasites have been shown to accumulate in the brain and other tissues during infection. This accumulation is thought to be involved in PbA-induced pathologies, which mechanisms are poorly understood. METHODS AND FINDINGS Using transgenic PbA parasites expressing the luciferase protein, we have assessed by real-time in vivo imaging the dynamic and temporal contribution of different immune factors in infected red blood cell (IRBC) accumulation and distribution in different organs during PbA infection. Using deficient mice or depleting antibodies, we observed that CD8(+) T cells and IFN-γ drive the rapid increase in total parasite biomass and accumulation of IRBC in the brain and in different organs 6-12 days post-infection, at a time when mice develop ECM. Other cells types like CD4(+) T cells, monocytes or neutrophils or cytokines such as IL-12 and TNF-α did not influence the early increase of total parasite biomass and IRBC accumulation in different organs. CONCLUSIONS CD8(+) T cells and IFN-γ are the major immune mediators controlling the time-dependent accumulation of P. berghei-infected red blood cells in tissues.
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Clemmer L, Martins YC, Zanini GM, Frangos JA, Carvalho LJM. Artemether and artesunate show the highest efficacies in rescuing mice with late-stage cerebral malaria and rapidly decrease leukocyte accumulation in the brain. Antimicrob Agents Chemother 2011; 55:1383-90. [PMID: 21220531 PMCID: PMC3067152 DOI: 10.1128/aac.01277-10] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2010] [Revised: 11/19/2010] [Accepted: 01/02/2011] [Indexed: 11/20/2022] Open
Abstract
The murine model of cerebral malaria (ECM) caused by Plasmodium berghei ANKA (PbA) infection in susceptible mice has been extensively used for studies of pathogenesis and identification of potential targets for human CM therapeutics. However, the model has been seldom explored to evaluate adjunctive therapies for this malaria complication. A first step toward this goal is to define a treatment protocol with an effective antimalarial drug able to rescue mice presenting late-stage ECM. We evaluated the efficacy of artemisinin, artemether, artesunate, and quinine given intraperitoneally once a day, and combinations with mefloquine, in suppressing PbA infection in mice with moderate parasitemia. Artemether, artesunate, and quinine were then evaluated for efficacy in rescuing PbA-infected mice with ECM, strictly defined by using objective criteria based on the presentation of clinical signs of neurological involvement, degree of hypothermia, and performance in a set of six motor behavior tests. Artemether at 25 mg/kg presented the fastest parasite killing ability in 24 h and fully avoided recrudescence in a 5-day treatment protocol. Artemether and artesunate were equally effective in rescuing mice with late-stage ECM (46 and 43% survival, respectively), whereas quinine had a poor performance (12.5% survival). Artemether caused a marked decrease in brain leukocyte accumulation 24 h after the first dose. In conclusion, artemether and artesunate are effective in rescuing mice with late-stage ECM and decrease brain inflammation. In addition, the described protocols for more strict clinical evaluation and for rescue treatment provide a framework for studies of CM adjunctive therapies using this mouse model.
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Imani PD, Musoke P, Byarugaba J, Tumwine JK. Human immunodeficiency virus infection and cerebral malaria in children in Uganda: a case-control study. BMC Pediatr 2011; 11:5. [PMID: 21235797 PMCID: PMC3035590 DOI: 10.1186/1471-2431-11-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Accepted: 01/14/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Human immunodeficiency virus (HIV)-1 infection increases the burden of malaria by increasing susceptibility to infection and decreasing the response to malarial treatment. HIV-1 has also been found to suppress the immune system and predispose to severe forms of malaria in adults. There is still a paucity of data on the association between HIV-1 infection and cerebral malaria in children. The aim of this study was to determine whether HIV-1 infection is a risk factor for cerebral malaria in children. METHOD We conducted an unmatched case-control study, in which 100 children with cerebral malaria were compared with 132 with uncomplicated malaria and 120 with no malaria. In stratified analyses we estimated odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for age. RESULTS HIV-1 infection was present in 9% of children with cerebral malaria compared to 2.3% in uncomplicated malaria (age-adjusted odds ratio (aOR) 5.94 (95% confidence interval (CI) 1.36-25.94, p = 0.012); and 2.5% in children with no malaria (aOR 3.85 (95% CI0.99-14.93, p = 0.037). The age-adjusted odds of being HIV-positive among children with cerebral malaria compared to the control groups (children with uncomplicated malaria and no malaria) was 4.98 (95% CI 1.54-16.07), p-value = 0.003. CONCLUSIONS HIV-1 infection is associated with clinical presentation of cerebral malaria in children. Clinicians should ensure that children diagnosed with HIV infection are initiated on cotrimoxazole prophylaxis as soon as the diagnosis is made and caretakers counselled on the importance of adherence to the cotrimoxazole towards reducing the risk of acquiring P.falciparum malaria and associated complications such as cerebral malaria. Other malaria preventive measures such as use of insecticide-treated mosquito nets should also be emphasized during counselling sessions.
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Eltahir EM, El Ghazali G, A-Elgadir TME, A-Elbasit IE, Elbashir MI, Giha HA. Raised plasma insulin level and homeostasis model assessment (HOMA) score in cerebral malaria: evidence for insulin resistance and marker of virulence. Acta Biochim Pol 2010; 57:513-520. [PMID: 21140005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 05/16/2010] [Accepted: 11/27/2010] [Indexed: 05/30/2023]
Abstract
OBJECTIVE To study the glycaemic profile of patients with severe malaria (SM). METHODS For this purpose, 110 SM patients were recruited. Pre-treatment random blood glucose and plasma insulin were measured in a subset of donors. An ex-vivo experiment was developed for estimation of glucose consumption by parasitized erythrocytes. RESULTS Hyperglycaemia was frequent in SM but more commonly associated with cerebral malaria (CM), while hyperinsulinaemia was recognized in severe-malarial-hypotension (median, 25 %-75 %, 188.2, 93.8-336.8 pmol/L). The plasma insulin level was positively correlated with age (CC = 0.457, p < 0.001) and negatively with parasitaemia (CC = -0.368, p = 0.045). Importantly, fatal-CM was associated with hyperglycaemia (12.22, 6.5-14.6 mmol/L), hyperinsulinaemia (141.0, 54.0-186.8 pmol/L) and elevated homeostasis model assessment (HOMA) values. However, there was a trend of higher glucose consumption by parasites in CM compared with that in uncomplicated malaria (UM). CONCLUSION Hyperglycaemia, hyperinsulinaemia and elevated HOMA are evidence for insulin resistance and possibly pancreatic B-cell dysfunction in fatal-CM.
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Nema N, Joseph D. Subhyaloid hemorrhage in cerebral malaria. J Vector Borne Dis 2010; 47:261-263. [PMID: 21178221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
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83
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Mbengue B, Niang B, Diatta B, Tall A, Garraud O, Perraut R, Dieye A. The use of crude Plasmodium falciparum antigens for comparison of antibody responses in patients with mild malaria vs. cerebral malaria. IRANIAN JOURNAL OF IMMUNOLOGY : IJI 2010; 7:150-161. [PMID: 20876986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
BACKGROUND Cerebral malaria (CM) is one of the major causes of death in African populations infected with Plasmodium falciparum. Only 1% of infected subjects develop CM. The reasons for these differences are not fully understood, but it is likely that the host humoral response against blood-stage antigens plays a role in protection from malaria, although the precise targets and mechanisms mediating immunity remain unclear. OBJECTIVE The purpose of this study was to distinguish between defined P. falciparum-specific Ab response patterns in patients presenting with mild malaria (MM) vs. CM. METHODS We used a panel of P. falciparum conserved antigens including crude blood-stage extracts schizont, merozoite and parasitised erythrocyte membranes and MSP-1p19, PfEB200, R23 and GST-5 recombinant antigens in a retrospective case-control study of symptomatic adults, one group presenting confirmed CM without fatal outcome and another group with MM. We further matched P. falciparum-specific Ab responses with those from individuals living in an endemic setting known to have protective immunity and considered them as "immune control" subjects (IC). Total IgG, IgM and IgG subclass Ab responses were determined using ELISA method. RESULTS Substantial Ab responses were found in symptomatic patients, significantly lower than the "immune control" subjects, and with a limited quantitative difference between MM versus CM. Interestingly, asynchronous IgM response was evidenced in CM contrary to MM. CONCLUSION Our results suggest that the contribution of an efficient IgG response against parasite multiplication is of importance in the evolution towards CM manifestation without fatal outcome and deserves further analysis for vaccine candidates.
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Reis PA, Comim CM, Hermani F, Silva B, Barichello T, Portella AC, Gomes FCA, Sab IM, Frutuoso VS, Oliveira MF, Bozza PT, Bozza FA, Dal-Pizzol F, Zimmerman GA, Quevedo J, Castro-Faria-Neto HC. Cognitive dysfunction is sustained after rescue therapy in experimental cerebral malaria, and is reduced by additive antioxidant therapy. PLoS Pathog 2010; 6:e1000963. [PMID: 20585569 PMCID: PMC2891838 DOI: 10.1371/journal.ppat.1000963] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Accepted: 05/25/2010] [Indexed: 11/19/2022] Open
Abstract
Neurological impairments are frequently detected in children surviving cerebral malaria (CM), the most severe neurological complication of infection with Plasmodium falciparum. The pathophysiology and therapy of long lasting cognitive deficits in malaria patients after treatment of the parasitic disease is a critical area of investigation. In the present study we used several models of experimental malaria with differential features to investigate persistent cognitive damage after rescue treatment. Infection of C57BL/6 and Swiss (SW) mice with Plasmodium berghei ANKA (PbA) or a lethal strain of Plasmodium yoelii XL (PyXL), respectively, resulted in documented CM and sustained persistent cognitive damage detected by a battery of behavioral tests after cure of the acute parasitic disease with chloroquine therapy. Strikingly, cognitive impairment was still present 30 days after the initial infection. In contrast, BALB/c mice infected with PbA, C57BL6 infected with Plasmodium chabaudi chabaudi and SW infected with non lethal Plasmodium yoelii NXL (PyNXL) did not develop signs of CM, were cured of the acute parasitic infection by chloroquine, and showed no persistent cognitive impairment. Reactive oxygen species have been reported to mediate neurological injury in CM. Increased production of malondialdehyde (MDA) and conjugated dienes was detected in the brains of PbA-infected C57BL/6 mice with CM, indicating high oxidative stress. Treatment of PbA-infected C57BL/6 mice with additive antioxidants together with chloroquine at the first signs of CM prevented the development of persistent cognitive damage. These studies provide new insights into the natural history of cognitive dysfunction after rescue therapy for CM that may have clinical relevance, and may also be relevant to cerebral sequelae of sepsis and other disorders.
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85
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Schmutzhard J, Kositz CH, Lackner P, Dietmann A, Fischer M, Glueckert R, Reindl M, Stephan K, Riechelmann H, Schrott-Fischer A, Schmutzhard E. Murine malaria is associated with significant hearing impairment. Malar J 2010; 9:159. [PMID: 20540722 PMCID: PMC2898786 DOI: 10.1186/1475-2875-9-159] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 06/11/2010] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Plasmodium falciparum malaria has been suspected to cause hearing loss. Developmental, cognitive and language disorders have been observed in children, surviving cerebral malaria. This prospective study aims to evaluate whether malaria influences hearing in mice. METHODS Twenty mice were included in a standardized murine cerebral malaria model. Auditory evoked brainstem responses were assessed before infection and at the peak of the illness. RESULTS A significant hearing impairment could be demonstrated in mice with malaria, especially the cerebral form. The control group did not show any alterations. No therapy was used. CONCLUSION This suggests that malaria itself leads to a hearing impairment in mice.
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Stevenson MM, Gros P, Olivier M, Fortin A, Serghides L. Cerebral malaria: human versus mouse studies. Trends Parasitol 2010; 26:274-5. [PMID: 20382077 DOI: 10.1016/j.pt.2010.03.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 03/15/2010] [Accepted: 03/16/2010] [Indexed: 11/16/2022]
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Riley EM, Couper KN, Helmby H, Hafalla JCR, de Souza JB, Langhorne J, Jarra WB, Zavala F. Neuropathogenesis of human and murine malaria. Trends Parasitol 2010; 26:277-8. [PMID: 20338809 DOI: 10.1016/j.pt.2010.03.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 02/26/2010] [Accepted: 03/01/2010] [Indexed: 01/18/2023]
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Mixson-Hayden T, Jain V, McCollum AM, Poe A, Nagpal AC, Dash AP, Stiles JK, Udhayakumar V, Singh N. Evidence of selective sweeps in genes conferring resistance to chloroquine and pyrimethamine in Plasmodium falciparum isolates in India. Antimicrob Agents Chemother 2010; 54:997-1006. [PMID: 20038626 PMCID: PMC2826016 DOI: 10.1128/aac.00846-09] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Revised: 07/17/2009] [Accepted: 12/15/2009] [Indexed: 11/20/2022] Open
Abstract
Treatment of Plasmodium falciparum is complicated by the emergence and spread of parasite resistance to many of the first-line drugs used to treat malaria. Antimalarial drug resistance has been associated with specific point mutations in several genes, suggesting that these single nucleotide polymorphisms can be useful in tracking the emergence of drug resistance. In India, P. falciparum infection can manifest itself as asymptomatic, mild, or severe malaria, with or without cerebral involvement. We tested whether chloroquine- and antifolate drug-resistant genotypes would be more commonly associated with cases of cerebral malaria than with cases of mild malaria in the province of Jabalpur, India, by genotyping the dhps, dhfr, pfmdr-1, and pfcrt genes using pyrosequencing, direct sequencing, and real-time PCR. Further, we used microsatellites surrounding the genes to determine the origins and spread of the drug-resistant genotypes in this area. Resistance to chloroquine was essentially fixed, with 95% of the isolates harboring the pfcrt K76T mutation. Resistant genotypes of dhfr, dhps, and pfmdr-1 were found in 94%, 17%, and 77% of the isolates, respectively. Drug-resistant genotypes were equally likely to be associated with cerebral malaria as with mild malaria. We found evidence of a selective sweep in pfcrt and, to a lesser degree, in dhfr, indicating high levels of resistance to chloroquine and evolving resistance to pyrimethamine. Microsatellites surrounding pfcrt indicate that the resistant genotypes (SVMNT) were most similar to those found in Papua New Guinea.
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Bansal D, Herbert F, Lim P, Deshpande P, Bécavin C, Guiyedi V, de Maria I, Rousselle JC, Namane A, Jain R, Cazenave PA, Mishra GC, Ferlini C, Fesel C, Benecke A, Pied S. IgG autoantibody to brain beta tubulin III associated with cytokine cluster-II discriminate cerebral malaria in central India. PLoS One 2009; 4:e8245. [PMID: 20011600 PMCID: PMC2788233 DOI: 10.1371/journal.pone.0008245] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Accepted: 11/10/2009] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND The main processes in the pathogenesis of cerebral malaria caused by Plasmodium falciparum involved sequestration of parasitized red blood cells and immunopathological responses. Among immune factors, IgG autoantibodies to brain antigens are increased in P. falciparum infected patients and correlate with disease severity in African children. Nevertheless, their role in the pathophysiology of cerebral malaria (CM) is not fully defined. We extended our analysis to an Indian population with genetic backgrounds and endemic and environmental status different from Africa to determine if these autoantibodies could be either a biomarker or a risk factor of developing CM. METHODS/PRINCIPAL FINDINGS We investigated the significance of these self-reactive antibodies in clinically well-defined groups of P. falciparum infected patients manifesting mild malaria (MM), severe non-cerebral malaria (SM), or cerebral malaria (CM) and in control subjects from Gondia, a malaria epidemic site in central India using quantitative immunoprinting and multivariate statistical analyses. A two-fold complete-linkage hierarchical clustering allows classifying the different patient groups and to distinguish the CM from the others on the basis of their profile of IgG reactivity to brain proteins defined by PANAMA Blot. We identified beta tubulin III (TBB3) as a novel discriminant brain antigen in the prevalence of CM. In addition, circulating IgG from CM patients highly react with recombinant TBB3. Overall, correspondence analyses based on singular value decomposition show a strong correlation between IgG anti-TBB3 and elevated concentration of cluster-II cytokine (IFNgamma, IL1beta, TNFalpha, TGFbeta) previously demonstrated to be a predictor of CM in the same population. CONCLUSIONS/SIGNIFICANCE Collectively, these findings validate the relationship between antibody response to brain induced by P. falciparum infection and plasma cytokine patterns with clinical outcome of malaria. They also provide significant insight into the immune mechanisms associated to CM by the identification of TBB3 as a new disease-specific marker and potential therapeutic target.
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Niikura M, Kamiya S, Nakane A, Kita K, Kobayashi F. IL-10 plays a crucial role for the protection of experimental cerebral malaria by co-infection with non-lethal malaria parasites. Int J Parasitol 2009; 40:101-8. [PMID: 19735663 DOI: 10.1016/j.ijpara.2009.08.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Revised: 08/14/2009] [Accepted: 08/17/2009] [Indexed: 11/18/2022]
Abstract
Cerebral malaria is an infrequent but serious complication of Plasmodium falciparum infection in humans. Co-infection with different Plasmodium species is common in endemic areas and the existence of benign malaria parasites, such as Plasmodium vivax, during P. falciparum infection has been considered to reduce the risk of developing pathogenesis. However, it is still unknown how disease severity is reduced in the host during co-infection. In the present study, we investigated the influence of co-infection with non-lethal malaria parasites, Plasmodium berghei (Pb) XAT strain, on the outcome of Pb ANKA strain infection which causes experimental cerebral malaria (ECM) in mice. The co-infection with non-lethal Pb XAT suppressed ECM caused by Pb ANKA infection and prolonged survival of mice. The production of TNF-alpha and IFN-gamma, which had been shown to be involved in development of ECM, was suppressed in co-infected mice early in infection. The suppression of ECM by co-infection with Pb XAT was abrogated in IL-10-deficient mice. IL-10 plays a crucial role in the suppression of ECM by co-infection with non-lethal malaria parasites, probably due to its suppressive effect on the induction of TNF-alpha and IFN-gamma. Co-infection with Pb XAT and Pb ANKA is a useful model for understanding how ECM is suppressed.
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Beghdadi W, Porcherie A, Schneider BS, Morisset S, Dubayle D, Peronet R, Dy M, Louis J, Arrang JM, Mécheri S. Histamine H(3) receptor-mediated signaling protects mice from cerebral malaria. PLoS One 2009; 4:e6004. [PMID: 19547708 PMCID: PMC2696087 DOI: 10.1371/journal.pone.0006004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 05/27/2009] [Indexed: 11/18/2022] Open
Abstract
Background Histamine is a biogenic amine that has been shown to contribute to several pathological conditions, such as allergic conditions, experimental encephalomyelitis, and malaria. In humans, as well as in murine models of malaria, increased plasma levels of histamine are associated with severity of infection. We reported recently that histamine plays a critical role in the pathogenesis of experimental cerebral malaria (CM) in mice infected with Plasmodium berghei ANKA. Histamine exerts its biological effects through four different receptors designated H1R, H2R, H3R, and H4R. Principal Findings In the present work, we explored the role of histamine signaling via the histamine H3 receptor (H3R) in the pathogenesis of murine CM. We observed that the lack of H3R expression (H3R−/− mice) accelerates the onset of CM and this was correlated with enhanced brain pathology and earlier and more pronounced loss of blood brain barrier integrity than in wild type mice. Additionally tele-methylhistamine, the major histamine metabolite in the brain, that was initially present at a higher level in the brain of H3R−/− mice was depleted more quickly post-infection in H3R−/− mice as compared to wild-type counterparts. Conclusions Our data suggest that histamine regulation through the H3R in the brain suppresses the development of CM. Thus modulating histamine signaling in the central nervous system, in combination with standard therapies, may represent a novel strategy to reduce the risk of progression to cerebral malaria.
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Ohnishi K. [Cerebral malaria]. BRAIN AND NERVE = SHINKEI KENKYU NO SHINPO 2009; 61:122-128. [PMID: 19235461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Cerebral malaria (CM) is a life-threatening complication of falciparum malaria and some types of disturbed consciousness problems are major symptoms of CM. Although the pathogenesis of CM is unknown, the sequestration, the binding of red blood cells containing mature stages of the malaria parasite to the endothelium of the cerebral microvasculature, and the disappearance of erythrocytes infected with mature malaria parasite in the peripheral blood stream, are thought to play a key role in its pathogenesis. Falciparum malaria patients with disturbed consciousness should be considered to suffer from CM; however it should also be examined as to whether other disease complications such as meningitis or hypoglycemia are associated with this condition. The brain CT or MRI of CM patients reveal no specific findings. CM is treated with an intravenous infusion of artesunate or an intravenous drip infusion of quinine. The prognosis of CM patients is very poor without rapid and adequate treatment; therefore, CM is an infectious disease warranting emergency treatment. The number of Japanese CM patients is believed to increase in the near future in accordance with the increase in the number of Japanese travelers visiting tropical or subtropical malaria-endemic areas. Therefore, Japanese clinicians should also be aware of CM, in case a falciparum malaria patient with some consciousness disturbance visits the clinic.
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93
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Beare NAV, Glover SJ, Molyneux M. Malarial retinopathy in cerebral malaria. Am J Trop Med Hyg 2009; 80:171. [PMID: 19190205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
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Kochar DK, Das A, Kochar SK, Saxena V, Sirohi P, Garg S, Kochar A, Khatri MP, Gupta V. Severe Plasmodium vivax malaria: a report on serial cases from Bikaner in northwestern India. Am J Trop Med Hyg 2009; 80:194-198. [PMID: 19190212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
Epidemiologic studies and clinical description of severe Plasmodium vivax malaria in adults living in malaria-endemic areas are rare and more attention is needed to understand the dynamics and its interaction with the immune system. This observational study included 1,091 adult patients admitted to medical wards of S. P. Medical College and associated group of hospitals in Bikaner, India from September 2003 through December 2005. The diagnosis of P. vivax malaria was established by peripheral blood film (PBF), rapid diagnostic test (RDT), and polymerase chain reaction (PCR), and severe malaria was categorized as per World Health Organization guidelines. Of 1,091 patients with malaria, 635 had P. falciparum malaria and 456 had P. vivax malaria. Among patients with severe manifestations, 40 had evidence of monoinfection of P. vivax malaria diagnosed by PBF, RDT, and PCR. Complications observed were hepatic dysfunction and jaundice in 23 (57.5%) patients, renal failure in 18 (45%) patients, severe anemia in 13 (32.5%) patients, cerebral malaria in 5 patients (12.5%), acute respiratory distress syndrome in 4 patients (10%), shock in 3 patients (7.5%), and hypoglycemia in 1 (2.5%) patient. Thrombocytopenia was observed in 5 (12.5%) patients, and multi-organ dysfunction was detected in 19 (47.5%) patients. Further large-scale multicentric epidemiologic studies are needed to define the basic pathology of this less known entity.
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White VA, Lewallen S, Beare NAV, Molyneux ME, Taylor TE. Retinal pathology of pediatric cerebral malaria in Malawi. PLoS One 2009; 4:e4317. [PMID: 19177166 PMCID: PMC2627904 DOI: 10.1371/journal.pone.0004317] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Accepted: 12/22/2008] [Indexed: 11/19/2022] Open
Abstract
Introduction The causes of coma and death in cerebral malaria remain unknown. Malarial retinopathy has been identified as an important clinical sign in the diagnosis and prognosis of cerebral malaria. As part of a larger autopsy study to determine causes of death in children with coma presenting to hospital in Blantyre, Malawi, who were fully evaluated clinically prior to death, we examined the histopathology of eyes of patients who died and underwent autopsy. Methodology/Principal Findings Children with coma were admitted to the pediatric research ward, classified according to clinical definitions as having cerebral malaria or another cause of coma, evaluated and treated. The eyes were examined by direct and indirect ophthalmoscopy. If a child died and permission was given, a standardized autopsy was carried out. The patient was then assigned an actual cause of death according to the autopsy findings. The eyes were examined pathologically for hemorrhages, cystoid macular edema, parasite sequestration and thrombi. They were stained immunohistochemically for fibrin and CD61 to identify the components of thrombi, β-amyloid precursor protein to detect axonal damage, for fibrinogen to identify vascular leakage and for glial fibrillary acidic protein to detect gliosis. Sixty-four eyes from 64 patients were examined: 35 with cerebral malaria and 29 with comas of other causes. Cerebral malaria was distinguished by sequestration of parasitized erythrocytes, the presence and severity of retinal hemorrhages, the presence of cystoid macular edema, the occurrence and number of fibrin-platelet thrombi, the presence and amount of axonal damage and vascular leakage. Conclusions/Significance We found significant differences in retinal histopathology between patients who died of cerebral malaria and those with other diagnoses. These histopathological findings offer insights into the etiology of malarial retinopathy and provide a pathological basis for recently described retinal capillary non-perfusion in children with malarial retinopathy. Because of the similarities between the retina and the brain it also suggests mechanisms that may contribute to coma and death in cerebral malaria.
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de Lagerie SB, Fernandez C, German-Fattal M, Gantier JC, Gimenez F, Farinotti R. Impact of cerebral malaria on brain distribution of mefloquine. Drug Metab Lett 2009; 3:15-17. [PMID: 19356112 DOI: 10.2174/187231209787176407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Cerebral malaria (CM) is the most severe complication of Plasmodium falciparum malaria. The aim of this study was to investigate the influence of CM on the cerebral uptake of mefloquine (MQ), in an experimental model of mice infected with Plasmodium berghei ANKA (PbA). Drug diffusion in brain is closely related to efflux pumps such as P-glycoprotein (P-gp/ABCB1/MDR1) and Breast Cancer Resistant Protein (BCRP/ABCG2), two major components of the blood-brain barrier (BBB) which can be modified by inflammation and/or infection. After a single IP dose, MQ concentrations were measured by liquid chromatography in blood and brains of mice infected with Plasmodium berghei ANKA and compared with that of non-infected mice. Our results show that MQ brain concentrations were decreased in CM mice versus healthy mice (0.77 versus 1.31 for brain/plasma concentrations). Although MQ is transported out of endothelial cells by P-glycoprotein, this result cannot be related to this transporter as we have previously shown that CM does not alter P-gp function (personal data). CM induces a reduction of MQ brain transport and, therefore, an increase of central toxicity due to MQ should not be expected during CM.
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Blanco YC, Farias AS, Goelnitz U, Lopes SCP, Arrais-Silva WW, Carvalho BO, Amino R, Wunderlich G, Santos LMB, Giorgio S, Costa FTM. Hyperbaric oxygen prevents early death caused by experimental cerebral malaria. PLoS One 2008; 3:e3126. [PMID: 18769544 PMCID: PMC2518956 DOI: 10.1371/journal.pone.0003126] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Accepted: 08/14/2008] [Indexed: 01/12/2023] Open
Abstract
Background Cerebral malaria (CM) is a syndrome characterized by neurological signs, seizures and coma. Despite the fact that CM presents similarities with cerebral stroke, few studies have focused on new supportive therapies for the disease. Hyperbaric oxygen (HBO) therapy has been successfully used in patients with numerous brain disorders such as stroke, migraine and atherosclerosis. Methodology/Principal Findings C57BL/6 mice infected with Plasmodium berghei ANKA (PbA) were exposed to daily doses of HBO (100% O2, 3.0 ATA, 1–2 h per day) in conditions well-tolerated by humans and animals, before or after parasite establishment. Cumulative survival analyses demonstrated that HBO therapy protected 50% of PbA-infected mice and delayed CM-specific neurological signs when administrated after patent parasitemia. Pressurized oxygen therapy reduced peripheral parasitemia, expression of TNF-α, IFN-γ and IL-10 mRNA levels and percentage of γδ and αβ CD4+ and CD8+ T lymphocytes sequestered in mice brains, thus resulting in a reduction of blood-brain barrier (BBB) dysfunction and hypothermia. Conclusions/Significance The data presented here is the first indication that HBO treatment could be used as supportive therapy, perhaps in association with neuroprotective drugs, to prevent CM clinical outcomes, including death.
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Togbe D, Loureiro de Sousa P, Fauconnier M, Boissay V, Fick L, Scheu S, Pfeffer K, Menard R, Grau GE, Doan BT, Beloeil JC, Renia L, Hansen AM, Ball HJ, Hunt NH, Ryffel B, Quesniaux VFJ. Both functional LTbeta receptor and TNF receptor 2 are required for the development of experimental cerebral malaria. PLoS One 2008; 3:e2608. [PMID: 18612394 PMCID: PMC2442868 DOI: 10.1371/journal.pone.0002608] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Accepted: 06/04/2008] [Indexed: 12/19/2022] Open
Abstract
Background TNF-related lymphotoxin α (LTα) is essential for the development of Plasmodium berghei ANKA (PbA)-induced experimental cerebral malaria (ECM). The pathway involved has been attributed to TNFR2. Here we show a second arm of LTα-signaling essential for ECM development through LTβ-R, receptor of LTα1β2 heterotrimer. Methodology/Principal Findings LTβR deficient mice did not develop the neurological signs seen in PbA induced ECM but died at three weeks with high parasitaemia and severe anemia like LTαβ deficient mice. Resistance of LTαβ or LTβR deficient mice correlated with unaltered cerebral microcirculation and absence of ischemia, as documented by magnetic resonance imaging and angiography, associated with lack of microvascular obstruction, while wild-type mice developed distinct microvascular pathology. Recruitment and activation of perforin+ CD8+ T cells, and their ICAM-1 expression were clearly attenuated in the brain of resistant mice. An essential contribution of LIGHT, another LTβR ligand, could be excluded, as LIGHT deficient mice rapidly succumbed to ECM. Conclusions/Significance LTβR expressed on radioresistant resident stromal, probably endothelial cells, rather than hematopoietic cells, are essential for the development of ECM, as assessed by hematopoietic reconstitution experiment. Therefore, the data suggest that both functional LTβR and TNFR2 signaling are required and non-redundant for the development of microvascular pathology resulting in fatal ECM.
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Hossain MA, Afroj S, Rahman MR, Yunus EB, Samad R, Asna ZH, Akter S, Faiz MA. Evaluation of alternative diagnostic techniques for diagnosis of cerebral malaria in a tertiary referral hospital in Bangladesh. Mymensingh Med J 2008; 17:180-185. [PMID: 18626455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Five alternative techniques for diagnosis of malaria were evaluated in 124 clinically diagnosed cerebral malaria cases admitted in a tertiary hospital in Bangladesh. Clinical diagnosis of cerebral malaria was done by WHO criteria. The tests were conventional routine malaria microscopy; prolonged microscopy; dipstick antigen capture assay (Para Sight TM-F test); pigments in peripheral leucocytes and routine microscopy repeated at 12 hours interval. First four tests were done at 0 hours of hospital admission and repeat routine microscopy was added at 12 hours interval. Diagnostic capability of the test was 64%, 65%, 69%, 27% and 63% respectively. None of the tests except pigments in peripheral leucocytes was superior at initial evaluation. Only the dipstick test added 5% more diagnostic possibility compared with routine microscopy as standard. Stratification of diagnostic capability in different ways improved diagnosis 15% and 11% in smear negative cases by dipstick and prolonged microscopy respectively. It was increased by 50% (5/10 patients) with dipstick test in the smear negative patients with history of anti-malarials prior to hospital admission.
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Van den Steen PE, Deroost K, Van Aelst I, Geurts N, Martens E, Struyf S, Nie CQ, Hansen DS, Matthys P, Van Damme J, Opdenakker G. CXCR3 determines strain susceptibility to murine cerebral malaria by mediating T lymphocyte migration toward IFN-gamma-induced chemokines. Eur J Immunol 2008; 38:1082-95. [PMID: 18383042 DOI: 10.1002/eji.200737906] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Cerebral malaria (CM) results from the binding of infected erythrocytes and leukocytes to brain endothelia. The precise mechanisms underlying lymphocyte recruitment and activation in CM remain unclear. Therefore, the expression of various chemokines was quantified in brains of mice infected with Plasmodium berghei ANKA (PbA). Several chemokines attracting monocytes and activated T-lymphocytes were expressed at high levels. Their expression was almost completely abrogated in IFN-gamma ligand and receptor KO mice, indicating that IFN-gamma is an essential chemokine inducer in vivo. Surprisingly, the expression levels of chemokines, IFN-gamma and also adhesion molecules in the brain were not lower in CM-resistant Balb/c and DBA/2 mice compared to CM-sensitive C57BL/6 and DBA/1 mice, although T lymphocyte sequestration in the brain was significantly less in CM-resistant than in CM-sensitive mice. This difference correlated with a higher up-regulation of the CXC chemokine receptor (CXCR)-3 on splenic T cells and a higher chemotactic response to IFN-gamma-inducible protein-10 (IP-10) in C57BL/6 compared to Balb/c mice. In conclusion, parasite-induced IFN-gamma in the brain results in high local expression levels of specific chemokines for monocytes and lymphocytes. The strain-dependent susceptibility to develop CM is more related to the expression of CXCR3 in circulating leukocytes than to the chemokine expression levels in the brain.
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