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In vitro manipulation of gene expression in larval Schistosoma: a model for postgenomic approaches in Trematoda. Parasitology 2009; 137:463-83. [PMID: 19961646 DOI: 10.1017/s0031182009991302] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
With rapid developments in DNA and protein sequencing technologies, combined with powerful bioinformatics tools, a continued acceleration of gene identification in parasitic helminths is predicted, potentially leading to discovery of new drug and vaccine targets, enhanced diagnostics and insights into the complex biology underlying host-parasite interactions. For the schistosome blood flukes, with the recent completion of genome sequencing and comprehensive transcriptomic datasets, there has accumulated massive amounts of gene sequence data, for which, in the vast majority of cases, little is known about actual functions within the intact organism. In this review we attempt to bring together traditional in vitro cultivation approaches and recent emergent technologies of molecular genomics, transcriptomics and genetic manipulation to illustrate the considerable progress made in our understanding of trematode gene expression and function during development of the intramolluscan larval stages. Using several prominent trematode families (Schistosomatidae, Fasciolidae, Echinostomatidae), we have focused on the current status of in vitro larval isolation/cultivation as a source of valuable raw material supporting gene discovery efforts in model digeneans that include whole genome sequencing, transcript and protein expression profiling during larval development, and progress made in the in vitro manipulation of genes and their expression in larval trematodes using transgenic and RNA interference (RNAi) approaches.
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152
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Oliveira KC, Carvalho MLP, Venancio TM, Miyasato PA, Kawano T, DeMarco R, Verjovski-Almeida S. Identification of the Schistosoma mansoni TNF-alpha receptor gene and the effect of human TNF-alpha on the parasite gene expression profile. PLoS Negl Trop Dis 2009; 3:e556. [PMID: 19956564 PMCID: PMC2779652 DOI: 10.1371/journal.pntd.0000556] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Accepted: 10/20/2009] [Indexed: 11/23/2022] Open
Abstract
Background Schistosoma mansoni is the major causative agent of schistosomiasis. The parasite takes advantage of host signals to complete its development in the human body. Tumor necrosis factor-alpha (TNF-α) is a human cytokine involved in skin inflammatory responses, and although its effect on the adult parasite's metabolism and egg-laying process has been previously described, a comprehensive assessment of the TNF-α pathway and its downstream molecular effects is lacking. Methodology/Principal Findings In the present work we describe a possible TNF-α receptor (TNFR) homolog gene in S. mansoni (SmTNFR). SmTNFR encodes a complete receptor sequence composed of 599 amino acids, and contains four cysteine-rich domains as described for TNFR members. Real-time RT-PCR experiments revealed that SmTNFR highest expression level is in cercariae, 3.5 (±0.7) times higher than in adult worms. Downstream members of the known human TNF-α pathway were identified by an in silico analysis, revealing a possible TNF-α signaling pathway in the parasite. In order to simulate parasite's exposure to human cytokine during penetration of the skin, schistosomula were exposed to human TNF-α just 3 h after cercariae-to-schistosomula in vitro transformation, and large-scale gene expression measurements were performed with microarrays. A total of 548 genes with significantly altered expression were detected, when compared to control parasites. In addition, treatment of adult worms with TNF-α caused a significantly altered expression of 1857 genes. Interestingly, the set of genes altered in adults is different from that of schistosomula, with 58 genes in common, representing 3% of altered genes in adults and 11% in 3 h-old early schistosomula. Conclusions/Significance We describe the possible molecular elements and targets involved in human TNF-α effect on S. mansoni, highlighting the mechanism by which recently transformed schistosomula may sense and respond to this host mediator at the site of cercarial penetration into the skin. Schistosoma mansoni is the major causative agent of schistosomiasis in the Americas. This parasite takes advantage of host signaling molecules such as cytokines and hormones to complete its development inside the host. Tumor necrosis factor-alpha (TNF-α) is one of the most important host cytokines involved in the inflammatory response. When cercariae, the infective stage, penetrates the human skin the release of TNF-α is started. In this work the authors describe the complete sequence of a possible TNF-α receptor in S. mansoni and detect that the receptor is most highly expressed in cercariae among all life cycle stages. Aiming to mimic the situation at the site of skin penetration, cercariae were mechanically transformed in vitro into schistosomula and exposed to human TNF-α. Exposure of early-developing schistosomula to the human hormone caused a large-scale change in the expression of parasite genes. Exposure of adult worms to human TNF-α caused gene expression changes as well, and the set of parasite altered genes in the adult parasite was different from that of schistosomula. This work increases the number of known signaling pathways of the parasite, and opens new perspectives into understanding the molecular components of TNF-α response as well as into possibly interfering with parasite–host interaction.
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Affiliation(s)
- Katia C. Oliveira
- Laboratory of Gene Expression in Eukaryotes, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Mariana L. P. Carvalho
- Laboratory of Gene Expression in Eukaryotes, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Thiago M. Venancio
- Laboratory of Gene Expression in Eukaryotes, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | | | - Toshie Kawano
- Laboratory of Parasitology, Instituto Butantan, São Paulo, Brazil
| | - Ricardo DeMarco
- Departamento de Física e Informática, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, Brazil
| | - Sergio Verjovski-Almeida
- Laboratory of Gene Expression in Eukaryotes, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
- * E-mail:
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153
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Mathieson W, Wilson RA. A comparative proteomic study of the undeveloped and developed Schistosoma mansoni egg and its contents: the miracidium, hatch fluid and secretions. Int J Parasitol 2009; 40:617-28. [PMID: 19917288 DOI: 10.1016/j.ijpara.2009.10.014] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 10/23/2009] [Accepted: 10/26/2009] [Indexed: 12/21/2022]
Abstract
The schistosome egg is the key agent responsible both for transmission of the parasite from human to molluscan host, and is the primary cause of pathogenesis in schistosomiasis. Characterisation of its proteome is a crucial step in understanding the egg's interactions with the mammalian host. We devised a scheme to isolate undeveloped eggs from mature schistosome eggs by Percoll gradient and then fractionate the mature egg into miracidial, hatch fluid and secreted protein preparations. The soluble proteins contained within the five preparations were separated by two-dimensional electrophoresis and their spot patterns compared by image analysis. Large numbers of representative spots were then excised and subjected to tandem mass spectrometry to obtain identities. In this way, the principal components of each sub-proteome were established. Chaperones were the most abundant category, with heat shock protein 70 (HSP70) dominant in the undeveloped egg and Schistosoma mansoni protein 40 (Smp-40) in the miracidium. Cytoskeletal proteins were expressed at similar levels in the undeveloped egg and miracidium, with tubulins the most abundant. The proteins of energy metabolism reflected the change from anaerobic to aerobic metabolism as the miracidium developed. None of the above categories was abundant in the hatch fluid but this peri-miracidial compartment was highly enriched for defence proteins such as thioredoxin. Hatch fluid also contained several host proteins and schistosome proteins of unknown function, highlighting its distinct nature and potentially its role. The egg secretions could not be compared with the other preparations due to their unique composition featuring the previously characterised IL-4-inducing principal of S. mansoni eggs (IPSE), Omega-1, egg secreted protein 15 (ESP15), a micro-exon gene 2 (MEG-2) protein and two members of the recently described MEG-3 family. This last preparation contains the subset of egg proteins that probably enables eggs to escape from host tissues and may also initiate granuloma formation, emphasising the need to establish fully the roles of its components in schistosome biology.
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Affiliation(s)
- William Mathieson
- Department of Biology, University of York, P.O. Box 373, York YO105YW, UK.
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154
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Drummond MG, Calzavara-Silva CE, D'Astolfo DS, Cardoso FC, Rajão MA, Mourão MM, Gava E, Oliveira SC, Macedo AM, Machado CR, Pena SDJ, Kitten GT, Franco GR. Molecular characterization of the Schistosoma mansoni zinc finger protein SmZF1 as a transcription factor. PLoS Negl Trop Dis 2009; 3:e547. [PMID: 19901992 PMCID: PMC2770324 DOI: 10.1371/journal.pntd.0000547] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Accepted: 10/09/2009] [Indexed: 11/20/2022] Open
Abstract
Background During its development, the parasite Schistosoma mansoni is exposed to different environments and undergoes many morphological and physiological transformations as a result of profound changes in gene expression. Characterization of proteins involved in the regulation of these processes is of importance for the understanding of schistosome biology. Proteins containing zinc finger motifs usually participate in regulatory processes and are considered the major class of transcription factors in eukaryotes. It has already been shown, by EMSA (Eletrophoretic Mobility Shift Assay), that SmZF1, a S. mansoni zinc finger (ZF) protein, specifically binds both DNA and RNA oligonucleotides. This suggests that this protein might act as a transcription factor in the parasite. Methodology/Principal Findings In this study we extended the characterization of SmZF1 by determining its subcellular localization and by verifying its ability to regulate gene transcription. We performed immunohistochemistry assays using adult male and female worms, cercariae and schistosomula to analyze the distribution pattern of SmZF1 and verified that the protein is mainly detected in the cells nuclei of all tested life cycle stages except for adult female worms. Also, SmZF1 was heterologously expressed in mammalian COS-7 cells to produce the recombinant protein YFP-SmZF1, which was mainly detected in the nucleus of the cells by confocal microscopy and Western blot assays. To evaluate the ability of this protein to regulate gene transcription, cells expressing YFP-SmZF1 were tested in a luciferase reporter system. In this system, the luciferase gene is downstream of a minimal promoter, upstream of which a DNA region containing four copies of the SmZF1 putative best binding site (D1-3DNA) was inserted. SmZF1 increased the reporter gene transcription by two fold (p≤0.003) only when its specific binding site was present. Conclusion Taken together, these results strongly support the hypothesis that SmZF1 acts as a transcription factor in S. mansoni. Schistosomes are parasites that exhibit a complex life cycle during which they progress through many morphological and physiological transformations. These transformations are likely accompanied by alterations in gene expression, making genetic regulation important for parasite development. Here we describe a Schistosoma mansoni protein (SmZF1) that may act as a parasite transcription factor. These factors are key proteins for gene regulation. We have previously demonstrated that SmZF1 is able to bind DNA and that its mRNA is present at different stages during the parasite life cycle. In this study we aimed to define if this protein can function as a transcription factor in S. mansoni. SmZF1 was detected in the nucleus of adult male worms, cercariae and schistosomula cells. It was not, however, observed in female cells, suggesting it to be gender specific. We used mammalian cells expressing recombinant SmZF1 to analyze if SmZF1 protein is able to activate/repress gene transcription and demonstrated that it increased the expression of a reporter gene by two-fold. The results obtained confirm SmZF1 as a S. mansoni transcription factor.
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Affiliation(s)
- Marcela G. Drummond
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Carlos E. Calzavara-Silva
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- Laboratório de Imunologia Celular e Molecular, Centro de Pesquisas René Rachou, FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | - Diego S. D'Astolfo
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Fernanda C. Cardoso
- Laboratório de Imunologia de Doenças Infecciosas, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Matheus A. Rajão
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Marina M. Mourão
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Elisandra Gava
- Laboratório do Desenvolvimento do Coração e Matriz Extracelular, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Sérgio C. Oliveira
- Laboratório de Imunologia de Doenças Infecciosas, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Andréa M. Macedo
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Carlos R. Machado
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Sérgio D. J. Pena
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Gregory T. Kitten
- Laboratório do Desenvolvimento do Coração e Matriz Extracelular, Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Glória R. Franco
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- * E-mail:
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155
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Liu W, Zhao R, McFarland C, Kieft J, Niedzwiecka A, Jankowska-Anyszka M, Stepinski J, Darzynkiewicz E, Jones DNM, Davis RE. Structural insights into parasite eIF4E binding specificity for m7G and m2,2,7G mRNA caps. J Biol Chem 2009; 284:31336-49. [PMID: 19710013 PMCID: PMC2781531 DOI: 10.1074/jbc.m109.049858] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 08/19/2009] [Indexed: 01/02/2023] Open
Abstract
The eukaryotic translation initiation factor eIF4E recognizes the mRNA cap, a key step in translation initiation. Here we have characterized eIF4E from the human parasite Schistosoma mansoni. Schistosome mRNAs have either the typical monomethylguanosine (m(7)G) or a trimethylguanosine (m(2,2,7)G) cap derived from spliced leader trans-splicing. Quantitative fluorescence titration analyses demonstrated that schistosome eIF4E has similar binding specificity for both caps. We present the first crystal structure of an eIF4E with similar binding specificity for m(7)G and m(2,2,7)G caps. The eIF4E.m(7)GpppG structure demonstrates that the schistosome protein binds monomethyl cap in a manner similar to that of single specificity eIF4Es and exhibits a structure similar to other known eIF4Es. The structure suggests an alternate orientation of a conserved, key Glu-90 in the cap-binding pocket that may contribute to dual binding specificity and a position for mRNA bound to eIF4E consistent with biochemical data. Comparison of NMR chemical shift perturbations in schistosome eIF4E on binding m(7)GpppG and m(2,2,7)GpppG identified key differences between the two complexes. Isothermal titration calorimetry demonstrated significant thermodynamics differences for the binding process with the two caps (m(7)G versus m(2,2,7)G). Overall the NMR and isothermal titration calorimetry data suggest the importance of intrinsic conformational flexibility in the schistosome eIF4E that enables binding to m(2,2,7)G cap.
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Affiliation(s)
- Weizhi Liu
- From the Departments of Biochemistry and Molecular Genetics and
| | - Rui Zhao
- From the Departments of Biochemistry and Molecular Genetics and
| | - Craig McFarland
- From the Departments of Biochemistry and Molecular Genetics and
| | - Jeffrey Kieft
- From the Departments of Biochemistry and Molecular Genetics and
| | - Anna Niedzwiecka
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, 02-089 Warsaw, Poland
- Biological Physics Group, Institute of Physics, Polish Academy of Sciences, 32/46 Lotnikow Avenue, 02-668 Warsaw, Poland
| | | | - Janusz Stepinski
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, 02-089 Warsaw, Poland
| | - Edward Darzynkiewicz
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, 02-089 Warsaw, Poland
| | - David N. M. Jones
- **Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045
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156
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Fitzpatrick JM, Peak E, Perally S, Chalmers IW, Barrett J, Yoshino TP, Ivens AC, Hoffmann KF. Anti-schistosomal intervention targets identified by lifecycle transcriptomic analyses. PLoS Negl Trop Dis 2009; 3:e543. [PMID: 19885392 PMCID: PMC2764848 DOI: 10.1371/journal.pntd.0000543] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 10/07/2009] [Indexed: 11/19/2022] Open
Abstract
Background Novel methods to identify anthelmintic drug and vaccine targets are urgently needed, especially for those parasite species currently being controlled by singular, often limited strategies. A clearer understanding of the transcriptional components underpinning helminth development will enable identification of exploitable molecules essential for successful parasite/host interactions. Towards this end, we present a combinatorial, bioinformatics-led approach, employing both statistical and network analyses of transcriptomic data, for identifying new immunoprophylactic and therapeutic lead targets to combat schistosomiasis. Methodology/Principal Findings Utilisation of a Schistosoma mansoni oligonucleotide DNA microarray consisting of 37,632 elements enabled gene expression profiling from 15 distinct parasite lifecycle stages, spanning three unique ecological niches. Statistical approaches of data analysis revealed differential expression of 973 gene products that minimally describe the three major characteristics of schistosome development: asexual processes within intermediate snail hosts, sexual maturation within definitive vertebrate hosts and sexual dimorphism amongst adult male and female worms. Furthermore, we identified a group of 338 constitutively expressed schistosome gene products (including 41 transcripts sharing no sequence similarity outside the Platyhelminthes), which are likely to be essential for schistosome lifecycle progression. While highly informative, statistics-led bioinformatics mining of the transcriptional dataset has limitations, including the inability to identify higher order relationships between differentially expressed transcripts and lifecycle stages. Network analysis, coupled to Gene Ontology enrichment investigations, facilitated a re-examination of the dataset and identified 387 clusters (containing 12,132 gene products) displaying novel examples of developmentally regulated classes (including 294 schistosomula and/or adult transcripts with no known sequence similarity outside the Platyhelminthes), which were undetectable by the statistical comparisons. Conclusions/Significance Collectively, statistical and network-based exploratory analyses of transcriptomic datasets have led to a thorough characterisation of schistosome development. Information obtained from these experiments highlighted key transcriptional programs associated with lifecycle progression and identified numerous anti-schistosomal candidate molecules including G-protein coupled receptors, tetraspanins, Dyp-type peroxidases, fucosyltransferases, leishmanolysins and the netrin/netrin receptor complex. Despite the implementation of focused and well-funded chemotherapeutic control initiatives over the last decade, schistosomiasis remains a significant cause of morbidity and mortality within countries of the developing world. There is, therefore, an urgent need for the rapid translation of genomic information into viable vaccines or new drug classes capable of eradicating the parasitic schistosome worms responsible for this neglected tropical disease. In our effort to identify potential targets for novel chemotherapeutic and immunoprophylactic interventions, we detail a combined bioinformatics approach, comprising exploratory statistical and network analyses, to thoroughly describe the transcriptional progression of Schistosoma mansoni across three environmental niches. Our results indicate that, although schistosomes are masters at host deception and survival, there are numerous exploitable candidate molecules displaying either differential or constitutive expression throughout the parasite's lifecycle. Importantly, some of these transcripts represent gene families not commonly found outside—or expanded within—the phylum Platyhelminthes, and thus represent priority targets. Many of the candidates identified herein will be subjected to ongoing and future hypothesis-led functional investigations. The completion of such specific examinations ultimately will contribute to the successful development of novel control strategies useful in the alleviation of schistosome-induced immunopathologies, morbidities and mortalities.
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Affiliation(s)
| | - Emily Peak
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, United Kingdom
| | - Samirah Perally
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, United Kingdom
| | - Iain W. Chalmers
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, United Kingdom
| | - John Barrett
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, United Kingdom
| | - Timothy P. Yoshino
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
| | | | - Karl F. Hoffmann
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, United Kingdom
- * E-mail:
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157
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Bos DH, Mayfield C, Minchella DJ. Analysis of regulatory protease sequences identified through bioinformatic data mining of the Schistosoma mansoni genome. BMC Genomics 2009; 10:488. [PMID: 19845954 PMCID: PMC2772863 DOI: 10.1186/1471-2164-10-488] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Accepted: 10/21/2009] [Indexed: 11/20/2022] Open
Abstract
Background New chemotherapeutic agents against Schistosoma mansoni, an etiological agent of human schistosomiasis, are a priority due to the emerging drug resistance and the inability of current drug treatments to prevent reinfection. Proteases have been under scrutiny as targets of immunological or chemotherapeutic anti-Schistosoma agents because of their vital role in many stages of the parasitic life cycle. Function has been established for only a handful of identified S. mansoni proteases, and the vast majority of these are the digestive proteases; very few of the conserved classes of regulatory proteases have been identified from Schistosoma species, despite their vital role in numerous cellular processes. To that end, we identified protease protein coding genes from the S. mansoni genome project and EST library. Results We identified 255 protease sequences from five catalytic classes using predicted proteins of the S. mansoni genome. The vast majority of these show significant similarity to proteins in KEGG and the Conserved Domain Database. Proteases include calpains, caspases, cytosolic and mitochondrial signal peptidases, proteases that interact with ubiquitin and ubiquitin-like molecules, and proteases that perform regulated intramembrane proteolysis. Comparative analysis of classes of important regulatory proteases find conserved active site domains, and where appropriate, signal peptides and transmembrane helices. Phylogenetic analysis provides support for inferring functional divergence among regulatory aspartic, cysteine, and serine proteases. Conclusion Numerous proteases are identified for the first time in S. mansoni. We characterized important regulatory proteases and focus analysis on these proteases to complement the growing knowledge base of digestive proteases. This work provides a foundation for expanding knowledge of proteases in Schistosoma species and examining their diverse function and potential as targets for new chemotherapies.
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Affiliation(s)
- David H Bos
- Department of Biological Sciences, Purdue University, 915 W State St, West Lafayette, IN 47907, USA.
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158
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Immunization with SmIg, a novel tegument protein fromSchistosoma mansoni, fails to induce protection in mice but reduces liver pathology. Parasitology 2009; 137:1079-88. [DOI: 10.1017/s0031182009991387] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
SUMMARYProteins associated with the schistosome tegument are of great importance for the development of new intervention strategies since they may be exposed on the surface of the parasite. Herein, we have isolated a cDNA clone encoding for theSchistosoma mansoniSmIg and its recombinant protein was tested as a potential vaccine candidate. Initially, its amino acid sequence was analysed by bioinformatics and shown to possess an N-terminal signal peptide, a C-terminal transmembrane helix, 4 glycosylation sites, an immunoglobulin conserved domain and 73% similarity with a hypotheticalS. japonicumprotein of unknown function. SmIg was produced byE. colias a recombinant protein (rSmIg) and its protective effectiveness was evaluated againstS. mansoniinfection with 100 cercariae in a murine model. Mice immunized with rSmIg induced an immune response characterized by dominant IgG1 isotype and significant levels of IFN-γ, TNF-α, IL-10 and IL-4. Although immunogenic, the recombinant vaccine failed to induce worm burden reduction when compared to the infected control group. However, rSmIg-immunized mice had significant reductions of liver granuloma volume and fibrosis content by 31·8% and 49%, respectively. In conclusion, SmIg is a new tegument protein fromS. mansonithat plays an important role in reducing pathology induced by parasite infection.
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159
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Han ZG, Brindley PJ, Wang SY, Chen Z. Schistosoma genomics: new perspectives on schistosome biology and host-parasite interaction. Annu Rev Genomics Hum Genet 2009; 10:211-40. [PMID: 19630560 DOI: 10.1146/annurev-genom-082908-150036] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Schistosomiasis, caused mainly by Schistosoma japonicum, S. mansoni, and S. hematobium, remains one of the most prevalent and serious parasitic diseases worldwide. The blood flukes have a complex life cycle requiring adaptation for survival in fresh water as free-living forms and as parasites in snail intermediate and vertebrate definitive hosts. Functional genomics analyses, including transcriptomic and proteomic approaches, have been performed on schistosomes, in particular S. mansoni and S. japonicum, using powerful high-throughput methodologies. These investigations have not only chartered gene expression profiles across genders and developmental stages within mammalian and snail hosts, but have also characterized the features of the surface tegument, the eggshell and excretory-secretory proteomes of schistosomes. The integration of the genomic, transcriptomic, and proteomic information, together with genetic manipulation on individual genes, will provide a global insight into the molecular architecture of the biology, pathogenesis, and host-parasite interactions of the human blood flukes. Importantly, these functional genomics analyses lay a foundation on which to develop new antischistosome vaccines as well as drug targets and diagnostic markers for treatment and control of schistosomiasis.
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Affiliation(s)
- Ze-Guang Han
- Shanghai-MOST Key Laboratory for Disease and Health Genomics, Chinese National Human Genome Center at Shanghai, Shanghai 201203, China.
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160
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Copeland CS, Marz M, Rose D, Hertel J, Brindley PJ, Santana CB, Kehr S, Attolini CSO, Stadler PF. Homology-based annotation of non-coding RNAs in the genomes of Schistosoma mansoni and Schistosoma japonicum. BMC Genomics 2009; 10:464. [PMID: 19814823 PMCID: PMC2770079 DOI: 10.1186/1471-2164-10-464] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Accepted: 10/08/2009] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Schistosomes are trematode parasites of the phylum Platyhelminthes. They are considered the most important of the human helminth parasites in terms of morbidity and mortality. Draft genome sequences are now available for Schistosoma mansoni and Schistosoma japonicum. Non-coding RNA (ncRNA) plays a crucial role in gene expression regulation, cellular function and defense, homeostasis, and pathogenesis. The genome-wide annotation of ncRNAs is a non-trivial task unless well-annotated genomes of closely related species are already available. RESULTS A homology search for structured ncRNA in the genome of S. mansoni resulted in 23 types of ncRNAs with conserved primary and secondary structure. Among these, we identified rRNA, snRNA, SL RNA, SRP, tRNAs and RNase P, and also possibly MRP and 7SK RNAs. In addition, we confirmed five miRNAs that have recently been reported in S. japonicum and found two additional homologs of known miRNAs. The tRNA complement of S. mansoni is comparable to that of the free-living planarian Schmidtea mediterranea, although for some amino acids differences of more than a factor of two are observed: Leu, Ser, and His are overrepresented, while Cys, Meth, and Ile are underrepresented in S. mansoni. On the other hand, the number of tRNAs in the genome of S. japonicum is reduced by more than a factor of four. Both schistosomes have a complete set of minor spliceosomal snRNAs. Several ncRNAs that are expected to exist in the S. mansoni genome were not found, among them the telomerase RNA, vault RNAs, and Y RNAs. CONCLUSION The ncRNA sequences and structures presented here represent the most complete dataset of ncRNA from any lophotrochozoan reported so far. This data set provides an important reference for further analysis of the genomes of schistosomes and indeed eukaryotic genomes at large.
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Affiliation(s)
- Claudia S Copeland
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstrasse 16-18, D-04107 Leipzig, Germany.
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Takahashi T, McDougall C, Troscianko J, Chen WC, Jayaraman-Nagarajan A, Shimeld SM, Ferrier DEK. An EST screen from the annelid Pomatoceros lamarckii reveals patterns of gene loss and gain in animals. BMC Evol Biol 2009; 9:240. [PMID: 19781084 PMCID: PMC2762978 DOI: 10.1186/1471-2148-9-240] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Accepted: 09/25/2009] [Indexed: 01/06/2023] Open
Abstract
Background Since the drastic reorganisation of the phylogeny of the animal kingdom into three major clades of bilaterians; Ecdysozoa, Lophotrochozoa and Deuterostomia, it became glaringly obvious that the selection of model systems with extensive molecular resources was heavily biased towards only two of these three clades, namely the Ecdysozoa and Deuterostomia. Increasing efforts have been put towards redressing this imbalance in recent years, and one of the principal phyla in the vanguard of this endeavour is the Annelida. Results In the context of this effort we here report our characterisation of an Expressed Sequence Tag (EST) screen in the serpulid annelid, Pomatoceros lamarckii. We have sequenced over 5,000 ESTs which consolidate into over 2,000 sequences (clusters and singletons). These sequences are used to build phylogenetic trees to estimate relative branch lengths amongst different taxa and, by comparison to genomic data from other animals, patterns of gene retention and loss are deduced. Conclusion The molecular phylogenetic trees including the P. lamarckii sequences extend early observations that polychaetes tend to have relatively short branches in such trees, and hence are useful taxa with which to reconstruct gene family evolution. Also, with the availability of lophotrochozoan data such as that of P. lamarckii, it is now possible to make much more accurate reconstructions of the gene complement of the ancestor of the bilaterians than was previously possible from comparisons of ecdysozoan and deuterostome genomes to non-bilaterian outgroups. It is clear that the traditional molecular model systems for protostomes (e.g. Drosophila melanogaster and Caenorhabditis elegans), which are restricted to the Ecdysozoa, have undergone extensive gene loss during evolution. These ecdysozoan systems, in terms of gene content, are thus more derived from the bilaterian ancestral condition than lophotrochozoan systems like the polychaetes, and thus cannot be used as good, general representatives of protostome genomes. Currently sequenced insect and nematode genomes are less suitable models for deducing bilaterian ancestral states than lophotrochozoan genomes, despite the array of powerful genetic and mechanistic manipulation techniques in these ecdysozoans. A distinct category of genes that includes those present in non-bilaterians and lophotrochozoans, but which are absent from ecdysozoans and deuterostomes, highlights the need for further lophotrochozoan data to gain a more complete understanding of the gene complement of the bilaterian ancestor.
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Affiliation(s)
- Tokiharu Takahashi
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester, UK.
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Abstract
RNA interference (RNAi) is a potent gene silencing process that is playing an increasingly important role in investigations of gene function in schistosomes. Here we review what is known about the process in these parasites and provide an update on the methodology and machinery of RNAi. Data are presented to demonstrate that: (1) not all schistosome genes can be suppressed to the same extent, using the methods employed here; (2) while there is variation in the level of suppression achieved for one target gene (SmAP) in adult parasites, all individuals exhibit robust (>80%) suppression; (3) short interfering RNAs (siRNAs) can effect suppression when delivered by soaking (and not just via electroporation, as reported previously); (4) Male/female adult pairs need not be separated prior to siRNA delivery by electroporation for effective gene suppression in both genders and (5) electroporation of siRNAs in medium is as efficient as in commercial electroporation buffer. Regarding the machinery of RNAi in schistosomes, a homologue of the C. elegans multi-membrane spanning, RNA importing protein SID-1 is identified in silico. The gene encoding this protein contains 21 exons and spans over 50 kb to potentially encode a 115,556 Mr protein (SmSID-1). These analyses, and a review of the literature, permit us to derive and present here a draft of potential RNAi pathways in schistosomes.
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Berriman M, Haas BJ, LoVerde PT, Wilson RA, Dillon GP, Cerqueira GC, Mashiyama ST, Al-Lazikani B, Andrade LF, Ashton PD, Aslett MA, Bartholomeu DC, Blandin G, Caffrey CR, Coghlan A, Coulson R, Day TA, Delcher A, DeMarco R, Djikeng A, Eyre T, Gamble JA, Ghedin E, Gu Y, Hertz-Fowler C, Hirai H, Hirai Y, Houston R, Ivens A, Johnston DA, Lacerda D, Macedo CD, McVeigh P, Ning Z, Oliveira G, Overington JP, Parkhill J, Pertea M, Pierce RJ, Protasio AV, Quail MA, Rajandream MA, Rogers J, Sajid M, Salzberg SL, Stanke M, Tivey AR, White O, Williams DL, Wortman J, Wu W, Zamanian M, Zerlotini A, Fraser-Liggett CM, Barrell BG, El-Sayed NM. The genome of the blood fluke Schistosoma mansoni. Nature 2009; 460:352-8. [PMID: 19606141 PMCID: PMC2756445 DOI: 10.1038/nature08160] [Citation(s) in RCA: 807] [Impact Index Per Article: 53.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2009] [Accepted: 05/22/2009] [Indexed: 11/24/2022]
Abstract
Schistosoma mansoni is responsible for the neglected tropical disease schistosomiasis that affects 210 million people in 76 countries. We report here analysis of the 363 megabase nuclear genome of the blood fluke. It encodes at least 11,809 genes, with an unusual intron size distribution, and novel families of micro-exon genes that undergo frequent alternate splicing. As the first sequenced flatworm, and a representative of the lophotrochozoa, it offers insights into early events in the evolution of the animals, including the development of a body pattern with bilateral symmetry, and the development of tissues into organs. Our analysis has been informed by the need to find new drug targets. The deficits in lipid metabolism that make schistosomes dependent on the host are revealed, while the identification of membrane receptors, ion channels and more than 300 proteases, provide new insights into the biology of the life cycle and novel targets. Bioinformatics approaches have identified metabolic chokepoints while a chemogenomic screen has pinpointed schistosome proteins for which existing drugs may be active. The information generated provides an invaluable resource for the research community to develop much needed new control tools for the treatment and eradication of this important and neglected disease.
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A family of diverse Kunitz inhibitors from Echinococcus granulosus potentially involved in host-parasite cross-talk. PLoS One 2009; 4:e7009. [PMID: 19759914 PMCID: PMC2740865 DOI: 10.1371/journal.pone.0007009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Accepted: 08/03/2009] [Indexed: 11/19/2022] Open
Abstract
The cestode Echinococcus granulosus, the agent of hydatidosis/echinococcosis, is remarkably well adapted to its definitive host. However, the molecular mechanisms underlying the successful establishment of larval worms (protoscoleces) in the dog duodenum are unknown. With the aim of identifying molecules participating in the E. granulosus-dog cross-talk, we surveyed the transcriptomes of protoscoleces and protoscoleces treated with pepsin at pH 2. This analysis identified a multigene family of secreted monodomain Kunitz proteins associated mostly with pepsin/H(+)-treated worms, suggesting that they play a role at the onset of infection. We present the relevant molecular features of eight members of the E. granulosus Kunitz family (EgKU-1 - EgKU-8). Although diverse, the family includes three pairs of close paralogs (EgKU-1/EgKU-4; EgKU-3/EgKU-8; EgKU-6/EgKU-7), which would be the products of recent gene duplications. In addition, we describe the purification of EgKU-1 and EgKU-8 from larval worms, and provide data indicating that some members of the family (notably, EgKU-3 and EgKU-8) are secreted by protoscoleces. Detailed kinetic studies with native EgKU-1 and EgKU-8 highlighted their functional diversity. Like most monodomain Kunitz proteins, EgKU-8 behaved as a slow, tight-binding inhibitor of serine proteases, with global inhibition constants (K(I) (*)) versus trypsins in the picomolar range. In sharp contrast, EgKU-1 did not inhibit any of the assayed peptidases. Interestingly, molecular modeling revealed structural elements associated with activity in Kunitz cation-channel blockers. We propose that this family of inhibitors has the potential to act at the E. granulosus-dog interface and interfere with host physiological processes at the initial stages of infection.
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Hewitson JP, Grainger JR, Maizels RM. Helminth immunoregulation: the role of parasite secreted proteins in modulating host immunity. Mol Biochem Parasitol 2009; 167:1-11. [PMID: 19406170 PMCID: PMC2706953 DOI: 10.1016/j.molbiopara.2009.04.008] [Citation(s) in RCA: 529] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Revised: 04/17/2009] [Accepted: 04/21/2009] [Indexed: 11/28/2022]
Abstract
Helminths are masterful immunoregulators. A characteristic feature of helminth infection is a Th2-dominated immune response, but stimulation of immunoregulatory cell populations, such as regulatory T cells and alternatively activated macrophages, is equally common. Typically, Th1/17 immunity is blocked and productive effector responses are muted, allowing survival of the parasite in a "modified Th2" environment. Drug treatment to clear the worms reverses the immunoregulatory effects, indicating that a state of active suppression is maintained by the parasite. Hence, research has focussed on "excretory-secretory" products released by live parasites, which can interfere with every aspect of host immunity from initial recognition to end-stage effector mechanisms. In this review, we survey our knowledge of helminth secreted molecules, and summarise current understanding of the growing number of individual helminth mediators that have been shown to target key receptors or pathways in the mammalian immune system.
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Affiliation(s)
| | | | - Rick M. Maizels
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, University of Edinburgh, West Mains Road, Edinburgh EH9 3JT, UK
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Phenotypic screen of early-developing larvae of the blood fluke, schistosoma mansoni, using RNA interference. PLoS Negl Trop Dis 2009; 3:e502. [PMID: 19668375 PMCID: PMC2719580 DOI: 10.1371/journal.pntd.0000502] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 07/17/2009] [Indexed: 11/19/2022] Open
Abstract
RNA interference (RNAi) represents the only method currently available for manipulating gene-specific expression in Schistosoma spp., although application of this technology as a functional genomic profiling tool has yet to be explored. In the present study 32 genes, including antioxidants, transcription factors, cell signaling molecules and metabolic enzymes, were selected to determine if gene knockdown by RNAi was associated with morphologically definable phenotypic changes in early intramolluscan larval development. Transcript selection was based on their high expression in in vitro cultured S. mansoni primary sporocysts and/or their potential involvement in developmental processes. Miracidia were allowed to transform to sporocysts in the presence of synthesized double-stranded RNAs (dsRNAs) and cultivated for 7 days, during which time developing larvae were closely observed for phenotypic changes including failure/delay in transformation, loss of motility, altered growth and death. Of the phenotypes evaluated, only one was consistently detected; namely a reduction in sporocyst size based on length measurements. The size-reducing phenotype was observed in 11 of the 33 (33%) dsRNA treatment groups, and of these 11 phenotype-associated genes (superoxide dismutase, Smad1, RHO2, Smad2, Cav2A, ring box, GST26, calcineurin B, Smad4, lactate dehydrogenase and EF1α), only 6 demonstrated a significant and consistent knockdown of specific transcript expression. Unexpectedly one phenotype-linked gene, superoxide dismutase (SOD), was highly induced (∼1600-fold) upon dsRNA exposure. Variation in dsRNA-mediated silencing effects also was evident in the group of sporocysts that lacked any definable phenotype. Out of 22 nonphenotype-expressing dsRNA treatments (myosin, PKCB, HEXBP, calcium channel, Sma2, RHO1, PKC receptor, DHHC, PepcK, calreticulin, calpain, Smeg, 14.3.3, K5, SPO1, SmZF1, fibrillarin, GST28, GPx, TPx1, TPx2 and TPx2/TPx1), 12 were assessed for the transcript levels. Of those, 6 genes exhibited consistent reductions in steady-state transcript levels, while expression level for the rest remained unchanged. Results demonstrate that the efficacy of dsRNA-treatment in producing consistent phenotypic changes and/or altered gene expression levels in S. mansoni sporocysts is highly dependent on the selected gene (or the specific dsRNA sequence used) and the timing of evaluation after treatment. Although RNAi holds great promise as a functional genomics tool for larval schistosomes, our finding of potential off-target or nonspecific effects of some dsRNA treatments and variable efficiencies in specific gene knockdown indicate a critical need for gene-specific testing and optimization as an essential part of experimental design, execution and data interpretation. RNA interference (RNAi) represents the only method currently available for manipulating gene-specific expression in human blood flukes, Schistosoma spp., although its application as a functional genomics tool in early intramolluscan larval stages has been limited to single gene analyses. Accelerating gene discovery efforts over the past 10 years have resulted in extensive, ever-increasing databases of genomic, transcriptomic and EST sequences. Unfortunately, our understanding of the function of the vast majority of these genes has not kept pace with their discovery, and this represents a significant barrier and the next real challenge for investigators of schistosomes, and other parasitic helminths. In the present study, we selected an array of 32 genes expressed in S. mansoni sporocysts to evaluate their susceptibility to double-stranded (ds)RNA treatment and to begin characterizing morphological phenotypes associated with a potential RNAi effect. Results demonstrate that gene knockdown and/or resulting phenotypes are highly transcript-dependent (specific dsRNA sequence used) and vary with time post-dsRNA exposure. Because of this potential variability in both transcript and phenotype expression in response to dsRNA treatment, our findings illustrate that, although a RNAi-type approach holds great promise as a functional reverse-genetics tool for larval schistosomes, its application requires caution in the design and execution of experiments and interpretation of results.
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Ittiprasert W, Nene R, Miller A, Raghavan N, Lewis F, Hodgson J, Knight M. Schistosoma mansoni infection of juvenile Biomphalaria glabrata induces a differential stress response between resistant and susceptible snails. Exp Parasitol 2009; 123:203-11. [PMID: 19660454 DOI: 10.1016/j.exppara.2009.07.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Revised: 06/20/2009] [Accepted: 07/03/2009] [Indexed: 10/20/2022]
Abstract
Schistosomes develop successfully in susceptible snails but are encapsulated and killed in resistant ones. Mechanism(s) shaping these outcomes involves the parasites ability to evade the snail's defenses. RNA analysis from resistant (BS-90), non-susceptible (LAC2) and susceptible (NMRI) juvenile Biomphalaria glabrata to Schistosoma mansoni revealed that stress-related genes, heat shock protein 70 (Hsp 70) and reverse transcriptase (RT), were dramatically co-induced early in susceptible snails, but not in resistant/non-susceptible ones. These transcripts were, however, down regulated upon exposure to irradiated parasites although penetration behavior of irradiated vs. normal parasites were the same, indicating that Hsp 70 and RT regulation was elicited by infection and not injury. Understanding molecular events involved in stress response transcriptional regulation of Hsp 70 in juvenile snails could pave a way towards the identification of genes involved in schistosome/snail interactions.
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Almeida CR, Stoco PH, Wagner G, Sincero TC, Rotava G, Bayer-Santos E, Rodrigues JB, Sperandio MM, Maia AA, Ojopi EP, Zaha A, Ferreira HB, Tyler KM, Dávila AM, Grisard EC, Dias-Neto E. Transcriptome analysis of Taenia solium cysticerci using Open Reading Frame ESTs (ORESTES). Parasit Vectors 2009; 2:35. [PMID: 19646239 PMCID: PMC2731055 DOI: 10.1186/1756-3305-2-35] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Accepted: 07/31/2009] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Human infection by the pork tapeworm Taenia solium affects more than 50 million people worldwide, particularly in underdeveloped and developing countries. Cysticercosis which arises from larval encystation can be life threatening and difficult to treat. Here, we investigate for the first time the transcriptome of the clinically relevant cysticerci larval form. RESULTS Using Expressed Sequence Tags (ESTs) produced by the ORESTES method, a total of 1,520 high quality ESTs were generated from 20 ORESTES cDNA mini-libraries and its analysis revealed fragments of genes with promising applications including 51 ESTs matching antigens previously described in other species, as well as 113 sequences representing proteins with potential extracellular localization, with obvious applications for immune-diagnosis or vaccine development. CONCLUSION The set of sequences described here will contribute to deciphering the expression profile of this important parasite and will be informative for the genome assembly and annotation, as well as for studies of intra- and inter-specific sequence variability. Genes of interest for developing new diagnostic and therapeutic tools are described and discussed.
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Affiliation(s)
- Carolina R Almeida
- Laboratórios de Protozoologia e de Bioinformática, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina (UFSC), Caixa postal 476, CEP 88040-970, Florianópolis, SC, Brazil.
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A wake up call for urinary schistosomiasis: reconciling research effort with public health importance. Parasitology 2009; 136:1593-610. [PMID: 19627633 DOI: 10.1017/s0031182009990552] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This review considers the current status of urinary schistosomiasis, caused by infection with Schistosoma haematobium, and argues that greater research effort and focus are needed to improve understanding of this neglected tropical disease (NTD). The inappropriateness of relying solely on data concerning the much more extensively studied intestinal form of schistosomiasis caused by S. mansoni is highlighted. The current lack of genome and transcriptome information for S. haematobium is directly hindering further targeted research and must be quickly rectified. Recent molecular phylogenies caution the expectation of similarities between schistosome species and highlight the close relationships of species within the S. haematobium group. Treatment, current and prospective drugs and vaccines, together with diagnosis are considered, highlighting the differences associated with urinary schistosomiasis. This infection has a significant and specific impact on the urino-genital system and has a strong association with bladder cancer, leading to severe and chronic morbidity. There is a clear need for new clinical initiatives in this area to better quantify the disease burden. Furthermore, emerging associations with HIV and other pathogens need to be closely monitored. Research is urgently needed to improve current knowledge in order to develop the next generation of control tools.
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170
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McManus DP, Li Y, Gray DJ, Ross AG. Conquering 'snail fever': schistosomiasis and its control in China. Expert Rev Anti Infect Ther 2009; 7:473-85. [PMID: 19400766 DOI: 10.1586/eri.09.17] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Schistosomiasis japonica is a serious parasitic disease and a major health risk for more than 60 million people living in the tropical and subtropical zones of south China. The disease is a zoonosis and its cause, the parasitic trematode Schistosoma japonicum, has a range of mammalian reservoirs, making control efforts difficult. Current control programs are heavily based on community chemotherapy with a single dose of the highly effective drug praziquantel. However, vaccines (for use in bovines and in humans) in combination with other control strategies are needed to eliminate the disease. In this review, we provide an overview of the transmission, clinical features, pathogenesis, diagnosis, treatment, genetics and susceptibility, epidemiology, and prospects for control of schistosomiasis japonica in China. The threat posed by the Three Gorges Dam may undermine control efforts because it will change the local ecology and associated schistosomiasis transmission risks over the next decade and beyond.
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Affiliation(s)
- Donald P McManus
- Molecular Parasitology Laboratory, Infectious Diseases Division, The Queensland Institute of Medical Research, PO Royal Brisbane Hospital, Brisbane, QLD 4029, Australia.
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Tissue specific profiling of females of Schistosoma japonicum by integrated laser microdissection microscopy and microarray analysis. PLoS Negl Trop Dis 2009; 3:e469. [PMID: 19564906 PMCID: PMC2696939 DOI: 10.1371/journal.pntd.0000469] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Accepted: 05/27/2009] [Indexed: 12/14/2022] Open
Abstract
Background The functions of many schistosome gene products remain to be characterized. A major step towards elucidating function of these genes would be in defining their sites of expression. This goal is rendered difficult to achieve by the generally small size of the parasites and the lack of a body cavity, which precludes analysis of transcriptional profiles of the tissues in isolation. Methodology/Principal Findings Here, we describe a combined laser microdissection microscopy (LMM) and microarray analysis approach to expedite tissue specific profiling and gene atlasing for tissues of adult female Schistosoma japonicum. This approach helps to solve the gene characterization “bottle-neck” brought about by acoelomy and the size of these parasites. Complementary RNA obtained after isolation from gastrodermis (parasite gut mucosa), vitelline glands and ovary by LMM were subjected to microarray analyses, resulting in identification of 147 genes upregulated in the gastrodermis, 4,149 genes in the ovary and 2,553 in the vitellaria. Conclusions This work will help to shed light on the molecular pathobiology of this debilitating human parasite and aid in the discovery of new targets for the development of anti-schistosome vaccines and drugs. Schistosomes are parasitic worms responsible for important human diseases in tropical and developing nations. There is urgent need to develop new drugs and vaccines to augment current treatments for this disease. In recent years, concerted efforts by many laboratories have led to extensive genetic sequencing of the parasites, and the publication of genome sequence for two agents of schistosomiasis appears imminent. This genetic information has revealed many molecules expressed by the schistosome parasites for which no functional information is available. This lack of information extends to ignorance of where in the complex multicellular schistosome parasites the genes are expressed. We integrated two molecular and cellular techniques to address these knowledge gaps. We used laser microdissection microscopy to dissect small but highly important tissues involved in nutrition and reproduction from sections of female Schistosoma japonicum. From these dissected tissues we then used a broad molecular biology method to identify the multiple genes active in these tissues. Our approach has allowed us to formulate the basis of a “gene atlas” for schistosome parasites, defining the expression repertoire of specific tissues. The better understanding of the roles of tissues in parasite biology, especially in development, reproduction and interactions with its human hosts, should promote future investigations into pathogenesis and control of these significant parasites.
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Two allelic isoforms of the serotonin transporter from Schistosoma mansoni display electrogenic transport and high selectivity for serotonin. Eur J Pharmacol 2009; 616:48-57. [PMID: 19549517 DOI: 10.1016/j.ejphar.2009.06.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Revised: 06/04/2009] [Accepted: 06/11/2009] [Indexed: 11/22/2022]
Abstract
The human blood fluke Schistosoma mansoni is the primary cause of schistosomiasis, a debilitating disease that affects 200 million individuals in over 70 countries. The biogenic amine serotonin is essential for the survival of the parasite and serotonergic proteins are potential novel drug targets for treating schistosomiasis. Here we characterize two novel serotonin transporter gene transcripts, SmSERT-A and SmSERT-B, from S.mansoni. Southern blot analysis shows that the two mRNAs are the products of different alleles of a single SmSERT gene locus. The two SmSERT forms differ in three amino acid positions near the N-terminus of the protein. Both SmSERTs are expressed in the adult form and in the sporocyst form (infected snails) of the parasite, but are absent from all other stages of the parasite's complex life cycle. Heterologous expression of the two cDNAs in mammalian cells resulted in saturable, sodium-dependent serotonin transport activity with an apparent affinity for serotonin comparable to that of the human serotonin transporter. Although the two SmSERTs are pharmacologically indistinguishable from each other, efflux experiments reveal notably higher substrate selectivity for serotonin compared with their mammalian counterparts. Several well-established substrates for human SERT including (+/-)MDMA, S-(+)amphetamine, RU 24969, and m-CPP are not transported by SmSERTs, underscoring the higher selectivity of the schistosomal isoforms. Voltage-clamp recordings of SmSERT substrate-elicited currents confirm the substrate selectivity observed in efflux experiments and suggest that it may be possible to exploit the electrogenic nature of SmSERT to screen for compounds that target the parasite in vivo.
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Dvorák J, Mashiyama ST, Sajid M, Braschi S, Delcroix M, Schneider EL, McKerrow WH, Bahgat M, Hansell E, Babbitt PC, Craik CS, McKerrow JH, Caffrey CR. SmCL3, a gastrodermal cysteine protease of the human blood fluke Schistosoma mansoni. PLoS Negl Trop Dis 2009; 3:e449. [PMID: 19488406 PMCID: PMC2685030 DOI: 10.1371/journal.pntd.0000449] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Accepted: 05/01/2009] [Indexed: 12/23/2022] Open
Abstract
Background Blood flukes of the genus Schistosoma are platyhelminth parasites that infect 200 million people worldwide. Digestion of nutrients from the host bloodstream is essential for parasite development and reproduction. A network of proteolytic enzymes (proteases) facilitates hydrolysis of host hemoglobin and serum proteins. Methodology/Principal Findings We identified a new cathepsin L termed SmCL3 using PCR strategies based on S. mansoni EST sequence data. An ortholog is present in Schistosoma japonicum. SmCL3 was heterologously expressed as an active enzyme in the yeast, Pichia pastoris. Recombinant SmCL3 has a broad pH activity range against peptidyl substrates and is inhibited by Clan CA protease inhibitors. Consistent with a function in degrading host proteins, SmCL3 hydrolyzes serum albumin and hemoglobin, is localized to the adult gastrodermis, and is expressed mainly in those life stages infecting the mammalian host. The predominant form of SmCL3 in the parasite exists as a zymogen, which is unusual for proteases. This zymogen includes an unusually long prodomain with alpha helical secondary structure motifs. The striking specificity of SmCL3 for amino acids with large aromatic side chains (Trp and Tyr) at the P2 substrate position, as determined with positional scanning-synthetic combinatorial library, is consistent with a molecular model that shows a large and deep S2 pocket. A sequence similarity network (SSN) view clusters SmCL3 and other cathepsins L in accordance with previous large-scale phylogenetic analyses that identify six super kingdoms. Conclusions/Significance SmCL3 is a gut-associated cathepsin L that may contribute to the network of proteases involved in degrading host blood proteins as nutrients. Furthermore, this enzyme exhibits some unusual sequence and biophysical features that may result in additional functions. The visualization of network inter-relationships among cathepsins L suggests that these enzymes are suitable ‘marker sequences’ for inclusion in future phylogenetic analyses. Parasitic infection caused by blood flukes of the genus Schistosoma is a major global health problem. More than 200 million people are infected. Identifying and characterizing the constituent enzymes of the parasite's biochemical pathways should reveal opportunities for developing new therapies (i.e., vaccines, drugs). Schistosomes feed on host blood, and a number of proteolytic enzymes (proteases) contribute to this process. We have identified and characterized a new protease, SmCL3 (for Schistosoma mansoni cathepsin L3), that is found within the gut tissue of the parasite. We have employed various biochemical and molecular biological methods and sequence similarity analyses to characterize SmCL3 and obtain insights into its possible functions in the parasite, as well as its evolutionary position among cathepsin L proteases in general. SmCL3 hydrolyzes major host blood proteins (serum albumin and hemoglobin) and is expressed in parasite life stages infecting the mammalian host. Enzyme substrate specificity detected by positional scanning-synthetic combinatorial library was confirmed by molecular modeling. A sequence analysis placed SmCL3 to the cluster of other cathepsins L in accordance with previous phylogenetic analyses.
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Affiliation(s)
- Jan Dvorák
- Sandler Center for Basic Research in Parasitic Diseases, California Institute for Quantitative Biosciences, University of California San Francisco, San Francisco, California, United States of America.
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174
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Lopes DO, Paiva LF, Martins MA, Cardoso FC, Rajão MA, Pinho JM, Caliari MV, Correa-Oliveira R, Mello SM, Leite LCC, Oliveira SC. Sm21.6 a novel EF-hand family protein member located on the surface of Schistosoma mansoni adult worm that failed to induce protection against challenge infection but reduced liver pathology. Vaccine 2009; 27:4127-35. [PMID: 19409948 DOI: 10.1016/j.vaccine.2009.04.068] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Revised: 03/26/2009] [Accepted: 04/21/2009] [Indexed: 01/24/2023]
Abstract
Schistosomiasis continues to be a significant public health problem that affects 200 million people worldwide. This is one of the most important parasitic diseases, and one whose effective control is unlikely in the absence of a vaccine. In this study, we have isolated a cDNA clone encoding the Schistosoma mansoni Sm21.6 protein that has 45% and 44% identity with Sm22.6 and Sj21.7 EF-hand containing antigens, respectively. Confocal microscopy analysis revealed that Sm21.6 is a membrane-associated protein localized on the S. mansoni adult worm. Mouse immunization with rSm21.6 induced a mixed Th1/Th2 cytokine profile and no protection against infection. However, vaccination with rSm21.6 reduced by 28% of liver granuloma numbers, 21% of granuloma area and 34% of fibrosis. Finally, rSm21.6 was recognized by sera from individuals resistant to reinfection compared with patients susceptible to reinfection and this molecule should be further studied as potential biomarker for disease resistance. In conclusion, Sm21.6 is a new tegument protein from S. mansoni that plays an important role in reducing pathology induced by parasite infection.
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Affiliation(s)
- Debora O Lopes
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Avenida Antonio Carlos 6627, Pampulha, Belo Horizonte 31270-901, MG, Brazil
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Characterization and binding affinities of SmLANP: a new Schistosoma mansoni member of the ANP32 family of regulatory proteins. Mol Biochem Parasitol 2009; 165:95-102. [PMID: 19428656 DOI: 10.1016/j.molbiopara.2009.01.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 01/15/2009] [Accepted: 01/16/2009] [Indexed: 11/20/2022]
Abstract
Members of the leucine-rich repeat protein family are involved in diverse functions including protein phosphatase 2-inhibition, cell cycle regulation, gene regulation and signalling pathways. A novel Schistosoma mansoni gene, called SmLANP, presenting homology to various genes coding for proteins that belong to the super family of leucine-rich repeat proteins, was characterized here. SmLANP was 1184bp in length as determined from cDNA and genomic sequences and encoded a 296 amino acid open reading frame that spanning from 6 to 894bp. The predicted amino acid sequence had a calculated molecular weight of 32kDa. Analysis of the predicted sequence indicated the presence of 3 leucine-rich domains (LRR) located in the N-terminal region and an aspartic acid rich region in the C-terminal end. SmLANP transcript is expressed in all stages of the S. mansoni life cycle analyzed, exhibiting the highest expression level in males. The SmLANP protein was expressed in a GST expression system and antibodies raised in mice against the recombinant protein. By immunolocalization assay, using adult worms, it was shown that the protein is mainly present in the cell nucleus through the whole body and strongly expressed along the tegument cell body nuclei of adult worms. As members of this family are usually involved in protein-protein interaction, a yeast two hybrid assay was conducted to identify putative binding partners for SmLANP. Thirty-six possible partners were identified, and a protein ATP synthase subunit alpha was confirmed by pull down assays, as a binding partner of the SmLANP protein.
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176
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Purinergic signaling and immune modulation at the schistosome surface? Trends Parasitol 2009; 25:256-60. [PMID: 19423396 DOI: 10.1016/j.pt.2009.03.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Revised: 02/25/2009] [Accepted: 03/04/2009] [Indexed: 12/20/2022]
Abstract
After tissue stress or injury, intracellular ATP can be released into the extracellular environment. This signals cell damage because extracellular ATP acts as a danger-associated molecular pattern (DAMP) that is potently proinflammatory. Vertebrates temper this effect by catabolizing ATP to adenosine - a strongly anti-inflammatory molecule - using a set of characterized ecto-enzymes (notably alkaline phosphatase, phosphodiesterase and ATP diphosphohydrolase). Strikingly, schistosomes in the bloodstream have this same set of ATP-catabolizing enzymes on their tegumental surfaces. It is our opinion that these function to remove the DAMP (ATP) released by host cells in response to schistosome intravascular migration. We propose this as one mechanism by which schistosomes prevent their hosts from focusing immunological mediators in their vicinity.
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177
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Gobert GN, Moertel L, Brindley PJ, McManus DP. Developmental gene expression profiles of the human pathogen Schistosoma japonicum. BMC Genomics 2009; 10:128. [PMID: 19320991 PMCID: PMC2670322 DOI: 10.1186/1471-2164-10-128] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Accepted: 03/25/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The schistosome blood flukes are complex trematodes and cause a chronic parasitic disease of significant public health importance worldwide, schistosomiasis. Their life cycle is characterised by distinct parasitic and free-living phases involving mammalian and snail hosts and freshwater. Microarray analysis was used to profile developmental gene expression in the Asian species, Schistosoma japonicum. Total RNAs were isolated from the three distinct environmental phases of the lifecycle -- aquatic/snail (eggs, miracidia, sporocysts, cercariae), juvenile (lung schistosomula and paired but pre-egg laying adults) and adult (paired, mature males and egg-producing females, both examined separately). Advanced analyses including ANOVA, principal component analysis, and hierarchal clustering provided a global synopsis of gene expression relationships among the different developmental stages of the schistosome parasite. RESULTS Gene expression profiles were linked to the major environmental settings through which the developmental stages of the fluke have to adapt during the course of its life cycle. Gene ontologies of the differentially expressed genes revealed a wide range of functions and processes. In addition, stage-specific, differentially expressed genes were identified that were involved in numerous biological pathways and functions including calcium signalling, sphingolipid metabolism and parasite defence. CONCLUSION The findings provide a comprehensive database of gene expression in an important human pathogen, including transcriptional changes in genes involved in evasion of the host immune response, nutrient acquisition, energy production, calcium signalling, sphingolipid metabolism, egg production and tegumental function during development. This resource should help facilitate the identification and prioritization of new anti-schistosome drug and vaccine targets for the control of schistosomiasis.
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Affiliation(s)
- Geoffrey N Gobert
- Division of Infectious Diseases & Immunology, Queensland Institute of Medical Research, Brisbane, Queensland, Australia.
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178
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Ting-An W, Hong-Xiang Z. PTK-pathways and TGF-beta signaling pathways in schistosomes. J Basic Microbiol 2009; 49:25-31. [PMID: 19253328 DOI: 10.1002/jobm.200800317] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Schistosome parasites have co-evolved an intricate relationship with their human and snail hosts as well as a novel interplay between the adult male and female parasites. Drug-induced suppression of female schistosome sexual maturation is an auspicious strategy to combat schistosomiasis since the eggs are the causative agent. Studies on signaling in schistosomes opens a new era for investigation of host-parasite and male-female interactions. We review the role of the TGF-beta signaling pathway in parasite development, host-parasite interactions and male-female interactions. This review also summarizes recent studies suggesting tyrosine kinases as important factors for the regulation of female gonad development. In this context, cytoplasmatic tyrosine kinases of the Src class seem to play especially dominant roles. Moreover, experimental data and theoretical concepts are provided supporting a crosstalk between tyrosine kinase and TGF-beta signaling in the production of vitellocytes. Finally, we take advantage of the schistosome genome project to propose a model for the regulation of vitelline-cell production and differentiation.
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Affiliation(s)
- Wang Ting-An
- Department of Pathogenic Organisms, Preclinical Medicine College, Soochow University, Suzhou, China
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179
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Wang X, Gobert GN, Feng X, Fu Z, Jin Y, Peng J, Lin J. Analysis of early hepatic stage schistosomula gene expression by subtractive expressed sequence tags library. Mol Biochem Parasitol 2009; 166:62-9. [PMID: 19428674 DOI: 10.1016/j.molbiopara.2009.02.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 02/24/2009] [Accepted: 02/25/2009] [Indexed: 01/12/2023]
Abstract
Schistosome parasites require a complex lifecycle requiring two hosts and aquatic phases of development. The schistosomula is a key phase of parasite development within the mammalian host, however relatively little is understood about the molecular processes underlying this stage. In this study 5723 subtractive expressed sequence tags (ESTs) were randomly selected from a 7 day hepatic schistosomula enriched library constructed using suppression subtractive hybridization method. Sequence analysis of these ESTs identified 1762 unique genes (contigs). Among them, 989 contigs were annotated with known genes, 311 contigs were homologous to established genes, 101 contigs were similar to established genes, 72 contigs were weakly similar to established genes and 289 sequences did not match any published sequences. Genes identified related to metabolism, cellular development, immune evasion and host-parasite interactions were identified as enriched in the hepatic schistosomula stage. The future identification of poorly annotated but stage-specific genes may potentially represent new drugs or vaccine targets, applicable for the future controlling of schistosomiasis.
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Affiliation(s)
- Xinzhi Wang
- Shanghai Institute of Veterinary Research, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology, Ministry of Agriculture of China, PR China
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180
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Rofatto HK, Tararam CA, Borges WC, Wilson RA, Leite LCC, Farias LP. Characterization of phosphodiesterase-5 as a surface protein in the tegument of Schistosoma mansoni. Mol Biochem Parasitol 2009; 166:32-41. [PMID: 19428670 DOI: 10.1016/j.molbiopara.2009.02.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Revised: 02/16/2009] [Accepted: 02/17/2009] [Indexed: 12/26/2022]
Abstract
Schistosoma mansoni is a major causative agent of schistosomiasis, an important parasitic disease that constitutes a severe health problem in developing countries. Even though an effective treatment exists, it does not prevent re-infection and the development of an effective vaccine still remains the most desirable means of control for this disease. In this work we describe the cloning and characterization of a S. mansoni nucleotide pyrophosphatase/phosphosdiesterase type 5 (SmNPP-5), previously identified in the tegument by proteomic studies. In silico analysis predicts an N-terminal signal peptide, three N-glycosylation sites and a C-terminal transmembrane domain similar to that described for mammalian isoforms. Real-time quantitative RT-PCR and Western blot analyses determined that SmNPP-5 is significantly upregulated in the transition from free-living cercaria to schistosomulum and adult worm parasitic stages; additionally, the native protein was demonstrated to be N-glycosylated. Immunolocalization experiments and tegument surface membrane preparations confirm the protein as a tegument surface protein. Furthermore, the ectolocalization of this enzyme was corroborated through the hydrolysis of the phosphodiesterase specific substrate (rho-Nph-5'-TMP) by living adult and 21-day-old worms. Interestingly, pre-incubation of adult and 21-day-old worms with anti-rSmNPP-5 antibody was able to reduce by 50-60% the enzyme activity. These results suggest that SmNPP-5 is closely associated with the new tegument surface generation after cercarial penetration, and being located at the host-parasite interface, is a potential target for immune intervention.
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181
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Schistosomes--proteomics studies for potential novel vaccines and drug targets. Drug Discov Today 2009; 14:472-8. [PMID: 19429506 DOI: 10.1016/j.drudis.2009.01.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Revised: 01/26/2009] [Accepted: 01/27/2009] [Indexed: 01/02/2023]
Abstract
Schistosomiasis is a major health problem and, despite decades of research, only one effective drug, Praziquantel is currently available. Recent expansion of sequence databases on Schistosoma mansoni and S. japonicum has permitted a wealth of novel proteomic studies on several aspects of the organization and development of the parasite in the human host. This unprecedented accumulation of molecular data is allowing a more rational approach to propose drug targets and vaccine candidates, such as proteins located at the parasite surface. Successful preliminary trials of two vaccine candidates that have been detected at the parasite surface by proteomics give grounds for believing that such an approach may provide a fresh start for the field.
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182
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Kašný M, Mikeš L, Hampl V, Dvořák J, Caffrey CR, Dalton JP, Horák P. Chapter 4 Peptidases of Trematodes. ADVANCES IN PARASITOLOGY 2009; 69:205-97. [DOI: 10.1016/s0065-308x(09)69004-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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183
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Ramos CRR, Spisni A, Oyama S, Sforça ML, Ramos HR, Vilar MM, Alves AC, Figueredo RCR, Tendler M, Zanchin NIT, Pertinhez TA, Ho PL. Stability improvement of the fatty acid binding protein Sm14 from S. mansoni by Cys replacement: structural and functional characterization of a vaccine candidate. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1794:655-62. [PMID: 19150418 DOI: 10.1016/j.bbapap.2008.12.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Revised: 11/21/2008] [Accepted: 12/04/2008] [Indexed: 11/25/2022]
Abstract
The Schistosoma mansoni fatty acid binding protein (FABP), Sm14, is a vaccine candidate against, S. mansoni and F. hepatica. Previously, we demonstrated the importance of a correct fold to achieve protection in immunized animals after cercariae challenge [[10]. C.R.R. Ramos, R.C.R. Figueredo, T.A. Pertinhez, M.M. Vilar, A.L.T.O. Nascimento, M. Tendler, I. Raw, A. Spisni, P.L. Ho, Gene structure and M20T polymorphism of the Schistosoma mansoni Sm14 fatty acid-binding protein: structural, functional and immunoprotection analysis. J. Biol. Chem. 278 (2003) 12745-12751.]. Here we show that the reduction of vaccine efficacy over time is due to protein dimerization and subsequent aggregation. We produced the mutants Sm14-M20(C62S) and Sm14-M20(C62V) that, as expected, did not dimerize in SDS-PAGE. Molecular dynamics calculations and unfolding experiments highlighted a higher structural stability of these mutants with respect to the wild-type. In addition, we found that the mutated proteins, after thermal denaturation, refolded to their active native molecular architecture as proved by the recovery of the fatty acid binding ability. Sm14-M20(C62V) turned out to be the more stable form over time, providing the basis to determine the first 3D solution structure of a Sm14 protein in its apo-form. Overall, Sm14-M20(C62V) possesses an improved structural stability over time, an essential feature to preserve its immunization capability and, in experimentally immunized animals, it exhibits a protection effect against S. mansoni cercariae infections comparable to the one obtained with the wild-type protein. These facts indicate this protein as a good lead molecule for large-scale production and for developing an effective Sm14 based anti-helminthes vaccine.
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Affiliation(s)
- Celso R R Ramos
- Biotechnology Center, Butantan Institute, Av. Vital Brasil 1500, 05503-900, São Paulo, SP, Brazil
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184
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Xue X, Sun J, Zhang Q, Wang Z, Huang Y, Pan W. Identification and characterization of novel microRNAs from Schistosoma japonicum. PLoS One 2008; 3:e4034. [PMID: 19107204 PMCID: PMC2603315 DOI: 10.1371/journal.pone.0004034] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Accepted: 11/20/2008] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Schistosomiasis japonica remains a major public health problem in China. Its pathogen, Schistosoma japonicum has a complex life cycle and a unique repertoire of genes expressed at different life cycle stages. Exploring schistosome gene regulation will yield the best prospects for new drug targets and vaccine candidates. MicroRNAs (miRNAs) are a highly conserved class of noncoding RNA that control many biological processes by sequence-specific inhibition of gene expression. Although a large number of miRNAs have been identified from plants to mammals, it remains no experimental proof whether schistosome exist miRNAs. METHODOLOGY AND RESULTS We have identified novel miRNAs from Schistosoma japonicum by cloning and sequencing a small (18-26 nt) RNA cDNA library from the adult worms. Five novel miRNAs were identified from 227 cloned RNA sequences and verified by Northern blot. Alignments of the miRNAs with corresponding family members indicated that four of them belong to a metazoan miRNA family: let-7, miR-71, bantam and miR-125. The fifth potentially new (non conserved) miRNA appears to belong to a previously undescribed family in the genus Schistosome. The novel miRNAs were designated as sja-let-7, sja-miR-71, sja-bantam, sja-miR-125 and sja-miR-new1, respectively. Expression of sja-let-7, sja-miR-71 and sja-bantam were analyzed in six stages of the life cycle, i.e. egg, miracidium, sporocyst, cercaria, schistosomulum, and adult worm, by a modified stem-loop reverse transcribed polymerase chain reaction (RT-PCR) method developed in our laboratory. The expression patterns of these miRNAs were highly stage-specific. In particular, sja-miR-71 and sja-bantam expression reach their peaks in the cercaria stage and then drop quickly to the nadirs in the schistosomulum stage, following penetration of cercaria into a mammalian host. CONCLUSIONS Authentic miRNAs were identified for the first time in S. japonicum, including a new schistosome family member. The different expression patterns of the novel miRNAs over the life stages of S. japonicum suggest that they may mediate important roles in Schistosome growth and development.
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Affiliation(s)
- Xiangyang Xue
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, China
- Department of Microbiology, Wenzhou Medical College, University-town, Wenzhou, China
| | - Jun Sun
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, China
| | - Qingfeng Zhang
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, China
| | - Zhangxun Wang
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, China
| | - Yufu Huang
- Department of Pathogenic Biology, Second Military Medical University, Shanghai, China
| | - Weiqing Pan
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, China
- Department of Pathogenic Biology, Second Military Medical University, Shanghai, China
- * E-mail:
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185
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Opisthorchis viverrini: Gene expression profiling of carcinogenic adult liver fluke worms using 5′ SAGE. Exp Parasitol 2008; 120:306-13. [DOI: 10.1016/j.exppara.2008.08.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2008] [Revised: 07/25/2008] [Accepted: 08/14/2008] [Indexed: 11/18/2022]
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186
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Roger E, Grunau C, Pierce RJ, Hirai H, Gourbal B, Galinier R, Emans R, Cesari IM, Cosseau C, Mitta G. Controlled chaos of polymorphic mucins in a metazoan parasite (Schistosoma mansoni) interacting with its invertebrate host (Biomphalaria glabrata). PLoS Negl Trop Dis 2008; 2:e330. [PMID: 19002242 PMCID: PMC2576457 DOI: 10.1371/journal.pntd.0000330] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Accepted: 10/10/2008] [Indexed: 01/21/2023] Open
Abstract
Invertebrates were long thought to possess only a simple, effective and hence non-adaptive defence system against microbial and parasitic attacks. However, recent studies have shown that invertebrate immunity also relies on immune receptors that diversify (e.g. in echinoderms, insects and mollusks (Biomphalaria glabrata)). Apparently, individual or population-based polymorphism-generating mechanisms exists that permit the survival of invertebrate species exposed to parasites. Consequently, the generally accepted arms race hypothesis predicts that molecular diversity and polymorphism also exist in parasites of invertebrates. We investigated the diversity and polymorphism of parasite molecules (Schistosoma mansoni Polymorphic Mucins, SmPoMucs) that are key factors for the compatibility of schistosomes interacting with their host, the mollusc Biomphalaria glabrata. We have elucidated the complex cascade of mechanisms acting both at the genomic level and during expression that confer polymorphism to SmPoMuc. We show that SmPoMuc is coded by a multi-gene family whose members frequently recombine. We show that these genes are transcribed in an individual-specific manner, and that for each gene, multiple splice variants exist. Finally, we reveal the impact of this polymorphism on the SmPoMuc glycosylation status. Our data support the view that S. mansoni has evolved a complex hierarchical system that efficiently generates a high degree of polymorphism—a “controlled chaos”—based on a relatively low number of genes. This contrasts with protozoan parasites that generate antigenic variation from large sets of genes such as Trypanosoma cruzi, Trypanosoma brucei and Plasmodium falciparum. Our data support the view that the interaction between parasites and their invertebrate hosts are far more complex than previously thought. While most studies in this matter have focused on invertebrate host diversification, we clearly show that diversifying mechanisms also exist on the parasite side of the interaction. Our findings shed new light on how and why invertebrate immunity develops. Contrary to the traditional view that immunity in invertebrates is limited to non-specific mechanisms, recent studies have shown that they have diverse, specific immune receptors. An example is provided by the FREPs of the mollusk Biomphalaria glabrata, polymorphic members of the immunoglobulin superfamily. This capacity for an individual or population-based polymorphic immune response raises the question of whether a corresponding polymorphism exists in parasites of invertebrates, as would be expected in an “arms race” between host and parasite. We have indeed identified such polymorphic molecules in Schistosoma mansoni, a flatworm parasite of B. glabrata, by comparing two strains of schistosome that are respectively compatible and incompatible with the same mollusk host strain. However, in contrast to antigenic variation in protozoan parasites that is based on an extensive gene repertoire, we show here that a high level of polymorphism in these S. mansoni polymorphic mucins (SmPoMucs) is generated from a low number of genes by a complex cascade of mechanisms, a “controlled chaos”.
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Affiliation(s)
- Emmanuel Roger
- Parasitologie Fonctionnelle et Evolutive, UMR 5244, CNRS Université de Perpignan, Perpignan, France
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Fantappíé MR, de Oliveira FMB, Santos RDMMD, Mansure JJ, Furtado DR, da Silva ICDA, Rumjanek FD. Control of transcription in Schistosoma mansoni: chromatin remodeling and other regulatory elements. Acta Trop 2008; 108:186-93. [PMID: 18191795 DOI: 10.1016/j.actatropica.2007.11.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Accepted: 11/30/2007] [Indexed: 10/22/2022]
Abstract
The platyhelminth parasite Schistosoma mansoni, the causative agent of schistosomiasis, is a dioecious parasite with a complex life cycle that includes two different hosts and two free-living stages. Yet very little is known about the biochemical details connected to these different transitions. In the present work, results will be presented showing the most recent results in S. mansoni regarding the characterization of transcription factors and coactivators that act directly on the transcriptional machinery and those that are involved with chromatin remodeling. It is hoped that the information gathered here may contribute towards the understanding of crucial events in the parasite life cycle. Likewise, the development of new drugs that could interfere with oogenesis and sexual maturation may eventually profit from the information contained herein.
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188
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Verjovski-Almeida S, DeMarco R. Current developments on Schistosoma proteomics. Acta Trop 2008; 108:183-5. [PMID: 18539255 DOI: 10.1016/j.actatropica.2008.04.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2007] [Revised: 04/18/2008] [Accepted: 04/23/2008] [Indexed: 10/22/2022]
Abstract
Several papers on Schistosoma mansoni and Schistosomajaponicum proteomes have been published worldwide in the past few years, representing an emerging field of study. Knowledge of the schistosome proteome may greatly enhance our understanding of schistosome physiological processes at the molecular level, and may provide new models for development of vaccines or drugs. Despite the importance of this approach, schistosome proteomic research in Brazil is still incipient. Here we review the development of schistosome proteomic research around the world and provide an appreciation on the future opportunities in Brazil.
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Oliveira G, Franco G, Verjovski-Almeida S. The Brazilian contribution to the study of the Schistosoma mansoni transcriptome. Acta Trop 2008; 108:179-82. [PMID: 18554565 DOI: 10.1016/j.actatropica.2008.04.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2007] [Revised: 12/12/2007] [Accepted: 04/28/2008] [Indexed: 10/22/2022]
Abstract
Brazilian scientists have made definitive contributions towards the understanding of the transcriptome of Schistosoma mansoni. The transcriptome, as a collection of expressed genes, was studied with two basic approaches, the sequencing of cloned cDNA ends and the production and sequencing of random fragments of cDNA. The data that was generated covers nearly the entire set of transcribed genes. These data have been important for gene discovery and annotation of gene function, annotation of the genome, construction of microarrays, identification of peptides in the study of the proteome and can be mined for splice variants, polymorphisms such as single nucleotide polymorphisms and microsatellites, for example. This review will describe the advances achieved with the contribution of Brazilian researchers to the understanding of the transcribed regions of the S. mansoni genome.
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Oliveira SC, Fonseca CT, Cardoso FC, Farias LP, Leite LC. Recent advances in vaccine research against schistosomiasis in Brazil. Acta Trop 2008; 108:256-62. [PMID: 18577363 DOI: 10.1016/j.actatropica.2008.05.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Revised: 04/09/2008] [Accepted: 05/29/2008] [Indexed: 01/09/2023]
Abstract
Schistosomiasis continues to be a significant public health problem in tropical countries such as Brazil. Even though drug treatment in endemic areas has been shown to be efficient for controlling morbidity, it does not reduce prevalence due to constant reinfections. Therefore, a long-term disease control strategy is needed combining mass chemotherapy with a protective vaccine. Although the field of vaccine development has experienced more failures than successes, encouraging results have been obtained in recent years using defined recombinant derived Schistosoma mansoni antigens. This article primarily reviews the progress in the development of a vaccine against S. mansoni in Brazil. We discuss here different forms of vaccine tested in Brazil in pre-clinical trials and immunologic studies performed with patients in endemic areas of schistosomiasis. Lastly, we reviewed the S. mansoni genomic projects developed in the country and the recent advances in the identification of new molecules with potential as vaccine targets.
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Gentile R, Oliveira G. Brazilian studies on the genetics of Schistosoma mansoni. Acta Trop 2008; 108:175-8. [PMID: 18831955 DOI: 10.1016/j.actatropica.2008.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 05/27/2008] [Accepted: 09/03/2008] [Indexed: 11/27/2022]
Abstract
The parasite Schistosoma is known to exhibit variations among species, strains and genera, such as, the levels of infectivity, pathogenicity and immunogenicity. These factors may differ among parasite populations according to the local epidemiological conditions. Diversity observed in Schistosoma mansoni from different geographical regions or within individuals of the same region can be determined by differences in the genotype of each parasite strain. However, until recently, finding adequate genetic markers to investigate infectivity or other epidemiological characteristics of a transmission area proved difficult. Several studies have been conducted to evaluate the genetic variability of S. mansoni, using different techniques. Intraspecific variability was observed in morphological characters, isoenzyme studies, mtDNA, ribosomal gene probes, random amplification of polymorphic DNA (RAPD) and microsatellites. The sequencing of the S. mansoni genome was the most important achievement concerning genetic approaches to the study of this parasite and may improve the development of drugs, vaccines and diagnostics of schistosomiasis. The knowledge of the genetic structure of schistosome populations in relation to epidemiological data and host variability is essential for the understanding of the epidemiology of the disease and the design of control strategies.
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Use of genomic DNA as an indirect reference for identifying gender-associated transcripts in morphologically identical, but chromosomally distinct, Schistosoma mansoni cercariae. PLoS Negl Trop Dis 2008; 2:e323. [PMID: 18941520 PMCID: PMC2565838 DOI: 10.1371/journal.pntd.0000323] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2008] [Accepted: 09/24/2008] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The use of DNA microarray technology to study global Schistosoma gene expression has led to the rapid identification of novel biological processes, pathways or associations. Implementation of standardized DNA microarray protocols across laboratories would assist maximal interpretation of generated datasets and extend productive application of this technology. METHODOLOGY/PRINCIPAL FINDINGS Utilizing a new Schistosoma mansoni oligonucleotide DNA microarray composed of 37,632 elements, we show that schistosome genomic DNA (gDNA) hybridizes with less variation compared to complex mixed pools of S. mansoni cDNA material (R = 0.993 for gDNA compared to R = 0.956 for cDNA during 'self versus self' hybridizations). Furthermore, these effects are species-specific, with S. japonicum or Mus musculus gDNA failing to bind significantly to S. mansoni oligonucleotide DNA microarrays (e.g R = 0.350 when S. mansoni gDNA is co-hybridized with S. japonicum gDNA). Increased median fluorescent intensities (209.9) were also observed for DNA microarray elements hybridized with S. mansoni gDNA compared to complex mixed pools of S. mansoni cDNA (112.2). Exploiting these valuable characteristics, S. mansoni gDNA was used in two-channel DNA microarray hybridization experiments as a common reference for indirect identification of gender-associated transcripts in cercariae, a schistosome life-stage in which there is no overt sexual dimorphism. This led to the identification of 2,648 gender-associated transcripts. When compared to the 780 gender-associated transcripts identified by hybridization experiments utilizing a two-channel direct method (co-hybridization of male and female cercariae cDNA), indirect methods using gDNA were far superior in identifying greater quantities of differentially expressed transcripts. Interestingly, both methods identified a concordant subset of 188 male-associated and 156 female-associated cercarial transcripts, respectively. Gene ontology classification of these differentially expressed transcripts revealed a greater diversity of categories in male cercariae. Quantitative real-time PCR analysis confirmed the DNA microarray results and supported the reliability of this platform for identifying gender-associated transcripts. CONCLUSIONS/SIGNIFICANCE Schistosome gDNA displays characteristics highly suitable for the comparison of two-channel DNA microarray results obtained from experiments conducted independently across laboratories. The schistosome transcripts identified here demonstrate, for the first time, that gender-associated patterns of expression are already well established in the morphologically identical, but chromosomally distinct, cercariae stage.
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Suttiprapa S, Mulvenna J, Huong NT, Pearson MS, Brindley PJ, Laha T, Wongkham S, Kaewkes S, Sripa B, Loukas A. Ov-APR-1, an aspartic protease from the carcinogenic liver fluke, Opisthorchis viverrini: functional expression, immunolocalization and subsite specificity. Int J Biochem Cell Biol 2008; 41:1148-56. [PMID: 18996218 DOI: 10.1016/j.biocel.2008.10.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Revised: 10/13/2008] [Accepted: 10/13/2008] [Indexed: 11/19/2022]
Abstract
The human liver fluke Opisthorchis viverrini is endemic in Thailand, Laos and Cambodia where long standing infection is associated with cancer of the bile ducts, cholangiocarcinoma. Here we describe a cathepsin D-like aspartic protease from the gut and other tissues in O. viverrini. Phylogenetic analysis indicated that Ov-APR-1 is cathepsin D-like, conforming with Clan AA, Family A1 of the MEROPS classification. Ov-APR-1 is expressed in the gut of the mature hermaphroditic parasite, in the reproductive tissues including the testis and immature spermatids, and the developing miracidium within the eggshell. The enzyme was also detected in the excretory/secretory products of cultured adult flukes, indicating a role in host-parasite relationships. A recombinant form of the enzyme expressed in Escherichia coli and refolded from denatured inclusion bodies underwent autocatalytic activation and demonstrated hydrolytic activity against the peptide substrate 7-methoxycoumarin-4-acetyl-GKPILFFRLK(DNP)-D-Arg-amide with a k(cat)/K(m)=1.7 x 10(4)M(-1)s(-1) and a pH optimum around pH 2.5-3.0. The recombinant enzyme digested hemoglobin and bovine serum albumin. Forty-six serum albumin peptides were detected after digestion with recombinant Ov-APR-1 and sequenced. Like many other aspartic proteases, Ov-APR-1 displayed promiscuous preferences for residues accommodated at the key subsites of the binding pocket although hydrophobic (Leu, Ala, Ile), positively charged (Lys) and bulky aromatic (Phe) residues, in that order, were preferred at P1. Similar residues were accommodated at P1' although even less selectivity was exerted at this position.
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Affiliation(s)
- Sutas Suttiprapa
- Liver Fluke and Cholangiocarcinoma Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
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Cardoso FC, Macedo GC, Gava E, Kitten GT, Mati VL, de Melo AL, Caliari MV, Almeida GT, Venancio TM, Verjovski-Almeida S, Oliveira SC. Schistosoma mansoni tegument protein Sm29 is able to induce a Th1-type of immune response and protection against parasite infection. PLoS Negl Trop Dis 2008; 2:e308. [PMID: 18827884 PMCID: PMC2553283 DOI: 10.1371/journal.pntd.0000308] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Accepted: 09/04/2008] [Indexed: 01/08/2023] Open
Abstract
Background Schistosomiasis continues to be a significant public health problem. This disease affects 200 million people worldwide and almost 800 million people are at risk of acquiring the infection. Although vaccine development against this disease has experienced more failures than successes, encouraging results have recently been obtained using membrane-spanning protein antigens from the tegument of Schistosoma mansoni. Our group recently identified Sm29, another antigen that is present at the adult worm tegument surface. In this study, we investigated murine cellular immune responses to recombinant (r) Sm29 and tested this protein as a vaccine candidate. Methods and Findings We first show that Sm29 is located on the surface of adult worms and lung-stage schistosomula through confocal microscopy. Next, immunization of mice with rSm29 engendered 51%, 60% and 50% reduction in adult worm burdens, in intestinal eggs and in liver granuloma counts, respectively (p<0.05). Protective immunity in mice was associated with high titers of specific anti-Sm29 IgG1 and IgG2a and elevated production of IFN-γ, TNF-α and IL-12, a typical Th1 response. Gene expression analysis of worms recovered from rSm29 vaccinated mice relative to worms from control mice revealed a significant (q<0.01) down-regulation of 495 genes and up-regulation of only 22 genes. Among down-regulated genes, many of them encode surface antigens and proteins associated with immune signals, suggesting that under immune attack schistosomes reduce the expression of critical surface proteins. Conclusion This study demonstrates that Sm29 surface protein is a new vaccine candidate against schistosomiasis and suggests that Sm29 vaccination associated with other protective critical surface antigens is the next logical strategy for improving protection. Schistosomiasis is the most important human helminth infection in terms of morbidity and mortality. Although the efforts to develop a vaccine against this disease have experienced failures, a new generation of surface antigens revealed by proteomic studies changed this scenario. Our group has characterized the protein Sm29 described previously as one of the most exposed and expressed antigens in the outer tegument of Schistosoma mansoni. Studies in patients living in endemic areas for schistosomiasis revealed high levels of IgG1 and IgG3 anti-Sm29 in resistant individuals. In this study, confocal microscope analysis showed Sm29 present in the surface of lung-stage schistosoluma and adult worms. Recombinant Sm29, when used as vaccine candidate, induced high levels of protection in mice. This protection was associated with a typical Th1 immune response and reduction of worm burden, liver granulomas and in intestinal eggs. Further, microarray analysis of worms recovered from vaccinated mice showed significant down-regulation of several genes encoding previously characterized vaccine candidates and/or molecules exposed on the surface, suggesting an immune evasion strategy of schistosomes under immune attack. These results demonstrated that Sm29 as one of the important antigens with potential to compose a vaccine against schistosomiasis.
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Affiliation(s)
- Fernanda C. Cardoso
- Departamento de Bioquímica e Imunologia do Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Gilson C. Macedo
- Departamento de Bioquímica e Imunologia do Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Elisandra Gava
- Departamento de Morfologia do Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Gregory T. Kitten
- Departamento de Morfologia do Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Vitor L. Mati
- Departamento de Parasitologia do Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Alan L. de Melo
- Departamento de Parasitologia do Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Marcelo V. Caliari
- Departamento de Patologia do Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Giulliana T. Almeida
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Thiago M. Venancio
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | | | - Sergio C. Oliveira
- Departamento de Bioquímica e Imunologia do Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- * E-mail:
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Microarray based analysis of temperature and oxidative stress induced messenger RNA in Schistosoma mansoni. Mol Biochem Parasitol 2008; 162:134-41. [PMID: 18775750 DOI: 10.1016/j.molbiopara.2008.08.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 08/10/2008] [Accepted: 08/11/2008] [Indexed: 01/06/2023]
Abstract
The body's defense against schistosome infection can take many forms. For example, upon developing acute schistosomiasis, patients often have fever coinciding with larval maturation, migration and early oviposition. As the infection becomes established, the parasite comes under oxidative stress generated by the host immune system. The most common treatment for schistosomiasis is the anti-helminthic drug praziquantel. Its effectiveness, however, is limited due to its inability to kill schistosomes 2-4 weeks post-infection. Clearly there is a need for new anti-schistosomal drugs. We hypothesize that gene products expressed as part of a protective response against heat and/or oxidative stress are potential therapeutic targets for future drug development. Using a 12,166 element oligonucleotide microarray to characterize Schistosoma mansoni genes induced by heat and oxidative stress we found that 1878 S. mansoni elements were significantly induced by heat stress. These included previously reported heat-shock genes expressing homologs of HSP40, HSP70 and HSP86. One thousand and one elements were induced by oxidative stress including those expressing homologs of superoxide dismutase, glutathione peroxidase and aldehyde dehydrogenase. Seventy-two elements were common to both stressors and could potentially be exploited in the development of novel anti-schistosomal therapeutics.
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Mutapi F, Burchmore R, Mduluza T, Midzi N, Turner CMR, Maizels RM. Age-related and infection intensity-related shifts in antibody recognition of defined protein antigens in a schistosome-exposed population. J Infect Dis 2008; 198:167-75. [PMID: 18549316 DOI: 10.1086/589511] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND This study compared patterns of recognition of defined Schistosoma haematobium adult worm antigens by serum antibodies from schistosome-exposed Zimbabweans aged 5-18 years. METHODS The population was stratified by age and infection intensity into 9 groups within which serum specimens were pooled and used to screen for protein recognition by 2-dimensional Western blotting. Recognized proteins were identified by electrospray ionizing tandem mass spectrometry. RESULTS A total of 71 antigens were recognized by >or=1 of the serum pools. The recognition varied distinctly with host age and infection intensity, with some isoform-specific responses. The repertoire of antigens recognized increased with age, peaking in the oldest participants whose had no or mild-to-moderate infection intensity. The intensity of antigen recognition also increased with age, peaking in the oldest participants with the heaviest infection intensity. CONCLUSIONS The recognition of specific schistosome antigens, both in terms of the diversity of antigens recognized and the intensity of antigen recognition, increased with duration of exposure to infection, supporting the hypothesis that the slow development of schistosome-acquired immunity is due to the slow accumulation of responsiveness to relevant parasite antigens.
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Affiliation(s)
- Francisca Mutapi
- Institute for Immunology & Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom.
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Hu X, Zhou H, Hu F, Xu J, Zhao Y, Yu X. Recognition and characterization of TGF-β receptor interacting protein 1 (TRIP-1) containing WD40 repeats from Clonorchis sinensis by bioinformatics, cloning, and expression in Escherichia coli. Parasitol Res 2008; 103:1151-8. [DOI: 10.1007/s00436-008-1109-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Accepted: 06/19/2008] [Indexed: 10/21/2022]
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Rinaldi G, Morales ME, Cancela M, Castillo E, Brindley PJ, Tort JF. Development of functional genomic tools in trematodes: RNA interference and luciferase reporter gene activity in Fasciola hepatica. PLoS Negl Trop Dis 2008; 2:e260. [PMID: 18612418 PMCID: PMC2440534 DOI: 10.1371/journal.pntd.0000260] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Accepted: 06/11/2008] [Indexed: 02/03/2023] Open
Abstract
The growing availability of sequence information from diverse parasites through genomic and transcriptomic projects offer new opportunities for the identification of key mediators in the parasite–host interaction. Functional genomics approaches and methods for the manipulation of genes are essential tools for deciphering the roles of genes and to identify new intervention targets in parasites. Exciting advances in functional genomics for parasitic helminths are starting to occur, with transgene expression and RNA interference (RNAi) reported in several species of nematodes, but the area is still in its infancy in flatworms, with reports in just three species. While advancing in model organisms, there is a need to rapidly extend these technologies to other parasites responsible for several chronic diseases of humans and cattle. In order to extend these approaches to less well studied parasitic worms, we developed a test method for the presence of a viable RNAi pathway by silencing the exogenous reporter gene, firefly luciferase (fLUC). We established the method in the human blood fluke Schistosoma mansoni and then confirmed its utility in the liver fluke Fasciola hepatica. We transformed newly excysted juveniles of F. hepatica by electroporation with mRNA of fLUC and three hours later were able to detect luciferase enzyme activity, concentrated mainly in the digestive ceca. Subsequently, we tested the presence of an active RNAi pathway in F. hepatica by knocking down the exogenous luciferase activity by introduction into the transformed parasites of double-stranded RNA (dsRNA) specific for fLUC. In addition, we tested the RNAi pathway targeting an endogenous F. hepatica gene encoding leucine aminopeptidase (FhLAP), and observed a significant reduction in specific mRNA levels. In summary, these studies demonstrated the utility of RNAi targeting reporter fLUC as a reporter gene assay to establish the presence of an intact RNAi pathway in helminth parasites. These could facilitate the study of gene function and the identification of relevant targets for intervention in organisms that are by other means intractable. More specifically, these results open new perspectives for functional genomics of F. hepatica, which hopefully can lead to the development of new interventions for fascioliasis. Reverse genetics tools allow assessing the function of unknown genes. Their application for the study of neglected infectious diseases could lead eventually to the identification of relevant gene products to be used in diagnosis, or as drug targets or immunization candidates. Being technically more simple and less demanding than other reverse genetics tools such as transgenesis or knockouts, the suppression of gene activity mediated by double-stranded RNA has emerged as a powerful tool for the analysis of gene function. RNAi appeared as an obvious alternative to apply in complex biological systems where information is still scarce, a situation common to several infectious and parasitic diseases. However, several technical or practical difficulties have hampered the development of this technique in parasites to the expectations originally generated. We developed a simple method to test the presence of a viable RNAi pathway by silencing an exogenous reporter gene. The method was tested in F. hepatica, describing the conditions for transfection and confirming the existence of a viable RNAi pathway in this parasite. The experimental design created can be useful as a first approach in organisms where genetic analysis is still unavailable, providing a tool to unravel gene function and probably advancing new candidates relevant in pathobiology, prevention or treatment.
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Affiliation(s)
- Gabriel Rinaldi
- Department of Tropical Medicine, Tulane University Health Sciences Center, New Orleans, Louisiana, United States of America
- Departamento de Genética, Facultad de Medicina, Universidad de la República, Udelar, Montevideo, Uruguay
| | - Maria E. Morales
- Department of Tropical Medicine, Tulane University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Martín Cancela
- Departamento de Genética, Facultad de Medicina, Universidad de la República, Udelar, Montevideo, Uruguay
| | - Estela Castillo
- Sección Bioquímica, Facultad de Ciencias, Universidad de la República, Udelar, Montevideo, Uruguay
| | - Paul J. Brindley
- Department of Tropical Medicine, Tulane University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - José F. Tort
- Departamento de Genética, Facultad de Medicina, Universidad de la República, Udelar, Montevideo, Uruguay
- * E-mail:
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Liu F, Chen P, Cui SJ, Wang ZQ, Han ZG. SjTPdb: integrated transcriptome and proteome database and analysis platform for Schistosoma japonicum. BMC Genomics 2008; 9:304. [PMID: 18578888 PMCID: PMC2447853 DOI: 10.1186/1471-2164-9-304] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2007] [Accepted: 06/26/2008] [Indexed: 11/22/2022] Open
Abstract
Background Schistosoma japonicum is one of the three major blood fluke species, the etiological agents of schistosomiasis which remains a serious public health problem with an estimated 200 million people infected in 76 countries. In recent years, enormous amounts of both transcriptomic and proteomic data of schistosomes have become available, providing information on gene expression profiles for developmental stages and tissues of S. japonicum. Here, we establish a public searchable database, termed SjTPdb, with integrated transcriptomic and proteomic data of S. japonicum, to enable more efficient access and utility of these data and to facilitate the study of schistosome biology, physiology and evolution. Description All the available ESTs, EST clusters, and the proteomic dataset of S. japonicum are deposited in SjTPdb. The core of the database is the 8,420 S. japonicum proteins translated from the EST clusters, which are well annotated for sequence similarity, structural features, functional ontology, genomic variations and expression patterns across developmental stages and tissues including the tegument and eggshell of this flatworm. The data can be queried by simple text search, BLAST search, search based on developmental stage of the life cycle, and an integrated search for more specific information. A PHP-based web interface allows users to browse and query SjTPdb, and moreover to switch to external databases by the following embedded links. Conclusion SjTPdb is the first schistosome database with detailed annotations for schistosome proteins. It is also the first integrated database of both transcriptome and proteome of S. japonicum, providing a comprehensive data resource and research platform to facilitate functional genomics of schistosome. SjTPdb is available from URL: .
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Affiliation(s)
- Feng Liu
- Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Shanghai, PR China.
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Bergquist R, Utzinger J, McManus DP. Trick or treat: the role of vaccines in integrated schistosomiasis control. PLoS Negl Trop Dis 2008; 2:e244. [PMID: 18575619 PMCID: PMC2430529 DOI: 10.1371/journal.pntd.0000244] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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