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Goes WM, Brasil CRF, Reis-Cunha JL, Coqueiro-Dos-Santos A, Grazielle-Silva V, de Souza Reis J, Souto TC, Laranjeira-Silva MF, Bartholomeu DC, Fernandes AP, Teixeira SMR. Complete assembly, annotation of virulence genes and CRISPR editing of the genome of Leishmania amazonensis PH8 strain. Genomics 2023; 115:110661. [PMID: 37263313 DOI: 10.1016/j.ygeno.2023.110661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 05/04/2023] [Accepted: 05/27/2023] [Indexed: 06/03/2023]
Abstract
We report the sequencing and assembly of the PH8 strain of Leishmania amazonensis one of the etiological agents of leishmaniasis. After combining data from long Pacbio reads, short Illumina reads and synteny with the Leishmania mexicana genome, the sequence of 34 chromosomes with 8317 annotated genes was generated. Multigene families encoding three virulence factors, A2, amastins and the GP63 metalloproteases, were identified and compared to their annotation in other Leishmania species. As they have been recently recognized as virulence factors essential for disease establishment and progression of the infection, we also identified 14 genes encoding proteins involved in parasite iron and heme metabolism and compared to genes from other Trypanosomatids. To follow these studies with a genetic approach to address the role of virulence factors, we tested two CRISPR-Cas9 protocols to generate L. amazonensis knockout cell lines, using the Miltefosine transporter gene as a proof of concept.
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Affiliation(s)
- Wanessa Moreira Goes
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Belo Horizonte, MG CEP 31.270-901, Brazil
| | - Carlos Rodolpho Ferreira Brasil
- Departamento de Análises Clínicas e Toxicológicas, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Belo Horizonte, MG CEP 31.270-901, Brazil
| | - João Luis Reis-Cunha
- Departamento de Veterinária Preventiva, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Belo Horizonte, MG CEP 31.270-901, Brazil; Departamento de Parasitologia, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Belo Horizonte, MG CEP 31.270-901, Brazil
| | - Anderson Coqueiro-Dos-Santos
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Belo Horizonte, MG CEP 31.270-901, Brazil
| | - Viviane Grazielle-Silva
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Belo Horizonte, MG CEP 31.270-901, Brazil
| | - Júlia de Souza Reis
- Departamento de Análises Clínicas e Toxicológicas, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Belo Horizonte, MG CEP 31.270-901, Brazil
| | - Tatiane Cristina Souto
- Departamento de Análises Clínicas e Toxicológicas, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Belo Horizonte, MG CEP 31.270-901, Brazil
| | - Maria Fernanda Laranjeira-Silva
- Departamento de Fisiologia, Universidade de São Paulo, Rua do Matão 101, Cidade Universitária, São Paulo, SP CEP 05508-900, Brazil
| | - Daniella Castanheira Bartholomeu
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Belo Horizonte, MG CEP 31.270-901, Brazil
| | - Ana Paula Fernandes
- Departamento de Análises Clínicas e Toxicológicas, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Belo Horizonte, MG CEP 31.270-901, Brazil; Centro de Tecnologia de Vacinas, Universidade Federal de Minas Gerais, Rua Professor José Vieira de Mendonça 770, Belo Horizonte, MG, CEP 31.210-360, Brazil
| | - Santuza Maria Ribeiro Teixeira
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, Belo Horizonte, MG CEP 31.270-901, Brazil; Centro de Tecnologia de Vacinas, Universidade Federal de Minas Gerais, Rua Professor José Vieira de Mendonça 770, Belo Horizonte, MG, CEP 31.210-360, Brazil.
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2
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Steverding D, do Nascimento LG, Perez-Castillo Y, de Sousa DP. Gallic Acid Alkyl Esters: Trypanocidal and Leishmanicidal Activity, and Target Identification via Modeling Studies. Molecules 2022; 27:molecules27185876. [PMID: 36144611 PMCID: PMC9501172 DOI: 10.3390/molecules27185876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 11/16/2022] Open
Abstract
Eight gallic acid alkyl esters (1−8) were synthesized via Fischer esterification and evaluated for their trypanocidal and leishmanicidal activity using bloodstream forms of Trypanosoma brucei and promastigotes of Leishmania major. The general cytotoxicity of the esters was evaluated with human HL-60 cells. The compounds displayed moderate to good trypanocidal but zero to low leishmanicidal activity. Gallic acid esters with alkyl chains of three or four carbon atoms in linear arrangement (propyl (4), butyl (5), and isopentyl (6)) were found to be the most trypanocidal compounds with 50% growth inhibition values of ~3 μM. On the other hand, HL-60 cells were less susceptible to the compounds, thus, resulting in moderate selectivity indices (ratio of cytotoxic to trypanocidal activity) of >20 for the esters 4−6. Modeling studies combining molecular docking and molecular dynamics simulations suggest that the trypanocidal mechanism of action of gallic acid alkyl esters could be related to the inhibition of the T. brucei alternative oxidase. This suggestion is supported by the observation that trypanosomes became immobile within minutes when incubated with the esters in the presence of glycerol as the sole substrate. These results indicate that gallic acid alkyl esters are interesting compounds to be considered for further antitrypanosomal drug development.
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Affiliation(s)
- Dietmar Steverding
- Bob Champion Research and Education Building, Norwich Medical School, University of East Anglia, Norwich NR4 7UQ, UK
- Correspondence: (D.S.); (D.P.d.S.)
| | - Lázaro Gomes do Nascimento
- Laboratory of Pharmaceutical Chemistry, Department of Pharmaceutical Sciences, Federal University of Paraíba, João Pessoa 58051-900, PB, Brazil
| | - Yunierkis Perez-Castillo
- Bio-Cheminformatics Research Group, Universidad de Las Américas, Quito 170516, Ecuador
- Facultad de Ingeniería y Ciencias Aplicadas, Área de Ciencias Aplicadas, Universidad de Las Américas, Quito 170516, Ecuador
| | - Damião Pergentino de Sousa
- Laboratory of Pharmaceutical Chemistry, Department of Pharmaceutical Sciences, Federal University of Paraíba, João Pessoa 58051-900, PB, Brazil
- Correspondence: (D.S.); (D.P.d.S.)
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3
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Espada CR, Quilles JC, Albuquerque-Wendt A, Cruz MC, Beneke T, Lorenzon LB, Gluenz E, Cruz AK, Uliana SRB. Effective Genome Editing in Leishmania ( Viannia) braziliensis Stably Expressing Cas9 and T7 RNA Polymerase. Front Cell Infect Microbiol 2021; 11:772311. [PMID: 34858879 PMCID: PMC8631273 DOI: 10.3389/fcimb.2021.772311] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 10/19/2021] [Indexed: 12/15/2022] Open
Abstract
Until 2015, loss-of-function studies to elucidate protein function in Leishmania relied on gene disruption through homologous recombination. Then, the CRISPR/Cas9 revolution reached these protozoan parasites allowing efficient genome editing with one round of transfection. In addition, the development of LeishGEdit, a PCR-based toolkit for generating knockouts and tagged lines using CRISPR/Cas9, allowed a more straightforward and effective genome editing. In this system, the plasmid pTB007 is delivered to Leishmania for episomal expression or integration in the β-tubulin locus and for the stable expression of T7 RNA polymerase and Cas9. In South America, and especially in Brazil, Leishmania (Viannia) braziliensis is the most frequent etiological agent of tegumentary leishmaniasis. The L. braziliensis β-tubulin locus presents significant sequence divergence in comparison with Leishmania major, which precludes the efficient integration of pTB007 and the stable expression of Cas9. To overcome this limitation, the L. major β-tubulin sequences, present in the pTB007, were replaced by a Leishmania (Viannia) β-tubulin conserved sequence generating the pTB007_Viannia plasmid. This modification allowed the successful integration of the pTB007_Viannia cassette in the L. braziliensis M2903 genome, and in silico predictions suggest that this can also be achieved in other Viannia species. The activity of Cas9 was evaluated by knocking out the flagellar protein PF16, which caused a phenotype of immobility in these transfectants. Endogenous PF16 was also successfully tagged with mNeonGreen, and an in-locus complementation strategy was employed to return a C-terminally tagged copy of the PF16 gene to the original locus, which resulted in the recovery of swimming capacity. The modified plasmid pTB007_Viannia allowed the integration and stable expression of both T7 RNA polymerase and Cas9 in L. braziliensis and provided an important tool for the study of the biology of this parasite.
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Affiliation(s)
- Caroline R Espada
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil.,Departamento de Biologia Celular e Molecular, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (FMRP-USP), Ribeirão Preto, Brazil
| | - José Carlos Quilles
- Departamento de Biologia Celular e Molecular, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (FMRP-USP), Ribeirão Preto, Brazil
| | - Andreia Albuquerque-Wendt
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom.,Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity & Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.,Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHTM), Universidade de Lisboa (UNL), Lisbon, Portugal
| | - Mario C Cruz
- Centro de Facilidades para Apoio à Pesquisa, Universidade de São Paulo (CEFAP-USP), São Paulo, Brazil
| | - Tom Beneke
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Lucas B Lorenzon
- Departamento de Biologia Celular e Molecular, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (FMRP-USP), Ribeirão Preto, Brazil
| | - Eva Gluenz
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom.,Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity & Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Angela K Cruz
- Departamento de Biologia Celular e Molecular, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (FMRP-USP), Ribeirão Preto, Brazil
| | - Silvia R B Uliana
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
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Camacho E, González-de la Fuente S, Solana JC, Rastrojo A, Carrasco-Ramiro F, Requena JM, Aguado B. Gene Annotation and Transcriptome Delineation on a De Novo Genome Assembly for the Reference Leishmania major Friedlin Strain. Genes (Basel) 2021; 12:genes12091359. [PMID: 34573340 PMCID: PMC8468144 DOI: 10.3390/genes12091359] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 08/20/2021] [Accepted: 08/27/2021] [Indexed: 01/05/2023] Open
Abstract
Leishmania major is the main causative agent of cutaneous leishmaniasis in humans. The Friedlin strain of this species (LmjF) was chosen when a multi-laboratory consortium undertook the objective of deciphering the first genome sequence for a parasite of the genus Leishmania. The objective was successfully attained in 2005, and this represented a milestone for Leishmania molecular biology studies around the world. Although the LmjF genome sequence was done following a shotgun strategy and using classical Sanger sequencing, the results were excellent, and this genome assembly served as the reference for subsequent genome assemblies in other Leishmania species. Here, we present a new assembly for the genome of this strain (named LMJFC for clarity), generated by the combination of two high throughput sequencing platforms, Illumina short-read sequencing and PacBio Single Molecular Real-Time (SMRT) sequencing, which provides long-read sequences. Apart from resolving uncertain nucleotide positions, several genomic regions were reorganized and a more precise composition of tandemly repeated gene loci was attained. Additionally, the genome annotation was improved by adding 542 genes and more accurate coding-sequences defined for around two hundred genes, based on the transcriptome delimitation also carried out in this work. As a result, we are providing gene models (including untranslated regions and introns) for 11,238 genes. Genomic information ultimately determines the biology of every organism; therefore, our understanding of molecular mechanisms will depend on the availability of precise genome sequences and accurate gene annotations. In this regard, this work is providing an improved genome sequence and updated transcriptome annotations for the reference L. major Friedlin strain.
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5
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Steverding D, Sidjui LS, Ferreira ÉR, Ngameni B, Folefoc GN, Mahiou-Leddet V, Ollivier E, Stephenson GR, Storr TE, Tyler KM. Trypanocidal and leishmanicidal activity of six limonoids. J Nat Med 2020; 74:606-611. [PMID: 32277328 PMCID: PMC7253382 DOI: 10.1007/s11418-020-01408-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 03/31/2020] [Indexed: 12/21/2022]
Abstract
Six limonoids [kotschyienone A and B (1, 2), 7-deacetylgedunin (3), 7-deacetyl-7-oxogedunin (4), andirobin (5) and methyl angolensate (6)] were investigated for their trypanocidal and leishmanicidal activities using bloodstream forms of Trypanosoma brucei and promastigotes of Leishmania major. Whereas all compounds showed anti-trypanosomal activity, only compounds 1–4 displayed anti-leishmanial activity. The 50% growth inhibition (GI50) values for the trypanocidal and leishmanicidal activity of the compounds ranged between 2.5 and 14.9 μM. Kotschyienone A (1) was found to be the most active compound with a minimal inhibition concentration (MIC) value of 10 μM and GI50 values between 2.5 and 2.9 μM. Only compounds 1 and 3 showed moderate cytotoxicity against HL-60 cells with MIC and GI50 values of 100 μM and 31.5–46.2 μM, respectively. Compound 1 was also found to show activity against intracellular amastigotes of L. major with a GI50 value of 1.5 μM. The results suggest that limonoids have potential as drug candidates for the development of new treatments against trypanosomiasis and leishmaniasis.
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Affiliation(s)
- Dietmar Steverding
- Bob Champion Research and Education Building, Norwich Medical School, University of East Anglia, Norwich, NR4 7UQ, UK.
| | - Lazare S Sidjui
- Institute of Medical Research and Medicinal Plant Studies, P.O. Box 13033, Yaoundé, Cameroon.,Bioorganic and Medicinal Chemistry Laboratory, Department of Organic Chemistry, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Éden Ramalho Ferreira
- BioMedical Research Centre, Norwich Medical School, University of East Anglia, Norwich, NR4 7TJ, UK.,Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Bathelemy Ngameni
- Department of Pharmacognosy and Pharmaceutical Chemistry, Faculty of Medicine and Biomedical Science, University of Yaoundé I, Yaoundé, Cameroon.
| | - Gabriel N Folefoc
- Bioorganic and Medicinal Chemistry Laboratory, Department of Organic Chemistry, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Valérie Mahiou-Leddet
- Aix-Marseille University, Avignon University, CNRS, IRD, IMBE, FAC PHARM, Marseille, France
| | - Evelyne Ollivier
- Aix-Marseille University, Avignon University, CNRS, IRD, IMBE, FAC PHARM, Marseille, France
| | | | - Thomas E Storr
- School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Kevin M Tyler
- BioMedical Research Centre, Norwich Medical School, University of East Anglia, Norwich, NR4 7TJ, UK
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Stiles JK, Hicock PI, Shah PH, Meade JC. Genomic organization, transcription, splicing and gene regulation inLeishmania. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2016. [DOI: 10.1080/00034983.1999.11813485] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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7
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Seidl A, Panzer M, Voehringer D. Protective immunity against the gastrointestinal nematode Nippostrongylus brasiliensis requires a broad T-cell receptor repertoire. Immunology 2011; 134:214-23. [PMID: 21896015 DOI: 10.1111/j.1365-2567.2011.03480.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The parasitic gastrointestinal nematode Nippostrongylus brasiliensis induces massive expansion of T helper type 2 (Th2) cells in the lung and small intestine. Th2 cells are a major source of interleukin-4 and interleukin-13, two cytokines that appear essential for rapid worm expulsion. It is unclear whether all Th2 cells induced during infection are pathogen-specific because Th2 cells might also be induced by parasite-derived superantigens or cytokine-mediated bystander activation. Bystander Th2 polarization could explain the largely unspecific B-cell response during primary infection. Furthermore, it is not known whether protective immunity depends on a polyclonal repertoire of T-cell receptor (TCR) specificities. To address these unresolved issues, we performed adoptive transfer experiments and analysed the TCR-Vβ repertoire before and after infection of mice with the helminth N. brasiliensis. The results demonstrate that all Th2 cells were generated by antigen-specific rather than superantigen-driven or cytokine-driven activation. Furthermore, we show that worm expulsion was impaired in mice with a limited repertoire of TCR specificities, indicating that a polyclonal T-cell response is required for protective immunity.
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Affiliation(s)
- Alexander Seidl
- Institute for Immunology, Ludwig-Maximilians-University, Munich, Germany
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Wang X, Jobe M, Tyler KM, Steverding D. Efficacy of common laboratory disinfectants and heat on killing trypanosomatid parasites. Parasit Vectors 2008; 1:35. [PMID: 18808700 PMCID: PMC2556999 DOI: 10.1186/1756-3305-1-35] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Accepted: 09/22/2008] [Indexed: 11/10/2022] Open
Abstract
The disinfectants TriGene, bleach, ethanol and liquid hand soap, and water and temperature were tested for their ability to kill bloodstream forms of Trypanosoma brucei, epimastigotes of Trypanosoma rangeli and promastigotes of Leishmania major. A 5-min exposure to 0.2% TriGene, 0.1% liquid hand soap and 0.05% bleach (0.05% NaOCl) killed all three trypanosomatids. Ethanol and water destroyed the parasites within 5 min at concentrations of 15–17.5% and 80–90%, respectively. All three organisms were also killed when treated for 5 min at 50°C. The results indicate that the disinfectants, water and temperature treatment (i.e. autoclaving) are suitable laboratory hygiene measures against trypanosomatid parasites.
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Affiliation(s)
- Xia Wang
- BioMedical Research Centre, School of Medicine, Health Policy and Practice, University of East Anglia, Norwich, NR4 7TJ, UK.
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9
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Worthey EA, Myler PJ. Protozoan genomes: gene identification and annotation. Int J Parasitol 2005; 35:495-512. [PMID: 15826642 DOI: 10.1016/j.ijpara.2005.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2004] [Revised: 01/25/2005] [Accepted: 02/06/2005] [Indexed: 12/01/2022]
Abstract
The draft sequence of several complete protozoan genomes is now available and genome projects are ongoing for a number of other species. Different strategies are being implemented to identify and annotate protein coding and RNA genes in these genomes, as well as study their genomic architecture. Since the genomes vary greatly in size, GC-content, nucleotide composition, and degree of repetitiveness, genome structure is often a factor in choosing the methodology utilised for annotation. In addition, the approach taken is dictated, to a greater or lesser extent, by the particular reasons for carrying out genome-wide analyses and the level of funding available for projects. Nevertheless, these projects have provided a plethora of material that will aid in understanding the biology and evolution of these parasites, as well as identifying new targets that can be used to design urgently required drug treatments for the diseases they cause.
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Affiliation(s)
- E A Worthey
- Seattle Biomedical Research Institute, 307 Westlake Ave N., Seattle, WA 98109-2591, USA
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10
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Abstract
A first generation cosmid contig map of the Leishmania major Friedlin genome has been constructed, and genomic sequencing is well underway. Chromosome 1 (Chr1) and Chr3 have been completely sequenced, and Chr4 is virtually complete. Sequencing of several other chromosomes is in progress and the complete genome sequence may be available as soon as 2003. More than 600 completely sequenced new genes have been identified, representing approximately 8% of the total gene complement (approximately 8,600 genes) of Leishmania. Notably, a large proportion (approximately 69%) of the genes remain unclassified, with 40% of these being potentially Leishmania- (or kinetoplastid-) specific. Most interestingly, the genes are organized into large (>100-300 kb) polycistronic clusters of adjacent genes on the same DNA strand. Chr1 contains two such clusters organized in a 'divergent' manner, whereas Chr3 contains two 'convergent' clusters, with a single 'divergent' gene at one telomere, with the two large clusters separated by a tRNA gene. Statistical analyses of Chr1 show that the 'divergent junction' region between the two polycistronic gene clusters may be a candidate for an origin of DNA replication.
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Affiliation(s)
- P J Myler
- Seattle Biomedical Research Institute, WA 98109-1651, USA.
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11
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Abstract
Despite the advances of modern medicine, the threat of chronic illness, disfigurement, or death that can result from parasitic infection still affects the majority of the world population, retarding economic development. For most parasitic diseases, current therapeutics often leave much to be desired in terms of administration regime, toxicity, or effectiveness and potential vaccines are a long way from market. Our best prospects for identifying new targets for drug, vaccine, and diagnostics development and for dissecting the biological basis of drug resistance, antigenic diversity, infectivity and pathology lie in parasite genome analysis, and international mapping and gene discovery initiatives are under way for a variety of protozoan and helminth parasites. These are far from ideal experimental organisms, and the influence of biological and genomic characteristics on experimental approaches is discussed, progress is reviewed and future prospects are examined.
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Affiliation(s)
- D A Johnston
- Department of Zoology, Natural History Museum, London, United Kingdom
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13
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Ravel C, Dubessay P, Bastien P, Blackwell JM, Ivens AC. The Complete Chromosomal Organization of the Reference Strain of the Leishmania Genome Project, L. major `Friedlin'. ACTA ACUST UNITED AC 1998; 14:301-3. [PMID: 17040794 DOI: 10.1016/s0169-4758(98)01275-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- C Ravel
- Laboratoire de Parasitologie, EP CNRS 0613 `Biologie Moléculaire et Génome des Protozoaires Parasites', Faculté de Médecine, Université Montpellier I, 34090 Montpellier, France
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14
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Fu G, Barker DC. Characterisation of Leishmania telomeres reveals unusual telomeric repeats and conserved telomere-associated sequence. Nucleic Acids Res 1998; 26:2161-7. [PMID: 9547275 PMCID: PMC147527 DOI: 10.1093/nar/26.9.2161] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Characterisation of the telomeres of Leishmania is important for understanding many aspects of the parasitic life of this primitive protozoan and for the completion of the physical map and sequencing of the genome. After sequencing more than 300 telomere-derived clones from Leishmania braziliensis and Leishmania major, a conserved 100 bp sequence was identified immediately adjacent to the telomere at the chromosome end and was named LCTAS (Leishmania conserved telomere-associated sequence). The LCTAS contains two conserved sequence boxes, and is present in all Leishmania species studied. The organisation of the LCTAS in the telomeric region differs between L. braziliensis and L. major: in L. major the LCTASs are tandemly repeated, while in L. braziliensis the LCTAS is present as a single copy per end. Two additional TASs with 1.6 kb and 274 bp repeat structures, which are apparently different to LCTAS, were isolated and mapped onto a L. braziliensis 250 kb multicopy minichromosome and the L. major chromosome 1, respectively. An unusual feature in L. braziliensis is that the telomeric repeats are often comprised of a novel tandem repeat CCCTAACCCGTGGA. A 'slippage' mechanism for LCTAS formation is proposed in this study as an alternative way for the synthesis and maintenance of telomeres and subtelomere regions.
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Affiliation(s)
- G Fu
- MRC Outstation of NIMR, Molteno Laboratories, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
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15
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Ivens AC, Lewis SM, Bagherzadeh A, Zhang L, Chan HM, Smith DF. A physical map of the Leishmania major Friedlin genome. Genome Res 1998; 8:135-45. [PMID: 9477341 PMCID: PMC310692 DOI: 10.1101/gr.8.2.135] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/1997] [Accepted: 01/14/1998] [Indexed: 02/06/2023]
Abstract
An extensive physical map of the Leishmania major Friedlin genome has been assembled by the combination of fingerprint analysis of a shuttle vector cosmid library and probe hybridization. The integrated data obtained for 9004 fingerprinted clones and 974 probes have placed 91.2% of the 33.58-Mb genome into contigs representing each of the 36 chromosomes. This first-generation map has already provided a suitable framework for both high-throughput DNA sequencing and functional studies of the L. major parasite.
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Affiliation(s)
- A C Ivens
- Department of Biochemistry, Imperial College of Science, Technology and Medicine, London SW7 2AZ, UK.
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16
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Reiner SL, Fowell DJ, Moskowitz NH, Swier K, Brown DR, Brown CR, Turck CW, Scott2 PA, Killeen N, Locksley3 RM. Control of Leishmania major by a Monoclonal αβ T Cell Repertoire. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.2.884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Little is known regarding the diversity of the host T cell response that is required to maintain immunologic control of microbial pathogens. Leishmania major persist as obligate intracellular parasites within macrophages of the mammalian host. Immunity is dependent upon activation of MHC class II-restricted T cells to an effector state capable of restricting growth and dissemination of the organisms. We generated α-β Leishmania-specific (ABLE) TCR transgenic mice with MHC class II-restricted T cells that recognized an immunodominant Leishmania Ag designated LACK. Naive T cells from ABLE mice proliferated in vitro after incubation with recombinant LACK or with Leishmania-parasitized macrophages and in vivo after injection into infected mice. Infected ABLE mice controlled Leishmania infection almost as well as wild-type mice despite a drastic reduction in the T cell repertoire. ABLE mice were crossed to mice with disruption of the TCR constant region α gene to create animals with a single αβ T cell repertoire. Although mice deficient in all αβ T cells (TCR-Cαo mice) failed to control L. major, mice with a monoclonal αβ T cell repertoire (ABLE TCR-Cαo mice) displayed substantial control. The immune system is capable of remarkable efficiency even when constrained to recognition of a single epitope from a complex organism.
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Affiliation(s)
- Steven L. Reiner
- *Department of Medicine, Committee on Immunology and Gwen Knapp Center for Lupus and Immunology Research, University of Chicago, Chicago, IL 60637; Departments of
| | | | - Naomi H. Moskowitz
- *Department of Medicine, Committee on Immunology and Gwen Knapp Center for Lupus and Immunology Research, University of Chicago, Chicago, IL 60637; Departments of
| | - Kevin Swier
- *Department of Medicine, Committee on Immunology and Gwen Knapp Center for Lupus and Immunology Research, University of Chicago, Chicago, IL 60637; Departments of
| | - Daniel R. Brown
- *Department of Medicine, Committee on Immunology and Gwen Knapp Center for Lupus and Immunology Research, University of Chicago, Chicago, IL 60637; Departments of
| | - Charles R. Brown
- *Department of Medicine, Committee on Immunology and Gwen Knapp Center for Lupus and Immunology Research, University of Chicago, Chicago, IL 60637; Departments of
| | - Christoph W. Turck
- †Medicine and
- §Howard Hughes Medical Institute, University of California, San Francisco, CA 94143; and
| | - Phillip A. Scott2
- ¶Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA 19104
| | | | - Richard M. Locksley3
- †Medicine and
- ‡Microbiology and Immunology, and
- §Howard Hughes Medical Institute, University of California, San Francisco, CA 94143; and
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