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Morrison LJ, Steketee PC, Tettey MD, Matthews KR. Pathogenicity and virulence of African trypanosomes: From laboratory models to clinically relevant hosts. Virulence 2023; 14:2150445. [PMID: 36419235 DOI: 10.1080/21505594.2022.2150445] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 11/17/2022] [Indexed: 11/25/2022] Open
Abstract
African trypanosomes are vector-borne protozoa, which cause significant human and animal disease across sub-Saharan Africa, and animal disease across Asia and South America. In humans, infection is caused by variants of Trypanosoma brucei, and is characterized by varying rate of progression to neurological disease, caused by parasites exiting the vasculature and entering the brain. Animal disease is caused by multiple species of trypanosome, primarily T. congolense, T. vivax, and T. brucei. These trypanosomes also infect multiple species of mammalian host, and this complexity of trypanosome and host diversity is reflected in the spectrum of severity of disease in animal trypanosomiasis, ranging from hyperacute infections associated with mortality to long-term chronic infections, and is also a main reason why designing interventions for animal trypanosomiasis is so challenging. In this review, we will provide an overview of the current understanding of trypanosome determinants of infection progression and severity, covering laboratory models of disease, as well as human and livestock disease. We will also highlight gaps in knowledge and capabilities, which represent opportunities to both further our fundamental understanding of how trypanosomes cause disease, as well as facilitating the development of the novel interventions that are so badly needed to reduce the burden of disease caused by these important pathogens.
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Affiliation(s)
- Liam J Morrison
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, UK
| | - Pieter C Steketee
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, UK
| | - Mabel D Tettey
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Keith R Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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Molecular Analysis of Trypanosome Infections in Algerian Camels. Acta Parasitol 2022; 67:1246-1253. [PMID: 35657485 PMCID: PMC9399045 DOI: 10.1007/s11686-022-00577-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/10/2022] [Indexed: 11/01/2022]
Abstract
PURPOSE Surra is an economically important livestock disease in many low- and middle-income countries, including those of Northern Africa. The disease is caused by the biting fly-transmitted subspecies Trypanosoma brucei evansi, which is very closely related to the tsetse-transmitted subspecies T. b. brucei and the sexually transmitted subspecies T. b. equiperdum. At least two phylogenetically distinct groups of T. b. evansi can be distinguished, called type A and type B. These evolved from T. b. brucei independently. The close relationships between the T. brucei subspecies and the multiple evolutionary origins of T. b. evansi pose diagnostic challenges. METHODS Here we use previously established and newly developed PCR assays based on nuclear and mitochondrial genetic markers to type the causative agent of recent trypanosome infections of camels in Southern Algeria. RESULTS/CONCLUSION We confirm that these infections have been caused by T. b. evansi type A. We also report a newly designed PCR assay specific for T. b. evansi type A that we expect will be of diagnostic use for the community.
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African trypanosome strategies for conquering new hosts and territories: the end of monophyly? Trends Parasitol 2022; 38:724-736. [DOI: 10.1016/j.pt.2022.05.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/16/2022] [Accepted: 05/17/2022] [Indexed: 11/22/2022]
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Oxidative Phosphorylation Is Required for Powering Motility and Development of the Sleeping Sickness Parasite Trypanosoma brucei in the Tsetse Fly Vector. mBio 2022; 13:e0235721. [PMID: 35012336 PMCID: PMC8749461 DOI: 10.1128/mbio.02357-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The single-celled parasite Trypanosoma brucei is transmitted by hematophagous tsetse flies. Life cycle progression from mammalian bloodstream form to tsetse midgut form and, subsequently, infective salivary gland form depends on complex developmental steps and migration within different fly tissues. As the parasite colonizes the glucose-poor insect midgut, ATP production is thought to depend on activation of mitochondrial amino acid catabolism via oxidative phosphorylation (OXPHOS). This process involves respiratory chain complexes and F1Fo-ATP synthase and requires protein subunits of these complexes that are encoded in the parasite's mitochondrial DNA (kDNA). Here, we show that progressive loss of kDNA-encoded functions correlates with a decreasing ability to initiate and complete development in the tsetse. First, parasites with a mutated F1Fo-ATP synthase with reduced capacity for OXPHOS can initiate differentiation from bloodstream to insect form, but they are unable to proliferate in vitro. Unexpectedly, these cells can still colonize the tsetse midgut. However, these parasites exhibit a motility defect and are severely impaired in colonizing or migrating to subsequent tsetse tissues. Second, parasites with a fully disrupted F1Fo-ATP synthase complex that is completely unable to produce ATP by OXPHOS can still differentiate to the first insect stage in vitro but die within a few days and cannot establish a midgut infection in vivo. Third, parasites lacking kDNA entirely can initiate differentiation but die soon after. Together, these scenarios suggest that efficient ATP production via OXPHOS is not essential for initial colonization of the tsetse vector but is required to power trypanosome migration within the fly. IMPORTANCE African trypanosomes cause disease in humans and their livestock and are transmitted by tsetse flies. The insect ingests these parasites with its blood meal, but to be transmitted to another mammal, the trypanosome must undergo complex development within the tsetse fly and migrate from the insect's gut to its salivary glands. Crucially, the parasite must switch from a sugar-based diet while in the mammal to a diet based primarily on amino acids when it develops in the insect. Here, we show that efficient energy production by an organelle called the mitochondrion is critical for the trypanosome's ability to swim and to migrate through the tsetse fly. Surprisingly, trypanosomes with impaired mitochondrial energy production are only mildly compromised in their ability to colonize the tsetse fly midgut. Our study adds a new perspective to the emerging view that infection of tsetse flies by trypanosomes is more complex than previously thought.
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A novel high-content phenotypic screen to identify inhibitors of mitochondrial DNA maintenance in trypanosomes. Antimicrob Agents Chemother 2021; 66:e0198021. [PMID: 34871097 PMCID: PMC8846439 DOI: 10.1128/aac.01980-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Kinetoplastid parasites cause diverse neglected diseases in humans and livestock, with an urgent need for new treatments. The survival of kinetoplastids depends on their uniquely structured mitochondrial genome (kDNA), the eponymous kinetoplast. Here, we report the development of a high-content screen for pharmacologically induced kDNA loss, based on specific staining of parasites and automated image analysis. As proof of concept, we screened a diverse set of ∼14,000 small molecules and exemplify a validated hit as a novel kDNA-targeting compound.
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Gahura O, Hierro-Yap C, Zíková A. Redesigned and reversed: architectural and functional oddities of the trypanosomal ATP synthase. Parasitology 2021; 148:1151-1160. [PMID: 33551002 PMCID: PMC8311965 DOI: 10.1017/s0031182021000202] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 01/23/2021] [Accepted: 01/26/2021] [Indexed: 12/23/2022]
Abstract
Mitochondrial F-type adenosine triphosphate (ATP) synthases are commonly introduced as highly conserved membrane-embedded rotary machines generating the majority of cellular ATP. This simplified view neglects recently revealed striking compositional diversity of the enzyme and the fact that in specific life stages of some parasites, the physiological role of the enzyme is to maintain the mitochondrial membrane potential at the expense of ATP rather than to produce ATP. In addition, mitochondrial ATP synthases contribute indirectly to the organelle's other functions because they belong to major determinants of submitochondrial morphology. Here, we review current knowledge about the trypanosomal ATP synthase composition and architecture in the context of recent advances in the structural characterization of counterpart enzymes from several eukaryotic supergroups. We also discuss the physiological function of mitochondrial ATP synthases in three trypanosomatid parasites, Trypanosoma cruzi, Trypanosoma brucei and Leishmania, with a focus on their disease-causing life cycle stages. We highlight the reversed proton-pumping role of the ATP synthase in the T. brucei bloodstream form, the enzyme's potential link to the regulation of parasite's glycolysis and its role in generating mitochondrial membrane potential in the absence of mitochondrial DNA.
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Affiliation(s)
- Ondřej Gahura
- Biology Centre, Czech Academy of Sciences, Branišovská 31, České Budějovice, 37005, Czech Republic
| | - Carolina Hierro-Yap
- Biology Centre, Czech Academy of Sciences, Branišovská 31, České Budějovice, 37005, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, České Budějovice, 37005, Czech Republic
| | - Alena Zíková
- Biology Centre, Czech Academy of Sciences, Branišovská 31, České Budějovice, 37005, Czech Republic
- Faculty of Science, University of South Bohemia, Branišovská 31, České Budějovice, 37005, Czech Republic
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Oldrieve G, Verney M, Jaron KS, Hébert L, Matthews KR. Monomorphic Trypanozoon: towards reconciling phylogeny and pathologies. Microb Genom 2021; 7. [PMID: 34397347 PMCID: PMC8549356 DOI: 10.1099/mgen.0.000632] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Trypanosoma brucei evansi and T. brucei equiperdum are animal infective trypanosomes conventionally classified by their clinical disease presentation, mode of transmission, host range, kinetoplast DNA (kDNA) composition and geographical distribution. Unlike other members of the subgenus Trypanozoon, they are non-tsetse transmitted and predominantly morphologically uniform (monomorphic) in their mammalian host. Their classification as independent species or subspecies has been long debated and genomic studies have found that isolates within T. brucei evansi and T. brucei equiperdum have polyphyletic origins. Since current taxonomy does not fully acknowledge these polyphyletic relationships, we re-analysed publicly available genomic data to carefully define each clade of monomorphic trypanosome. This allowed us to identify, and account for, lineage-specific variation. We included a recently published isolate, IVM-t1, which was originally isolated from the genital mucosa of a horse with dourine and typed as T. equiperdum. Our analyses corroborate previous studies in identifying at least four distinct monomorphic T. brucei clades. We also found clear lineage-specific variation in the selection efficacy and heterozygosity of the monomorphic lineages, supporting their distinct evolutionary histories. The inferred evolutionary position of IVM-t1 suggests its reassignment to the T. brucei evansi type B clade, challenging the relationship between the Trypanozoon species, the infected host, mode of transmission and the associated pathological phenotype. The analysis of IVM-t1 also provides, to our knowledge, the first evidence of the expansion of T. brucei evansi type B, or a fifth monomorphic lineage represented by IVM-t1, outside of Africa, with important possible implications for disease diagnosis.
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Affiliation(s)
- Guy Oldrieve
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Mylène Verney
- Unité PhEED, Laboratoire de Santé Animale, Site de Normandie, ANSES, RD675, 1443012 Goustranville, France
| | - Kamil S Jaron
- Institute of Evolutionary Biology, Ashworth Laboratories, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, UK
| | - Laurent Hébert
- Unité PhEED, Laboratoire de Santé Animale, Site de Normandie, ANSES, RD675, 1443012 Goustranville, France
| | - Keith R Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
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Tavares KCS, Casagrande Dambrós MG, Antunes ASL, Danziato PM, Stoco PH, Schlindwein AD, Moreira RS, Miletti LC. Selenocysteine in Trypanosoma evansi: Identification of the Genes selb, selc, seld, pstk, seltryp and the Selenophosphate Synthetase Protein. ACTA PROTOZOOL 2021. [DOI: 10.4467/16890027ap.21.003.14063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Selenoproteins have been described in all three domains of life and their function has been mainly associated with oxidative stress defense. Canonical elements required for selenoprotein production have been identified in members of the kinetoplastid group supporting the existence of a complete selenocysteine synthesis pathway in these organisms. Currently, nothing is known regarding the selenocysteine pathway in Trypanosoma evansi. In this study, we identified the expression of the elements selB, selC, selD, PSTK and selTRYP at the mRNA level in T. evansi. All translated proteins (selD, PSTK, selTRYP and selB) have the domains predicted and higher identity with Trypanosoma brucei. gambiense. The selenophosphate synthetase protein was localized in the cytoplasm. Our results support the existence of an active selenocysteine pathway in T. evansi.
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Affiliation(s)
- Kaio Cesar Simiano Tavares
- Laboratório de Hemoparasitas e Vetores Centro de Ciências Agroveterinárias (CAV), Universidade do Estado de Santa Catarina (UDESC).; Experimental Biology Center (NUBEX), Universidade de Fortaleza
| | | | | | | | | | | | - Renato Simões Moreira
- Laboratório de Hemoparasitas e Vetores Centro de Ciências Agroveterinárias (CAV), Universidade do Estado de Santa Catarina (UDESC); Instituto Federal de Santa Catarina (IFSC)
| | - Luiz Claudio Miletti
- Laboratório de Hemoparasitas e Vetores Centro de Ciências Agroveterinárias (CAV), Universidade do Estado de Santa Catarina (UDESC)
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Zhang N, Jiang N, Zhang K, Zheng L, Zhang D, Sang X, Feng Y, Chen R, Yang N, Wang X, Cheng Z, Suo X, Lun Z, Chen Q. Landscapes of Protein Posttranslational Modifications of African Trypanosoma Parasites. iScience 2020; 23:101074. [PMID: 32403088 PMCID: PMC7218301 DOI: 10.1016/j.isci.2020.101074] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/22/2020] [Accepted: 04/14/2020] [Indexed: 12/13/2022] Open
Abstract
Proteins of all living cells undergo a myriad of post-translational modifications (PTMs) that are critical to multifarious life processes. In this study, we describe the first comprehensive multiple PTM-omics atlas in parallel with quantitative proteome analyses of two representative species of African trypanosomes, Trypanosoma brucei and Trypanosoma evansi. Ten PTM types with approximately 40,000 modified sites and 150 histone marks with a fine map on each protein of the two African trypanosomes were accomplished. The two biologically different trypanosomal species displayed distinct PTM-omic features, regulation pathways, and networks. Modifications in the proteins involved in the redox system were mainly upregulated in T. brucei, whereas proteins associated with motility were predominantly modified in T. evansi. The establishment of a database of multiple PTMs in the two parasites provides us with a deep insight into the biological mechanisms that underpin life processes in trypanosomes with different life cycles.
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Affiliation(s)
- Naiwen Zhang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China
| | - Ning Jiang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China
| | - Kai Zhang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China
| | - Lili Zheng
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China
| | - Di Zhang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China
| | - Xiaoyu Sang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China
| | - Ying Feng
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China
| | - Ran Chen
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China
| | - Na Yang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China
| | - Xinyi Wang
- College of Basic Sciences, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China
| | - Zhongyi Cheng
- Jingjie PTM Biolab (Hangzhou) Co. Ltd, Hangzhou 310018, China
| | - Xun Suo
- National Animal Protozoa Laboratory & College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Zhaorong Lun
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Qijun Chen
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, 120 Dongling Road, Shenyang 110866, China; The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, 120 Dongling Road, Shenyang 110866, China.
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10
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Cooper S, Wadsworth ES, Ochsenreiter T, Ivens A, Savill NJ, Schnaufer A. Assembly and annotation of the mitochondrial minicircle genome of a differentiation-competent strain of Trypanosoma brucei. Nucleic Acids Res 2019; 47:11304-11325. [PMID: 31665448 PMCID: PMC6868439 DOI: 10.1093/nar/gkz928] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 10/03/2019] [Accepted: 10/08/2019] [Indexed: 01/10/2023] Open
Abstract
Kinetoplastids are protists defined by one of the most complex mitochondrial genomes in nature, the kinetoplast. In the sleeping sickness parasite Trypanosoma brucei, the kinetoplast is a chain mail-like network of two types of interlocked DNA molecules: a few dozen ∼23-kb maxicircles (homologs of the mitochondrial genome of other eukaryotes) and thousands of ∼1-kb minicircles. Maxicircles encode components of respiratory chain complexes and the mitoribosome. Several maxicircle-encoded mRNAs undergo extensive post-transcriptional RNA editing via addition and deletion of uridines. The process is mediated by hundreds of species of minicircle-encoded guide RNAs (gRNAs), but the precise number of minicircle classes and gRNA genes was unknown. Here we present the first essentially complete assembly and annotation of the kinetoplast genome of T. brucei. We have identified 391 minicircles, encoding not only ∼930 predicted 'canonical' gRNA genes that cover nearly all known editing events (accessible via the web at http://hank.bio.ed.ac.uk), but also ∼370 'non-canonical' gRNA genes of unknown function. Small RNA transcriptome data confirmed expression of the majority of both categories of gRNAs. Finally, we have used our data set to refine definitions for minicircle structure and to explore dynamics of minicircle copy numbers.
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Affiliation(s)
- Sinclair Cooper
- Institute of Immunology & Infection Research, University of Edinburgh, Edinburgh, Scotland EH9 3FL, UK
| | - Elizabeth S Wadsworth
- Institute of Immunology & Infection Research, University of Edinburgh, Edinburgh, Scotland EH9 3FL, UK
| | | | - Alasdair Ivens
- Institute of Immunology & Infection Research, University of Edinburgh, Edinburgh, Scotland EH9 3FL, UK
| | - Nicholas J Savill
- Institute of Immunology & Infection Research, University of Edinburgh, Edinburgh, Scotland EH9 3FL, UK
| | - Achim Schnaufer
- Institute of Immunology & Infection Research, University of Edinburgh, Edinburgh, Scotland EH9 3FL, UK
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Kariuki CK, Stijlemans B, Magez S. The Trypanosomal Transferrin Receptor of Trypanosoma Brucei-A Review. Trop Med Infect Dis 2019; 4:tropicalmed4040126. [PMID: 31581506 PMCID: PMC6958415 DOI: 10.3390/tropicalmed4040126] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 09/19/2019] [Accepted: 09/25/2019] [Indexed: 02/06/2023] Open
Abstract
Iron is an essential element for life. Its uptake and utility requires a careful balancing with its toxic capacity, with mammals evolving a safe and bio-viable means of its transport and storage. This transport and storage is also utilized as part of the iron-sequestration arsenal employed by the mammalian hosts’ ‘nutritional immunity’ against parasites. Interestingly, a key element of iron transport, i.e., serum transferrin (Tf), is an essential growth factor for parasitic haemo-protozoans of the genus Trypanosoma. These are major mammalian parasites causing the diseases human African trypanosomosis (HAT) and animal trypanosomosis (AT). Using components of their well-characterized immune evasion system, bloodstream Trypanosoma brucei parasites adapt and scavenge for the mammalian host serum transferrin within their broad host range. The expression site associated genes (ESAG6 and 7) are utilized to construct a heterodimeric serum Tf binding complex which, within its niche in the flagellar pocket, and coupled to the trypanosomes’ fast endocytic rate, allows receptor-mediated acquisition of essential iron from their environment. This review summarizes current knowledge of the trypanosomal transferrin receptor (TfR), with emphasis on the structure and function of the receptor, both in physiological conditions as well as in conditions where the iron supply to parasites is being limited. Potential applications using current knowledge of the parasite receptor are also briefly discussed, primarily focused on potential therapeutic interventions.
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Affiliation(s)
- Christopher K. Kariuki
- Laboratory of Cellular and Molecular Interactions (CMIM), Vrije Universiteit Brussels, Brussels, 1050 Ixelles, Belgium;
- Department of Tropical and Infectious Diseases, Institute of Primate Research (IPR), 00502 Nairobi, Kenya
- Correspondence: (C.K.K.); (S.M.); Tel.: +322-629-1975 (C.K.K.); +82-32626-4207 (S.M.)
| | - Benoit Stijlemans
- Laboratory of Cellular and Molecular Interactions (CMIM), Vrije Universiteit Brussels, Brussels, 1050 Ixelles, Belgium;
- Myeloid Cell Immunology Lab, VIB Center for Inflammation Research, Brussels, 9052 Gent, Belgium
| | - Stefan Magez
- Laboratory of Cellular and Molecular Interactions (CMIM), Vrije Universiteit Brussels, Brussels, 1050 Ixelles, Belgium;
- Laboratory for Biomedical Research, Ghent University Global Campus, Yeonsu-Gu, Incheon 219220, Korea
- Correspondence: (C.K.K.); (S.M.); Tel.: +322-629-1975 (C.K.K.); +82-32626-4207 (S.M.)
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In-depth analysis of the genome of Trypanosoma evansi, an etiologic agent of surra. SCIENCE CHINA-LIFE SCIENCES 2019; 62:406-419. [PMID: 30685829 DOI: 10.1007/s11427-018-9473-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Accepted: 12/29/2018] [Indexed: 12/16/2022]
Abstract
Trypanosoma evansi is the causative agent of the animal trypanosomiasis surra, a disease with serious economic burden worldwide. The availability of the genome of its closely related parasite Trypanosoma brucei allows us to compare their genetic and evolutionarily shared and distinct biological features. The complete genomic sequence of the T. evansi YNB strain was obtained using a combination of genomic and transcriptomic sequencing, de novo assembly, and bioinformatic analysis. The genome size of the T. evansi YNB strain was 35.2 Mb, showing 96.59% similarity in sequence and 88.97% in scaffold alignment with T. brucei. A total of 8,617 protein-coding genes, accounting for 31% of the genome, were predicted. Approximately 1,641 alternative splicing events of 820 genes were identified, with a majority mediated by intron retention, which represented a major difference in post-transcriptional regulation between T. evansi and T. brucei. Disparities in gene copy number of the variant surface glycoprotein, expression site-associated genes, microRNAs, and RNA-binding protein were clearly observed between the two parasites. The results revealed the genomic determinants of T. evansi, which encoded specific biological characteristics that distinguished them from other related trypanosome species.
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Cuypers B, Van den Broeck F, Van Reet N, Meehan CJ, Cauchard J, Wilkes JM, Claes F, Goddeeris B, Birhanu H, Dujardin JC, Laukens K, Büscher P, Deborggraeve S. Genome-Wide SNP Analysis Reveals Distinct Origins of Trypanosoma evansi and Trypanosoma equiperdum. Genome Biol Evol 2018; 9:1990-1997. [PMID: 28541535 PMCID: PMC5566637 DOI: 10.1093/gbe/evx102] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2017] [Indexed: 12/22/2022] Open
Abstract
Trypanosomes cause a variety of diseases in man and domestic animals in Africa, Latin America, and Asia. In the Trypanozoon subgenus, Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense cause human African trypanosomiasis, whereas Trypanosoma brucei brucei, Trypanosoma evansi, and Trypanosoma equiperdum are responsible for nagana, surra, and dourine in domestic animals, respectively. The genetic relationships between T. evansi and T. equiperdum and other Trypanozoon species remain unclear because the majority of phylogenetic analyses has been based on only a few genes. In this study, we have conducted a phylogenetic analysis based on genome-wide SNP analysis comprising 56 genomes from the Trypanozoon subgenus. Our data reveal that T. equiperdum has emerged at least once in Eastern Africa and T. evansi at two independent occasions in Western Africa. The genomes within the T. equiperdum and T. evansi monophyletic clusters show extremely little variation, probably due to the clonal spread linked to the independence from tsetse flies for their transmission.
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Affiliation(s)
- Bart Cuypers
- Biomedical Sciences Department, Institute of Tropical Medicine, Antwerp, Belgium.,Department of Mathematics and Computer Sciences, University of Antwerp, Belgium
| | | | - Nick Van Reet
- Biomedical Sciences Department, Institute of Tropical Medicine, Antwerp, Belgium
| | - Conor J Meehan
- Biomedical Sciences Department, Institute of Tropical Medicine, Antwerp, Belgium
| | - Julien Cauchard
- Anses Dozulé Laboratory for Equine Diseases, Goustranville, France
| | - Jonathan M Wilkes
- Wellcome Trust Centre of Molecular Parasitology, University of Glasgow, United Kingdom
| | - Filip Claes
- Food and Agriculture Organization of the United Nations (FAO), Regional Office for Asia and the Pacific, Bangkok, Thailand
| | | | - Hadush Birhanu
- College of Veterinary Medicine, Mekelle University, Tigray, Ethiopia
| | - Jean-Claude Dujardin
- Biomedical Sciences Department, Institute of Tropical Medicine, Antwerp, Belgium.,Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Kris Laukens
- Department of Mathematics and Computer Sciences, University of Antwerp, Belgium
| | - Philippe Büscher
- Biomedical Sciences Department, Institute of Tropical Medicine, Antwerp, Belgium
| | - Stijn Deborggraeve
- Biomedical Sciences Department, Institute of Tropical Medicine, Antwerp, Belgium
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14
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Kamidi CM, Saarman NP, Dion K, Mireji PO, Ouma C, Murilla G, Aksoy S, Schnaufer A, Caccone A. Multiple evolutionary origins of Trypanosoma evansi in Kenya. PLoS Negl Trop Dis 2017; 11:e0005895. [PMID: 28880965 PMCID: PMC5605091 DOI: 10.1371/journal.pntd.0005895] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 09/19/2017] [Accepted: 08/22/2017] [Indexed: 11/19/2022] Open
Abstract
Trypanosoma evansi is the parasite causing surra, a form of trypanosomiasis in camels and other livestock, and a serious economic burden in Kenya and many other parts of the world. Trypanosoma evansi transmission can be sustained mechanically by tabanid and Stomoxys biting flies, whereas the closely related African trypanosomes T. brucei brucei and T. b. rhodesiense require cyclical development in tsetse flies (genus Glossina) for transmission. In this study, we investigated the evolutionary origins of T. evansi. We used 15 polymorphic microsatellites to quantify levels and patterns of genetic diversity among 41 T. evansi isolates and 66 isolates of T. b. brucei (n = 51) and T. b. rhodesiense (n = 15), including many from Kenya, a region where T. evansi may have evolved from T. brucei. We found that T. evansi strains belong to at least two distinct T. brucei genetic units and contain genetic diversity that is similar to that in T. brucei strains. Results indicated that the 41 T. evansi isolates originated from multiple T. brucei strains from different genetic backgrounds, implying independent origins of T. evansi from T. brucei strains. This surprising finding further suggested that the acquisition of the ability of T. evansi to be transmitted mechanically, and thus the ability to escape the obligate link with the African tsetse fly vector, has occurred repeatedly. These findings, if confirmed, have epidemiological implications, as T. brucei strains from different genetic backgrounds can become either causative agents of a dangerous, cosmopolitan livestock disease or of a lethal human disease, like for T. b. rhodesiense.
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Affiliation(s)
- Christine M. Kamidi
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
- Department of Biomedical Sciences and Technology, School of Public Health and Community Development, Maseno University, Maseno, Kenya
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, CT, United States of America
| | - Norah P. Saarman
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, CT, United States of America
| | - Kirstin Dion
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, CT, United States of America
| | - Paul O. Mireji
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, CT, United States of America
- Centre for Geographic Medicine Research Coast, Kenya Medical Research Institute, Kilifi, Kenya
| | - Collins Ouma
- Department of Biomedical Sciences and Technology, School of Public Health and Community Development, Maseno University, Maseno, Kenya
| | - Grace Murilla
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Kikuyu, Kenya
| | - Serap Aksoy
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, CT, United States of America
| | - Achim Schnaufer
- Centre for Immunity, Infection & Evolution, and Institute of Immunology & Infection Research, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Adalgisa Caccone
- Yale School of Public Health, Department of Epidemiology of Microbial Diseases, New Haven, CT, United States of America
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, CT, United States of America
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15
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Bassarak B, Moser I, Menge C. In vitro production of Trypanosoma equiperdum antigen and its evaluation for use in serodiagnosis of dourine. Vet Parasitol 2016; 223:133-40. [PMID: 27198790 DOI: 10.1016/j.vetpar.2016.04.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 04/19/2016] [Accepted: 04/20/2016] [Indexed: 11/19/2022]
Abstract
A modified Baltz's in vitro cultivation system for the propagation of Trypanosoma equiperdum strain OVI was established to develop a replacement for the conventional production procedure of dourine diagnostic antigen in rats. To increase trypanosome yields we designed an optimized culture medium by addition of supplemental compounds. Trypanosomes were adapted to this medium by two succeeding cultivation steps which led to a substantial proliferation rate and an increased cell density tolerance, respectively. As a result, adapted parasites could be propagated to maximum cell densities of >2×10(6) cells/ml, facilitating in vitro antigen production in preparative quantities comparable to the conventional method. A panel of 180 horse field sera, previously sent for testing to the German National Reference Laboratory for Dourine, was tested by complement fixation test using culture-derived as well as conventionally produced dourine antigen. Cohen's kappa values for results obtained with two batches of culture-derived antigen as compared to conventional antigen were 0.91 (95% confidence interval [CI]: 82.2-99.7) and 0.83 (95% CI: 70.3-95.3), respectively. Performance of antigens for diagnostic purposes was characterized in an inter-laboratory comparative study deploying 14 sera from horses with defined dourine statuses. Complement fixation test results from 15 participating European laboratories showed a diagnostic sensitivity of 94.1% (95% CI: 89.4-98.7) and a diagnostic specificity of 96.2% (95% CI: 92.5-99.9) for conventional antigen and a slightly higher diagnostic sensitivity of 96.0% (95% CI: 92.2-99.8) and a diagnostic specificity of 97.1% (95% CI: 94.0-100) for culture-derived antigen. We conclude that our novel approach for dourine antigen production from in vitro-grown trypanosomes described and evaluated herein meets the requirements for the prospective purpose in quantitative and qualitative terms and should be considered by the competent authorities as an alternative for the animal experiment currently prescribed by international standards.
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Affiliation(s)
- Björn Bassarak
- Friedrich-Loeffler-Institut/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Naumburger Straße 96a, 07743 Jena, Germany; German National Reference Laboratory for Dourine, Friedrich-Loeffler-Institut/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Naumburger Straße 96a, 07743 Jena, Germany.
| | - Irmgard Moser
- Friedrich-Loeffler-Institut/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Naumburger Straße 96a, 07743 Jena, Germany; German National Reference Laboratory for Dourine, Friedrich-Loeffler-Institut/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Naumburger Straße 96a, 07743 Jena, Germany.
| | - Christian Menge
- Friedrich-Loeffler-Institut/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Naumburger Straße 96a, 07743 Jena, Germany.
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16
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Sánchez E, Perrone T, Recchimuzzi G, Cardozo I, Biteau N, Aso PM, Mijares A, Baltz T, Berthier D, Balzano-Nogueira L, Gonzatti MI. Molecular characterization and classification of Trypanosoma spp. Venezuelan isolates based on microsatellite markers and kinetoplast maxicircle genes. Parasit Vectors 2015; 8:536. [PMID: 26467019 PMCID: PMC4607141 DOI: 10.1186/s13071-015-1129-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 10/01/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Livestock trypanosomoses, caused by three species of the Trypanozoon subgenus, Trypanosoma brucei brucei, T. evansi and T. equiperdum is widely distributed throughout the world and constitutes an important limitation for the production of animal protein. T. evansi and T. equiperdum are morphologically indistinguishable parasites that evolved from a common ancestor but acquired important biological differences, including host range, mode of transmission, distribution, clinical symptoms and pathogenicity. At a molecular level, T. evansi is characterized by the complete loss of the maxicircles of the kinetoplastic DNA, while T. equiperdum has retained maxicircle fragments similar to those present in T. brucei. T. evansi causes the disease known as Surra, Derrengadera or "mal de cadeiras", while T. equiperdum is the etiological agent of dourine or "mal du coit", characterized by venereal transmission and white patches in the genitalia. METHODS Nine Venezuelan Trypanosoma spp. isolates, from horse, donkey or capybara were genotyped and classified using microsatellite analyses and maxicircle genes. The variables from the microsatellite data and the Procyclin PE repeats matrices were combined using the Hill-Smith method and compared to a group of T. evansi, T. equiperdum and T. brucei reference strains from South America, Asia and Africa using Coinertia analysis. Four maxicircle genes (cytb, cox1, a6 and nd8) were amplified by PCRfrom TeAp-N/D1 and TeGu-N/D1, the two Venezuelan isolates that grouped with the T. equiperdum STIB841/OVI strain. These maxicircle sequences were analyzed by nucleotide BLAST and aligned toorthologous genes from the Trypanozoon subgenus by MUSCLE tools. Phylogenetic trees were constructed using Maximum Parsimony (MP) and Maximum Likelihood (ML) with the MEGA5.1® software. RESULTS We characterized microsatellite markers and Procyclin PE repeats of nine Venezuelan Trypanosoma spp. isolates with various degrees of virulence in a mouse model, and compared them to a panel of T. evansi and T. equiperdum reference strains. Coinertia analysis of the combined repeats and previously reported T. brucei brucei microsatellite genotypes revealed three distinct groups. Seven of the Venezuelan isolates grouped with globally distributed T. evansi strains, while TeAp-N/D1 and TeGu-N/D1 strains clustered in a separate group with the T. equiperdum STIB841/OVI strain isolated in South Africa. A third group included T. brucei brucei, two strains previously classified as T. evansi (GX and TC) and one as T. equiperdum (BoTat-1.1). Four maxicircle genes, Cytochrome b, Cythocrome Oxidase subunit 1, ATP synthase subunit 6 and NADH dehydrogenase subunit 8, were identified in the two Venezuelan strains clustering with the T. equiperdum STIB841/OVI strain. Phylogenetic analysis of the cox1 gene sequences further separated these two Venezuelan T. equiperdum strains: TeAp-N/D1 grouped with T. equiperdum strain STIB818 and T. brucei brucei, and TeGu-N/D1 with the T. equiperdum STIB841/OVI strain. CONCLUSION Based on the Coinertia analysis and maxicircle gene sequence phylogeny, TeAp-N/D1 and TeGu-N/D1 constitute the first confirmed T. equiperdum strains described from Latin America.
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Affiliation(s)
- E Sánchez
- Laboratorio de Fisiología de Parásitos. Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela.
| | - T Perrone
- Laboratorio de Fisiología de Parásitos. Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela.
| | - G Recchimuzzi
- Grupo de Bioquímica e Inmunología de Hemoparásitos. Departamento de Biología Celular, Universidad Simón Bolívar, Caracas, 1080, Venezuela.
| | - I Cardozo
- Laboratorio de Fisiología de Parásitos. Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela.
| | - N Biteau
- Laboratoire de Microbiologie Fondamentale et Pathogénicité, Université Bordeaux. UMR-CNRS 5234, 146, Rue Léo Saignat, 33076, Bordeaux, Cedex, France.
| | - P M Aso
- Grupo de Bioquímica e Inmunología de Hemoparásitos. Departamento de Biología Celular, Universidad Simón Bolívar, Caracas, 1080, Venezuela.
| | - A Mijares
- Laboratorio de Fisiología de Parásitos. Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela.
| | - T Baltz
- Laboratoire de Microbiologie Fondamentale et Pathogénicité, Université Bordeaux. UMR-CNRS 5234, 146, Rue Léo Saignat, 33076, Bordeaux, Cedex, France.
| | - D Berthier
- CIRAD, UMR InterTryp, F-34398, Montpellier, France.
| | - L Balzano-Nogueira
- Laboratorio de Biometría y Estadística, Área de Agricultura y Soberanía Alimentaria, Instituto de Estudios Avanzados, Caracas, 1015A, Venezuela.
| | - M I Gonzatti
- Grupo de Bioquímica e Inmunología de Hemoparásitos. Departamento de Biología Celular, Universidad Simón Bolívar, Caracas, 1080, Venezuela.
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Frolov AO, Malysheva MN, Yurchenko V, Kostygov AY. Back to monoxeny: Phytomonas nordicus descended from dixenous plant parasites. Eur J Protistol 2015; 52:1-10. [PMID: 26555733 DOI: 10.1016/j.ejop.2015.08.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 08/06/2015] [Accepted: 08/15/2015] [Indexed: 11/30/2022]
Abstract
The trypanosomatid Phytomonas nordicus parasitizing the predatory bug Troilus luridus was described at the twilight of the morphotype-based systematics. Despite its monoxenous life cycle, this species was attributed to the dixenous genus Phytomonas due to the presence of long twisted promastigotes and development of flagellates in salivary glands. However, these characteristics were considered insufficient for proving the phytomonad nature of the species and therefore its description remained virtually unnoticed. Here, we performed molecular phylogenetic analyses using 18S ribosomal RNA (rRNA) gene and region containing internal trascribed spacers (ITS) 1 and 2 and convincingly demonstrated the affinity of P. nordicus to the genus Phytomonas. In addition, we investigated its development in the salivary glands. We argue that in many aspects the life cycle of monoxenous P. nordicus resembles that of its dixenous relatives represented by tomato-parasitizing Phytomonas serpens.
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Affiliation(s)
- Alexander O Frolov
- Zoological Institute of the Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia
| | - Marina N Malysheva
- Zoological Institute of the Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia
| | - Vyacheslav Yurchenko
- Life Science Research Centre, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic; Biology Centre, Institute of Parasitology, Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Alexei Yu Kostygov
- Zoological Institute of the Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia; Life Science Research Centre, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00 Ostrava, Czech Republic.
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18
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Greif G, Rodriguez M, Reyna-Bello A, Robello C, Alvarez-Valin F. Kinetoplast adaptations in American strains from Trypanosoma vivax. Mutat Res 2015; 773:69-82. [PMID: 25847423 DOI: 10.1016/j.mrfmmm.2015.01.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 01/06/2015] [Accepted: 01/17/2015] [Indexed: 05/24/2023]
Abstract
The mitochondrion role changes during the digenetic life cycle of African trypanosomes. Owing to the low abundance of glucose in the insect vector (tsetse flies) the parasites are dependent upon a fully functional mitochondrion, capable of performing oxidative phosphorylation. Nevertheless, inside the mammalian host (bloodstream forms), which is rich in nutrients, parasite proliferation relies on glycolysis, and the mitochondrion is partially redundant. In this work we perform a comparative study of the mitochondrial genome (kinetoplast) in different strains of Trypanosoma vivax. The comparison was conducted between a West African strain that goes through a complete life cycle and two American strains that are mechanically transmitted (by different vectors) and remain as bloodstream forms only. It was found that while the African strain has a complete and apparently fully functional kinetoplast, the American T. vivax strains have undergone a drastic process of mitochondrial genome degradation, in spite of the recent introduction of these parasites in America. Many of their genes exhibit different types of mutations that are disruptive of function such as major deletions, frameshift causing indels and missense mutations. Moreover, all but three genes (A6-ATPase, RPS12 and MURF2) are not edited in the American strains, whereas editing takes place normally in all (editable) genes from the African strain. Two of these genes, A6-ATPase and RPS12, are known to play an essential function during bloodstream stage. Analysis of the minicircle population shows that its diversity has been greatly reduced, remaining mostly those minicircles that carry guide RNAs necessary for the editing of A6-ATPase and RPS12. The fact that these two genes remain functioning normally, as opposed to that reported in Trypanosoma brucei-like trypanosomes that restrict their life cycle to the bloodstream forms, along with other differences, is indicative that the American T. vivax strains are following a novel evolutionary pathway.
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Affiliation(s)
- Gonzalo Greif
- Unidad de Biología Molecular, Institut Pasteur de Montevideo, Uruguay
| | - Matías Rodriguez
- Sección Biomatemática, Facultad de Ciencias, Universidad de la Republica, Uruguay
| | - Armando Reyna-Bello
- Departamento de Ciencias de la Vida, Carrera en Ingeniería en Biotecnología, Universidad de las Fuerzas Armadas, Ecuador; Centro de Estudios Biomédicos y Veterinarios, Universidad Nacional Experimental Simón Rodríguez-IDECYT, Caracas, Venezuela
| | - Carlos Robello
- Unidad de Biología Molecular, Institut Pasteur de Montevideo, Uruguay; Departamento de Bioquímica, Facultad de Medicina, Universidad de la República Uruguay
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Misra KK, Roy S, Choudhury A. Biology of Trypanosoma (Trypanozoon) evansi in experimental heterologous mammalian hosts. J Parasit Dis 2015; 40:1047-61. [PMID: 27605836 DOI: 10.1007/s12639-014-0633-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 12/09/2014] [Indexed: 12/14/2022] Open
Abstract
Trypanosoma (Trypanozoon) evansi is a causative agent of the dreadful mammalian disease trypanosomiasis or 'Surra' and carried as a latent parasite in domestic cattle but occasionally proves fatal when transmitted to horses and camel. Sporadic outbreak of 'Surra' to different animals (beside their natural hosts) reminds that T. evansi may be zoonotic, as their close relative cause sleeping sickness to human being. This haemoflagellate is mechanically transmitted by horse fly and its effect on different host varies depending on certain factors including the effectiveness of transmission by mechanical vector, the suitability and susceptibility of the host as well as most importantly the ability of the disease establishment of parasite to adapt itself to the host's resistance, etc. The course of the disease caused by T. evansi is similar to that of human sleeping sickness caused by T. (T.) brucei gambiense. The target organs and symptoms show close similarity. T. evansi can successfully be transmitted among unnatural hosts i.e., other classes of vertebrates, like chicken. In transmission experiments, the unnatural hosts may sometimes induce profound changes in the biology of trypanosomes. Hence, in present study the observations are the biology of different morphological changes of T. evansi as well as its ability of disease formation within some heterologous mammal viz., albino rat, guineapig, bandicoot, mongoose, domestic cat and common monkey. Blood smears of infected albino rats, bandicoot, and mongoose revealed only monomorphic form. Interestingly, blood smears of infected cat and monkey, T. evansi shows slender trypomastigote form and short intermediate form whereas organ smears shows other two forms of haemoflagellate viz., sphaeromastigote and amastigote form. The haemoflagellate maintains a common reproductive cycle in all the experimental heterologous hosts whereas disease symptoms differ. T. evansi infected cat and monkey shows nervous symptoms. Infected monkey expresses some symptoms similar to that of human sleeping sickness disease. Thus the paper highlights zoonotic potentialities of T. evansi.
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Affiliation(s)
- K K Misra
- Department of Zoology, R. B. C. College, Naihati, India ; Department of Zoology, Asutosh College, Kolkata, India
| | - S Roy
- City College, Kolkata, India
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20
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Carnes J, Anupama A, Balmer O, Jackson A, Lewis M, Brown R, Cestari I, Desquesnes M, Gendrin C, Hertz-Fowler C, Imamura H, Ivens A, Kořený L, Lai DH, MacLeod A, McDermott SM, Merritt C, Monnerat S, Moon W, Myler P, Phan I, Ramasamy G, Sivam D, Lun ZR, Lukeš J, Stuart K, Schnaufer A. Genome and phylogenetic analyses of Trypanosoma evansi reveal extensive similarity to T. brucei and multiple independent origins for dyskinetoplasty. PLoS Negl Trop Dis 2015; 9:e3404. [PMID: 25568942 PMCID: PMC4288722 DOI: 10.1371/journal.pntd.0003404] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 11/09/2014] [Indexed: 11/18/2022] Open
Abstract
Two key biological features distinguish Trypanosoma evansi from the T. brucei group: independence from the tsetse fly as obligatory vector, and independence from the need for functional mitochondrial DNA (kinetoplast or kDNA). In an effort to better understand the molecular causes and consequences of these differences, we sequenced the genome of an akinetoplastic T. evansi strain from China and compared it to the T. b. brucei reference strain. The annotated T. evansi genome shows extensive similarity to the reference, with 94.9% of the predicted T. b. brucei coding sequences (CDS) having an ortholog in T. evansi, and 94.6% of the non-repetitive orthologs having a nucleotide identity of 95% or greater. Interestingly, several procyclin-associated genes (PAGs) were disrupted or not found in this T. evansi strain, suggesting a selective loss of function in the absence of the insect life-cycle stage. Surprisingly, orthologous sequences were found in T. evansi for all 978 nuclear CDS predicted to represent the mitochondrial proteome in T. brucei, although a small number of these may have lost functionality. Consistent with previous results, the F1FO-ATP synthase γ subunit was found to have an A281 deletion, which is involved in generation of a mitochondrial membrane potential in the absence of kDNA. Candidates for CDS that are absent from the reference genome were identified in supplementary de novo assemblies of T. evansi reads. Phylogenetic analyses show that the sequenced strain belongs to a dominant group of clonal T. evansi strains with worldwide distribution that also includes isolates classified as T. equiperdum. At least three other types of T. evansi or T. equiperdum have emerged independently. Overall, the elucidation of the T. evansi genome sequence reveals extensive similarity of T. brucei and supports the contention that T. evansi should be classified as a subspecies of T. brucei.
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Affiliation(s)
- Jason Carnes
- Seattle Biomedical Research Institute, Seattle, United States of America
| | - Atashi Anupama
- Seattle Biomedical Research Institute, Seattle, United States of America
| | - Oliver Balmer
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Andrew Jackson
- Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Michael Lewis
- Department of Pathogen Molecular Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Rob Brown
- Seattle Biomedical Research Institute, Seattle, United States of America
| | - Igor Cestari
- Seattle Biomedical Research Institute, Seattle, United States of America
| | - Marc Desquesnes
- CIRAD, UMR-InterTryp, Montpellier, France
- Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand
| | - Claire Gendrin
- Seattle Biomedical Research Institute, Seattle, United States of America
| | - Christiane Hertz-Fowler
- Centre for Genomic Research, Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Hideo Imamura
- Unit of Molecular Parasitology, Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - Alasdair Ivens
- Centre of Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Luděk Kořený
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic
- Faculty of Sciences, University of South Bohemia, Centre, České Budějovice (Budweis), Czech Republic
| | - De-Hua Lai
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic
- Faculty of Sciences, University of South Bohemia, Centre, České Budějovice (Budweis), Czech Republic
- Center for Parasitic Organisms, State Key Laboratory of Biocontrol, School of Life Sciences, and Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, People′s Republic of China
| | - Annette MacLeod
- Wellcome Trust Centre for Molecular Parasitology, Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | | | - Chris Merritt
- Seattle Biomedical Research Institute, Seattle, United States of America
| | - Severine Monnerat
- Seattle Biomedical Research Institute, Seattle, United States of America
| | - Wonjong Moon
- Seattle Biomedical Research Institute, Seattle, United States of America
| | - Peter Myler
- Seattle Biomedical Research Institute, Seattle, United States of America
| | - Isabelle Phan
- Seattle Biomedical Research Institute, Seattle, United States of America
| | - Gowthaman Ramasamy
- Seattle Biomedical Research Institute, Seattle, United States of America
| | - Dhileep Sivam
- Seattle Biomedical Research Institute, Seattle, United States of America
| | - Zhao-Rong Lun
- Center for Parasitic Organisms, State Key Laboratory of Biocontrol, School of Life Sciences, and Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, People′s Republic of China
- * E-mail: (ZRL); (JL); (KS); (AS)
| | - Julius Lukeš
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic
- Faculty of Sciences, University of South Bohemia, Centre, České Budějovice (Budweis), Czech Republic
- Canadian Institute for Advanced Research, Toronto, Canada
- * E-mail: (ZRL); (JL); (KS); (AS)
| | - Ken Stuart
- Seattle Biomedical Research Institute, Seattle, United States of America
- Department of Global Health, University of Washington, Seattle, United States of America
- * E-mail: (ZRL); (JL); (KS); (AS)
| | - Achim Schnaufer
- Centre of Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
- Institute of Immunology & Infection Research, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail: (ZRL); (JL); (KS); (AS)
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Abstract
I knew nothing and had thought nothing about parasites until 1971. In fact, if you had asked me before then, I might have commented that parasites were rather disgusting. I had been at the Johns Hopkins School of Medicine for three years, and I was on the lookout for a new project. In 1971, I came across a paper in the Journal of Molecular Biology by Larry Simpson, a classmate of mine in graduate school. Larry's paper described a remarkable DNA structure known as kinetoplast DNA (kDNA), isolated from a parasite. kDNA, the mitochondrial genome of trypanosomatids, is a DNA network composed of several thousand interlocked DNA rings. Almost nothing was known about it. I was looking for a project on DNA replication, and I wanted it to be both challenging and important. I had no doubt that working with kDNA would be a challenge, as I would be exploring uncharted territory. I was also sure that the project would be important when I learned that parasites with kDNA threaten huge populations in underdeveloped tropical countries. Looking again at Larry's paper, I found the electron micrographs of the kDNA networks to be rather beautiful. I decided to take a chance on kDNA. Little did I know then that I would devote the next forty years of my life to studying kDNA replication.
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Affiliation(s)
- Paul T Englund
- From the Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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22
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Desquesnes M, Holzmuller P, Lai DH, Dargantes A, Lun ZR, Jittaplapong S. Trypanosoma evansi and surra: a review and perspectives on origin, history, distribution, taxonomy, morphology, hosts, and pathogenic effects. BIOMED RESEARCH INTERNATIONAL 2013; 2013:194176. [PMID: 24024184 PMCID: PMC3760267 DOI: 10.1155/2013/194176] [Citation(s) in RCA: 203] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Accepted: 07/05/2013] [Indexed: 11/17/2022]
Abstract
Trypanosoma evansi, the agent of "surra," is a salivarian trypanosome, originating from Africa. It is thought to derive from Trypanosoma brucei by deletion of the maxicircle kinetoplastic DNA (genetic material required for cyclical development in tsetse flies). It is mostly mechanically transmitted by tabanids and stomoxes, initially to camels, in sub-Saharan area. The disease spread from North Africa towards the Middle East, Turkey, India, up to 53° North in Russia, across all South-East Asia, down to Indonesia and the Philippines, and it was also introduced by the conquistadores into Latin America. It can affect a very large range of domestic and wild hosts including camelids, equines, cattle, buffaloes, sheep, goats, pigs, dogs and other carnivores, deer, gazelles, and elephants. It found a new large range of wild and domestic hosts in Latin America, including reservoirs (capybaras) and biological vectors (vampire bats). Surra is a major disease in camels, equines, and dogs, in which it can often be fatal in the absence of treatment, and exhibits nonspecific clinical signs (anaemia, loss of weight, abortion, and death), which are variable from one host and one place to another; however, its immunosuppressive effects interfering with intercurrent diseases or vaccination campaigns might be its most significant and questionable aspect.
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Affiliation(s)
- Marc Desquesnes
- Cirad-Bios, UMR-InterTryp, Montpellier 34000, France
- Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
| | | | - De-Hua Lai
- Center for Parasitic Organisms, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | | | - Zhao-Rong Lun
- Center for Parasitic Organisms, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Sathaporn Jittaplapong
- Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok 10900, Thailand
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23
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Single point mutations in ATP synthase compensate for mitochondrial genome loss in trypanosomes. Proc Natl Acad Sci U S A 2013; 110:14741-6. [PMID: 23959897 DOI: 10.1073/pnas.1305404110] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Viability of the tsetse fly-transmitted African trypanosome Trypanosoma brucei depends on maintenance and expression of its kinetoplast (kDNA), the mitochondrial genome of this parasite and a putative target for veterinary and human antitrypanosomatid drugs. However, the closely related animal pathogens T. evansi and T. equiperdum are transmitted independently of tsetse flies and survive without a functional kinetoplast for reasons that have remained unclear. Here, we provide definitive evidence that single amino acid changes in the nuclearly encoded F1FO-ATPase subunit γ can compensate for complete physical loss of kDNA in these parasites. Our results provide insight into the molecular mechanism of compensation for kDNA loss by showing FO-independent generation of the mitochondrial membrane potential with increased dependence on the ADP/ATP carrier. Our findings also suggest that, in the pathogenic bloodstream stage of T. brucei, the huge and energetically demanding apparatus required for kDNA maintenance and expression serves the production of a single F1FO-ATPase subunit. These results have important implications for drug discovery and our understanding of the evolution of these parasites.
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24
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Mariod AA, Abdelwahab SI. Sclerocarya birrea(Marula), An African Tree of Nutritional and Medicinal Uses: A Review. FOOD REVIEWS INTERNATIONAL 2012. [DOI: 10.1080/87559129.2012.660716] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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25
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Paris Z, Hashimi H, Lun S, Alfonzo JD, Lukeš J. Futile import of tRNAs and proteins into the mitochondrion of Trypanosoma brucei evansi. Mol Biochem Parasitol 2011; 176:116-20. [PMID: 21195112 PMCID: PMC3042029 DOI: 10.1016/j.molbiopara.2010.12.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Revised: 12/17/2010] [Accepted: 12/22/2010] [Indexed: 11/30/2022]
Abstract
Trypanosoma brucei brucei has two distinct developmental stages, the procyclic stage in the insect and the bloodstream stage in the mammalian host. The significance of each developmental stage is punctuated by specific changes in metabolism. In the insect, T. b. brucei is strictly dependent on mitochondrial function and thus respiration to generate the bulk of its ATP, whereas in the mammalian host it relies heavily on glycolysis. These observations have raised questions about the importance of mitochondrial function in the bloodstream stage. Peculiarly, akinetoplastic strains of Trypanosoma brucei evansi that lack mitochondrial DNA do exist in the wild and are developmentally locked in the glycolysis-dependent bloodstream stage. Using RNAi we show that two mitochondrion-imported proteins, mitochondrial RNA polymerase and guide RNA associated protein 1, are still imported into the nucleic acids-lacking organelle of T. b. evansi, making the need for these proteins futile. We also show that, like in the T. b. brucei procyclic stage, the mitochondria of both bloodstream stage of T. b. brucei and T. b. evansi import various tRNAs, including those that undergo thiolation. However, we were unable to detect mitochondrial thiolation in the akinetoplastic organelle. Taken together, these data suggest a lack of connection between nuclear and mitochondrial communication in strains of T. b. evansi that lost mitochondrial genome and that do not required an insect vector for survival.
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Affiliation(s)
- Zdenĕk Paris
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 37005, České Budějovice (Budweis), Czech Republic
| | - Hassan Hashimi
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 37005, České Budějovice (Budweis), Czech Republic
- Faculty of Science, University of South Bohemia, 37005 České Budějovice (Budweis), Czech Republic
| | - Sijia Lun
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 37005, České Budějovice (Budweis), Czech Republic
| | - Juan D. Alfonzo
- Department of Microbiology and OSU Center for RNA Biology, The Ohio State University, Columbus, 43210 Ohio, USA
| | - Julius Lukeš
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 37005, České Budějovice (Budweis), Czech Republic
- Faculty of Science, University of South Bohemia, 37005 České Budějovice (Budweis), Czech Republic
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26
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Abstract
Vector-borne parasites cause major human diseases of the developing world, including malaria, human African trypanosomiasis, Chagas disease, leishmaniasis, filariasis, and schistosomiasis. Although the life cycles of these parasites were defined over 100 years ago, the strategies they use to optimize their successful transmission are only now being understood in molecular terms. Parasites are now known to monitor their environment in both their host and vector and in response to other parasites. This allows them to adapt their developmental cycles and to counteract any unfavorable conditions they encounter. Here, I review the interactions that parasites engage in with their hosts and vectors to maximize their survival and spread.
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Affiliation(s)
- Keith R Matthews
- Centre for Immunity, Infection, and Evolution, Institute for Immunology and Infection Research, Ashworth Laboratories, School of Biological Sciences, King's Buildings, University of Edinburgh, Edinburgh EH9 3JT, UK
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27
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Schnaufer A. Evolution of dyskinetoplastic trypanosomes: how, and how often? Trends Parasitol 2011; 26:557-8. [PMID: 20801716 DOI: 10.1016/j.pt.2010.08.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 08/03/2010] [Accepted: 08/09/2010] [Indexed: 11/16/2022]
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28
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Molecular identification and phylogenetic analysis of Trypanosoma evansi from dromedary camels (Camelus dromedarius) in Egypt, a pilot study. Acta Trop 2011; 117:39-46. [PMID: 20887705 DOI: 10.1016/j.actatropica.2010.09.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Revised: 09/14/2010] [Accepted: 09/22/2010] [Indexed: 11/20/2022]
Abstract
Animal trypanosomiasis is one of the major constraints of livestock industry in developing countries. In the present study, prevalence of Trypanosome evansi was assessed in the blood of dromedary camels (Camelus dromedarius) brought to Al Bassatein abattoir, Cairo, Egypt, by mouse inoculation test out of 84 tested camels, 4 animals (4.7%) were infected. Molecular analysis was achieved by PCR amplification and sequence analysis of part of ribosomal RNA gene including 18S, ITS1, 5.8S and ITS2 regions. Despite the conserved nature of 18S region, ITS region showed obvious heterogeneity compared to analogous sequences in database. Analysis of transferrin receptor encoding gene (ESAG6) showed variable repertoire in the studied isolates, which may indicate to a novel structure of T. evansi population from Egypt and/or a difference in host range. Furthermore, analysis of variable surface glycoprotein RoTat 1.2 gene marker revealed some heterogeneity at this gene locus. To our knowledge, this is the first molecular analysis of T. evansi in Egypt.
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29
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The killing of African trypanosomes by ethidium bromide. PLoS Pathog 2010; 6:e1001226. [PMID: 21187912 PMCID: PMC3002999 DOI: 10.1371/journal.ppat.1001226] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Accepted: 11/11/2010] [Indexed: 11/19/2022] Open
Abstract
Introduced in the 1950s, ethidium bromide (EB) is still used as an anti-trypanosomal drug for African cattle although its mechanism of killing has been unclear and controversial. EB has long been known to cause loss of the mitochondrial genome, named kinetoplast DNA (kDNA), a giant network of interlocked minicircles and maxicircles. However, the existence of viable parasites lacking kDNA (dyskinetoplastic) led many to think that kDNA loss could not be the mechanism of killing. When recent studies indicated that kDNA is indeed essential in bloodstream trypanosomes and that dyskinetoplastic cells survive only if they have a compensating mutation in the nuclear genome, we investigated the effect of EB on kDNA and its replication. We here report some remarkable effects of EB. Using EM and other techniques, we found that binding of EB to network minicircles is low, probably because of their association with proteins that prevent helix unwinding. In contrast, covalently-closed minicircles that had been released from the network for replication bind EB extensively, causing them, after isolation, to become highly supertwisted and to develop regions of left-handed Z-DNA (without EB, these circles are fully relaxed). In vivo, EB causes helix distortion of free minicircles, preventing replication initiation and resulting in kDNA loss and cell death. Unexpectedly, EB also kills dyskinetoplastic trypanosomes, lacking kDNA, by inhibiting nuclear replication. Since the effect on kDNA occurs at a >10-fold lower EB concentration than that on nuclear DNA, we conclude that minicircle replication initiation is likely EB's most vulnerable target, but the effect on nuclear replication may also contribute to cell killing.
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30
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Cristodero M, Seebeck T, Schneider A. Mitochondrial translation is essential in bloodstream forms of Trypanosoma brucei. Mol Microbiol 2010; 78:757-69. [PMID: 20969649 DOI: 10.1111/j.1365-2958.2010.07368.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The parasitic protozoa Trypanosoma brucei has a complex life cycle. Oxidative phosphorylation is highly active in the procyclic form but absent from bloodstream cells. The mitochondrial genome encodes several gene products that are required for oxidative phosphorylation, but it completely lacks tRNA genes. For mitochondrial translation to occur, the import of cytosolic tRNAs is therefore essential for procyclic T. brucei. Whether the same is true for the bloodstream form has not been studied so far. Here we show that the steady-state levels of mitochondrial tRNAs are essentially the same in both life stages. Editing of the imported tRNA(Trp) also occurs in both forms as well as in mitochondria of Trypanosoma evansi, which lacks a genome and a translation system. These results show that mitochondrial tRNA import is a constitutive process that must be mediated by proteins that are expressed in both forms of the life cycle and that are not encoded in the mitochondrial genome. Moreover, bloodstream cells lacking either mitochondria-specific translation elongation factor Tu or mitochondrial tryptophanyl-tRNA synthetase are not viable indicating that mitochondrial translation is also essential in this stage. Both of these proteins show trypanosomatid-specific features and may therefore be excellent novel drug targets.
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Affiliation(s)
- Marina Cristodero
- Department of Chemistry and Biochemistry, University of Bern, Freiestr. 3, CH-3012 Bern, Switzerland
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31
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Trypanosoma brucei: two steps to spread out from Africa. Trends Parasitol 2010; 26:424-7. [DOI: 10.1016/j.pt.2010.05.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2010] [Revised: 05/21/2010] [Accepted: 05/24/2010] [Indexed: 11/21/2022]
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32
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DEAD-box RNA helicase is dispensable for mitochondrial translation in Trypanosoma brucei. Exp Parasitol 2010; 127:300-3. [PMID: 20599983 DOI: 10.1016/j.exppara.2010.06.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 06/20/2010] [Accepted: 06/29/2010] [Indexed: 12/13/2022]
Abstract
DEAD-box RNA helicase, a putative subunit of the mitochondrial ribosome of Trypanosoma brucei, has been down-regulated in the procyclic and bloodstream stage by RNA interference. Although ablation of the transcript leads to a week growth phenotype in the procyclic cells, the protein does not seem to be essential for mitochondrial translation under standard cultivation conditions, as shown by an assay that allows visualization of the de novo synthesized proteins. Furthermore, we show that synthesis of cytochrome c oxidase subunit I and cytochrome b does not occur in the mitochondrion of the bloodstream stage.
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33
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Tang SC, Shapiro TA. Newly identified antibacterial compounds are topoisomerase poisons in African trypanosomes. Antimicrob Agents Chemother 2010; 54:620-6. [PMID: 20008775 PMCID: PMC2812133 DOI: 10.1128/aac.01025-09] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 09/24/2009] [Accepted: 12/06/2009] [Indexed: 11/20/2022] Open
Abstract
Human African trypanosomiasis, caused by the Trypanosoma brucei protozoan parasite, is fatal when left untreated. Current therapies are antiquated, and there is a need for new pharmacologic agents against T. brucei targets that have no human ortholog. Trypanosomes have a single mitochondrion with a unique mitochondrial DNA, known as kinetoplast DNA (kDNA), a topologically complex network that contains thousands of interlocking circular DNAs, termed minicircles (approximately 1 kb) and maxicircles (approximately 23 kb). Replication of kDNA depends on topoisomerases, enzymes that catalyze reactions that change DNA topology. T. brucei has an unusual type IA topoisomerase that is dedicated to kDNA metabolism. This enzyme has no ortholog in humans, and RNA interference (RNAi) studies have shown that it is essential for parasite survival, making it an ideal drug target. In a large chemical library screen, two compounds were recently identified as poisons of bacterial topoisomerase IA. We found that these compounds are trypanocidal in the low micromolar range and that they promote the formation of linearized minicircles covalently bound to protein on the 5' end, consistent with the poisoning of mitochondrial topoisomerase IA. Surprisingly, however, band depletion studies showed that it is topoisomerase IImt, and not topoisomerase IAmt, that is trapped. Both compounds are planar aromatic polycyclic structures that intercalate into and unwind DNA. These findings reinforce the utility of topoisomerase IImt as a target for development of new drugs for African sleeping sickness.
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Affiliation(s)
- Sonya C. Tang
- Division of Clinical Pharmacology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Theresa A. Shapiro
- Division of Clinical Pharmacology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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34
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Perrone T, Gonzatti M, Villamizar G, Escalante A, Aso P. Molecular profiles of Venezuelan isolates of Trypanosoma sp. by random amplified polymorphic DNA method. Vet Parasitol 2009; 161:194-200. [DOI: 10.1016/j.vetpar.2009.01.034] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 11/23/2008] [Accepted: 01/15/2009] [Indexed: 10/21/2022]
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