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Cordon-Obras C, Gomez-Liñan C, Torres-Rusillo S, Vidal-Cobo I, Lopez-Farfan D, Barroso-Del Jesus A, Rojas-Barros D, Carrington M, Navarro M. Identification of sequence-specific promoters driving polycistronic transcription initiation by RNA polymerase II in trypanosomes. Cell Rep 2022; 38:110221. [PMID: 35021094 DOI: 10.1016/j.celrep.2021.110221] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 10/18/2021] [Accepted: 12/15/2021] [Indexed: 11/20/2022] Open
Abstract
Protein-coding genes in trypanosomes occur in polycistronic transcription units (PTUs). How RNA polymerase II (Pol II) initiates transcription of PTUs has not been resolved; the current model favors chromatin modifications inducing transcription rather than sequence-specific promoters. Here, we uncover core promoters by functional characterization of Pol II peaks identified by chromatin immunoprecipitation sequencing (ChIP-seq). Two distinct promoters are located between divergent PTUs, each driving unidirectional transcription. Detailed analysis identifies a 75-bp promoter that is necessary and sufficient to drive full reporter expression and contains functional motifs. Analysis of further promoters suggests transcription initiation is regulated and promoters are either focused or dispersed. In contrast to the previous model of unregulated and promoter-independent transcription initiation, we find that sequence-specific promoters determine the initiation of Pol II transcription of protein-coding genes PTUs. These findings in Trypanosoma brucei suggest that in addition of chromatin modifications, promoter motifs-based regulation of gene expression is deeply conserved among eukaryotes.
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Affiliation(s)
- Carlos Cordon-Obras
- Instituto de Parasitología y Biomedicina López Neyra, Consejo Superior de Investigaciones Científicas, IPBLN-CSIC, 18016 Granada, Spain
| | - Claudia Gomez-Liñan
- Instituto de Parasitología y Biomedicina López Neyra, Consejo Superior de Investigaciones Científicas, IPBLN-CSIC, 18016 Granada, Spain
| | - Sara Torres-Rusillo
- Instituto de Parasitología y Biomedicina López Neyra, Consejo Superior de Investigaciones Científicas, IPBLN-CSIC, 18016 Granada, Spain
| | - Isabel Vidal-Cobo
- Instituto de Parasitología y Biomedicina López Neyra, Consejo Superior de Investigaciones Científicas, IPBLN-CSIC, 18016 Granada, Spain
| | - Diana Lopez-Farfan
- Instituto de Parasitología y Biomedicina López Neyra, Consejo Superior de Investigaciones Científicas, IPBLN-CSIC, 18016 Granada, Spain
| | - Alicia Barroso-Del Jesus
- Instituto de Parasitología y Biomedicina López Neyra, Consejo Superior de Investigaciones Científicas, IPBLN-CSIC, 18016 Granada, Spain
| | - Domingo Rojas-Barros
- Instituto de Parasitología y Biomedicina López Neyra, Consejo Superior de Investigaciones Científicas, IPBLN-CSIC, 18016 Granada, Spain
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK
| | - Miguel Navarro
- Instituto de Parasitología y Biomedicina López Neyra, Consejo Superior de Investigaciones Científicas, IPBLN-CSIC, 18016 Granada, Spain.
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2
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Franco JR, Cecchi G, Paone M, Diarra A, Grout L, Kadima Ebeja A, Simarro PP, Zhao W, Argaw D. The elimination of human African trypanosomiasis: Achievements in relation to WHO road map targets for 2020. PLoS Negl Trop Dis 2022; 16:e0010047. [PMID: 35041668 PMCID: PMC8765662 DOI: 10.1371/journal.pntd.0010047] [Citation(s) in RCA: 50] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 12/02/2021] [Indexed: 11/19/2022] Open
Abstract
Background In the 20th century, epidemics of human African trypanosomiasis (HAT) ravaged communities in a number of African countries. The latest surge in disease transmission was recorded in the late 1990s, with more than 35,000 cases reported annually in 1997 and 1998. In 2013, after more than a decade of sustained control efforts and steady progress, the World Health Assembly resolved to target the elimination of HAT as a public health problem by 2020. We report here on recent progress towards this goal. Methodology/principal findings With 992 and 663 cases reported in 2019 and 2020 respectively, the first global target was amply achieved (i.e. fewer than 2,000 HAT cases/year). Areas at moderate or higher risk of HAT, where more than 1 case/10,000 people/year are reported, shrunk to 120,000 km2 for the five-year period 2016–2020. This reduction of 83% from the 2000–2004 baseline (i.e. 709,000 km2) is slightly below the target (i.e. 90% reduction). As a result, the second global target for HAT elimination as a public health problem cannot be considered fully achieved yet. The number of health facilities able to diagnose and treat HAT expanded (+9.6% compared to a 2019 survey), thus reinforcing the capacity for passive detection and improving epidemiological knowledge of the disease. Active surveillance for gambiense HAT was sustained. In particular, 2.8 million people were actively screened in 2019 and 1.6 million in 2020, the decrease in 2020 being mainly caused by COVID-19-related restrictions. Togo and Côte d’Ivoire were the first countries to be validated for achieving elimination of HAT as a public health problem at the national level; applications from three additional countries are under review by the World Health Organization (WHO). Conclusions/significance The steady progress towards the elimination of HAT is a testament to the power of multi-stakeholder commitment and coordination. At the end of 2020, the World Health Assembly endorsed a new road map for 2021–2030 that set new bold targets for neglected tropical diseases. While rhodesiense HAT remains among the diseases targeted for elimination as a public health problem, gambiense HAT is targeted for elimination of transmission. The goal for gambiense HAT is expected to be particularly arduous, as it might be hindered by cryptic reservoirs and a number of other challenges (e.g. further integration of HAT surveillance and control into national health systems, availability of skilled health care workers, development of more effective and adapted tools, and funding for and coordination of elimination efforts). Human African trypanosomiasis (HAT) is a lethal neglected tropical disease (NTD) transmitted by the bite of infected tsetse flies. The disease is also known as “sleeping sickness”. During the 20th century it caused enormous suffering in the endemic areas in sub-Saharan Africa. HAT transmission last soared in the late 1990s, triggering a renewed, coordinated and very successful control effort. In this paper, we present achievements towards HAT elimination, with a focus on the WHO road map targets for 2020. In particular, reported cases continue to decline, from over 30,000 cases per year at the turn of the century to 663 cases in 2020. Despite the impact of the COVID-19 pandemic, HAT surveillance was largely sustained, and the network of health facilities able to diagnose and treat the disease further expanded. Looking to the future, the World Health Organization (WHO) set bold new targets for HAT in its 2021–2030 road map for NTDs, namely: the elimination of transmission of gambiense HAT, which occurs in western and central Africa, and the elimination as a public health problem of rhodesiense HAT, which is found in eastern and southern Africa. The strong commitment of national health authorities and the international community will be essential if these goals are to be achieved.
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Affiliation(s)
- Jose R. Franco
- World Health Organization, Control of Neglected Tropical Diseases, Prevention Treatment and Care, Geneva, Switzerland
- * E-mail:
| | - Giuliano Cecchi
- Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy
| | - Massimo Paone
- Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy
| | - Abdoulaye Diarra
- World Health Organization, Regional Office for Africa, Communicable Disease Unit, Brazzaville, Congo
| | - Lise Grout
- World Health Organization, Control of Neglected Tropical Diseases, Prevention Treatment and Care, Geneva, Switzerland
| | - Augustin Kadima Ebeja
- World Health Organization, Regional Office for Africa, Communicable Disease Unit, Brazzaville, Congo
| | - Pere P. Simarro
- Consultant, World Health Organization, Control of Neglected Tropical Diseases, Innovative and Intensified Disease Management, Geneva, Switzerland
| | - Weining Zhao
- Food and Agriculture Organization of the United Nations, Animal Production and Health Division, Rome, Italy
| | - Daniel Argaw
- World Health Organization, Control of Neglected Tropical Diseases, Prevention Treatment and Care, Geneva, Switzerland
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De Niz M, Brás D, Ouarné M, Pedro M, Nascimento AM, Henao Misikova L, Franco CA, Figueiredo LM. Organotypic endothelial adhesion molecules are key for Trypanosoma brucei tropism and virulence. Cell Rep 2021; 36:109741. [PMID: 34551286 PMCID: PMC8480282 DOI: 10.1016/j.celrep.2021.109741] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 06/29/2021] [Accepted: 08/28/2021] [Indexed: 11/23/2022] Open
Abstract
Trypanosoma brucei is responsible for lethal diseases in humans and cattle in Sub-Saharan Africa. These extracellular parasites extravasate from the blood circulation into several tissues. The importance of the vasculature in tissue tropism is poorly understood. Using intravital imaging and bioluminescence, we observe that gonadal white adipose tissue and pancreas are the two main parasite reservoirs. We show that reservoir establishment happens before vascular permeability is compromised, suggesting that extravasation is an active mechanism. Blocking endothelial surface adhesion molecules (E-selectin, P-selectins, or ICAM2) significantly reduces extravascular parasite density in all organs and delays host lethality. Remarkably, blocking CD36 has a specific effect on adipose tissue tropism that is sufficient to delay lethality, suggesting that establishment of the adipose tissue reservoir is necessary for parasite virulence. This work demonstrates the importance of the vasculature in a T. brucei infection and identifies organ-specific adhesion molecules as key players for tissue tropism. Our study investigates the blood vasculature for T. brucei reservoir establishment We show the pancreas is a large extravascular reservoir We establish that T. brucei tropism is linked to organotypic adhesion molecules Interfering with adhesion molecules impacts parasite virulence and host survival
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Affiliation(s)
- Mariana De Niz
- Instituto de Medicina Molecular Joao Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa 1649-028, Portugal
| | - Daniela Brás
- Instituto de Medicina Molecular Joao Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa 1649-028, Portugal
| | - Marie Ouarné
- Instituto de Medicina Molecular Joao Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa 1649-028, Portugal
| | - Mafalda Pedro
- Instituto de Medicina Molecular Joao Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa 1649-028, Portugal; Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica 2825-149, Portugal
| | - Ana M Nascimento
- Instituto de Medicina Molecular Joao Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa 1649-028, Portugal; Bioimaging Unit, Instituto de Medicina Molecular Joao Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa 1649-028, Portugal
| | - Lenka Henao Misikova
- Instituto de Medicina Molecular Joao Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa 1649-028, Portugal
| | - Claudio A Franco
- Instituto de Medicina Molecular Joao Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa 1649-028, Portugal
| | - Luisa M Figueiredo
- Instituto de Medicina Molecular Joao Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa 1649-028, Portugal.
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4
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Abstract
Trypanosoma brucei is a protozoan parasite that causes human and animal African trypanosomiases (HAT and AAT). In the mammalian host, the parasite lives entirely extracellularly, in both the blood and interstitial spaces in tissues. Although most T. brucei research has focused on the biology of blood- and central nervous system (CNS)-resident parasites, a number of recent studies have highlighted parasite reservoirs in the dermis and adipose tissue, leading to a renewed interest in tissue-resident parasite populations. In light of this renewed interest, work describing tissue-resident parasites can serve as a valuable resource to inform future investigations of tissue-resident T. brucei. Here, we review this body of literature, which describes infections in humans, natural hosts, and experimental animal models, providing a wealth of information on the distribution and biology of extravascular parasites, the corresponding immune response in each tissue, and resulting host pathology. We discuss the implications of these studies and future questions in the study of extravascular T. brucei.
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Affiliation(s)
- Nathan P. Crilly
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- Department of Molecular and Comparative Pathology, Johns Hopkins School of Medicine, Baltimore Maryland, United States of America
| | - Monica R. Mugnier
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
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5
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Rout S, Oeljeklaus S, Makki A, Tachezy J, Warscheid B, Schneider A. Determinism and contingencies shaped the evolution of mitochondrial protein import. Proc Natl Acad Sci U S A 2021; 118:e2017774118. [PMID: 33526678 PMCID: PMC8017667 DOI: 10.1073/pnas.2017774118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial protein import requires outer membrane receptors that evolved independently in different lineages. Here we used quantitative proteomics and in vitro binding assays to investigate the substrate preferences of ATOM46 and ATOM69, the two mitochondrial import receptors of Trypanosoma brucei The results show that ATOM46 prefers presequence-containing, hydrophilic proteins that lack transmembrane domains (TMDs), whereas ATOM69 prefers presequence-lacking, hydrophobic substrates that have TMDs. Thus, the ATOM46/yeast Tom20 and the ATOM69/yeast Tom70 pairs have similar substrate preferences. However, ATOM46 mainly uses electrostatic, and Tom20 hydrophobic, interactions for substrate binding. In vivo replacement of T. brucei ATOM46 by yeast Tom20 did not restore import. However, replacement of ATOM69 by the recently discovered Tom36 receptor of Trichomonas hydrogenosomes, while not allowing for growth, restored import of a large subset of trypanosomal proteins that lack TMDs. Thus, even though ATOM69 and Tom36 share the same domain structure and topology, they have different substrate preferences. The study establishes complementation experiments, combined with quantitative proteomics, as a highly versatile and sensitive method to compare in vivo preferences of protein import receptors. Moreover, it illustrates the role determinism and contingencies played in the evolution of mitochondrial protein import receptors.
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Affiliation(s)
- Samuel Rout
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, CH-3012 Bern, Switzerland
| | - Silke Oeljeklaus
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Abhijith Makki
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, 12843 Prague, Czech Republic
| | - Jan Tachezy
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, 12843 Prague, Czech Republic
| | - Bettina Warscheid
- Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany;
| | - André Schneider
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, CH-3012 Bern, Switzerland;
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Mokdadi M, Abdelkrim YZ, Banroques J, Huvelle E, Oualha R, Yeter-Alat H, Guizani I, Barhoumi M, Tanner NK. The In Silico Identification of Potential Members of the Ded1/DDX3 Subfamily of DEAD-Box RNA Helicases from the Protozoan Parasite Leishmania infantum and Their Analyses in Yeast. Genes (Basel) 2021; 12:genes12020212. [PMID: 33535521 PMCID: PMC7912733 DOI: 10.3390/genes12020212] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 01/27/2021] [Accepted: 01/29/2021] [Indexed: 12/14/2022] Open
Abstract
DEAD-box RNA helicases are ubiquitous proteins found in all kingdoms of life and that are associated with all processes involving RNA. Their central roles in biology make these proteins potential targets for therapeutic or prophylactic drugs. The Ded1/DDX3 subfamily of DEAD-box proteins is of particular interest because of their important role(s) in translation. In this paper, we identified and aligned the protein sequences of 28 different DEAD-box proteins from the kinetoplast-protozoan parasite Leishmania infantum, which is the cause of the visceral form of leishmaniasis that is often lethal if left untreated, and compared them with the consensus sequence derived from DEAD-box proteins in general, and from the Ded1/DDX3 subfamily in particular, from a wide variety of other organisms. We identified three potential homologs of the Ded1/DDX3 subfamily and the equivalent proteins from the related protozoan parasite Trypanosoma brucei, which is the causative agent of sleeping sickness. We subsequently tested these proteins for their ability to complement a yeast strain deleted for the essential DED1 gene. We found that the DEAD-box proteins from Trypanosomatids are highly divergent from other eukaryotes, and consequently they are suitable targets for protein-specific drugs.
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Affiliation(s)
- Molka Mokdadi
- Expression Génétique Microbienne, UMR8261 CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France; (M.M.); (Y.Z.A.); (J.B.); (E.H.); (H.Y.-A.)
- PSL Research University, 75005 Paris, France
- Laboratory of Molecular Epidemiology and Experimental Pathology (LR16IPT04), Institut Pasteur de Tunis, Université de Tunis El Manar, 13 Place Pasteur, BP74 Tunis-Belvédère 1002, Tunisia; (R.O.); (I.G.)
- Institut National des Sciences Appliquées et Technologies, Université de Carthage, CEDEX, Tunis 1080, Tunisia
| | - Yosser Zina Abdelkrim
- Expression Génétique Microbienne, UMR8261 CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France; (M.M.); (Y.Z.A.); (J.B.); (E.H.); (H.Y.-A.)
- Laboratory of Molecular Epidemiology and Experimental Pathology (LR16IPT04), Institut Pasteur de Tunis, Université de Tunis El Manar, 13 Place Pasteur, BP74 Tunis-Belvédère 1002, Tunisia; (R.O.); (I.G.)
| | - Josette Banroques
- Expression Génétique Microbienne, UMR8261 CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France; (M.M.); (Y.Z.A.); (J.B.); (E.H.); (H.Y.-A.)
- PSL Research University, 75005 Paris, France
| | - Emmeline Huvelle
- Expression Génétique Microbienne, UMR8261 CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France; (M.M.); (Y.Z.A.); (J.B.); (E.H.); (H.Y.-A.)
- PSL Research University, 75005 Paris, France
| | - Rafeh Oualha
- Laboratory of Molecular Epidemiology and Experimental Pathology (LR16IPT04), Institut Pasteur de Tunis, Université de Tunis El Manar, 13 Place Pasteur, BP74 Tunis-Belvédère 1002, Tunisia; (R.O.); (I.G.)
| | - Hilal Yeter-Alat
- Expression Génétique Microbienne, UMR8261 CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France; (M.M.); (Y.Z.A.); (J.B.); (E.H.); (H.Y.-A.)
- PSL Research University, 75005 Paris, France
| | - Ikram Guizani
- Laboratory of Molecular Epidemiology and Experimental Pathology (LR16IPT04), Institut Pasteur de Tunis, Université de Tunis El Manar, 13 Place Pasteur, BP74 Tunis-Belvédère 1002, Tunisia; (R.O.); (I.G.)
| | - Mourad Barhoumi
- Laboratory of Molecular Epidemiology and Experimental Pathology (LR16IPT04), Institut Pasteur de Tunis, Université de Tunis El Manar, 13 Place Pasteur, BP74 Tunis-Belvédère 1002, Tunisia; (R.O.); (I.G.)
- Correspondence: (M.B.); (N.K.T.); Tel.: +216-71 843 755 (ext. 544) (M.B.); +33-1-58-41-52-37 (N.K.T.); Fax: +216-71-791-833 (M.B.); +33-1-58-41-50-25 (N.K.T.)
| | - N. Kyle Tanner
- Expression Génétique Microbienne, UMR8261 CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France; (M.M.); (Y.Z.A.); (J.B.); (E.H.); (H.Y.-A.)
- PSL Research University, 75005 Paris, France
- Correspondence: (M.B.); (N.K.T.); Tel.: +216-71 843 755 (ext. 544) (M.B.); +33-1-58-41-52-37 (N.K.T.); Fax: +216-71-791-833 (M.B.); +33-1-58-41-50-25 (N.K.T.)
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7
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de Morais MC, de Souza JV, da Silva Maia Bezerra Filho C, Dolabella SS, de Sousa DP. Trypanocidal Essential Oils: A Review. Molecules 2020; 25:molecules25194568. [PMID: 33036315 PMCID: PMC7583723 DOI: 10.3390/molecules25194568] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 09/07/2020] [Accepted: 09/08/2020] [Indexed: 12/22/2022] Open
Abstract
Trypanosomiases are diseases caused by parasitic protozoan trypanosomes of the genus Trypanosoma. In humans, this includes Chagas disease and African trypanosomiasis. There are few therapeutic options, and there is low efficacy to clinical treatment. Therefore, the search for new drugs for the trypanosomiasis is urgent. This review describes studies of the trypanocidal properties of essential oils, an important group of natural products widely found in several tropical countries. Seventy-seven plants were selected from literature for the trypanocidal activity of their essential oils. The main chemical constituents and mechanisms of action are also discussed. In vitro and in vivo experimental data show the therapeutic potential of these natural products for the treatment of infections caused by species of Trypanosoma.
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Affiliation(s)
- Mayara Castro de Morais
- Laboratory of Pharmaceutical Chemistry, Department of Pharmaceutical Sciences, Federal University of Paraíba, 58051-900 João Pessoa, Paraíba, Brazil; (M.C.d.M.); (J.V.d.S.); (C.d.S.M.B.F.)
| | - Jucieudo Virgulino de Souza
- Laboratory of Pharmaceutical Chemistry, Department of Pharmaceutical Sciences, Federal University of Paraíba, 58051-900 João Pessoa, Paraíba, Brazil; (M.C.d.M.); (J.V.d.S.); (C.d.S.M.B.F.)
| | - Carlos da Silva Maia Bezerra Filho
- Laboratory of Pharmaceutical Chemistry, Department of Pharmaceutical Sciences, Federal University of Paraíba, 58051-900 João Pessoa, Paraíba, Brazil; (M.C.d.M.); (J.V.d.S.); (C.d.S.M.B.F.)
| | - Silvio Santana Dolabella
- Laboratory of Entomology and Tropical Parasitology, Department of Morphology, Federal University of Sergipe, 49100-000 São Cristóvão, Sergipe, Brazil;
| | - Damião Pergentino de Sousa
- Laboratory of Pharmaceutical Chemistry, Department of Pharmaceutical Sciences, Federal University of Paraíba, 58051-900 João Pessoa, Paraíba, Brazil; (M.C.d.M.); (J.V.d.S.); (C.d.S.M.B.F.)
- Correspondence: ; Tel.: +55-83-3216-7347
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8
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Leal AZ, Schwebs M, Briggs E, Weisert N, Reis H, Lemgruber L, Luko K, Wilkes J, Butter F, McCulloch R, Janzen CJ. Genome maintenance functions of a putative Trypanosoma brucei translesion DNA polymerase include telomere association and a role in antigenic variation. Nucleic Acids Res 2020; 48:9660-9680. [PMID: 32890403 PMCID: PMC7515707 DOI: 10.1093/nar/gkaa686] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 08/03/2020] [Accepted: 09/03/2020] [Indexed: 12/17/2022] Open
Abstract
Maintenance of genome integrity is critical to guarantee transfer of an intact genome from parent to offspring during cell division. DNA polymerases (Pols) provide roles in both replication of the genome and the repair of a wide range of lesions. Amongst replicative DNA Pols, translesion DNA Pols play a particular role: replication to bypass DNA damage. All cells express a range of translesion Pols, but little work has examined their function in parasites, including whether the enzymes might contribute to host-parasite interactions. Here, we describe a dual function of one putative translesion Pol in African trypanosomes, which we now name TbPolIE. Previously, we demonstrated that TbPolIE is associated with telomeric sequences and here we show that RNAi-mediated depletion of TbPolIE transcripts results in slowed growth, altered DNA content, changes in cell morphology, and increased sensitivity to DNA damaging agents. We also show that TbPolIE displays pronounced localization at the nuclear periphery, and that its depletion leads to chromosome segregation defects and increased levels of endogenous DNA damage. Finally, we demonstrate that TbPolIE depletion leads to deregulation of telomeric variant surface glycoprotein genes, linking the function of this putative translesion DNA polymerase to host immune evasion by antigenic variation.
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Affiliation(s)
- Andrea Zurita Leal
- The Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Marie Schwebs
- Department of Cell & Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Emma Briggs
- The Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Nadine Weisert
- Department of Cell & Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Helena Reis
- Department of Cell & Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Leandro Lemgruber
- The Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Katarina Luko
- Quantitative Proteomics, Institute of Molecular Biology (IMB), Mainz, Germany
| | - Jonathan Wilkes
- The Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Falk Butter
- Quantitative Proteomics, Institute of Molecular Biology (IMB), Mainz, Germany
| | - Richard McCulloch
- The Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Christian J Janzen
- Department of Cell & Developmental Biology, Biocenter, University of Würzburg, Würzburg, Germany
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Briggs E, Crouch K, Lemgruber L, Hamilton G, Lapsley C, McCulloch R. Trypanosoma brucei ribonuclease H2A is an essential R-loop processing enzyme whose loss causes DNA damage during transcription initiation and antigenic variation. Nucleic Acids Res 2019; 47:9180-9197. [PMID: 31350892 PMCID: PMC6753483 DOI: 10.1093/nar/gkz644] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 07/09/2019] [Accepted: 07/16/2019] [Indexed: 12/21/2022] Open
Abstract
Ribonucleotides represent a threat to DNA genome stability and transmission. Two types of Ribonuclease H (RNase H) excise ribonucleotides when they form part of the DNA strand, or hydrolyse RNA when it base-pairs with DNA in structures termed R-loops. Loss of either RNase H is lethal in mammals, whereas yeast survives the absence of both enzymes. RNase H1 loss is tolerated by the parasite Trypanosoma brucei but no work has examined the function of RNase H2. Here we show that loss of T. brucei RNase H2 (TbRH2A) leads to growth and cell cycle arrest that is concomitant with accumulation of nuclear damage at sites of RNA polymerase (Pol) II transcription initiation, revealing a novel and critical role for RNase H2. Differential gene expression analysis reveals limited overall changes in RNA levels for RNA Pol II genes after TbRH2A loss, but increased perturbation of nucleotide metabolic genes. Finally, we show that TbRH2A loss causes R-loop and DNA damage accumulation in telomeric RNA Pol I transcription sites, also leading to altered gene expression. Thus, we demonstrate separation of function between two nuclear T. brucei RNase H enzymes during RNA Pol II transcription, but overlap in function during RNA Pol I-mediated gene expression during host immune evasion.
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Affiliation(s)
- Emma Briggs
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK
| | - Kathryn Crouch
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK
| | - Leandro Lemgruber
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK
| | - Graham Hamilton
- Glasgow Polyomics, University of Glasgow, Wolfson Wohl Cancer Research Centre, Garscube Estate, Switchback Rd, Bearsden G61 1QH, UK
| | - Craig Lapsley
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK
| | - Richard McCulloch
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow G12 8TA, UK
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10
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Currier RB, Ulrich K, Leroux AE, Dirdjaja N, Deambrosi M, Bonilla M, Ahmed YL, Adrian L, Antelmann H, Jakob U, Comini MA, Krauth-Siegel RL. An essential thioredoxin-type protein of Trypanosoma brucei acts as redox-regulated mitochondrial chaperone. PLoS Pathog 2019; 15:e1008065. [PMID: 31557263 PMCID: PMC6783113 DOI: 10.1371/journal.ppat.1008065] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 10/08/2019] [Accepted: 09/02/2019] [Indexed: 12/22/2022] Open
Abstract
Most known thioredoxin-type proteins (Trx) participate in redox pathways, using two highly conserved cysteine residues to catalyze thiol-disulfide exchange reactions. Here we demonstrate that the so far unexplored Trx2 from African trypanosomes (Trypanosoma brucei) lacks protein disulfide reductase activity but functions as an effective temperature-activated and redox-regulated chaperone. Immunofluorescence microscopy and fractionated cell lysis revealed that Trx2 is located in the mitochondrion of the parasite. RNA-interference and gene knock-out approaches showed that depletion of Trx2 impairs growth of both mammalian bloodstream and insect stage procyclic parasites. Procyclic cells lacking Trx2 stop proliferation under standard culture conditions at 27°C and are unable to survive prolonged exposure to 37°C, indicating that Trx2 plays a vital role that becomes augmented under heat stress. Moreover, we found that Trx2 contributes to the in vivo infectivity of T. brucei. Remarkably, a Trx2 version, in which all five cysteines were replaced by serine residues, complements for the wildtype protein in conditional knock-out cells and confers parasite infectivity in the mouse model. Characterization of the recombinant protein revealed that Trx2 can coordinate an iron sulfur cluster and is highly sensitive towards spontaneous oxidation. Moreover, we discovered that both wildtype and mutant Trx2 protect other proteins against thermal aggregation and preserve their ability to refold upon return to non-stress conditions. Activation of the chaperone function of Trx2 appears to be triggered by temperature-mediated structural changes and inhibited by oxidative disulfide bond formation. Our studies indicate that Trx2 acts as a novel chaperone in the unique single mitochondrion of T. brucei and reveal a new perspective regarding the physiological function of thioredoxin-type proteins in trypanosomes.
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Affiliation(s)
- Rachel B. Currier
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
| | - Kathrin Ulrich
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | | | - Natalie Dirdjaja
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
| | - Matías Deambrosi
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Mariana Bonilla
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
- Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | | | - Lorenz Adrian
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research–UFZ, Leipzig, Germany
- Fachgebiet Geobiotechnologie, Technische Universität Berlin, Berlin, Germany
| | - Haike Antelmann
- Institut für Biologie-Mikrobiologie, Freie Universität Berlin, Berlin, Germany
| | - Ursula Jakob
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Marcelo A. Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
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11
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Ndungu K, Thungu D, Wamwiri F, Mireji P, Ngae G, Gitonga P, Mulinge J, Auma J, Thuita J. Route of inoculation influences Trypanosoma congolense and Trypanosoma brucei brucei virulence in Swiss white mice. PLoS One 2019; 14:e0218441. [PMID: 31220132 PMCID: PMC6586304 DOI: 10.1371/journal.pone.0218441] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 06/03/2019] [Indexed: 11/28/2022] Open
Abstract
Experiments on infections caused by trypanosomes are widely performed in Swiss white mice through various inoculation routes. To better understand the effect of route of trypanosome inoculation on disease outcomes in this model, we characterised the virulence of two isolates, Trypanosoma brucei KETRI 2710 and T. congolense KETRI 2765 in Swiss white mice. For each of the isolates, five routes of parasite inoculation, namely intraperitoneal (IP), subcutaneous (SC), intramuscular (IM) intradermal (ID) and intravenous (IV) were compared using groups (n = 6) of mice, with each mouse receiving 1x104 trypanosomes. We subsequently assessed impact of the routes on disease indices that included pre-patent period (PP), parasitaemia levels, Packed Cell Volume (PCV), bodyweight changes and survival time. Pre-patent period for IP inoculated mice was a mean ± SE of 3.8 ± 0.2 and 6.5 ± 0.0 for the T brucei and T. congolense isolates respectively; the PP for mice groups inoculated using other routes were not significantly different(p> 0.05) irrespective of route of inoculation and species of trypanosomes. With ID and IP routes, parasitaemia was significantly higher in T. brucei and significantly lower in T. congolense infected mice and the progression to peak parasitaemia routes showed no significant different between the routes of either species of trypanosome. The IM and ID routes in T. congolense inoculations, and IP and IV in T. b. brucei induced the fastest and slowest parasitaemia progressions respectively. There were significant differences in rates of reduction of PCV with time post infection in mice infected by the two species and which was more pronounced in sc and ip injected mice. No significant differences in mice body weight changes and survivorship was observed between the routes of inoculation. Inoculation route therefore appears to be a critical determinant of pathogenicity of Trypanosoma congolense and Trypanosoma brucei brucei in murine mouse model of African trypanosomiasis.
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Affiliation(s)
- Kariuki Ndungu
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
- * E-mail:
| | - Daniel Thungu
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
| | - Florence Wamwiri
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
| | - Paul Mireji
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
- Centre for Geographic Medicine Research—Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - Geoffrey Ngae
- Food Crops Research Institute, Kenya Agricultural and Livestock Research Organization, Nairobi, Kenya
| | - Purity Gitonga
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
| | | | - Joanna Auma
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
| | - John Thuita
- Meru University of Science and Technology, Meru, Kenya
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12
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Bocquet L, Sahpaz S, Bonneau N, Beaufay C, Mahieux S, Samaillie J, Roumy V, Jacquin J, Bordage S, Hennebelle T, Chai F, Quetin-Leclercq J, Neut C, Rivière C. Phenolic Compounds from Humulus lupulus as Natural Antimicrobial Products: New Weapons in the Fight against Methicillin Resistant Staphylococcus aureus, Leishmania mexicana and Trypanosoma brucei Strains. Molecules 2019; 24:molecules24061024. [PMID: 30875854 PMCID: PMC6472001 DOI: 10.3390/molecules24061024] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/09/2019] [Accepted: 03/10/2019] [Indexed: 12/23/2022] Open
Abstract
New anti-infective agents are urgently needed to fight microbial resistance. Methicillin-resistant Staphylococcus aureus (MRSA) strains are particularly responsible for complicated pathologies that are difficult to treat due to their virulence and the formation of persistent biofilms forming a complex protecting shell. Parasitic infections caused by Trypanosoma brucei and Leishmania mexicana are also of global concern, because of the mortality due to the low number of safe and effective treatments. Female inflorescences of hop produce specialized metabolites known for their antimicrobial effects but underexploited to fight against drug-resistant microorganisms. In this study, we assessed the antimicrobial potential of phenolic compounds against MRSA clinical isolates, T. brucei and L. mexicana. By fractionation process, we purified the major prenylated chalcones and acylphloroglucinols, which were quantified by UHPLC-UV in different plant parts, showing their higher content in the active flowers extract. Their potent antibacterial action (MIC < 1 µg/mL for the most active compound) was demonstrated against MRSA strains, through kill curves, post-antibiotic effects, anti-biofilm assays and synergy studies with antibiotics. An antiparasitic activity was also shown for some purified compounds, particularly on T. brucei (IC50 < 1 to 11 µg/mL). Their cytotoxic activity was assessed both on cancer and non-cancer human cell lines.
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Affiliation(s)
- Laetitia Bocquet
- EA 7394-ICV, Charles Viollette Research Institute, SFR Condorcet FR CNRS 3417, Univ. Lille, INRA, ISA-Yncréa, Univ. Artois, University Littoral Côte d'Opale, 3 rue du Professeur Laguesse, 59000 Lille, France.
| | - Sevser Sahpaz
- EA 7394-ICV, Charles Viollette Research Institute, SFR Condorcet FR CNRS 3417, Univ. Lille, INRA, ISA-Yncréa, Univ. Artois, University Littoral Côte d'Opale, 3 rue du Professeur Laguesse, 59000 Lille, France.
| | - Natacha Bonneau
- EA 7394-ICV, Charles Viollette Research Institute, SFR Condorcet FR CNRS 3417, Univ. Lille, INRA, ISA-Yncréa, Univ. Artois, University Littoral Côte d'Opale, 3 rue du Professeur Laguesse, 59000 Lille, France.
| | - Claire Beaufay
- Pharmacognosy Research group, Louvain Drug Research Institute, Université Catholique de Louvain, 1200 Brussels, Belgium.
| | - Séverine Mahieux
- U995-LIRIC, Lille Inflammation Research International Center, University Lille, Inserm, CHU Lille, 59000 Lille, France.
| | - Jennifer Samaillie
- EA 7394-ICV, Charles Viollette Research Institute, SFR Condorcet FR CNRS 3417, Univ. Lille, INRA, ISA-Yncréa, Univ. Artois, University Littoral Côte d'Opale, 3 rue du Professeur Laguesse, 59000 Lille, France.
| | - Vincent Roumy
- EA 7394-ICV, Charles Viollette Research Institute, SFR Condorcet FR CNRS 3417, Univ. Lille, INRA, ISA-Yncréa, Univ. Artois, University Littoral Côte d'Opale, 3 rue du Professeur Laguesse, 59000 Lille, France.
| | - Justine Jacquin
- EA 7394-ICV, Charles Viollette Research Institute, SFR Condorcet FR CNRS 3417, Univ. Lille, INRA, ISA-Yncréa, Univ. Artois, University Littoral Côte d'Opale, 3 rue du Professeur Laguesse, 59000 Lille, France.
| | - Simon Bordage
- EA 7394-ICV, Charles Viollette Research Institute, SFR Condorcet FR CNRS 3417, Univ. Lille, INRA, ISA-Yncréa, Univ. Artois, University Littoral Côte d'Opale, 3 rue du Professeur Laguesse, 59000 Lille, France.
| | - Thierry Hennebelle
- EA 7394-ICV, Charles Viollette Research Institute, SFR Condorcet FR CNRS 3417, Univ. Lille, INRA, ISA-Yncréa, Univ. Artois, University Littoral Côte d'Opale, 3 rue du Professeur Laguesse, 59000 Lille, France.
| | - Feng Chai
- U1008-Controlled Drug Delivery Systems and Biomaterials, University Lille, Inserm, CHU Lille, 59000 Lille, France.
| | - Joëlle Quetin-Leclercq
- Pharmacognosy Research group, Louvain Drug Research Institute, Université Catholique de Louvain, 1200 Brussels, Belgium.
| | - Christel Neut
- U995-LIRIC, Lille Inflammation Research International Center, University Lille, Inserm, CHU Lille, 59000 Lille, France.
| | - Céline Rivière
- EA 7394-ICV, Charles Viollette Research Institute, SFR Condorcet FR CNRS 3417, Univ. Lille, INRA, ISA-Yncréa, Univ. Artois, University Littoral Côte d'Opale, 3 rue du Professeur Laguesse, 59000 Lille, France.
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13
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Weiss BL, Maltz MA, Vigneron A, Wu Y, Walter KS, O’Neill MB, Wang J, Aksoy S. Colonization of the tsetse fly midgut with commensal Kosakonia cowanii Zambiae inhibits trypanosome infection establishment. PLoS Pathog 2019; 15:e1007470. [PMID: 30817773 PMCID: PMC6394900 DOI: 10.1371/journal.ppat.1007470] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 12/27/2018] [Indexed: 11/18/2022] Open
Abstract
Tsetse flies (Glossina spp.) vector pathogenic trypanosomes (Trypanosoma spp.) in sub-Saharan Africa. These parasites cause human and animal African trypanosomiases, which are debilitating diseases that inflict an enormous socio-economic burden on inhabitants of endemic regions. Current disease control strategies rely primarily on treating infected animals and reducing tsetse population densities. However, relevant programs are costly, labor intensive and difficult to sustain. As such, novel strategies aimed at reducing tsetse vector competence require development. Herein we investigated whether Kosakonia cowanii Zambiae (Kco_Z), which confers Anopheles gambiae with resistance to Plasmodium, is able to colonize tsetse and induce a trypanosome refractory phenotype in the fly. Kco_Z established stable infections in tsetse’s gut and exhibited no adverse effect on the fly’s survival. Flies with established Kco_Z infections in their gut were significantly more refractory to infection with two distinct trypanosome species (T. congolense, 6% infection; T. brucei, 32% infection) than were age-matched flies that did not house the exogenous bacterium (T. congolense, 36% infected; T. brucei, 70% infected). Additionally, 52% of Kco_Z colonized tsetse survived infection with entomopathogenic Serratia marcescens, compared with only 9% of their wild-type counterparts. These parasite and pathogen refractory phenotypes result from the fact that Kco_Z acidifies tsetse’s midgut environment, which inhibits trypanosome and Serratia growth and thus infection establishment. Finally, we determined that Kco_Z infection does not impact the fecundity of male or female tsetse, nor the ability of male flies to compete with their wild-type counterparts for mates. We propose that Kco_Z could be used as one component of an integrated strategy aimed at reducing the ability of tsetse to transmit pathogenic trypanosomes. Tsetse flies transmit pathogenic African trypanosomes, which are the causative agents of socio-economically devastating human and animal African trypanosomiases. These diseases are currently controlled in large part by reducing the population size of tsetse vectors through the use of insecticides, traps and sterile insect technique. However, logistic and monetary hurdles often preclude the prolonged application of procedures necessary to maintain these control programs. Thus, novel strategies, including those aimed at sustainably reducing the ability of tsetse to transmit trypanosomes, are presently under development. Herein we stably colonize tsetse flies with a bacterium (Kosakonia cowanii Zambiae, Kco_Z) that acidifies their midgut, thus rendering the environment inhospitable to infection with two distinct, epidemiologically important trypanosome strains as well as an entomopathogenic bacteria. In addition to inducing a trypanosome refractory phenotype, colonization of tsetse with Kco_Z exerts only a modest fitness cost on the fly. Taken together, these findings suggest that Kco_Z could be applied to enhance the effectiveness of currently employed tsetse control programs.
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Affiliation(s)
- Brian L. Weiss
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
- * E-mail: (BLW); (SA)
| | - Michele A. Maltz
- Southern Connecticut State University, New Haven, Connecticut, United States of America
| | - Aurélien Vigneron
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
| | - Yineng Wu
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
| | - Katharine S. Walter
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
| | - Michelle B. O’Neill
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
| | - Jingwen Wang
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
| | - Serap Aksoy
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, Connecticut, United States of America
- * E-mail: (BLW); (SA)
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14
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Yagüe-Capilla M, García-Caballero D, Aguilar-Pereyra F, Castillo-Acosta VM, Ruiz-Pérez LM, Vidal AE, González-Pacanowska D. Base excision repair plays an important role in the protection against nitric oxide- and in vivo-induced DNA damage in Trypanosoma brucei. Free Radic Biol Med 2019; 131:59-71. [PMID: 30472364 DOI: 10.1016/j.freeradbiomed.2018.11.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 10/22/2018] [Accepted: 11/21/2018] [Indexed: 11/17/2022]
Abstract
Uracil-DNA glycosylase (UNG) initiates the base excision repair pathway by excising uracil from DNA. We have previously shown that Trypanosoma brucei cells defective in UNG exhibit reduced infectivity thus demonstrating the relevance of this glycosylase for survival within the mammalian host. In the early steps of the immune response, nitric oxide (NO) is released by phagocytes, which in combination with oxygen radicals produce reactive nitrogen species (RNS). These species can react with DNA generating strand breaks and base modifications including deaminations. Since deaminated cytosines are the main substrate for UNG, we hypothesized that the glycosylase might confer protection towards nitrosative stress. Our work establishes the occurrence of genotoxic damage in Trypanosoma brucei upon exposure to NO in vitro and shows that deficient base excision repair results in increased levels of damage in DNA and a hypermutator phenotype. We also evaluate the incidence of DNA damage during infection in vivo and show that parasites recovered from mice exhibit higher levels of DNA strand breaks, base deamination and repair foci compared to cells cultured in vitro. Notably, the absence of UNG leads to reduced infectivity and enhanced DNA damage also in animal infections. By analysing mRNA and protein levels, we found that surviving UNG-KO trypanosomes highly express tryparedoxin peroxidase involved in trypanothione/tryparedoxin metabolism. These observations suggest that the immune response developed by the host enhances the activation of genes required to counteract oxidative stress and emphasize the importance of DNA repair pathways in the protection to genotoxic and oxidative stress in trypanosomes.
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Affiliation(s)
- Miriam Yagüe-Capilla
- Instituto de Parasitología y Biomedicina "López-Neyra". Consejo Superior de Investigaciones Científicas. Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento, 17, 18016 Armilla, Granada, Spain
| | - Daniel García-Caballero
- Instituto de Parasitología y Biomedicina "López-Neyra". Consejo Superior de Investigaciones Científicas. Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento, 17, 18016 Armilla, Granada, Spain
| | - Fernando Aguilar-Pereyra
- Instituto de Parasitología y Biomedicina "López-Neyra". Consejo Superior de Investigaciones Científicas. Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento, 17, 18016 Armilla, Granada, Spain
| | - Víctor M Castillo-Acosta
- Instituto de Parasitología y Biomedicina "López-Neyra". Consejo Superior de Investigaciones Científicas. Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento, 17, 18016 Armilla, Granada, Spain
| | - Luis M Ruiz-Pérez
- Instituto de Parasitología y Biomedicina "López-Neyra". Consejo Superior de Investigaciones Científicas. Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento, 17, 18016 Armilla, Granada, Spain
| | - Antonio E Vidal
- Instituto de Parasitología y Biomedicina "López-Neyra". Consejo Superior de Investigaciones Científicas. Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento, 17, 18016 Armilla, Granada, Spain
| | - Dolores González-Pacanowska
- Instituto de Parasitología y Biomedicina "López-Neyra". Consejo Superior de Investigaciones Científicas. Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento, 17, 18016 Armilla, Granada, Spain.
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15
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Briggs E, Crouch K, Lemgruber L, Lapsley C, McCulloch R. Ribonuclease H1-targeted R-loops in surface antigen gene expression sites can direct trypanosome immune evasion. PLoS Genet 2018; 14:e1007729. [PMID: 30543624 PMCID: PMC6292569 DOI: 10.1371/journal.pgen.1007729] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 10/01/2018] [Indexed: 11/19/2022] Open
Abstract
Switching of the Variant Surface Glycoprotein (VSG) in Trypanosoma brucei provides a crucial host immune evasion strategy that is catalysed both by transcription and recombination reactions, each operating within specialised telomeric VSG expression sites (ES). VSG switching is likely triggered by events focused on the single actively transcribed ES, from a repertoire of around 15, but the nature of such events is unclear. Here we show that RNA-DNA hybrids, called R-loops, form preferentially within sequences termed the 70 bp repeats in the actively transcribed ES, but spread throughout the active and inactive ES, in the absence of RNase H1, which degrades R-loops. Loss of RNase H1 also leads to increased levels of VSG coat switching and replication-associated genome damage, some of which accumulates within the active ES. This work indicates VSG ES architecture elicits R-loop formation, and that these RNA-DNA hybrids connect T. brucei immune evasion by transcription and recombination.
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Affiliation(s)
- Emma Briggs
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
| | - Kathryn Crouch
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
| | - Leandro Lemgruber
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
| | - Craig Lapsley
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
| | - Richard McCulloch
- The Wellcome Centre for Molecular Parasitology, University of Glasgow, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, Glasgow, United Kingdom
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16
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Pineda E, Thonnus M, Mazet M, Mourier A, Cahoreau E, Kulyk H, Dupuy JW, Biran M, Masante C, Allmann S, Rivière L, Rotureau B, Portais JC, Bringaud F. Glycerol supports growth of the Trypanosoma brucei bloodstream forms in the absence of glucose: Analysis of metabolic adaptations on glycerol-rich conditions. PLoS Pathog 2018; 14:e1007412. [PMID: 30383867 PMCID: PMC6245841 DOI: 10.1371/journal.ppat.1007412] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 11/20/2018] [Accepted: 10/16/2018] [Indexed: 12/18/2022] Open
Abstract
The bloodstream forms of Trypanosoma brucei (BSF), the parasite protist causing sleeping sickness, primarily proliferate in the blood of their mammalian hosts. The skin and adipose tissues were recently identified as additional major sites for parasite development. Glucose was the only carbon source known to be used by bloodstream trypanosomes to feed their central carbon metabolism, however, the metabolic behaviour of extravascular tissue-adapted parasites has not been addressed yet. Since the production of glycerol is an important primary function of adipocytes, we have adapted BSF trypanosomes to a glucose-depleted but glycerol-rich culture medium (CMM_Glyc/GlcNAc) and compared their metabolism and proteome to those of parasites grown in standard glucose-rich conditions (CMM_Glc). BSF were shown to consume 2-folds more oxygen per consumed carbon unit in CMM_Glyc/GlcNAc and were 11.5-times more sensitive to SHAM, a specific inhibitor of the plant-like alternative oxidase (TAO), which is the only mitochondrial terminal oxidase expressed in BSF. This is consistent with (i) the absolute requirement of the mitochondrial respiratory activity to convert glycerol into dihydroxyacetone phosphate, as deduced from the updated metabolic scheme and (ii) with the 1.8-fold increase of the TAO expression level compared to the presence of glucose. Proton NMR analysis of excreted end products from glycerol and glucose metabolism showed that these two carbon sources are metabolised through the same pathways, although the contributions of the acetate and succinate branches are more important in the presence of glycerol than glucose (10.2% versus 3.4% of the excreted end products, respectively). In addition, metabolomic analyses by mass spectrometry showed that, in the absence of glucose, 13C-labelled glycerol was incorporated into hexose phosphates through gluconeogenesis. As expected, RNAi-mediated down-regulation of glycerol kinase expression abolished glycerol metabolism and was lethal for BSF grown in CMM_Glyc/GlcNAc. Interestingly, BSF have adapted their metabolism to grow in CMM_Glyc/GlcNAc by concomitantly increasing their rate of glycerol consumption and decreasing that of glucose. However, the glycerol kinase activity was 7.8-fold lower in CMM_Glyc/GlcNAc, as confirmed by both western blotting and proteomic analyses. This suggests that the huge excess in glycerol kinase that is not absolutely required for glycerol metabolism, might be used for another yet undetermined non-essential function in glucose rich-conditions. Altogether, these data demonstrate that BSF trypanosomes are well-adapted to glycerol-rich conditions that could be encountered by the parasite in extravascular niches, such as the skin and adipose tissues. Until very recently, the bloodstream forms (BSF) of the Trypanosoma brucei group species have been considered to propagate exclusively in the mammalian fluids, including the blood, the lymphatic network and the cerebrospinal fluid. All these fluids are rich in glucose, which is widely considered by the scientific community as the only carbon source used by the parasite to feed its central carbon metabolism and its ATP production. Here, we show for the first time that the BSF trypanosomes efficiently grow in glucose-free conditions as long as glycerol is supplied. The raison d'être of this capacity developed by BSF trypanosomes to grow in glycerol-rich conditions regardless of the glucose concentration, including in glucose-free conditions, is not yet understood. However, the recent discovery that trypanosomes colonize and proliferate in the skin and the adipose tissues of their mammalian hosts may provide a rational explanation for the development of a glycerol-based metabolism in BSF. Indeed, the adipocytes composing adipose tissues and also abundantly present in subcutaneous layers excrete large amounts of glycerol produced from the catabolism of glucose and triglycerides. We also show that BSF trypanosomes adapted to glucose-depleted conditions activate gluconeogenesis to produce the essential hexose phosphates from glycerol metabolism. Interestingly, the constitutive expression of the key gluconeogenic enzyme fructose-1,6-bisphosphatase, which is not used for glycolysis, suggests that BSF trypanosomes maintained in the standard glucose-rich medium are pre-adapted to glucose-depleted conditions. This further strengthens the new paradigm that BSF trypanosomes can use glycerol in tissues producing this carbon source, such as the skin the adipose tissues.
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Affiliation(s)
- Erika Pineda
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, Bordeaux, France
| | - Magali Thonnus
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, Bordeaux, France
| | - Muriel Mazet
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, Bordeaux, France
- Centre de Résonance Magnétique des Systèmes Biologiques (CRMSB), Université de Bordeaux, CNRS UMR-5536, Bordeaux, France
| | - Arnaud Mourier
- Institute of Biochemistry and Genetics of the Cell (IBGC) du CNRS, Université de Bordeaux, Bordeaux, France
| | - Edern Cahoreau
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
| | - Hanna Kulyk
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
| | - Jean-William Dupuy
- Centre de Génomique Fonctionnelle, Plateforme Protéome, Université de Bordeaux, Bordeaux, France
| | - Marc Biran
- Centre de Résonance Magnétique des Systèmes Biologiques (CRMSB), Université de Bordeaux, CNRS UMR-5536, Bordeaux, France
| | - Cyril Masante
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, Bordeaux, France
| | - Stefan Allmann
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, Bordeaux, France
- Centre de Résonance Magnétique des Systèmes Biologiques (CRMSB), Université de Bordeaux, CNRS UMR-5536, Bordeaux, France
| | - Loïc Rivière
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, Bordeaux, France
| | - Brice Rotureau
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, Department of Parasites and Insect Vectors, INSERM U1201, Institut Pasteur, Paris, France
| | | | - Frédéric Bringaud
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, Bordeaux, France
- Centre de Résonance Magnétique des Systèmes Biologiques (CRMSB), Université de Bordeaux, CNRS UMR-5536, Bordeaux, France
- * E-mail:
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Figarella K, Uzcategui NL, Mogk S, Wild K, Fallier-Becker P, Neher JJ, Duszenko M. Morphological changes, nitric oxide production, and phagocytosis are triggered in vitro in microglia by bloodstream forms of Trypanosoma brucei. Sci Rep 2018; 8:15002. [PMID: 30302029 PMCID: PMC6177420 DOI: 10.1038/s41598-018-33395-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 09/27/2018] [Indexed: 01/18/2023] Open
Abstract
The flagellated parasite Trypanosoma brucei is the causative agent of Human African Trypanosomiasis (HAT). By a mechanism not well understood yet, trypanosomes enter the central nervous system (CNS), invade the brain parenchyma, and cause a fatal encephalopathy if is not treated. Trypanosomes are fast dividing organisms that, without any immune response, would kill the host in a short time. However, infected individuals survive either 6-12 months or more than 3 years for the acute and chronic forms, respectively. Thus, only when the brain defense collapses a lethal encephalopathy will occur. Here, we evaluated interactions between trypanosomes and microglial cells, which are the primary immune effector cells within the CNS. Using co-cultures of primary microglia and parasites, we found clear evidences of trypanosome phagocytosis by microglial cells. Microglia activation was also evident; analysis of its ultrastructure showed changes that have been reported in activated microglia undergoing oxidative stress caused by infections or degenerative diseases. Accordingly, an increase of the nitric oxide production was detected in supernatants of microglia/parasite co-cultures. Altogether, our results demonstrate that microglial cells respond to the presence of the parasite, leading to parasite's engulfment and elimination.
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Affiliation(s)
- Katherine Figarella
- Interfaculty Institute for Biochemistry, University of Tübingen, Tübingen, Germany.
- Institute for Neurophysiology, University of Tübingen, Tübingen, Germany.
| | - Nestor L Uzcategui
- Institute for Anatomy, Central University of Venezuela, Caracas, Venezuela
| | - Stefan Mogk
- Interfaculty Institute for Biochemistry, University of Tübingen, Tübingen, Germany
| | - Katleen Wild
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany and Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Petra Fallier-Becker
- Institute of Pathology and Neuropathology, University Hospital of Tübingen, Tübingen, Germany
| | - Jonas J Neher
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany and Department of Cellular Neurology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Michael Duszenko
- Interfaculty Institute for Biochemistry, University of Tübingen, Tübingen, Germany
- Faculty of Medicine, Tongji University, Shanghai, China
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18
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Brew-Appiah RAT, Sanguinet KA. Considerations of AOX Functionality Revealed by Critical Motifs and Unique Domains. Int J Mol Sci 2018; 19:ijms19102972. [PMID: 30274246 PMCID: PMC6213860 DOI: 10.3390/ijms19102972] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 09/14/2018] [Accepted: 09/28/2018] [Indexed: 12/28/2022] Open
Abstract
An understanding of the genes and mechanisms regulating environmental stress in crops is critical for boosting agricultural yield and safeguarding food security. Under adverse conditions, response pathways are activated for tolerance or resistance. In multiple species, the alternative oxidase (AOX) genes encode proteins which help in this process. Recently, this gene family has been extensively investigated in the vital crop plants, wheat, barley and rice. Cumulatively, these three species and/or their wild ancestors contain the genes for AOX1a, AOX1c, AOX1e, and AOX1d, and common patterns in the protein isoforms have been documented. Here, we add more information on these trends by emphasizing motifs that could affect expression, and by utilizing the most recent discoveries from the AOX isoform in Trypanosoma brucei to highlight clade-dependent biases. The new perspectives may have implications on how the AOX gene family has evolved and functions in monocots. The common or divergent amino acid substitutions between these grasses and the parasite are noted, and the potential effects of these changes are discussed. There is the hope that the insights gained will inform the way future AOX research is performed in monocots, in order to optimize crop production for food, feed, and fuel.
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Affiliation(s)
- Rhoda A T Brew-Appiah
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA 99164-6420, USA.
| | - Karen A Sanguinet
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA 99164-6420, USA.
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Caljon G, Mabille D, Stijlemans B, De Trez C, Mazzone M, Tacchini-Cottier F, Malissen M, Van Ginderachter JA, Magez S, De Baetselier P, Van Den Abbeele J. Neutrophils enhance early Trypanosoma brucei infection onset. Sci Rep 2018; 8:11203. [PMID: 30046157 PMCID: PMC6060092 DOI: 10.1038/s41598-018-29527-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 07/11/2018] [Indexed: 01/06/2023] Open
Abstract
In this study, Trypanosoma brucei was naturally transmitted to mice through the bites of infected Glossina morsitans tsetse flies. Neutrophils were recruited rapidly to the bite site, whereas monocytes were attracted more gradually. Expression of inflammatory cytokines (il1b, il6), il10 and neutrophil chemokines (cxcl1, cxcl5) was transiently up-regulated at the site of parasite inoculation. Then, a second influx of neutrophils occurred that coincided with the previously described parasite retention and expansion in the ear dermis. Congenital and experimental neutropenia models, combined with bioluminescent imaging, indicate that neutrophils do not significantly contribute to dermal parasite control and elicit higher systemic parasitemia levels during the infection onset. Engulfment of parasites by neutrophils in the skin was rarely observed and was restricted to parasites with reduced motility/viability, whereas live parasites escaped phagocytosis. To our knowledge, this study represents the first description of a trypanosome infection promoting role of early innate immunological reactions following an infective tsetse fly bite. Our data indicate that the trypanosome is not hindered in its early development and benefits from the host innate responses with the neutrophils being important regulators of the early infection, as already demonstrated for the sand fly transmitted Leishmania parasite.
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Affiliation(s)
- Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Wilrijk, Belgium.
| | - Dorien Mabille
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Wilrijk, Belgium
| | - Benoît Stijlemans
- Myeloid Cell Immunology Lab, VIB Center for Inflammation Research, Ghent, Belgium
- Unit of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Carl De Trez
- Unit of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Massimiliano Mazzone
- Laboratory of Tumor Inflammation and Angiogenesis, Center for Cancer Biology, VIB, Leuven, Belgium
- Laboratory of Tumor Inflammation and Angiogenesis, Center for Cancer Biology, Department of Oncology, KU Leuven, Leuven, Belgium
| | - Fabienne Tacchini-Cottier
- Department of Biochemistry, WHO-Immunology Research and Training Center, University of Lausanne, Epalinges, Switzerland
| | - Marie Malissen
- Centre d'Immunologie de Marseille-Luminy, Aix Marseille Université UM2, Inserm U1104, CNRS UMR7280, F-13288, Marseille, France
| | - Jo A Van Ginderachter
- Myeloid Cell Immunology Lab, VIB Center for Inflammation Research, Ghent, Belgium
- Unit of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Stefan Magez
- Unit of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Ghent University Global Campus, Incheon, South Korea
| | - Patrick De Baetselier
- Myeloid Cell Immunology Lab, VIB Center for Inflammation Research, Ghent, Belgium
- Unit of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Jan Van Den Abbeele
- Unit of Veterinary Protozoology, Department of Biomedical Sciences, Institute of Tropical Medicine Antwerp (ITM), Antwerp, Belgium.
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20
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Kelner A, Tinti M, Guther MLS, Foth BJ, Chappell L, Berriman M, Cowling VH, Ferguson MAJ. The mRNA cap methyltransferase gene TbCMT1 is not essential in vitro but is a virulence factor in vivo for bloodstream form Trypanosoma brucei. PLoS One 2018; 13:e0201263. [PMID: 30040830 PMCID: PMC6057678 DOI: 10.1371/journal.pone.0201263] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/11/2018] [Indexed: 01/16/2023] Open
Abstract
Messenger RNA is modified by the addition of a 5' methylated cap structure, which protects the transcript and recruits protein complexes that mediate RNA processing and/or the initiation of translation. Two genes encoding mRNA cap methyltransferases have been identified in T. brucei: TbCMT1 and TbCGM1. Here we analysed the impact of TbCMT1 gene deletion on bloodstream form T. brucei cells. TbCMT1 was dispensable for parasite proliferation in in vitro culture. However, significantly decreased parasitemia was observed in mice inoculated with TbCMT1 null and conditional null cell lines. Using RNA-Seq, we observed that several cysteine peptidase mRNAs were downregulated in TbCMT1 null cells lines. The cysteine peptidase Cathepsin-L was also shown to be reduced at the protein level in TbCMT1 null cell lines. Our data suggest that TbCMT1 is not essential to bloodstream form T. brucei growth in vitro or in vivo but that it contributes significantly to parasite virulence in vivo.
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Affiliation(s)
- Anna Kelner
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Michele Tinti
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Maria Lucia S. Guther
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | | | - Lia Chappell
- The Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | | | - Victoria Haigh Cowling
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
- * E-mail: (MAJF); (VHC)
| | - Michael A. J. Ferguson
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
- * E-mail: (MAJF); (VHC)
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21
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Peacock L, Kay C, Bailey M, Gibson W. Shape-shifting trypanosomes: Flagellar shortening followed by asymmetric division in Trypanosoma congolense from the tsetse proventriculus. PLoS Pathog 2018; 14:e1007043. [PMID: 29772025 PMCID: PMC5957336 DOI: 10.1371/journal.ppat.1007043] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 04/18/2018] [Indexed: 11/18/2022] Open
Abstract
Trypanosomatids such as Leishmania and Trypanosoma are digenetic, single-celled, parasitic flagellates that undergo complex life cycles involving morphological and metabolic changes to fit them for survival in different environments within their mammalian and insect hosts. According to current consensus, asymmetric division enables trypanosomatids to achieve the major morphological rearrangements associated with transition between developmental stages. Contrary to this view, here we show that the African trypanosome Trypanosoma congolense, an important livestock pathogen, undergoes extensive cell remodelling, involving shortening of the cell body and flagellum, during its transition from free-swimming proventricular forms to attached epimastigotes in vitro. Shortening of the flagellum was associated with accumulation of PFR1, a major constituent of the paraflagellar rod, in the mid-region of the flagellum where it was attached to the substrate. However, the PFR1 depot was not essential for attachment, as it accumulated several hours after initial attachment of proventricular trypanosomes. Detergent and CaCl2 treatment failed to dislodge attached parasites, demonstrating the robust nature of flagellar attachment to the substrate; the PFR1 depot was also unaffected by these treatments. Division of the remodelled proventricular trypanosome was asymmetric, producing a small daughter cell. Each mother cell went on to produce at least one more daughter cell, while the daughter trypanosomes also proliferated, eventually resulting in a dense culture of epimastigotes. Here, by observing the synchronous development of the homogeneous population of trypanosomes in the tsetse proventriculus, we have been able to examine the transition from proventricular forms to attached epimastigotes in detail in T. congolense. This transition is difficult to observe in vivo as it happens inside the mouthparts of the tsetse fly. In T. brucei, this transition is achieved by asymmetric division of long trypomastigotes in the proventriculus, yielding short epimastigotes, which go on to colonise the salivary glands. Thus, despite their close evolutionary relationship and shared developmental route within the vector, T. brucei and T. congolense have evolved different ways of accomplishing the same developmental transition from proventricular form to attached epimastigote. Tsetse-transmitted trypanosomes are parasitic protists that cause severe human and livestock diseases in tropical Africa. During their developmental cycle in the tsetse fly, these trypanosomes undergo complex cycles of differentiation and proliferation. Here we have investigated part of the developmental cycle of the major livestock pathogen Trypanosoma congolense as it moves from the fly midgut via the foregut to the mouthparts, where it reacquires infectivity to mammalian hosts. This transition is difficult to observe in vivo because of the small numbers of migratory trypanosomes and their inaccessibility in the fly. However, prior to migration, trypanosomes accumulate in the proventriculus, the valve that separates the foregut from the midgut, and we were able to observe the behaviour of these cells in vitro. On release from the proventriculus, these trypanosomes readily attach to a glass microscope slide and then undergo drastic remodelling to become short, stout cells, before each produces a small daughter cell. Each mother cell goes on to produce at least one further daughter trypanosome in the same way, while the daughter cells also proliferate as attached cells. We assume that these events would normally happen in vivo inside the tsetse proboscis. In T. brucei the equivalent developmental transition takes place in the proventriculus or foregut in free-swimming rather than attached cells, and is achieved via an asymmetric division. Thus, despite their close evolutionary relationship, these two trypanosome species have evolved different ways of accomplishing what is essentially the same developmental transition.
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Affiliation(s)
- Lori Peacock
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
- Bristol Veterinary School, University of Bristol, Langford, Bristol, United Kingdom
| | - Christopher Kay
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Mick Bailey
- Bristol Veterinary School, University of Bristol, Langford, Bristol, United Kingdom
| | - Wendy Gibson
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
- * E-mail:
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22
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Ebersoll S, Musunda B, Schmenger T, Dirdjaja N, Bonilla M, Manta B, Ulrich K, Comini MA, Krauth-Siegel RL. A glutaredoxin in the mitochondrial intermembrane space has stage-specific functions in the thermo-tolerance and proliferation of African trypanosomes. Redox Biol 2018; 15:532-547. [PMID: 29413965 PMCID: PMC5975080 DOI: 10.1016/j.redox.2018.01.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 01/23/2018] [Indexed: 12/30/2022] Open
Abstract
Trypanosoma brucei glutaredoxin 2 (Grx2) is a dithiol glutaredoxin that is specifically located in the mitochondrial intermembrane space. Bloodstream form parasites lacking Grx2 or both, Grx2 and the cytosolic Grx1, are viable in vitro and infectious to mice suggesting that neither oxidoreductase is needed for survival or infectivity to mammals. A 37 °C to 39 °C shift changes the cellular redox milieu of bloodstream cells to more oxidizing conditions and induces a significantly stronger growth arrest in wildtype parasites compared to the mutant cells. Grx2-deficient cells ectopically expressing the wildtype form of Grx2 with its C31QFC34 active site, but not the C34S mutant, regain the sensitivity of the parental strain, indicating that the physiological role of Grx2 requires both active site cysteines. In the procyclic insect stage of the parasite, Grx2 is essential. Both alleles can be replaced if procyclic cells ectopically express authentic or C34S, but not C31S/C34S Grx2, pointing to a redox role that relies on a monothiol mechanism. RNA-interference against Grx2 causes a virtually irreversible proliferation defect. The cells adopt an elongated morphology but do not show any significant alteration in the cell cycle. The growth retardation is attenuated by high glucose concentrations. Under these conditions, procyclic cells obtain ATP by substrate level phosphorylation suggesting that Grx2 might regulate a respiratory chain component. Bloodstream T. brucei lacking glutaredoxin 2 are fully viable in vitro and in vivo. A temperature rise shifts the cellular redox state to more oxidizing conditions. Glutaredoxin 2-deficiency confers bloodstream cells with thermo-tolerance. The insect stage requires redox-active glutaredoxin 2 for viability and morphology.
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Affiliation(s)
- Samantha Ebersoll
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Blessing Musunda
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Torsten Schmenger
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Natalie Dirdjaja
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Mariana Bonilla
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400, Montevideo, Uruguay
| | - Bruno Manta
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400, Montevideo, Uruguay
| | - Kathrin Ulrich
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Marcelo A Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400, Montevideo, Uruguay
| | - R Luise Krauth-Siegel
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
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23
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Käser S, Willemin M, Schnarwiler F, Schimanski B, Poveda-Huertes D, Oeljeklaus S, Haenni B, Zuber B, Warscheid B, Meisinger C, Schneider A. Biogenesis of the mitochondrial DNA inheritance machinery in the mitochondrial outer membrane of Trypanosoma brucei. PLoS Pathog 2017; 13:e1006808. [PMID: 29287109 PMCID: PMC5764417 DOI: 10.1371/journal.ppat.1006808] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 01/11/2018] [Accepted: 12/13/2017] [Indexed: 12/22/2022] Open
Abstract
Mitochondria cannot form de novo but require mechanisms that mediate their inheritance to daughter cells. The parasitic protozoan Trypanosoma brucei has a single mitochondrion with a single-unit genome that is physically connected across the two mitochondrial membranes with the basal body of the flagellum. This connection, termed the tripartite attachment complex (TAC), is essential for the segregation of the replicated mitochondrial genomes prior to cytokinesis. Here we identify a protein complex consisting of three integral mitochondrial outer membrane proteins-TAC60, TAC42 and TAC40-which are essential subunits of the TAC. TAC60 contains separable mitochondrial import and TAC-sorting signals and its biogenesis depends on the main outer membrane protein translocase. TAC40 is a member of the mitochondrial porin family, whereas TAC42 represents a novel class of mitochondrial outer membrane β-barrel proteins. Consequently TAC40 and TAC42 contain C-terminal β-signals. Thus in trypanosomes the highly conserved β-barrel protein assembly machinery plays a major role in the biogenesis of its unique mitochondrial genome segregation system.
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Affiliation(s)
- Sandro Käser
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Mathilde Willemin
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Felix Schnarwiler
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Bernd Schimanski
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Daniel Poveda-Huertes
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
- Faculty of Biology, University of Freiburg, Freiburg im Breisgau, Germany
| | - Silke Oeljeklaus
- Department of Biochemistry and Functional Proteomics, Faculty of Biology, University of Freiburg, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Beat Haenni
- Institute of Anatomy, University of Bern, Bern, Switzerland
| | - Benoît Zuber
- Institute of Anatomy, University of Bern, Bern, Switzerland
| | - Bettina Warscheid
- Department of Biochemistry and Functional Proteomics, Faculty of Biology, University of Freiburg, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Chris Meisinger
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - André Schneider
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
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24
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Eze JI, Ekelozie CF, Nweze NE. Immunomodulatory activity of Buchholzia coriacea seed methanol extract on Trypanosoma brucei brucei infected mice. Pharm Biol 2017; 55:636-640. [PMID: 27951754 PMCID: PMC6130747 DOI: 10.1080/13880209.2016.1265988] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 08/24/2016] [Accepted: 11/22/2016] [Indexed: 06/06/2023]
Abstract
CONTEXT The seeds of Buchholzia coriacea Engler (Capparaceae) are used in Eastern Nigeria to treat feverish conditions, and to treat malaria and sleeping sickness that cause fever. OBJECTIVE The current study assesses the immunomodulatory activity of Buchholzia coriacea seed extract on Trypanosoma brucei brucei infected mice. MATERIALS AND METHODS Delayed hypersensitivity reaction, humoral antibody response and in-vivo leucocyte mobilization tests were assessed in three different experiments to determine the effect of the extract on immune response. Seventy-five (75) mice (25 mice per experiment) were used for the study and were each infected with 1.00 × 106 trypanosomes intra-peritoneally. Groups A, B and C were given 250, 500 and 1000 mg/kg of the extract, respectively, group D received 7.5 mg/kg body weight of levamisole and group E was the control. Sheep RBCs were used as antigen. RESULTS The acute toxicity tests did not cause clinical signs or death within 24 h post treatment at all the doses tested. The extract inhibited delayed hypersensitivity reaction by 20.9 and 20.8% at 250 and 500 mg/kg, respectively, while at 1000 mg/kg, the paw size increased (-101.9%) when compared with the control. The extract elevated the antibody titre from 1.60 ± 0.40 for control to 8.00 ± 3.58 for 500 mg/kg group. The extract increased in total leucocytes counts. DISCUSSION AND CONCLUSION The extract has a very wide safety margin and was able to improve immune response. The results of the present study showed that Buchholzia coriacea seed methanol extract possesses immunostimulatory activity on trypanosome-infected mice.
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MESH Headings
- Animals
- Capparaceae/chemistry
- Chemotaxis, Leukocyte/drug effects
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Edema/immunology
- Edema/parasitology
- Edema/prevention & control
- Hypersensitivity, Delayed/immunology
- Hypersensitivity, Delayed/parasitology
- Hypersensitivity, Delayed/prevention & control
- Immunity, Humoral/drug effects
- Immunologic Factors/isolation & purification
- Immunologic Factors/pharmacology
- Immunologic Factors/toxicity
- Lethal Dose 50
- Male
- Methanol/chemistry
- Mice
- Phytotherapy
- Plant Extracts/isolation & purification
- Plant Extracts/pharmacology
- Plant Extracts/toxicity
- Plants, Medicinal
- Seeds/chemistry
- Solvents/chemistry
- Trypanocidal Agents/isolation & purification
- Trypanocidal Agents/pharmacology
- Trypanocidal Agents/toxicity
- Trypanosoma brucei brucei/drug effects
- Trypanosoma brucei brucei/immunology
- Trypanosoma brucei brucei/pathogenicity
- Trypanosomiasis, African/drug therapy
- Trypanosomiasis, African/immunology
- Trypanosomiasis, African/parasitology
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Affiliation(s)
- James I. Eze
- Department of Veterinary Medicine, University of Nigeria, Nsukka, Nigeria
| | - Chioma F. Ekelozie
- Department of Veterinary Medicine, University of Nigeria, Nsukka, Nigeria
| | - Nwakego E. Nweze
- Department of Veterinary Medicine, University of Nigeria, Nsukka, Nigeria
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25
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Pinger J, Chowdhury S, Papavasiliou FN. Variant surface glycoprotein density defines an immune evasion threshold for African trypanosomes undergoing antigenic variation. Nat Commun 2017; 8:828. [PMID: 29018220 PMCID: PMC5635023 DOI: 10.1038/s41467-017-00959-w] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Accepted: 08/02/2017] [Indexed: 11/15/2022] Open
Abstract
Trypanosoma brucei is a protozoan parasite that evades its host's adaptive immune response by repeatedly replacing its dense variant surface glycoprotein (VSG) coat from its large genomic VSG repertoire. While the mechanisms regulating VSG gene expression and diversification have been examined extensively, the dynamics of VSG coat replacement at the protein level, and the impact of this process on successful immune evasion, remain unclear. Here we evaluate the rate of VSG replacement at the trypanosome surface following a genetic VSG switch, and show that full coat replacement requires several days to complete. Using in vivo infection assays, we demonstrate that parasites undergoing coat replacement are only vulnerable to clearance via early IgM antibodies for a limited time. Finally, we show that IgM loses its ability to mediate trypanosome clearance at unexpectedly early stages of coat replacement based on a critical density threshold of its cognate VSGs on the parasite surface. Trypanosoma brucei evades the host immune system through replacement of a variant surface glycoprotein (VSG) coat. Here, the authors show that VSG replacement takes several days to complete, and the parasite is vulnerable to the host immune system for a short period of time during the process.
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Affiliation(s)
- Jason Pinger
- The Rockefeller University, Laboratory of Lymphocyte Biology, 1230 York Avenue, New York, NY, 10065, USA.
- The David Rockefeller Graduate School, 1230 York Avenue, New York, NY, 10065, USA.
| | - Shanin Chowdhury
- The Rockefeller University, Laboratory of Lymphocyte Biology, 1230 York Avenue, New York, NY, 10065, USA
| | - F Nina Papavasiliou
- The Rockefeller University, Laboratory of Lymphocyte Biology, 1230 York Avenue, New York, NY, 10065, USA.
- Division of Immune Diversity, German Cancer Research Center, Im Neuenheimer Feld 280, Heidelberg, 69120, Germany.
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26
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Boehm CM, Obado S, Gadelha C, Kaupisch A, Manna PT, Gould GW, Munson M, Chait BT, Rout MP, Field MC. The Trypanosome Exocyst: A Conserved Structure Revealing a New Role in Endocytosis. PLoS Pathog 2017; 13:e1006063. [PMID: 28114397 PMCID: PMC5256885 DOI: 10.1371/journal.ppat.1006063] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 11/14/2016] [Indexed: 01/10/2023] Open
Abstract
Membrane transport is an essential component of pathogenesis for most infectious organisms. In African trypanosomes, transport to and from the plasma membrane is closely coupled to immune evasion and antigenic variation. In mammals and fungi an octameric exocyst complex mediates late steps in exocytosis, but comparative genomics suggested that trypanosomes retain only six canonical subunits, implying mechanistic divergence. We directly determined the composition of the Trypanosoma brucei exocyst by affinity isolation and demonstrate that the parasite complex is nonameric, retaining all eight canonical subunits (albeit highly divergent at the sequence level) plus a novel essential subunit, Exo99. Exo99 and Sec15 knockdowns have remarkably similar phenotypes in terms of viability and impact on morphology and trafficking pathways. Significantly, both Sec15 and Exo99 have a clear function in endocytosis, and global proteomic analysis indicates an important role in maintaining the surface proteome. Taken together these data indicate additional exocyst functions in trypanosomes, which likely include endocytosis, recycling and control of surface composition. Knockdowns in HeLa cells suggest that the role in endocytosis is shared with metazoan cells. We conclude that, whilst the trypanosome exocyst has novel components, overall functionality appears conserved, and suggest that the unique subunit may provide therapeutic opportunities.
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Affiliation(s)
- Cordula M. Boehm
- Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee, United Kingdom
| | - Samson Obado
- The Rockefeller University, 1230 York Avenue, New York, NY, United States of America
| | - Catarina Gadelha
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Alexandra Kaupisch
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Paul T. Manna
- Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee, United Kingdom
| | - Gwyn W. Gould
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Mary Munson
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Brian T. Chait
- The Rockefeller University, 1230 York Avenue, New York, NY, United States of America
| | - Michael P. Rout
- The Rockefeller University, 1230 York Avenue, New York, NY, United States of America
| | - Mark C. Field
- Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee, United Kingdom
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27
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Dauchy FA, Bonhivers M, Landrein N, Dacheux D, Courtois P, Lauruol F, Daulouède S, Vincendeau P, Robinson DR. Trypanosoma brucei CYP51: Essentiality and Targeting Therapy in an Experimental Model. PLoS Negl Trop Dis 2016; 10:e0005125. [PMID: 27855164 PMCID: PMC5113867 DOI: 10.1371/journal.pntd.0005125] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 10/24/2016] [Indexed: 01/03/2023] Open
Abstract
Trypanosoma brucei gambiense is the main causative agent of Human African Trypanosomiasis (HAT), also known as sleeping sickness. Because of limited alternatives and treatment toxicities, new therapeutic options are urgently needed for patients with HAT. Sterol 14alpha-demethylase (CYP51) is a potential drug target but its essentiality has not been determined in T. brucei. We used a tetracycline-inducible RNAi system to assess the essentiality of CYP51 in T. brucei bloodstream form (BSF) cells and we evaluated the effect of posaconazole, a well-tolerated triazole drug, within a panel of virulent strains in vitro and in a murine model. Expression of CYP51 in several T. brucei cell lines was demonstrated by western blot and its essentiality was demonstrated by RNA interference (CYP51RNAi) in vitro. Following reduction of TbCYP51 expression by RNAi, cell growth was reduced and eventually stopped compared to WT or non-induced cells, showing the requirement of CYP51 in T. brucei. These phenotypes were rescued by addition of ergosterol. Additionally, CYP51RNAi induction caused morphological defects with multiflagellated cells (p<0.05), suggesting cytokinesis dysfunction. The survival of CYP51RNAi Doxycycline-treated mice (p = 0.053) and of CYP51RNAi 5-day pre-induced Doxycycline-treated mice (p = 0.008) were improved compared to WT showing a CYP51 RNAi effect on trypanosomal virulence in mice. The posaconazole concentrations that inhibited parasite growth by 50% (IC50) were 8.5, 2.7, 1.6 and 0.12 μM for T. b. brucei 427 90-13, T. b. brucei Antat 1.1, T. b. gambiense Feo (Feo/ITMAP/1893) and T. b. gambiense Biyamina (MHOM/SD/82), respectively. During infection with these last three virulent strains, posaconazole-eflornithine and nifurtimox-eflornithine combinations showed similar improvement in mice survival (p≤0.001). Our results provide support for a CYP51 targeting based treatment in HAT. Thus posaconazole used in combination may represent a therapeutic alternative for trypanosomiasis.
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Affiliation(s)
- Frédéric-Antoine Dauchy
- University of Bordeaux, laboratoire de parasitologie, France
- IRD-CIRAD-University of Bordeaux, France
- University Hospital of Bordeaux, Department of infectious and tropical diseases, Hôpital Pellegrin, France
- * E-mail:
| | - Mélanie Bonhivers
- University of Bordeaux, Microbiologie Fondamentale et Pathogénicité, France
- CNRS, Microbiologie Fondamentale et Pathogénicité, France
| | - Nicolas Landrein
- University of Bordeaux, Microbiologie Fondamentale et Pathogénicité, France
- CNRS, Microbiologie Fondamentale et Pathogénicité, France
| | - Denis Dacheux
- University of Bordeaux, Microbiologie Fondamentale et Pathogénicité, France
- CNRS, Microbiologie Fondamentale et Pathogénicité, France
- Bordeaux INP, ENSTBB, Microbiologie Fondamentale et Pathogénicité, France
| | - Pierrette Courtois
- University of Bordeaux, laboratoire de parasitologie, France
- IRD-CIRAD-University of Bordeaux, France
| | - Florian Lauruol
- University of Bordeaux, laboratoire de parasitologie, France
- IRD-CIRAD-University of Bordeaux, France
| | - Sylvie Daulouède
- University of Bordeaux, laboratoire de parasitologie, France
- IRD-CIRAD-University of Bordeaux, France
| | - Philippe Vincendeau
- University of Bordeaux, laboratoire de parasitologie, France
- IRD-CIRAD-University of Bordeaux, France
- University Hospital of Bordeaux, laboratoire de parasitologie, Hôpital Pellegrin, France
| | - Derrick R. Robinson
- University of Bordeaux, Microbiologie Fondamentale et Pathogénicité, France
- CNRS, Microbiologie Fondamentale et Pathogénicité, France
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28
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Hovel-Miner G, Mugnier MR, Goldwater B, Cross GAM, Papavasiliou FN. A Conserved DNA Repeat Promotes Selection of a Diverse Repertoire of Trypanosoma brucei Surface Antigens from the Genomic Archive. PLoS Genet 2016; 12:e1005994. [PMID: 27149665 PMCID: PMC4858185 DOI: 10.1371/journal.pgen.1005994] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 03/28/2016] [Indexed: 12/02/2022] Open
Abstract
African trypanosomes are mammalian pathogens that must regularly change their protein coat to survive in the host bloodstream. Chronic trypanosome infections are potentiated by their ability to access a deep genomic repertoire of Variant Surface Glycoprotein (VSG) genes and switch from the expression of one VSG to another. Switching VSG expression is largely based in DNA recombination events that result in chromosome translocations between an acceptor site, which houses the actively transcribed VSG, and a donor gene, drawn from an archive of more than 2,000 silent VSGs. One element implicated in these duplicative gene conversion events is a DNA repeat of approximately 70 bp that is found in long regions within each BES and short iterations proximal to VSGs within the silent archive. Early observations showing that 70-bp repeats can be recombination boundaries during VSG switching led to the prediction that VSG-proximal 70-bp repeats provide recombinatorial homology. Yet, this long held assumption had not been tested and no specific function for the conserved 70-bp repeats had been demonstrated. In the present study, the 70-bp repeats were genetically manipulated under conditions that induce gene conversion. In this manner, we demonstrated that 70-bp repeats promote access to archival VSGs. Synthetic repeat DNA sequences were then employed to identify the length, sequence, and directionality of repeat regions required for this activity. In addition, manipulation of the 70-bp repeats allowed us to observe a link between VSG switching and the cell cycle that had not been appreciated. Together these data provide definitive support for the long-standing hypothesis that 70-bp repeats provide recombinatorial homology during switching. Yet, the fact that silent archival VSGs are selected under these conditions suggests the 70-bp repeats also direct DNA pairing and recombination machinery away from the closest homologs (silent BESs) and toward the rest of the archive. Chromosomal translocations can fuel genetic change or cause catastrophic genomic damage. African trypanosomes, exemplified by Trypanosoma brucei sub-species, are unicellular parasites that can chronically infect their human and livestock hosts by using a strategy of antigenic variation by which they repeatedly change their protein coats. Switching the surface coat requires the accurate selection and translocation of a single silent coat gene, from a large genomic archive, into an actively transcribed site. How the coat genes from within this deep archive are selected and activated was unproven. Here we show that a specific repetitive DNA sequence is required to access coat genes from diverse sites within the genome. The likely outcome of restricting this process of coat gene selection in natural infections would be a reduction in the chronic nature of African trypanosomiasis.
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Affiliation(s)
- Galadriel Hovel-Miner
- The Rockefeller University, Laboratory of Lymphocyte Biology, New York, New York, United States of America
- The George Washington University, Department of Microbiology Immunology, and Tropical Medicine, Washington, DC, United States of America
- * E-mail:
| | - Monica R. Mugnier
- The Rockefeller University, Laboratory of Lymphocyte Biology, New York, New York, United States of America
| | - Benjamin Goldwater
- The Rockefeller University, Laboratory of Lymphocyte Biology, New York, New York, United States of America
| | - George A. M. Cross
- The Rockefeller University, Laboratory of Molecular Parasitology, New York, New York, United States of America
| | - F. Nina Papavasiliou
- The Rockefeller University, Laboratory of Lymphocyte Biology, New York, New York, United States of America
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29
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Sun YN, No JH, Lee GY, Li W, Yang SY, Yang G, Schmidt TJ, Kang JS, Kim YH. Phenolic Constituents of Medicinal Plants with Activity against Trypanosoma brucei. Molecules 2016; 21:480. [PMID: 27077842 PMCID: PMC6273235 DOI: 10.3390/molecules21040480] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 04/01/2016] [Accepted: 04/01/2016] [Indexed: 11/24/2022] Open
Abstract
Neglected tropical diseases (NTDs) affect over one billion people all over the world. These diseases are classified as neglected because they impact populations in areas with poor financial conditions and hence do not attract sufficient research investment. Human African Trypanosomiasis (HAT or sleeping sickness), caused by the parasite Trypanosoma brucei, is one of the NTDs. The current therapeutic interventions for T. brucei infections often have toxic side effects or require hospitalization so that they are not available in the rural environments where HAT occurs. Furthermore, parasite resistance is increasing, so that there is an urgent need to identify novel lead compounds against this infection. Recognizing the wide structural diversity of natural products, we desired to explore and identify novel antitrypanosomal chemotypes from a collection of natural products obtained from plants. In this study, 440 pure compounds from various medicinal plants were tested against T. brucei by in a screening using whole cell in vitro assays. As the result, twenty-two phenolic compounds exhibited potent activity against cultures of T. brucei. Among them, eight compounds—4, 7, 11, 14, 15, 18, 20, and 21—showed inhibitory activity against T. brucei, with IC50 values below 5 µM, ranging from 0.52 to 4.70 μM. Based on these results, we attempt to establish some general trends with respect to structure-activity relationships, which indicate that further investigation and optimization of these derivatives might enable the preparation of potentially useful compounds for treating HAT.
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Affiliation(s)
- Ya Nan Sun
- College of Pharmacy, Chungnam National University, Daejeon 305-764, Korea.
| | - Joo Hwan No
- Leishmania Research Laboratory, Institut Pasteur Korea, 696 Sampyeong-dong, Bundang-gu, Seongnam-si, Gyeonggi 463-400, Korea.
| | - Ga Young Lee
- College of Pharmacy, Chungnam National University, Daejeon 305-764, Korea.
| | - Wei Li
- School of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 712-749, Korea.
| | - Seo Young Yang
- College of Pharmacy, Chungnam National University, Daejeon 305-764, Korea.
| | - Gyongseon Yang
- Leishmania Research Laboratory, Institut Pasteur Korea, 696 Sampyeong-dong, Bundang-gu, Seongnam-si, Gyeonggi 463-400, Korea.
| | - Thomas J Schmidt
- Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Münster, PharmaCampus, Corrensstrasse 48, D-48149 Münster, Germany.
| | - Jong Seong Kang
- College of Pharmacy, Chungnam National University, Daejeon 305-764, Korea.
| | - Young Ho Kim
- College of Pharmacy, Chungnam National University, Daejeon 305-764, Korea.
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30
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Schulz D, Mugnier MR, Paulsen EM, Kim HS, Chung CWW, Tough DF, Rioja I, Prinjha RK, Papavasiliou FN, Debler EW. Bromodomain Proteins Contribute to Maintenance of Bloodstream Form Stage Identity in the African Trypanosome. PLoS Biol 2015; 13:e1002316. [PMID: 26646171 PMCID: PMC4672894 DOI: 10.1371/journal.pbio.1002316] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 10/30/2015] [Indexed: 01/01/2023] Open
Abstract
Trypanosoma brucei, the causative agent of African sleeping sickness, is transmitted to its mammalian host by the tsetse. In the fly, the parasite's surface is covered with invariant procyclin, while in the mammal it resides extracellularly in its bloodstream form (BF) and is densely covered with highly immunogenic Variant Surface Glycoprotein (VSG). In the BF, the parasite varies this highly immunogenic surface VSG using a repertoire of ~2500 distinct VSG genes. Recent reports in mammalian systems point to a role for histone acetyl-lysine recognizing bromodomain proteins in the maintenance of stem cell fate, leading us to hypothesize that bromodomain proteins may maintain the BF cell fate in trypanosomes. Using small-molecule inhibitors and genetic mutants for individual bromodomain proteins, we performed RNA-seq experiments that revealed changes in the transcriptome similar to those seen in cells differentiating from the BF to the insect stage. This was recapitulated at the protein level by the appearance of insect-stage proteins on the cell surface. Furthermore, bromodomain inhibition disrupts two major BF-specific immune evasion mechanisms that trypanosomes harness to evade mammalian host antibody responses. First, monoallelic expression of the antigenically varied VSG is disrupted. Second, rapid internalization of antibodies bound to VSG on the surface of the trypanosome is blocked. Thus, our studies reveal a role for trypanosome bromodomain proteins in maintaining bloodstream stage identity and immune evasion. Importantly, bromodomain inhibition leads to a decrease in virulence in a mouse model of infection, establishing these proteins as potential therapeutic drug targets for trypanosomiasis. Our 1.25Å resolution crystal structure of a trypanosome bromodomain in complex with I-BET151 reveals a novel binding mode of the inhibitor, which serves as a promising starting point for rational drug design.
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Affiliation(s)
- Danae Schulz
- Laboratory of Lymphocyte Biology, The Rockefeller University, New York, New York, United States of America
| | - Monica R. Mugnier
- Laboratory of Lymphocyte Biology, The Rockefeller University, New York, New York, United States of America
| | - Eda-Margaret Paulsen
- Laboratory of Cell Biology, The Rockefeller University, New York, New York, United States of America
| | - Hee-Sook Kim
- Laboratory of Lymphocyte Biology, The Rockefeller University, New York, New York, United States of America
| | - Chun-wa W. Chung
- Computational and Structural Chemistry, GlaxoSmithKline R&D, Medicines Research Centre, Stevenage, United Kingdom
| | - David F. Tough
- Epinova DPU, Immuno-Inflammation Therapy Area, GlaxoSmithKline, Medicines Research Centre, Stevenage, United Kingdom
| | - Inmaculada Rioja
- Epinova DPU, Immuno-Inflammation Therapy Area, GlaxoSmithKline, Medicines Research Centre, Stevenage, United Kingdom
| | - Rab K. Prinjha
- Epinova DPU, Immuno-Inflammation Therapy Area, GlaxoSmithKline, Medicines Research Centre, Stevenage, United Kingdom
| | - F. Nina Papavasiliou
- Laboratory of Lymphocyte Biology, The Rockefeller University, New York, New York, United States of America
- * E-mail:
| | - Erik W. Debler
- Laboratory of Cell Biology, The Rockefeller University, New York, New York, United States of America
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31
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Levy GV, Bañuelos CP, Níttolo AG, Ortiz GE, Mendiondo N, Moretti G, Tekiel VS, Sánchez DO. Depletion of the SR-Related Protein TbRRM1 Leads to Cell Cycle Arrest and Apoptosis-Like Death in Trypanosoma brucei. PLoS One 2015; 10:e0136070. [PMID: 26284933 PMCID: PMC4540419 DOI: 10.1371/journal.pone.0136070] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 07/29/2015] [Indexed: 11/19/2022] Open
Abstract
Arginine-Serine (RS) domain-containing proteins are RNA binding proteins with multiple functions in RNA metabolism. In mammalian cells this group of proteins is also implicated in regulation and coordination of cell cycle and apoptosis. In trypanosomes, an early branching group within the eukaryotic lineage, this group of proteins is represented by 3 members, two of them are SR proteins and have been recently shown to be involved in rRNA processing as well as in pre-mRNA splicing and stability. Here we report our findings on the 3rd member, the SR-related protein TbRRM1. In the present study, we showed that TbRRM1 ablation by RNA-interference in T. brucei procyclic cells leads to cell-cycle block, abnormal cell elongation compatible with the nozzle phenotype and cell death by an apoptosis-like mechanism. Our results expand the role of the trypanosomal RS-domain containing proteins in key cellular processes such as cell cycle and apoptosis-like death, roles also carried out by the mammalian SR proteins, and thus suggesting a conserved function in this phylogenetically conserved protein family.
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Affiliation(s)
- Gabriela V. Levy
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (IIB-UNSAM)—Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 25 de Mayo y Francia. Gral. San Martín, Buenos Aires, Argentina
- * E-mail:
| | - Carolina P. Bañuelos
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (IIB-UNSAM)—Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 25 de Mayo y Francia. Gral. San Martín, Buenos Aires, Argentina
| | - Analía G. Níttolo
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (IIB-UNSAM)—Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 25 de Mayo y Francia. Gral. San Martín, Buenos Aires, Argentina
| | - Gastón E. Ortiz
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (IIB-UNSAM)—Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 25 de Mayo y Francia. Gral. San Martín, Buenos Aires, Argentina
| | - Nicolás Mendiondo
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (IIB-UNSAM)—Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 25 de Mayo y Francia. Gral. San Martín, Buenos Aires, Argentina
| | - Georgina Moretti
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (IIB-UNSAM)—Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 25 de Mayo y Francia. Gral. San Martín, Buenos Aires, Argentina
| | - Valeria S. Tekiel
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (IIB-UNSAM)—Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 25 de Mayo y Francia. Gral. San Martín, Buenos Aires, Argentina
| | - Daniel O. Sánchez
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (IIB-UNSAM)—Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 25 de Mayo y Francia. Gral. San Martín, Buenos Aires, Argentina
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Castillo-Acosta VM, Ruiz-Pérez LM, Van Damme EJM, Balzarini J, González-Pacanowska D. Exposure of Trypanosoma brucei to an N-acetylglucosamine-binding lectin induces VSG switching and glycosylation defects resulting in reduced infectivity. PLoS Negl Trop Dis 2015; 9:e0003612. [PMID: 25746926 PMCID: PMC4351956 DOI: 10.1371/journal.pntd.0003612] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 02/10/2015] [Indexed: 12/22/2022] Open
Abstract
Trypanosoma brucei variant surface glycoproteins (VSG) are glycosylated by both paucimannose and oligomannose structures which are involved in the formation of a protective barrier against the immune system. Here, we report that the stinging nettle lectin (UDA), with predominant N-acetylglucosamine-binding specificity, interacts with glycosylated VSGs and kills parasites by provoking defects in endocytosis together with impaired cytokinesis. Prolonged exposure to UDA induced parasite resistance based on a diminished capacity to bind the lectin due to an enrichment of biantennary paucimannose and a reduction of triantennary oligomannose structures. Two molecular mechanisms involved in resistance were identified: VSG switching and modifications in N-glycan composition. Glycosylation defects were correlated with the down-regulation of the TbSTT3A and/or TbSTT3B genes (coding for oligosaccharyltransferases A and B, respectively) responsible for glycan specificity. Furthermore, UDA-resistant trypanosomes exhibited severely impaired infectivity indicating that the resistant phenotype entails a substantial fitness cost. The results obtained further support the modification of surface glycan composition resulting from down-regulation of the genes coding for oligosaccharyltransferases as a general resistance mechanism in response to prolonged exposure to carbohydrate-binding agents.
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Affiliation(s)
- Víctor M. Castillo-Acosta
- Instituto de Parasitología y Biomedicina “López-Neyra”, Consejo Superior de Investigaciones Científicas, Parque Tecnológico de Ciencias de la Salud, Granada, Spain
| | - Luis M. Ruiz-Pérez
- Instituto de Parasitología y Biomedicina “López-Neyra”, Consejo Superior de Investigaciones Científicas, Parque Tecnológico de Ciencias de la Salud, Granada, Spain
| | - Els J. M. Van Damme
- Laboratory of Biochemistry and Glycobiology, Department of Molecular Biotechnology, Ghent University, Ghent, Belgium
| | - Jan Balzarini
- Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Dolores González-Pacanowska
- Instituto de Parasitología y Biomedicina “López-Neyra”, Consejo Superior de Investigaciones Científicas, Parque Tecnológico de Ciencias de la Salud, Granada, Spain
- * E-mail:
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Stijlemans B, Leng L, Brys L, Sparkes A, Vansintjan L, Caljon G, Raes G, Van Den Abbeele J, Van Ginderachter JA, Beschin A, Bucala R, De Baetselier P. MIF contributes to Trypanosoma brucei associated immunopathogenicity development. PLoS Pathog 2014; 10:e1004414. [PMID: 25255103 PMCID: PMC4177988 DOI: 10.1371/journal.ppat.1004414] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Accepted: 08/21/2014] [Indexed: 12/15/2022] Open
Abstract
African trypanosomiasis is a chronic debilitating disease affecting the health and economic well-being of many people in developing countries. The pathogenicity associated with this disease involves a persistent inflammatory response, whereby M1-type myeloid cells, including Ly6Chigh inflammatory monocytes, are centrally implicated. A comparative gene analysis between trypanosusceptible and trypanotolerant animals identified MIF (macrophage migrating inhibitory factor) as an important pathogenic candidate molecule. Using MIF-deficient mice and anti-MIF antibody treated mice, we show that MIF mediates the pathogenic inflammatory immune response and increases the recruitment of inflammatory monocytes and neutrophils to contribute to liver injury in Trypanosoma brucei infected mice. Moreover, neutrophil-derived MIF contributed more significantly than monocyte-derived MIF to increased pathogenic liver TNF production and liver injury during trypanosome infection. MIF deficient animals also featured limited anemia, coinciding with increased iron bio-availability, improved erythropoiesis and reduced RBC clearance during the chronic phase of infection. Our data suggest that MIF promotes the most prominent pathological features of experimental trypanosome infections (i.e. anemia and liver injury), and prompt considering MIF as a novel target for treatment of trypanosomiasis-associated immunopathogenicity. Uncontrolled inflammation is a major contributor to pathogenicity development during many chronic parasitic infections, including African trypanosome infections. Hence, therapies should aim at re-establishing the balance between pro- and anti-inflammatory responses to reduce tissue damage. Our experiments uncovered that macrophage migration inhibitory factor (MIF) plays a pivotal role in trypanosomiasis-associated pathogenicity development. Hereby, MIF-deficient and neutralizing anti-MIF antibody-treated wild type (WT) T. brucei-infected mice exhibited decreased inflammatory responses, reduced liver damage and anemia (i.e. the most prominent pathogenicity features) compared to WT control mice. The reduced tissue damage coincided with reduced infiltration of pathogenic monocytic cells and neutrophils, whereby neutrophil-derived MIF contributed more significantly than monocyte-derived MIF to tissue damage. MIF also promoted anemia development by suppressing red blood cell production and enhancing their clearance. The clinical significance of these findings follows from human genetic data indicating that low-expression (protective) MIF alleles are enriched in Africans. The current findings therefore offer promise for human translation and open the possibility of assessing MIF levels or MIF genotype as an indication of an individual's risk for severe trypanosomiasis. Furthermore, given the unmet medical need of African trypanosomiasis affecting millions of people, these findings highlight MIF as a potential new therapeutic target for treatment of trypanosomiasis-associated pathogenicity.
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Affiliation(s)
- Benoît Stijlemans
- Department of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Myeloid Cell Immunology Laboratory, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
- * E-mail:
| | - Lin Leng
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Lea Brys
- Department of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Myeloid Cell Immunology Laboratory, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
| | - Amanda Sparkes
- Department of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Myeloid Cell Immunology Laboratory, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
| | - Liese Vansintjan
- Department of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Myeloid Cell Immunology Laboratory, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
| | - Guy Caljon
- Unit of Veterinary Protozoology, Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Geert Raes
- Department of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Myeloid Cell Immunology Laboratory, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
| | - Jan Van Den Abbeele
- Unit of Veterinary Protozoology, Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Jo A. Van Ginderachter
- Department of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Myeloid Cell Immunology Laboratory, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
| | - Alain Beschin
- Department of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Myeloid Cell Immunology Laboratory, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
| | - Richard Bucala
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Patrick De Baetselier
- Department of Cellular and Molecular Immunology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Myeloid Cell Immunology Laboratory, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
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Ouaissi A. Functional genomics and immunological approaches toward a comprehensive view of protozoan parasite virulence factors. Expert Rev Anti Infect Ther 2014; 5:535-8. [PMID: 17678416 DOI: 10.1586/14787210.5.4.535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Vale GA, Hargrove JW, Chamisa A, Hall DR, Mangwiro C, Torr SJ. Factors affecting the propensity of tsetse flies to enter houses and attack humans inside: increased risk of sleeping sickness in warmer climates. PLoS Negl Trop Dis 2013; 7:e2193. [PMID: 23638209 PMCID: PMC3636123 DOI: 10.1371/journal.pntd.0002193] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 03/25/2013] [Indexed: 11/18/2022] Open
Abstract
Background Sleeping sickness, or human African trypanosomiasis, is caused by two species of Trypanosoma brucei that are transmitted to humans by tsetse flies (Glossina spp.) when these insects take a bloodmeal. It is commonly assumed that humans must enter the normal woodland habitat of the flies to become infected, but recent studies found that tsetse frequently attack humans inside buildings. Factors affecting human/tsetse contact in buildings need identification. Methodology/Principal Findings In Zimbabwe, tsetse were allowed access to a house via an open door. Those in the house at sunset, and those alighting on humans in the house during the day, were caught using hand-nets. Total catches were unaffected by: (i) the presence of humans in the house and at the door, (ii) wood smoke from a fire inside the house or just outside, (iii) open windows, and (iv) chemicals simulating the odor of cattle or of humans. Catches increased about 10-fold with rising ambient temperatures, and during the hottest months the proportion of the total catch that was taken from the humans increased from 5% to 13%. Of the tsetse caught from humans, 62% consisted of female G. morsitans morstans and both sexes of G. pallidipes, i.e., the group of tsetse that normally alight little on humans. Some of the tsetse caught were old enough to be effective vectors. Conclusion/Significance Present results confirm previous suggestions that buildings provide a distinctive and important venue for transmission of sleeping sickness, especially since the normal repellence of humans and smoke seems poorly effective in such places. The importance of the venue would be increased in warmer climates. To identify factors affecting the contact between tsetse and humans in buildings, we caught tsetse that (i) accumulated in a large thatched house in Zimbabwe, and (ii) alighted on humans in the house during the day. In accord with earlier work, the numbers accumulating increased about 10-fold with rising ambient temperature. However, it was surprising that the numbers were unaffected by the presence of humans or artificial human odor in the house, or by wood smoke or a simulation of ox odor, since these factors can affect greatly the catches at baits in woodland. Tsetse that alighted on humans in the house contained a high proportion of those classes of tsetse that seldom alight on humans. Some of the alighting flies were old enough to be vectors of sleeping sickness. Our results emphasize that buildings are venues for important and distinctive contact between humans and tsetse, and that the risk of disease transmission there may be greater in warmer climates.
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Affiliation(s)
- Glyn A Vale
- Natural Resources Institute, University of Greenwich, Chatham, UK.
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Gulde PE, Christen L, Brown SV, Williams N. Three distinct isoforms of ATP synthase subunit c are expressed in T. brucei and assembled into the mitochondrial ATP synthase complex. PLoS One 2013; 8:e54039. [PMID: 23326569 PMCID: PMC3542316 DOI: 10.1371/journal.pone.0054039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 12/07/2012] [Indexed: 11/18/2022] Open
Abstract
One striking feature of the biology of trypanosomes is the changes in mitochondrial structure and function that occur as these parasites transition from one life cycle stage to another. Our laboratory has been interested in the role the mitochondrial ATP synthase plays in mitochondrial changes through the life cycle. Analysis of the recently completed T. brucei genome suggested that there may be multiple putative genes encoding ATP synthase subunit c. While homologous in their 3' ends, these genes differ in their 5' ends and, if expressed, would result in three distinct proteins. Our analysis showed that all three of the possible transcripts were detected in both procyclic and bloodstream stages, although the c-3 transcript was less abundant than that for c-1 or c-2. The three isoforms of subunit c are produced in both the bloodstream and procyclic stages and their mature protein products possess distinct N-terminal regions of the protein as found within mitochondria. All three isoforms are also incorporated into the assembled ATP synthase complex from procyclic cells. Although multiple subunit c genes have been found in other organisms, they produce identical polypeptides and the finding of significant differences in the mature proteins is unique to T. brucei.
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Affiliation(s)
- Paul E. Gulde
- Department of Microbiology and Immunology and Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
| | - Linda Christen
- Department of Microbiology and Immunology and Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
| | - Silvia V. Brown
- Department of Microbiology and Immunology and Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
| | - Noreen Williams
- Department of Microbiology and Immunology and Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
- * E-mail:
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World Health Organization. Control and surveillance of human African trypanosomiasis. World Health Organ Tech Rep Ser 2013;:1-237. [PMID: 24552089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In the 1960s, it appeared that human African trypanosomiasis (HAT) could be effectively controlled, but by the beginning of the twenty-first century several decades of neglect had led to alarming numbers of reported new cases, with an estimated 300 000 people infected. The World Health Organization (WHO) responded with a series of initiatives aimed at bringing HAT under control again. Since 2001, the pharmaceutical companies that produce drugs for HAT have committed themselves to providing them free of charge to WHO for distribution for the treatment of patients. In addition, funds have been provided to WHO to support national sleeping sickness control programmes to boost control and surveillance of the disease. That, coupled with bilateral cooperation and the work of nongovernmental organizations, helped reverse the upward trend in HAT prevalence. By 2012, the number of reported cases was fewer than 8000. This success in bringing HAT under control led to its inclusion in the WHO Roadmap for eradication, elimination and control of neglected tropical diseases, with a target set to eliminate the disease as a public health problem by 2020. A further target has been set, by countries in which HAT is endemic, to eliminate gambiense HAT by reducing the incidence of infection to zero in a defined geographical area. This report provides information about new diagnostic approaches, new therapeutic regimens and better understanding of the distribution of the disease with high-quality mapping. The roles of human and animal reservoirs and the tsetse fly vectors that transmit the parasites are emphasized. The new information has formed the basis for an integrated strategy with which it is hoped that elimination of gambiense HAT will be achieved. The report also contains recommendations on the approaches that will lead to elimination of the disease.
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Savage AF, Cerqueira GC, Regmi S, Wu Y, El Sayed NM, Aksoy S. Transcript expression analysis of putative Trypanosoma brucei GPI-anchored surface proteins during development in the tsetse and mammalian hosts. PLoS Negl Trop Dis 2012; 6:e1708. [PMID: 22724039 PMCID: PMC3378594 DOI: 10.1371/journal.pntd.0001708] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 05/11/2012] [Indexed: 11/26/2022] Open
Abstract
Human African Trypanosomiasis is a devastating disease caused by the parasite Trypanosoma brucei. Trypanosomes live extracellularly in both the tsetse fly and the mammal. Trypanosome surface proteins can directly interact with the host environment, allowing parasites to effectively establish and maintain infections. Glycosylphosphatidylinositol (GPI) anchoring is a common posttranslational modification associated with eukaryotic surface proteins. In T. brucei, three GPI-anchored major surface proteins have been identified: variant surface glycoproteins (VSGs), procyclic acidic repetitive protein (PARP or procyclins), and brucei alanine rich proteins (BARP). The objective of this study was to select genes encoding predicted GPI-anchored proteins with unknown function(s) from the T. brucei genome and characterize the expression profile of a subset during cyclical development in the tsetse and mammalian hosts. An initial in silico screen of putative T. brucei proteins by Big PI algorithm identified 163 predicted GPI-anchored proteins, 106 of which had no known functions. Application of a second GPI-anchor prediction algorithm (FragAnchor), signal peptide and trans-membrane domain prediction software resulted in the identification of 25 putative hypothetical proteins. Eighty-one gene products with hypothetical functions were analyzed for stage-regulated expression using semi-quantitative RT-PCR. The expression of most of these genes were found to be upregulated in trypanosomes infecting tsetse salivary gland and proventriculus tissues, and 38% were specifically expressed only by parasites infecting salivary gland tissues. Transcripts for all of the genes specifically expressed in salivary glands were also detected in mammalian infective metacyclic trypomastigotes, suggesting a possible role for these putative proteins in invasion and/or establishment processes in the mammalian host. These results represent the first large-scale report of the differential expression of unknown genes encoding predicted T. brucei surface proteins during the complete developmental cycle. This knowledge may form the foundation for the development of future novel transmission blocking strategies against metacyclic parasites. Human African Trypanosomiasis (HAT) is a fatal disease caused by African trypanosomes and transmitted by an infected tsetse fly. Presently, there are no vaccines to prevent mammalian infections. Proteins expressed on the trypanosome surface can influence the host environment and allow for their transmission. Potentially accessible to the adaptive immune systems of vertebrate hosts, these proteins could serve as future vaccine targets. Identification and characterization of these currently unknown proteins can help us develop strategies to alter the host environment, making it inhospitable for the parasite, thereby reducing disease transmission. While there is extensive knowledge about trypanosome development in the mammalian host, less is known about the molecular events in the tsetse fly, particularly the salivary gland stages. We used an in silico approach to identify putative surface proteins from the known genome sequence of Trypanosoma brucei, and we describe the stage specific expression of these genes during development in the tsetse fly and mammalian host. Our findings show that a majority of unknown transcripts encoding predicted surface proteins are expressed by the parasites infecting tsetse salivary glands. These data will help focus future investigations into transmission-blocking approaches targeting the expressed antigens of trypanosomes infecting tsetse salivary glands.
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Affiliation(s)
- Amy F. Savage
- Division of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut, United States of America
| | - Gustavo C. Cerqueira
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute (MPRI), University of Maryland, College Park, Maryland, United States of America
| | - Sandesh Regmi
- Division of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut, United States of America
| | - Yineng Wu
- Division of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut, United States of America
| | - Najib M. El Sayed
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute (MPRI), University of Maryland, College Park, Maryland, United States of America
- Center for Bioinformatics and Computational Biology, College of Chemical & Life Sciences, University of Maryland, College Park, Maryland, United States of America
| | - Serap Aksoy
- Division of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut, United States of America
- * E-mail:
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Huang G, Fang J, Sant'Anna C, Li ZH, Wellems DL, Rohloff P, Docampo R. Adaptor protein-3 (AP-3) complex mediates the biogenesis of acidocalcisomes and is essential for growth and virulence of Trypanosoma brucei. J Biol Chem 2011; 286:36619-30. [PMID: 21880705 PMCID: PMC3196089 DOI: 10.1074/jbc.m111.284661] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 08/24/2011] [Indexed: 12/19/2022] Open
Abstract
Acidocalcisomes are acidic calcium and polyphosphate storage organelles found in a diverse range of organisms. Here we present evidence that the biogenesis of acidocalcisomes in Trypanosoma brucei is linked to the expression of adaptor protein-3 (AP-3) complex. Localization studies in cell lines expressing β3 and δ subunits of AP-3 fused to epitope tags revealed their partial co-localization with the vacuolar proton pyrophosphatase, a marker of acidocalcisomes, with the Golgi marker Golgi reassembly and stacking protein, and with antibodies against the small GTPase Rab11. Ablation of the β3 subunit by RNA interference (RNAi) resulted in disappearance of acidocalcisomes from both procyclic and bloodstream form trypanosomes, as revealed by immmunofluorescence and electron microscopy assays, with no alterations in trafficking of different markers to lysosomes. Knockdown of the β3 subunit resulted in lower acidic calcium, pyrophosphate, and polyphosphate content as well as defects in growth in culture, resistance to osmotic stress, and virulence in mice. Similar results were obtained by knocking down the expression of the δ subunit of AP-3. These results indicate that AP-3 is essential for the biogenesis of acidocalcisomes and for growth and virulence of T. brucei.
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Affiliation(s)
- Guozhong Huang
- From the Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia 30602
| | - Jianmin Fang
- From the Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia 30602
| | - Celso Sant'Anna
- From the Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia 30602
| | - Zhu-Hong Li
- From the Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia 30602
| | - Dianne L. Wellems
- From the Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia 30602
| | - Peter Rohloff
- From the Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia 30602
| | - Roberto Docampo
- From the Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia 30602
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Diechtierow M, Krauth-Siegel RL. A tryparedoxin-dependent peroxidase protects African trypanosomes from membrane damage. Free Radic Biol Med 2011; 51:856-68. [PMID: 21640819 DOI: 10.1016/j.freeradbiomed.2011.05.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 05/11/2011] [Accepted: 05/11/2011] [Indexed: 01/18/2023]
Abstract
Hydroperoxide detoxification in African trypanosomes is achieved by 2-Cys-peroxiredoxin (TXNPx)- and non-selenium glutathione peroxidase (Px)-type enzymes which both obtain their reducing equivalents from the unique trypanothione/tryparedoxin system. Previous RNA interference approaches revealed that the cytosolic TXNPx and the Px-type enzymes are essential for Trypanosoma brucei. Because of partially overlapping in vitro substrate specificities and subcellular localisation the physiological function of the individual enzymes was not yet clear. As shown here, TXNPx and Px are expressed at comparable levels and in their active reduced state. Px-overexpressing parasites were less sensitive toward linoleic acid hydroperoxide but not hydrogen peroxide. Kinetic studies confirmed that Px-but not TXNPx-reduces lipophilic hydroperoxides including phospholipids with high efficiency. Most interestingly, the severe proliferation defect of Px-depleted bloodstream cells could be rescued by Trolox, but not by hydrophilic antioxidants, in the medium. This allowed us to knock-out the three Px genes individually and thus to distinguish their in vivo role. Deletion of the cytosolic Px I and II resulted in extremely fast membrane peroxidation followed by cell lysis. Cells lacking specifically the mitochondrial Px III showed a transient growth retardation and cardiolipin peroxidation but adapted within 24h to normal proliferation.
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Affiliation(s)
- Michael Diechtierow
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
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Gadelha C, Holden JM, Allison HC, Field MC. Specializations in a successful parasite: what makes the bloodstream-form African trypanosome so deadly? Mol Biochem Parasitol 2011; 179:51-8. [PMID: 21763356 DOI: 10.1016/j.molbiopara.2011.06.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Revised: 06/14/2011] [Accepted: 06/15/2011] [Indexed: 12/24/2022]
Abstract
Most trypanosomatid parasites have both arthropod and mammalian or plant hosts, and the ability to survive and complete a developmental program in each of these very different environments is essential for life cycle progression and hence being a successful pathogen. For African trypanosomes, where the mammalian stage is exclusively extracellular, this presents specific challenges and requires evasion of both the acquired and innate immune systems, together with adaptation to a specific nutritional environment and resistance to mechanical and biochemical stresses. Here we consider the basis for these adaptations, the specific features of the mammalian infective trypanosome that are required to meet these challenges, and how these processes both inform on basic parasite biology and present potential therapeutic targets.
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Uppaluri S, Nagler J, Stellamanns E, Heddergott N, Herminghaus S, Engstler M, Pfohl T. Impact of microscopic motility on the swimming behavior of parasites: straighter trypanosomes are more directional. PLoS Comput Biol 2011; 7:e1002058. [PMID: 21698122 PMCID: PMC3116898 DOI: 10.1371/journal.pcbi.1002058] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 03/31/2011] [Indexed: 11/18/2022] Open
Abstract
Microorganisms, particularly parasites, have developed sophisticated swimming mechanisms to cope with a varied range of environments. African Trypanosomes, causative agents of fatal illness in humans and animals, use an insect vector (the Tsetse fly) to infect mammals, involving many developmental changes in which cell motility is of prime importance. Our studies reveal that differences in cell body shape are correlated with a diverse range of cell behaviors contributing to the directional motion of the cell. Straighter cells swim more directionally while cells that exhibit little net displacement appear to be more bent. Initiation of cell division, beginning with the emergence of a second flagellum at the base, correlates to directional persistence. Cell trajectory and rapid body fluctuation correlation analysis uncovers two characteristic relaxation times: a short relaxation time due to strong body distortions in the range of 20 to 80 ms and a longer time associated with the persistence in average swimming direction in the order of 15 seconds. Different motility modes, possibly resulting from varying body stiffness, could be of consequence for host invasion during distinct infective stages.
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Affiliation(s)
- Sravanti Uppaluri
- Max-Planck-Institute for Dynamics and Self-Organization, Göttingen, Germany
| | - Jan Nagler
- Max-Planck-Institute for Dynamics and Self-Organization, Göttingen, Germany
- Institute for Nonlinear Dynamics, Faculty of Physics, Georg-August-Universität, Göttingen, Germany
| | - Eric Stellamanns
- Max-Planck-Institute for Dynamics and Self-Organization, Göttingen, Germany
| | - Niko Heddergott
- Biozentrum, Department for Cell and Developmental Biology, University of Würzburg, Würzburg, Germany
| | | | - Markus Engstler
- Biozentrum, Department for Cell and Developmental Biology, University of Würzburg, Würzburg, Germany
| | - Thomas Pfohl
- Max-Planck-Institute for Dynamics and Self-Organization, Göttingen, Germany
- Department of Chemistry, University of Basel, Basel, Switzerland
- * E-mail:
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Šíma M, Havelková H, Quan L, Svobodová M, Jarošíková T, Vojtíšková J, Stassen APM, Demant P, Lipoldová M. Genetic control of resistance to Trypanosoma brucei brucei infection in mice. PLoS Negl Trop Dis 2011; 5:e1173. [PMID: 21666791 PMCID: PMC3110168 DOI: 10.1371/journal.pntd.0001173] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 04/04/2011] [Indexed: 11/29/2022] Open
Abstract
Background Trypanosoma brucei brucei infects livestock, with severe effects in horses and dogs. Mouse strains differ greatly in susceptibility to this parasite. However, no genes controlling these differences were mapped. Methods We studied the genetic control of survival after T. b. brucei infection using recombinant congenic (RC) strains, which have a high mapping power. Each RC strain of BALB/c-c-STS/A (CcS/Dem) series contains a different random subset of 12.5% genes from the parental “donor” strain STS/A and 87.5% genes from the “background” strain BALB/c. Although BALB/c and STS/A mice are similarly susceptible to T. b. brucei, the RC strain CcS-11 is more susceptible than either of them. We analyzed genetics of survival in T. b. brucei-infected F2 hybrids between BALB/c and CcS-11. CcS-11 strain carries STS-derived segments on eight chromosomes. They were genotyped in the F2 hybrid mice and their linkage with survival was tested by analysis of variance. Results We mapped four Tbbr (Trypanosoma brucei brucei response) loci that influence survival after T. b. brucei infection. Tbbr1 (chromosome 3) and Tbbr2 (chromosome 12) have effects on survival independent of inter-genic interactions (main effects). Tbbr3 (chromosome 7) influences survival in interaction with Tbbr4 (chromosome 19). Tbbr2 is located on a segment 2.15 Mb short that contains only 26 genes. Conclusion This study presents the first identification of chromosomal loci controlling susceptibility to T. b. brucei infection. While mapping in F2 hybrids of inbred strains usually has a precision of 40–80 Mb, in RC strains we mapped Tbbr2 to a 2.15 Mb segment containing only 26 genes, which will enable an effective search for the candidate gene. Definition of susceptibility genes will improve the understanding of pathways and genetic diversity underlying the disease and may result in new strategies to overcome the active subversion of the immune system by T. b. brucei. Trypanosoma brucei are extracellular protozoa transmitted to mammalian host by the tsetse fly. They developed several mechanisms that subvert host's immune defenses. Therefore analysis of genes affecting host's resistance to infection can reveal critical aspects of host-parasite interactions. Trypanosoma brucei brucei infects many animal species including livestock, with particularly severe effects in horses and dogs. Mouse strains differ greatly in susceptibility to T. b. brucei. However, genes controlling susceptibility to this parasite have not been mapped. We analyzed the genetic control of survival after T. b. brucei infection using CcS/Dem recombinant congenic (RC) strains, each of which contains a different random set of 12.5% genes of their donor parental strain STS/A on the BALB/c genetic background. The RC strain CcS-11 is even more susceptible to parasites than BALB/c or STS/A. In F2 hybrids between BALB/c and CcS-11 we detected and mapped four loci, Tbbr1-4 (Trypanosoma brucei brucei response 1–4), that control survival after T. b. brucei infection. Tbbr1 (chromosome 3) and Tbbr2 (chromosome 12) have independent effects, Tbbr3 (chromosome 7) and Tbbr4 (chromosome 19) were detected by their mutual inter-genic interaction. Tbbr2 was precision mapped to a segment of 2.15 Mb that contains 26 genes.
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Affiliation(s)
- Matyáš Šíma
- Laboratory of Molecular and Cellular Immunology, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Helena Havelková
- Laboratory of Molecular and Cellular Immunology, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Lei Quan
- Roswell Park Cancer Institute, Buffalo, New York, United States of America
| | | | - Taťána Jarošíková
- Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czech Republic
| | - Jarmila Vojtíšková
- Laboratory of Molecular and Cellular Immunology, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Alphons P. M. Stassen
- Department of Genetics and Cell Biology/Clinical Genetics, Maastricht University, Maastricht, The Netherlands
| | - Peter Demant
- Roswell Park Cancer Institute, Buffalo, New York, United States of America
| | - Marie Lipoldová
- Laboratory of Molecular and Cellular Immunology, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
- * E-mail:
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Abstract
Trypanosoma brucei is the causative agent of human African trypanosomiasis (sleeping sickness) which is fatal if left untreated. This disease occurs in 36 African countries, south of the Sahara, where 60 million people are at risk of acquiring infection. The current chemotherapy relies on only four drugs, three of which were developed more than 60 years ago. These drugs have many limitations, ranging from oral inabsorption, acute toxicities, short duration of action and the emergence of trypanosomal resistance. Despite decades of use of most of the current trypanocides, little is known about their mode of action. That being said, African trypanosomes continue to be among the most extensively studied parasitic protists to date. Many of their intriguing biological features have been well documented and can be viewed as attractive targets for antitrypanosomal chemotherapy. A considerable number of natural products with diverse molecular structures have revealed antiparasitic potency in the laboratory and represent interesting lead compounds for the development of new and urgently needed antiparasitics. The major validated drug targets in T. brucei are discussed with particular emphasis on those known to be attacked by natural compounds.
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Affiliation(s)
- Véronique Hannaert
- Research Unit for Tropical Diseases, de Duve Institute and Laboratory of Biochemistry, Université catholique de Louvain, Brussels, Belgium.
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Louw CA, Ludewig MH, Mayer J, Blatch GL. The Hsp70 chaperones of the Tritryps are characterized by unusual features and novel members. Parasitol Int 2010; 59:497-505. [PMID: 20816852 DOI: 10.1016/j.parint.2010.08.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 08/10/2010] [Accepted: 08/23/2010] [Indexed: 12/13/2022]
Abstract
Proteins belonging to the Hsp70 class of molecular chaperones are highly conserved and ubiquitous, performing an essential role in the maintenance of cellular homeostasis in almost all known organisms. Trypanosoma brucei, Trypanosoma cruzi and Leishmania major are human parasites collectively known as the Tritryps. The Tritryps undergo extensive morphological changes during their life cycles, largely triggered by the marked differences between conditions in their insect vector and human host. Hsp70s are synthesised in response to these marked changes in environment and are proposed to be required for these parasites to successfully transition between differentiation stages while remaining viable and infective. While the Tritryps Hsp70 complement consists of homologues of all the major eukaryotic Hsp70s, there are a number of novel members, and some unique structural features. This review critically evaluates the current knowledge on the Tritryps Hsp70 proteins with an emphasis on T. brucei, and highlights some novel and previously unstudied aspects of these multifaceted molecular chaperones.
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Affiliation(s)
- Cassandra A Louw
- Biomedical and Biotechnology Research Unit, Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, P.O. Box 94, Grahamstown, 6140, South Africa
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Abstract
African trypanosomes evade the host immune response through antigenic variation, which is achieved by periodically expressing different variant surface glycoproteins (VSGs). VSG expression is monoallelic such that only one of approximately 15 telomeric VSG expression sites (ESs) is transcribed at a time. Epigenetic regulation is involved in VSG control but our understanding of the mechanisms involved remains incomplete. Histone deacetylases are potential drug targets for diseases caused by protozoan parasites. Here, using recombinant expression we show that the essential Trypanosoma brucei deacetylases, DAC1 (class I) and DAC3 (class II) display histone deacetylase activity. Both DAC1 and DAC3 are nuclear proteins in the bloodstream stage parasite, while only DAC3 remains concentrated in the nucleus in insect-stage cells. Consistent with developmentally regulated localization, DAC1 antagonizes SIR2rp1-dependent telomeric silencing only in the bloodstream form, indicating a conserved role in the control of silent chromatin domains. In contrast, DAC3 is specifically required for silencing at VSG ES promoters in both bloodstream and insect-stage cells. We conclude that DAC1 and DAC3 play distinct roles in subtelomeric gene silencing and that DAC3 represents the first readily druggable target linked to VSG ES control in the African trypanosome.
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Affiliation(s)
- Qiao-Ping Wang
- London School of Hygiene and Tropical MedicineKeppel Street, London WC1E 7HT, UK
- Center for Parasitic Organisms, State Key Laboratory of Biocontrol, School of Life Sciences, Key Laboratory of Tropical Diseases Control, Ministry of Education, Zhongshan Medical College, Sun Yat-Sen UniversityGuangzhou 510275, China
| | - Taemi Kawahara
- London School of Hygiene and Tropical MedicineKeppel Street, London WC1E 7HT, UK
| | - David Horn
- London School of Hygiene and Tropical MedicineKeppel Street, London WC1E 7HT, UK
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Ene AC, Atawodi SE, Ameh DA, Nnamani CN, Apeh YEO. Antitrypanosomal effects of petroleum ether, chloroform and methanol extracts of Artemisia maciverae Linn. Indian J Exp Biol 2009; 47:981-986. [PMID: 20329702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Petroleum ether, chloroform and methanol extracts of A. maciverae were studied in vitro and in vivo for activity against Trypanosoma brucei brucei in Swiss albino mice. Thereafter, the chloroform extract which showed the highest activity in both in vitro and in vivo assessments was subjected to bioassay-guided fractionation. The crude extracts and the fractions of the chloroform extract of A. maciverae were screened for phytochemicals and secondary metabolites. Combined fractions 54-57 of this extract showed the highest in vitro antitrypanosomal activity, and at 10 mg/kg body weight, this fraction cleared the parasitemia completely from T. brucei brucei infected Swiss albino mice after 7 days of treatment. There was no statistically significant difference in the level of parasitemia when the infected mice treated with this fraction was compared with the standard trypanocidal drug, diminal. The results of the phytochemical analysis showed that the crude extracts contained secondary metabolites like flavonoids, triterpenes, terpenoids, tannins, phlobatannins and alkaloids, while the active fraction contains only triterpenes and alkaloids. It can be inferred that fraction 54-57 contains the active component responsible for the high antitrypanosomal activity of the chloroform extract of A. maciverae.
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Affiliation(s)
- A C Ene
- Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria
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Morrison LJ, Tait A, McLellan S, Sweeney L, Turner CMR, MacLeod A. A major genetic locus in Trypanosoma brucei is a determinant of host pathology. PLoS Negl Trop Dis 2009; 3:e557. [PMID: 19956590 PMCID: PMC2780326 DOI: 10.1371/journal.pntd.0000557] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Accepted: 10/22/2009] [Indexed: 11/18/2022] Open
Abstract
The progression and variation of pathology during infections can be due to components from both host or pathogen, and/or the interaction between them. The influence of host genetic variation on disease pathology during infections with trypanosomes has been well studied in recent years, but the role of parasite genetic variation has not been extensively studied. We have shown that there is parasite strain-specific variation in the level of splenomegaly and hepatomegaly in infected mice and used a forward genetic approach to identify the parasite loci that determine this variation. This approach allowed us to dissect and identify the parasite loci that determine the complex phenotypes induced by infection. Using the available trypanosome genetic map, a major quantitative trait locus (QTL) was identified on T. brucei chromosome 3 (LOD = 7.2) that accounted for approximately two thirds of the variance observed in each of two correlated phenotypes, splenomegaly and hepatomegaly, in the infected mice (named TbOrg1). In addition, a second locus was identified that contributed to splenomegaly, hepatomegaly and reticulocytosis (TbOrg2). This is the first use of quantitative trait locus mapping in a diploid protozoan and shows that there are trypanosome genes that directly contribute to the progression of pathology during infections and, therefore, that parasite genetic variation can be a critical factor in disease outcome. The identification of parasite loci is a first step towards identifying the genes that are responsible for these important traits and shows the power of genetic analysis as a tool for dissecting complex quantitative phenotypic traits. Trypanosomes are single-celled organisms that are transmitted between animal hosts by the tsetse fly. These parasites infect a wide range of mammals and in sub-Saharan Africa are extensively debilitating to livestock, and some species are also able to infect humans causing a disease, sleeping sickness, that is usually fatal unless treated. Some trypanosome strains cause more severe disease than others, and studying these differences may allow the identification of how serious disease is caused. We approached this problem by looking at how differences in disease symptoms (enlarged spleen and liver, and reduced blood cell numbers) that are caused in infections in mice with two strains of Trypanosoma brucei, TREU927 and STIB247. These disease manifestations are clinically relevant in human and livestock trypanosome infections. Examining how the symptoms are inherited in infections with offspring of a cross between the two strains allowed the identification of a region of the T. brucei genome that contains a gene (or several genes) that contributes significantly towards the enlarged spleen and liver observed in infected mice. This is a first step towards identifying the parasite genes that cause disease in the host (virulence factors), which may provide routes for developing novel therapies against the disease.
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Affiliation(s)
- Liam J Morrison
- Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Biomedical Research Centre, Glasgow, United Kingdom.
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Akoda K, Van den Bossche P, Marcotty T, Kubi C, Coosemans M, De Deken R, Van den Abbeele J. Nutritional stress affects the tsetse fly's immune gene expression. Med Vet Entomol 2009; 23:195-201. [PMID: 19712150 DOI: 10.1111/j.1365-2915.2009.00799.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Tsetse-transmitted trypanosomiasis poses a serious threat to human and animal health in sub-Saharan Africa. The majority of tsetse flies (Glossina spp.) in a natural population will not develop a mature infection of either Trypanosoma congolense or Trypanosoma brucei sp. because of refractoriness, a phenomenon that is affected by different factors, including the tsetse fly's immune defence. Starvation of tsetse flies significantly increases their susceptibility to the establishment of a trypanosome infection. This paper reports the effects of nutritional stress (starvation) on (a) uninduced baseline levels of gene expression of the antimicrobial peptides attacin, defensin and cecropin in the tsetse fly, and (b) levels of expression induced in response to bacterial (Escherichia coli) or trypanosomal challenge. In newly emerged, unfed tsetse flies, starvation significantly lowers baseline levels of antimicrobial peptide gene expression, especially for attacin and cecropin. In response to trypanosome challenge, only non-starved older flies showed a significant increase in antimicrobial peptide gene expression within 5 days of ingestion of a trypanosome-containing bloodmeal, especially with T. brucei bloodstream forms. These data suggest that a decreased expression of immune genes in newly hatched flies or a lack of immune responsiveness to trypanosomes in older flies, both occurring as a result of fly starvation, may be among the factors contributing to the increased susceptibility of nutritionally stressed tsetse flies to trypanosome infection.
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Affiliation(s)
- K Akoda
- Department of Animal Health, Institute of Tropical Medicine, Antwerp, Belgium
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