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Parthasarathy A, Kalesh K. Defeating the trypanosomatid trio: proteomics of the protozoan parasites causing neglected tropical diseases. RSC Med Chem 2020; 11:625-645. [PMID: 33479664 PMCID: PMC7549140 DOI: 10.1039/d0md00122h] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 05/12/2020] [Indexed: 12/20/2022] Open
Abstract
Mass spectrometry-based proteomics enables accurate measurement of the modulations of proteins on a large scale upon perturbation and facilitates the understanding of the functional roles of proteins in biological systems. It is a particularly relevant methodology for studying Leishmania spp., Trypanosoma cruzi and Trypanosoma brucei, as the gene expression in these parasites is primarily regulated by posttranscriptional mechanisms. Large-scale proteomics studies have revealed a plethora of information regarding modulated proteins and their molecular interactions during various life processes of the protozoans, including stress adaptation, life cycle changes and interactions with the host. Important molecular processes within the parasite that regulate the activity and subcellular localisation of its proteins, including several co- and post-translational modifications, are also accurately captured by modern proteomics mass spectrometry techniques. Finally, in combination with synthetic chemistry, proteomic techniques facilitate unbiased profiling of targets and off-targets of pharmacologically active compounds in the parasites. This provides important data sets for their mechanism of action studies, thereby aiding drug development programmes.
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Affiliation(s)
- Anutthaman Parthasarathy
- Rochester Institute of Technology , Thomas H. Gosnell School of Life Sciences , 85 Lomb Memorial Dr , Rochester , NY 14623 , USA
| | - Karunakaran Kalesh
- Department of Chemistry , Durham University , Lower Mount Joy, South Road , Durham DH1 3LE , UK .
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Neopterin and CXCL-13 in Diagnosis and Follow-Up of Trypanosoma brucei gambiense Sleeping Sickness: Lessons from the Field in Angola. BIOMED RESEARCH INTERNATIONAL 2019; 2019:6070176. [PMID: 31886231 PMCID: PMC6914994 DOI: 10.1155/2019/6070176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 09/10/2019] [Accepted: 10/08/2019] [Indexed: 11/26/2022]
Abstract
Human African Trypanosomiasis may become manageable in the next decade with fexinidazole. However, currently stage diagnosis remains difficult to implement in the field and requires a lumbar puncture. Our study of an Angolan cohort of T. b. gambiense-infected patients used other staging criteria than those recommended by the WHO. We compared WHO criteria (cell count and parasite identification in the CSF) with two biomarkers (neopterin and CXCL-13) which have proven potential to diagnose disease stage or relapse. Biological, clinical, and neurological data were analysed from a cohort of 83 patients. A neopterin concentration below 15.5 nmol/L in the CSF denoted patients with stage 1 disease, and a concentration above 60.31 nmol/L characterized patients with advanced stage 2 (trypanosomes in CSF and/or cytorachia higher than 20 cells) disease. CXCL-13 levels below 91.208 pg/mL denoted patients with stage 1 disease, and levels of CXCL-13 above 395.45 pg/mL denoted patients with advanced stage 2 disease. Values between these cut-offs may represent patients with intermediate stage disease. Our work supports the existence of an intermediate stage in HAT, and CXCL-13 and neopterin levels may help to characterize it.
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Allain T, Fekete E, Buret AG. Giardia Cysteine Proteases: The Teeth behind the Smile. Trends Parasitol 2019; 35:636-648. [DOI: 10.1016/j.pt.2019.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/03/2019] [Accepted: 06/06/2019] [Indexed: 01/15/2023]
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De Niz M, Nacer A, Frischknecht F. Intravital microscopy: Imaging host-parasite interactions in the brain. Cell Microbiol 2019; 21:e13024. [PMID: 30830993 DOI: 10.1111/cmi.13024] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 02/14/2019] [Accepted: 02/24/2019] [Indexed: 12/31/2022]
Abstract
Intravital fluorescence microscopy (IVM) is a powerful technique for imaging multiple organs, including the brain of living mice and rats. It enables the direct visualisation of cells in situ providing a real-life view of biological processes that in vitro systems cannot. In addition, to the technological advances in microscopy over the last decade, there have been supporting innovations in data storage and analytical packages that enable the visualisation and analysis of large data sets. Here, we review the advantages and limitations of techniques predominantly used for brain IVM, including thinned skull windows, open skull cortical windows, and a miniaturised optical system based on microendoscopic probes that can be inserted into deep tissues. Further, we explore the relevance of these techniques for the field of parasitology. Several protozoan infections are associated with neurological symptoms including Plasmodium spp., Toxoplasma spp., and Trypanosoma spp. IVM has led to crucial findings on these parasite species, which are discussed in detail in this review.
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Affiliation(s)
- Mariana De Niz
- Institute of Cell Biology, University of Bern, Bern, Switzerland.,Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasglow, UK
| | - Adéla Nacer
- Division of Bacteriology, National Institute for Biological Standards and Control, Medicines and Healthcare products Regulatory Agency, EN63QG, Potters Bar, UK
| | - Friedrich Frischknecht
- Parasitology-Centre for Infectious Diseases, University of Heidelberg Medical School, Heidelberg, Germany
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Bonnet J, Garcia C, Leger T, Couquet MP, Vignoles P, Vatunga G, Ndung'u J, Boudot C, Bisser S, Courtioux B. Proteome characterization in various biological fluids of Trypanosoma brucei gambiense-infected subjects. J Proteomics 2018; 196:150-161. [PMID: 30414516 DOI: 10.1016/j.jprot.2018.11.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 10/02/2018] [Accepted: 11/05/2018] [Indexed: 02/04/2023]
Abstract
Human African trypanosomiasis (HAT) is a neglected tropical disease that is endemic in sub-Saharan Africa. Control of the disease has been recently improved by better screening and treatment strategies, and the disease is on the WHO list of possible elimination. However, some physiopathological aspects of the disease transmission and progression remain unclear. We propose a new proteomic approach to identify new targets and thus possible new biomarkers of the disease. We also focused our attention on fluids classically associated with HAT (serum and cerebrospinal fluid (CSF)) and on the more easily accessible biological fluids urine and saliva. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) established the proteomic profile of patients with early and late stage disease. The serum, CSF, urine and saliva of 3 uninfected controls, 3 early stage patients and 4 late stage patients were analyzed. Among proteins identified, in CSF, urine and saliva, respectively, 37, 8 and 24 proteins were differentially expressed and showed particular interest with regards to their function. The most promising proteins (Neogenin, Neuroserpin, secretogranin 2 in CSF; moesin in urine and intelectin 2 in saliva) were quantified by enzyme-linked immunosorbent assay in a confirmatory cohort of 14 uninfected controls, 23 patients with early stage disease and 43 patients with late stage disease. The potential of two proteins, neuroserpin and moesin, with the latter present in urine, were further characterized. Our results showed the potential of proteomic analysis to discover new biomarkers and provide the basis of the establishment of a new proteomic catalogue applied to HAT-infected subjects and controls. SIGNIFICANCE: Sleeping sickness, also called Human African Trypanosomiasis (HAT), is a parasitic infection caused by a parasitic protozoan, Trypanosoma brucei gambiense or T. b. rhodesiense which are transmitted via an infected tsetse fly: Glossina. For both, the haemolymphatic stage (or first stage) signs and symptoms are intermittent fever, lymphadenopathy, hepatosplenomegaly, headaches, pruritus, and for T. b. rhodesiense infection a chancre is often formed at the bite site. Meningoencephalitic stage (or second stage) occurs when parasites invade the CNS, it is characterised by neurological signs and symptoms such as altered gait, tremors, neuropathy, somnolence which can lead to coma and death if untreated. first stage of the disease is characterizing by fevers, headaches, itchiness, and joint pains and progressive lethargy corresponding to the second stage with confusion, poor coordination, numbness and trouble sleeping. Actually, diagnosing HAT requires specialized expertise and significant resources such as well-equipped health centers and qualified staff. Such resources are lacking in many endemic areas that are often in rural locales, so many individuals with HAT die before the diagnosis is established. In this study, we analysed by mass spectrometry the entire proteome of serum, CSF, urine and saliva samples from infected and non-infected Angolan individuals to define new biomarkers of the disease. This work of proteomics analysis is a preliminary stage to the characterization of the whole proteome, of these 4 biological fluids, of HAT patients. We have identified 69 new biomarkers. Five of them have been thoroughly investigated by ELISA quantification. Neuroserpine and Moesin are respectively promising new biomarkers in CSF and urine's patient for a better diagnosis.
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Affiliation(s)
- Julien Bonnet
- Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, CNRS FR 3503 GEIST, University of Limoges, INSERM UMR 1094 Tropical Neuroepidemiology, Limoges, France.
| | - Camille Garcia
- Jacques Monod Institute, Proteomics Facility, University Paris Diderot Sorbonne Paris Cité, Paris, France..
| | - Thibaut Leger
- Jacques Monod Institute, Proteomics Facility, University Paris Diderot Sorbonne Paris Cité, Paris, France..
| | - Marie-Pauline Couquet
- Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, CNRS FR 3503 GEIST, University of Limoges, INSERM UMR 1094 Tropical Neuroepidemiology, Limoges, France.
| | - Philippe Vignoles
- Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, CNRS FR 3503 GEIST, University of Limoges, INSERM UMR 1094 Tropical Neuroepidemiology, Limoges, France.
| | - Gedeao Vatunga
- Instituto de Combate e controlo das Tripanossomiases (ICCT), Luanda, Angola.
| | - Joseph Ndung'u
- Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland.
| | - Clotilde Boudot
- Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, CNRS FR 3503 GEIST, University of Limoges, INSERM UMR 1094 Tropical Neuroepidemiology, Limoges, France.
| | - Sylvie Bisser
- Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, CNRS FR 3503 GEIST, University of Limoges, INSERM UMR 1094 Tropical Neuroepidemiology, Limoges, France; Pasteur Institute in French Guiana, 23 Boulevard Pasteur, 973006, Cayenne Cedex, French Guiana.
| | - Bertrand Courtioux
- Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, CNRS FR 3503 GEIST, University of Limoges, INSERM UMR 1094 Tropical Neuroepidemiology, Limoges, France.
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Ueno N, Lodoen MB. From the blood to the brain: avenues of eukaryotic pathogen dissemination to the central nervous system. Curr Opin Microbiol 2015; 26:53-9. [PMID: 26048316 PMCID: PMC10538213 DOI: 10.1016/j.mib.2015.05.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 05/07/2015] [Accepted: 05/08/2015] [Indexed: 12/25/2022]
Abstract
Infection of the central nervous system (CNS) is a significant cause of morbidity and mortality, and treatments available to combat the highly debilitating symptoms of CNS infection are limited. The mechanisms by which pathogens in the circulation overcome host immunity and breach the blood-brain barrier are active areas of investigation. In this review, we discuss recent work that has significantly advanced our understanding of the avenues of pathogen dissemination to the CNS for four eukaryotic pathogens of global health importance: Toxoplasma gondii, Plasmodium falciparum, Trypanosoma brucei, and Cryptococcus neoformans. These studies highlight the remarkable diversity of pathogen strategies for trafficking to the brain and will ultimately contribute to an improved ability to combat life-threatening CNS disease.
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Affiliation(s)
- Norikiyo Ueno
- Department of Molecular Biology and Biochemistry and the Institute for Immunology, University of California, Irvine, CA, USA
| | - Melissa B Lodoen
- Department of Molecular Biology and Biochemistry and the Institute for Immunology, University of California, Irvine, CA, USA.
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7
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Tryps and trips: cell trafficking across the 100-year-old blood-brain barrier. Trends Neurosci 2014; 37:325-33. [PMID: 24780507 PMCID: PMC4045197 DOI: 10.1016/j.tins.2014.03.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 03/27/2014] [Accepted: 03/28/2014] [Indexed: 01/03/2023]
Abstract
The blood–brain barrier (BBB) was discovered one century ago by the use of trypan dyes. The discovery initiated the targeted brain delivery of drugs. Trypan dyes were developed to kill African trypanosomes that cause sleeping sickness. Trypanosomes disclose cell trafficking in and out of the BBB. Disturbed gating at the BBB may cause neurodegeneration.
One hundred years ago, Edwin E. Goldmann discovered the blood–brain barrier (BBB) using trypan dyes. These dyes were developed and named by Paul Ehrlich during his search for drugs to kill African trypanosomes (extracellular parasites that cause sleeping sickness) while sparing host cells. For Ehrlich, this was the first strategy based on the ‘chemotherapy’ concept he had introduced. The discovery of the BBB revealed, however, the difficulties in drug delivery to the brain. Mechanisms by which parasites enter, dwell, and exit the brain currently provide novel views on cell trafficking across the BBB. These mechanisms also highlight the role of pericytes and endocytosis regulation in BBB functioning and in disrupted BBB gating, which may be involved in the pathogenesis of neurodegeneration.
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Abstract
Invasion of the central nervous system (CNS) is a most devastating complication of a parasitic infection. Several physical and immunological barriers provide obstacles to such an invasion. In this broad overview focus is given to the physical barriers to neuroinvasion of parasites provided at the portal of entry of the parasites, i.e., the skin and epithelial cells of the gastrointestinal tract, and between the blood and the brain parenchyma, i.e., the blood-brain barrier (BBB). A description is given on how human pathogenic parasites can reach the CNS via the bloodstream either as free-living or extracellular parasites, by embolization of eggs, or within red or white blood cells when adapted to intracellular life. Molecular mechanisms are discussed by which parasites can interact with or pass across the BBB. The possible targeting of the circumventricular organs by parasites, as well as the parasites' direct entry to the brain from the nasal cavity through the olfactory nerve pathway, is also highlighted. Finally, examples are given which illustrate different mechanisms by which parasites can cause dysfunction or damage in the CNS related to toxic effects of parasite-derived molecules or to immune responses to the infection.
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Abstract
Parasitic infections of the central nervous system (CNS) include two broad categories of infectious organisms: single-celled protozoa and multicellular metazoa. The protozoal infections include malaria, American trypanosomiasis, human African trypanosomiasis, toxoplasmosis, amebiasis, microsporidiasis, and leishmaniasis. The metazoal infections are grouped into flatworms, which include trematoda and cestoda, and roundworms or nematoda. Trematoda infections include schistosomiasis and paragonimiasis. Cestoda infections include cysticercosis, coenurosis, hydatidosis, and sparganosis. Nematoda infections include gnathostomiasis, angiostrongyliasis, toxocariasis, strongyloidiasis, filariasis, baylisascariasis, dracunculiasis, micronemiasis, and lagochilascariasis. The most common route of CNS invasion is through the blood. In some cases, the parasite invades the olfactory neuroepithelium in the nasal mucosa and penetrates the brain via the subarachnoid space or reaches the CNS through neural foramina of the skull base around the cranial nerves or vessels. The neuropathological changes vary greatly, depending on the type and size of the parasite, geographical strain variations in parasitic virulence, immune evasion by the parasite, and differences in host immune response. Congestion of the leptomeninges, cerebral edema, hemorrhage, thrombosis, vasculitis, necrosis, calcification, abscesses, meningeal and perivascular polymorphonuclear and mononuclear inflammatory infiltrate, microglial nodules, gliosis, granulomas, and fibrosis can be found affecting isolated or multiple regions of the CNS, or even diffusely spread. Some infections may be present as an expanding mass lesion. The parasites can be identified by conventional histology, immunohistochemistry, in situ hybridization, and PCR.
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Affiliation(s)
- José Eymard Homem Pittella
- Pathology Service, Hospital das Clínicas, Medical Faculty of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
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Lavrado J, Mackey Z, Hansell E, McKerrow JH, Paulo A, Moreira R. Antitrypanosomal and cysteine protease inhibitory activities of alkyldiamine cryptolepine derivatives. Bioorg Med Chem Lett 2012; 22:6256-60. [DOI: 10.1016/j.bmcl.2012.07.104] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 07/30/2012] [Accepted: 07/31/2012] [Indexed: 11/16/2022]
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Jamonneau V, Ilboudo H, Kaboré J, Kaba D, Koffi M, Solano P, Garcia A, Courtin D, Laveissière C, Lingue K, Büscher P, Bucheton B. Untreated human infections by Trypanosoma brucei gambiense are not 100% fatal. PLoS Negl Trop Dis 2012; 6:e1691. [PMID: 22720107 PMCID: PMC3373650 DOI: 10.1371/journal.pntd.0001691] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 04/30/2012] [Indexed: 02/04/2023] Open
Abstract
The final outcome of infection by Trypanosoma brucei gambiense, the main agent of sleeping sickness, has always been considered as invariably fatal. While scarce and old reports have mentioned cases of self-cure in untreated patients, these studies suffered from the lack of accurate diagnostic tools available at that time. Here, using the most specific and sensitive tools available to date, we report on a long-term follow-up (15 years) of a cohort of 50 human African trypanosomiasis (HAT) patients from the Ivory Coast among whom 11 refused treatment after their initial diagnosis. In 10 out of 11 subjects who continued to refuse treatment despite repeated visits, parasite clearance was observed using both microscopy and polymerase chain reaction (PCR). Most of these subjects (7/10) also displayed decreasing serological responses, becoming progressively negative to trypanosome variable antigens (LiTat 1.3, 1.5 and 1.6). Hence, in addition to the “classic” lethal outcome of HAT, we show that alternative natural progressions of HAT may occur: progression to an apparently aparasitaemic and asymptomatic infection associated with strong long-lasting serological responses and progression to an apparently spontaneous resolution of infection (with negative results in parasitological tests and PCR) associated with a progressive drop in antibody titres as observed in treated cases. While this study does not precisely estimate the frequency of the alternative courses for this infection, it is noteworthy that in the field national control programs encounter a significant proportion of subjects displaying positive serologic test results but negative results in parasitological testing. These findings demonstrate that a number of these subjects display such infection courses. From our point of view, recognising that trypanotolerance exists in humans, as is now widely accepted for animals, is a major step forward for future research in the field of HAT. The existence of a diversity of infection outcomes – ranging from self-cure to asymptomatic, severe or fatal cases – is now widely recognised for most parasitic and infectious diseases. The dogma concerning sleeping sickness, however, is still that infection is 100% fatal. Here we describe a 15-year follow-up of patients diagnosed with human African trypanosomiasis (HAT) in the Ivory Coast but who refused treatment. Our results, based on clinical, serological, molecular, and parasitological investigations, combining diagnostic tools for the field and highly specific and sensitive laboratory tests, constitute the most comprehensive study on the natural evolution of Trypanosoma brucei gambiense infection in its human host. At least two alternative natural progressions of HAT to the “classic” fatal disease were identified: a progression to an apparently aparasitaemic and asymptomatic infection and a progression to an apparently spontaneous resolution of infection. We believe that recognising that trypanotolerance exists in humans is a major step forward for future research aimed at identifying human-specific defence and immune mechanisms involved in the control of T.b. gambiense infection and thus new candidate therapeutic or prophylactic targets.
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Affiliation(s)
- Vincent Jamonneau
- Institut de Recherche pour le Développement, Unité Mixte de Recherche IRD-CIRAD 177, Campus International de Baillarguet, Montpellier, France.
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Tucker IG, Yang L, Mujoo H. Delivery of drugs to the brain via the blood brain barrier using colloidal carriers. J Microencapsul 2012; 29:475-86. [PMID: 22563886 DOI: 10.3109/02652048.2012.658445] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Delivering drugs to the brain is challenging given the selective permeability of the blood brain barrier (BBB). Targeted colloidal carriers containing drug payloads offer some promise for enhanced and perhaps selective delivery to brain. This review examines the recent literature and identifies issues to be addressed if these systems are to be rationally designed. These include opsonization of nanoparticles and off-target clearance; the cerebral microvasculature, flow of nanoparticles in capillaries and binding to the capillary wall; and transcytosis. Capillary architecture, blood flow and BBB permeability are affected by disease and age and there are species differences. These complexities caution against making extravagant claims for a particular nanosystem but they also highlight the rich opportunities and need for critical research in this field.
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Affiliation(s)
- Ian G Tucker
- School of Pharmacy, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
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Abstract
The blood-brain barrier (BBB) is a structural and functional barrier that protects the central nervous system (CNS) from invasion by blood-borne pathogens including parasites. However, some intracellular and extracellular parasites can traverse the BBB during the course of infection and cause neurological disturbances and/or damage which are at times fatal. The means by which parasites cross the BBB and how the immune system controls the parasites within the brain are still unclear. In this review we present the current understanding of the processes utilized by two human neuropathogenic parasites, Trypanosoma brucei spp and Toxoplasma gondii, to go across the BBB and consequences of CNS invasion. We also describe briefly other parasites that can invade the brain and how they interact with or circumvent the BBB. The roles played by parasite-derived and host-derived molecules during parasitic and white blood cell invasion of the brain are discussed.
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Affiliation(s)
- Willias Masocha
- Department of Applied Therapeutics, Faculty of Pharmacy, Kuwait University, Kuwait City, Kuwait
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Kangethe RT, Boulangé AF, Coustou V, Baltz T, Coetzer TH. Trypanosoma brucei brucei oligopeptidase B null mutants display increased prolyl oligopeptidase-like activity. Mol Biochem Parasitol 2012; 182:7-16. [DOI: 10.1016/j.molbiopara.2011.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 10/07/2011] [Accepted: 11/14/2011] [Indexed: 01/08/2023]
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Deborggraeve S, Lejon V, Ekangu RA, Mumba Ngoyi D, Pati Pyana P, Ilunga M, Mulunda JP, Büscher P. Diagnostic accuracy of PCR in gambiense sleeping sickness diagnosis, staging and post-treatment follow-up: a 2-year longitudinal study. PLoS Negl Trop Dis 2011; 5:e972. [PMID: 21364966 PMCID: PMC3042993 DOI: 10.1371/journal.pntd.0000972] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 01/25/2011] [Indexed: 12/01/2022] Open
Abstract
Background The polymerase chain reaction (PCR) has been proposed for diagnosis, staging and post-treatment follow-up of sleeping sickness but no large-scale clinical evaluations of its diagnostic accuracy have taken place yet. Methodology/Principal Findings An 18S ribosomal RNA gene targeting PCR was performed on blood and cerebrospinal fluid (CSF) of 360 T. brucei gambiense sleeping sickness patients and on blood of 129 endemic controls from the Democratic Republic of Congo. Sensitivity and specificity (with 95% confidence intervals) of PCR for diagnosis, disease staging and treatment failure over 2 years follow-up post-treatment were determined. Reference standard tests were trypanosome detection for diagnosis and trypanosome detection and/or increased white blood cell concentration in CSF for staging and detection of treatment failure. PCR on blood showed a sensitivity of 88.4% (84.4–92.5%) and a specificity of 99.2% (97.7–100%) for diagnosis, while for disease staging the sensitivity and specificity of PCR on cerebrospinal fluid were 88.4% (84.8–91.9%) and 82.9% (71.2–94.6%), respectively. During follow-up after treatment, PCR on blood had low sensitivity to detect treatment failure. In cerebrospinal fluid, PCR positivity vanished slowly and was observed until the end of the 2 year follow-up in around 20% of successfully treated patients. Conclusions/Significance For T.b. gambiense sleeping sickness diagnosis and staging, PCR performed better than, or similar to, the current parasite detection techniques but it cannot be used for post-treatment follow-up. Continued PCR positivity in one out of five cured patients points to persistence of living or dead parasites or their DNA after successful treatment and may necessitate the revision of some paradigms about the pathophysiology of sleeping sickness. Post-treatment follow-up is crucial for sleeping sickness patient management and still relies on microscopic examination of the cerebrospinal fluid (CSF). Detection of the parasites DNA with the polymerase chain reaction (PCR) is proposed as a promising and possibly non-invasive alternative for monitoring treatment outcome, but has never been evaluated. We performed PCR on blood and CSF of 360 Trypanosoma brucei gambiense sleeping sickness patients, before treatment and during 2 years after treatment, and on blood of 129 controls. We found that performance of PCR to diagnose sleeping sickness and detect brain involvement was better or similar to current diagnostic techniques. However, we observed that PCR was unreliable for monitoring treatment outcome. Continued PCR positivity in cured patients points to persistence of parasites, or their DNA, after successful treatment, challenging the dogma that in sleeping sickness cure equals parasite elimination. In conclusion, we do not recommend PCR for treatment outcome assessment in sleeping sickness.
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Affiliation(s)
- Stijn Deborggraeve
- Department of Parasitology, Institute of Tropical Medicine, Antwerp, Belgium
- Rega Institute, Catholic University of Leuven, Leuven, Belgium
| | - Veerle Lejon
- Department of Parasitology, Institute of Tropical Medicine, Antwerp, Belgium
- * E-mail:
| | - Rosine Ali Ekangu
- Department of Parasitology, Institute of Tropical Medicine, Antwerp, Belgium
- Department of Parasitology, Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo
| | - Dieudonné Mumba Ngoyi
- Department of Parasitology, Institute of Tropical Medicine, Antwerp, Belgium
- Department of Parasitology, Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo
| | - Patient Pati Pyana
- Department of Parasitology, Institute of Tropical Medicine, Antwerp, Belgium
- Department of Parasitology, Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo
| | - Médard Ilunga
- Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Mbuji-Mayi, Democratic Republic of the Congo
| | - Jean Pierre Mulunda
- Programme National de Lutte contre la Trypanosomiase Humaine Africaine, Mbuji-Mayi, Democratic Republic of the Congo
| | - Philippe Büscher
- Department of Parasitology, Institute of Tropical Medicine, Antwerp, Belgium
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Elsheikha HM, Khan NA. Protozoa traversal of the blood–brain barrier to invade the central nervous system. FEMS Microbiol Rev 2010; 34:532-53. [DOI: 10.1111/j.1574-6976.2010.00215.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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Rodrigues AC, Garcia HA, Ortiz PA, Cortez AP, Martinkovic F, Paiva F, Batista JS, Minervino AH, Campaner M, Pral EM, Alfieri SC, Teixeira MMG. Cysteine proteases of Trypanosoma (Megatrypanum) theileri: cathepsin L-like gene sequences as targets for phylogenetic analysis, genotyping diagnosis. Parasitol Int 2010; 59:318-25. [PMID: 20230907 DOI: 10.1016/j.parint.2010.03.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Revised: 03/01/2010] [Accepted: 03/08/2010] [Indexed: 10/19/2022]
Abstract
Although Trypanosomatheileri and allied trypanosomes are the most widespread trypanosomes in bovids little is known about proteolytic enzymes in these species. We have characterized genes encoding for cathepsin L-like (CATL) cysteine proteases from isolates of cattle, water buffalo and deer that largely diverged from homologues of other trypanosome species. Analysis of 78 CATL catalytic domain sequences from 22 T. theileri trypanosomes disclosed 6 genotypes tightly clustered together into the T. theileri clade. The CATL genes in these trypanosomes are organized in tandem arrays of approximately 1.7kb located in 2 chromosomal bands of 600-720kb. A diagnostic PCR assay targeting CATL sequences detected T. theileri of all genotypes from cattle, buffaloes and cervids and also from tabanid vectors. Expression of T. theileri cysteine proteases was demonstrated by proteolytic activity in gelatin gels and hydrolysis of Z-Phe-Arg-AMC substrate. Results from this work agree with previous data using ribosomal and spliced leader genes demonstrating that CATL gene sequences are useful for diagnosis, population genotyping and evolutionary studies of T. theileri trypanosomes.
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Affiliation(s)
- Adriana C Rodrigues
- Departamento de Parasitologia, Universidade de São Paulo, São Paulo, SP, Brazil
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Abstract
SUMMARYNeurological involvement following trypanosome infection has been recognised for over a century. However, there are still many unanswered questions concerning the mechanisms used by the parasite to gain entry to the CNS and the pathogenesis of the resulting neuroinflammatory reaction. There is a paucity of material from human cases of the disease therefore the majority of current research relies on the use of animal models of trypanosome infection. This review reports contemporary knowledge, from both animal models and human samples, regarding parasite invasion of the CNS and the neuropathological changes that accompany trypanosome infection and disease progression. The effects of trypanosomes on the blood-brain barrier are discussed and possible key molecules in parasite penetration of the barrier highlighted. Changes in the balance of CNS cytokines and chemokines are also described. The article closes by summarising the effects of trypanosome infection on the circadian sleep-wake cycle, and sleep structure, in relation to neuroinflammation and parasite location within the CNS. Although a great deal of progress has been made in recent years, the advent and application of sophisticated analysis techniques, to decipher the complexities of HAT pathogenesis, herald an exciting and rewarding period for advances in trypanosome research.
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Giroud C, Ottones F, Coustou V, Dacheux D, Biteau N, Miezan B, Van Reet N, Carrington M, Doua F, Baltz T. Murine Models for Trypanosoma brucei gambiense disease progression--from silent to chronic infections and early brain tropism. PLoS Negl Trop Dis 2009; 3:e509. [PMID: 19721701 PMCID: PMC2728506 DOI: 10.1371/journal.pntd.0000509] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Accepted: 07/28/2009] [Indexed: 11/19/2022] Open
Abstract
Background Human African trypanosomiasis (HAT) caused by Trypanosoma brucei gambiense remains highly prevalent in west and central Africa and is lethal if left untreated. The major problem is that the disease often evolves toward chronic or asymptomatic forms with low and fluctuating parasitaemia producing apparently aparasitaemic serological suspects who remain untreated because of the toxicity of the chemotherapy. Whether the different types of infections are due to host or parasite factors has been difficult to address, since T. b. gambiense isolated from patients is often not infectious in rodents thus limiting the variety of isolates. Methodology/Principal findings T. b. gambiense parasites were outgrown directly from the cerebrospinal fluid of infected patients by in vitro culture and analyzed for their molecular polymorphisms. Experimental murine infections showed that these isolates could be clustered into three groups with different characteristics regarding their in vivo infection properties, immune response and capacity for brain invasion. The first isolate induced a classical chronic infection with a fluctuating blood parasitaemia, an invasion of the central nervous system (CNS), a trypanosome specific-antibody response and death of the animals within 6–8 months. The second group induced a sub-chronic infection resulting in a single wave of parasitaemia after infection, followed by a low parasitaemia with no parasites detected by microscope observations of blood but detected by PCR, and the presence of a specific antibody response. The third isolate induced a silent infection characterised by the absence of microscopically detectable parasites throughout, but infection was detectable by PCR during the whole course of infection. Additionally, specific antibodies were barely detectable when mice were infected with a low number of this group of parasites. In both sub-chronic and chronic infections, most of the mice survived more than one year without major clinical symptoms despite an early dissemination and growth of the parasites in different organs including the CNS, as demonstrated by bioluminescent imaging. Conclusions/Significance Whereas trypanosome characterisation assigned all these isolates to the homogeneous Group I of T. b. gambiense, they clearly induce very different infections in mice thus mimicking the broad clinical diversity observed in HAT due to T. b. gambiense. Therefore, these murine models will be very useful for the understanding of different aspects of the physiopathology of HAT and for the development of new diagnostic tools and drugs. Trypanosoma brucei gambiense is responsible for more than 90% of reported cases of human African trypanosomosis (HAT). Infection can last for months or even years without major signs or symptoms of infection, but if left untreated, sleeping sickness is always fatal. In the present study, different T. b. gambiense field isolates from the cerebrospinal fluid of patients with HAT were adapted to growth in vitro. These isolates belong to the homogeneous Group 1 of T. b. gambiense, which is known to induce a chronic infection in humans. In spite of this, these isolates induced infections ranging from chronic to silent in mice, with variations in parasitaemia, mouse lifespan, their ability to invade the CNS and to elicit specific immune responses. In addition, during infection, an unexpected early tropism for the brain as well as the spleen and lungs was observed using bioluminescence analysis. The murine models presented in this work provide new insights into our understanding of HAT and allow further studies of parasite tropism during infection, which will be very useful for the treatment and the diagnosis of the disease.
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Affiliation(s)
- Christiane Giroud
- UMR 5234, Centre National de Recherche Scientifique, IFR66, Université Bordeaux 2, Bordeaux, France
| | - Florence Ottones
- UMR 5234, Centre National de Recherche Scientifique, IFR66, Université Bordeaux 2, Bordeaux, France
| | - Virginie Coustou
- UMR 5234, Centre National de Recherche Scientifique, IFR66, Université Bordeaux 2, Bordeaux, France
| | - Denis Dacheux
- UMR 5234, Centre National de Recherche Scientifique, IFR66, Université Bordeaux 2, Bordeaux, France
| | - Nicolas Biteau
- UMR 5234, Centre National de Recherche Scientifique, IFR66, Université Bordeaux 2, Bordeaux, France
| | - Benjamin Miezan
- Projet de recherches cliniques sur la trypanosomiase (PRCT), Daloa, Ivory Coast
| | - Nick Van Reet
- Institute of Tropical Medicine Antwerp, Department of Parasitology, Antwerp, Belgium
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Felix Doua
- Projet de recherches cliniques sur la trypanosomiase (PRCT), Daloa, Ivory Coast
| | - Théo Baltz
- UMR 5234, Centre National de Recherche Scientifique, IFR66, Université Bordeaux 2, Bordeaux, France
- * E-mail:
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Rodgers J. Human African trypanosomiasis, chemotherapy and CNS disease. J Neuroimmunol 2009; 211:16-22. [DOI: 10.1016/j.jneuroim.2009.02.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Accepted: 02/05/2009] [Indexed: 11/28/2022]
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Ralston KS, Kabututu ZP, Melehani JH, Oberholzer M, Hill KL. The Trypanosoma brucei flagellum: moving parasites in new directions. Annu Rev Microbiol 2009; 63:335-62. [PMID: 19575562 PMCID: PMC3821760 DOI: 10.1146/annurev.micro.091208.073353] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
African trypanosomes are devastating human and animal pathogens. Trypanosoma brucei rhodesiense and T. b. gambiense subspecies cause the fatal human disease known as African sleeping sickness. It is estimated that several hundred thousand new infections occur annually and the disease is fatal if untreated. T. brucei is transmitted by the tsetse fly and alternates between bloodstream-form and insect-form life cycle stages that are adapted to survive in the mammalian host and the insect vector, respectively. The importance of the flagellum for parasite motility and attachment to the tsetse fly salivary gland epithelium has been appreciated for many years. Recent studies have revealed both conserved and novel features of T. brucei flagellum structure and composition, as well as surprising new functions that are outlined here. These discoveries are important from the standpoint of understanding trypanosome biology and identifying novel drug targets, as well as for advancing our understanding of fundamental aspects of eukaryotic flagellum structure and function.
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Affiliation(s)
- Katherine S. Ralston
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California 90095
| | - Zakayi P. Kabututu
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California 90095
| | - Jason H. Melehani
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California 90095
| | - Michael Oberholzer
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California 90095
| | - Kent L. Hill
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California 90095
- Molecular Biology Institute, University of California, Los Angeles, California 90095
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Nikolskaia OV, de A. Lima APC, Kim YV, Lonsdale-Eccles JD, Fukuma T, Scharfstein J, Grab DJ. Blood-brain barrier traversal by African trypanosomes requires calcium signaling induced by parasite cysteine protease. J Clin Invest 2006; 116:2739-47. [PMID: 16998589 PMCID: PMC1570376 DOI: 10.1172/jci27798] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2005] [Accepted: 08/08/2006] [Indexed: 11/17/2022] Open
Abstract
In this study we investigated why bloodstream forms of Trypanosoma brucei gambiense cross human brain microvascular endothelial cells (BMECs), a human blood-brain barrier (BBB) model system, at much greater efficiency than do T. b. brucei. After noting that T. b. gambiense displayed higher levels of cathepsin L-like cysteine proteases, we investigated whether these enzymes contribute to parasite crossing. First, we found that T. b. gambiense crossing of human BMECs was abrogated by N-methylpiperazine-urea-Phe-homopheylalanine-vinylsulfone-benzene (K11777), an irreversible inhibitor of cathepsin L-like cysteine proteases. Affinity labeling and immunochemical studies characterized brucipain as the K11777-sensitive cysteine protease expressed at higher levels by T. b. gambiense. K11777-treated T. b. gambiense failed to elicit calcium fluxes in BMECs, suggesting that generation of activation signals for the BBB is critically dependant on brucipain activity. Strikingly, crossing of T. b. brucei across the BBB was enhanced upon incubation with brucipain-rich supernatants derived from T. b. gambiense. The effects of the conditioned medium, which correlated with ability to evoke calcium fluxes, were canceled by K11777, but not by the cathepsin B inhibitor CA074. Collectively, these in vitro studies implicate brucipain as a critical driver of T. b. gambiense transendothelial migration of the human BBB.
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Affiliation(s)
- Olga V. Nikolskaia
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Center for Biophysical Sciences and Engineering, University of Alabama, Birmingham, Alabama, USA.
Department of Parasitology, Kurume University School of Medicine, Fukuoka, Japan
| | - Ana Paula C. de A. Lima
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Center for Biophysical Sciences and Engineering, University of Alabama, Birmingham, Alabama, USA.
Department of Parasitology, Kurume University School of Medicine, Fukuoka, Japan
| | - Yuri V. Kim
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Center for Biophysical Sciences and Engineering, University of Alabama, Birmingham, Alabama, USA.
Department of Parasitology, Kurume University School of Medicine, Fukuoka, Japan
| | - John D. Lonsdale-Eccles
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Center for Biophysical Sciences and Engineering, University of Alabama, Birmingham, Alabama, USA.
Department of Parasitology, Kurume University School of Medicine, Fukuoka, Japan
| | - Toshihide Fukuma
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Center for Biophysical Sciences and Engineering, University of Alabama, Birmingham, Alabama, USA.
Department of Parasitology, Kurume University School of Medicine, Fukuoka, Japan
| | - Julio Scharfstein
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Center for Biophysical Sciences and Engineering, University of Alabama, Birmingham, Alabama, USA.
Department of Parasitology, Kurume University School of Medicine, Fukuoka, Japan
| | - Dennis J. Grab
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Center for Biophysical Sciences and Engineering, University of Alabama, Birmingham, Alabama, USA.
Department of Parasitology, Kurume University School of Medicine, Fukuoka, Japan
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Kim KS. Microbial translocation of the blood–brain barrier. Int J Parasitol 2006; 36:607-14. [PMID: 16542662 DOI: 10.1016/j.ijpara.2006.01.013] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2005] [Revised: 01/19/2006] [Accepted: 01/30/2006] [Indexed: 11/23/2022]
Abstract
A major contributing factor to high mortality and morbidity associated with CNS infection is the incomplete understanding of the pathogenesis of this disease. Relatively small numbers of pathogens account for most cases of CNS infections in humans, but it is unclear how such pathogens cross the blood-brain barrier (BBB) and cause infections. The development of the in vitro BBB model using human brain microvascular endothelial cells has facilitated our understanding of the microbial translocation of the BBB, a key step for the acquisition of CNS infections. Recent studies have revealed that microbial translocation of the BBB involves host cell actin cytoskeletal rearrangements, most likely as the result of specific microbial-host interactions. A better understanding of microbial-host interactions that are involved in microbial translocation of the BBB should help in developing new strategies to prevent CNS infections. This review summarises our current understanding of the pathogenic mechanisms involved in translocation of the BBB by meningitis-causing bacteria, fungi and parasites.
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Affiliation(s)
- Kwang Sik Kim
- Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Park 256, Baltimore, MD 21287, USA.
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