1
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Wu D, Kong X, Zhang W, Di W. Reconstruction of the TGF-β signaling pathway of Fasciola gigantica. Parasitol Res 2023; 123:51. [PMID: 38095703 DOI: 10.1007/s00436-023-08064-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 10/24/2023] [Indexed: 12/18/2023]
Abstract
In the present study, we reconstructed the transforming growth factor beta (TGF-β) signaling pathway for Fasciola gigantica, which is a neglected tropical pathogen. We defined the components involved in the TGF-β signaling pathway and investigated the transcription profiles of these genes for all developmental stages of F. gigantica. In addition, the presence of these components in excretory and secretory products (FgESP) was predicted via signal peptide annotation. The core components of the TGF-β signaling pathway have been detected in F. gigantica; classical and nonclassical single transduction pathways were constructed. Four ligands have been detected, which may mediate the TGF-β signaling pathway and BMP signaling pathway. Two ligand-binding type II receptors were detected, and inhibitory Smad7 was not detected. TLP, BMP-3, BMP-1, and ActRIb showed higher transcription in 42-day juvenile and 70-day juvenile, while ActRIIa, Smad1, ActRIIb, Smad8, KAT2B, and PP2A showed higher transcription in egg. TLM, Ski, Smad6, BMPRI, p70S6K, Smad2, Smad3, TgfβRI, Smad4, and p300 showed higher transcription in metacercariae. Four ligands, 2 receptors and 3 Smads are predicted to be present in the FgESP, suggesting their potential extrinsic function. This study should help to understand signal transduction in the TGF-β signaling pathway in F. gigantica. In addition, this study helps to illustrate the complex mechanisms involved in developmental processes and F. gigantica - host interaction and paves the way for further characterization of the signaling pathway in trematodes.
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Affiliation(s)
- Dongqi Wu
- College of Animal Science and Technology, Guangxi University, Nanning, Guangxi, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Guangxi University, Nanning, Guangxi, China
| | - Xinping Kong
- College of Animal Science and Technology, Guangxi University, Nanning, Guangxi, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Guangxi University, Nanning, Guangxi, China
| | - Weiyu Zhang
- College of Animal Science and Technology, Guangxi University, Nanning, Guangxi, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Guangxi University, Nanning, Guangxi, China
| | - Wenda Di
- College of Animal Science and Technology, Guangxi University, Nanning, Guangxi, China.
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Guangxi University, Nanning, Guangxi, China.
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2
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Kaethner M, Epping K, Bernthaler P, Rudolf K, Thomann I, Leitschuh N, Bergmann M, Spiliotis M, Koziol U, Brehm K. Transforming growth factor-β signalling regulates protoscolex formation in the Echinococcus multilocularis metacestode. Front Cell Infect Microbiol 2023; 13:1153117. [PMID: 37033489 PMCID: PMC10073696 DOI: 10.3389/fcimb.2023.1153117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 02/23/2023] [Indexed: 04/11/2023] Open
Abstract
The lethal zoonosis alveolar echinococcosis (AE) is caused by tumor-like, infiltrative growth of the metacestode larval stage of the tapeworm Echinococcus multilocularis. We previously showed that the metacestode is composed of posteriorized tissue and that the production of the subsequent larval stage, the protoscolex, depends on re-establishment of anterior identities within the metacestode germinative layer. It is, however, unclear so far how protoscolex differentiation in Echinococcus is regulated. We herein characterized the full complement of E. multilocularis TGFβ/BMP receptors, which is composed of one type II and three type I receptor serine/threonine kinases. Functional analyzes showed that all Echinococcus TGFβ/BMP receptors are enzymatically active and respond to host derived TGFβ/BMP ligands for activating downstream Smad transcription factors. In situ hybridization experiments demonstrated that the Echinococcus TGFβ/BMP receptors are mainly expressed by nerve and muscle cells within the germinative layer and in developing brood capsules. Interestingly, the production of brood capsules, which later give rise to protoscoleces, was strongly suppressed in the presence of inhibitors directed against TGFβ/BMP receptors, whereas protoscolex differentiation was accelerated in response to host BMP2 and TGFβ. Apart from being responsive to host TGFβ/BMP ligands, protoscolex production also correlated with the expression of a parasite-derived TGFβ-like ligand, EmACT, which is expressed in early brood capsules and which is strongly expressed in anterior domains during protoscolex development. Taken together, these data indicate an important role of TGFβ/BMP signalling in Echinococcus anterior pole formation and protoscolex development. Since TGFβ is accumulating around metacestode lesions at later stages of the infection, the host immune response could thus serve as a signal by which the parasite senses the time point at which protoscoleces must be produced. Overall, our data shed new light on molecular mechanisms of host-parasite interaction during AE and are relevant for the development of novel treatment strategies.
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Affiliation(s)
- Marc Kaethner
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Kerstin Epping
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Peter Bernthaler
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Kilian Rudolf
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Irena Thomann
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Nadine Leitschuh
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
- Laboratory of Microbiology and Biotechnology, Department of Food Technology, Fulda University of Applied Sciences, Fulda, Germany
| | - Monika Bergmann
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Markus Spiliotis
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Uriel Koziol
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
- Sección Biología Celular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Klaus Brehm
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
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3
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Maruszewska-Cheruiyot M, Stear MJ, Machcińska M, Donskow-Łysoniewska K. Importance of TGFβ in Cancer and Nematode Infection and Their Interaction-Opinion. Biomolecules 2022; 12:1572. [PMID: 36358922 PMCID: PMC9687433 DOI: 10.3390/biom12111572] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/20/2022] [Accepted: 10/24/2022] [Indexed: 09/29/2023] Open
Abstract
Historically, there has been little interaction between parasitologists and oncologists, although some helminth infections predispose to the development of tumours. In addition, both parasites and tumours need to survive immune attack. Recent research suggests that both tumours and parasites suppress the immune response to increase their chances of survival. They both co-opt the transforming growth factor beta (TGFβ) signalling pathway to modulate the immune response to their benefit. In particular, there is concern that suppression of the immune response by nematodes and their products could enhance susceptibility to tumours in both natural and artificial infections.
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Affiliation(s)
| | - Michael James Stear
- Department of Animal, Plant and Soil Science, Agribio, La Trobe University, Bundoora 3086, Australia
| | - Maja Machcińska
- Department of Experimental Immunotherapy, Faculty of Medicine, Lazarski University, 02-662 Warsaw, Poland
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4
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Mierzejewski K, Stryiński R, Łopieńska-Biernat E, Mateos J, Bogacka I, Carrera M. A Complex Proteomic Response of the Parasitic Nematode Anisakis simplex s.s. to Escherichia coliLipopolysaccharide. Mol Cell Proteomics 2021; 20:100166. [PMID: 34673282 PMCID: PMC8605257 DOI: 10.1016/j.mcpro.2021.100166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 09/06/2021] [Accepted: 10/15/2021] [Indexed: 12/23/2022] Open
Abstract
Helminths are masters at manipulating host's immune response. Especially, parasitic nematodes have evolved strategies that allow them to evade, suppress, or modulate host's immune response to persist and spread in the host's organism. While the immunomodulatory effects of nematodes on their hosts are studied with a great commitment, very little is known about nematodes' own immune system, immune response to their pathogens, and interactions between parasites and bacteria in the host's organism. To illustrate the response of the parasitic nematode Anisakis simplex s.s. during simulated interaction with Escherichia coli, different concentrations of lipopolysaccharide (LPS) were used, and the proteomic analysis with isobaric mass tags for relative and absolute quantification (tandem mass tag-based LC-MS/MS) was performed. In addition, gene expression and biochemical analyses of selected markers of oxidative stress were determined. The results revealed 1148 proteins in a group of which 115 were identified as differentially regulated proteins, for example, peroxiredoxin, thioredoxin, and macrophage migration inhibitory factor. Gene Ontology annotation and Reactome pathway analysis indicated that metabolic pathways related to catalytic activity, oxidation-reduction processes, antioxidant activity, response to stress, and innate immune system were the most common, in which differentially regulated proteins were involved. Further biochemical analyses let us confirm that the LPS induced the oxidative stress response, which plays a key role in the innate immunity of parasitic nematodes. Our findings, to our knowledge, indicate for the first time, the complexity of the interaction of parasitic nematode, A. simplex s.s. with bacterial LPS, which mimics the coexistence of helminth and gut bacteria in the host. The simulation of this crosstalk led us to conclude that the obtained results could be hugely valuable in the integrated systems biology approach to describe a relationship between parasite, host, and its commensal bacteria.
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Affiliation(s)
- Karol Mierzejewski
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland.
| | - Robert Stryiński
- Department of Biochemistry, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Elżbieta Łopieńska-Biernat
- Department of Biochemistry, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | | | - Iwona Bogacka
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Mónica Carrera
- Department of Food Technology, Marine Research Institute (IIM), Spanish National Research Council (CSIC), Vigo, Spain.
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5
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Doenhoff MJ, Modha J, Walker AJ. Failure of in vitro-cultured schistosomes to produce eggs: how does the parasite meet its needs for host-derived cytokines such as TGF-β? Int J Parasitol 2019; 49:747-757. [PMID: 31348959 DOI: 10.1016/j.ijpara.2019.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 05/03/2019] [Accepted: 05/09/2019] [Indexed: 12/20/2022]
Abstract
When adult schistosome worm pairs are transferred from experimental hosts to in vitro culture they cease producing viable eggs within a few days. Female worms in unisexual infections fail to mature, and when mature adult females are separated from male partners they regress sexually. Worms cultured from the larval stage are also permanently reproductively defective. The cytokine transforming growth factor beta derived from the mammalian host is considered important in stimulating schistosome female worm maturation and maintenance of fecundity. The means by which schistosomes acquire TGF-β have not been elucidated, but direct uptake in vivo seems unlikely as the concentration of free, biologically active cytokine in host blood is very low. Here we review the complexities of schistosome development and male-female interactions, and we speculate about two possibilities on how worms obtain the TGF-β they are assumed to need: (i) worms may have mechanisms to free active cytokine from the latency-inducing complex of proteins in which it is associated, and/or (ii) they may obtain the cytokine from alpha 2-macroglobulin, a blood-borne protease inhibitor to which TGF-β can bind. These ideas are experimentally testable.
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Affiliation(s)
- Michael J Doenhoff
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
| | - Jay Modha
- Modha Biomedical Ltd, 9B St Cuthberts Avenue, Great Glen, Leicester LE8 9EJ, UK
| | - Anthony J Walker
- Molecular Parasitology Laboratory, School of Life Sciences Pharmacy and Chemistry, Kingston University, Kingston University, Penrhyn Road, Kingston upon Thames, Surrey KT1 2EE, UK
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6
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Maizels RM, Smits HH, McSorley HJ. Modulation of Host Immunity by Helminths: The Expanding Repertoire of Parasite Effector Molecules. Immunity 2018; 49:801-818. [PMID: 30462997 PMCID: PMC6269126 DOI: 10.1016/j.immuni.2018.10.016] [Citation(s) in RCA: 221] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/13/2018] [Accepted: 10/30/2018] [Indexed: 02/09/2023]
Abstract
Helminths are extraordinarily successful parasites due to their ability to modulate the host immune response. They have evolved a spectrum of immunomodulatory molecules that are now beginning to be defined, heralding a molecular revolution in parasite immunology. These discoveries have the potential both to transform our understanding of parasite adaptation to the host and to develop possible therapies for immune-mediated disease. In this review we will summarize the current state of the art in parasite immunomodulation and discuss perspectives on future areas for research and discovery.
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Affiliation(s)
- Rick M Maizels
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK.
| | | | - Henry J McSorley
- Centre for Inflammation Research, University of Edinburgh, Edinburgh, UK.
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7
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Smyth DJ, Harcus Y, White MPJ, Gregory WF, Nahler J, Stephens I, Toke-Bjolgerud E, Hewitson JP, Ivens A, McSorley HJ, Maizels RM. TGF-β mimic proteins form an extended gene family in the murine parasite Heligmosomoides polygyrus. Int J Parasitol 2018; 48:379-385. [PMID: 29510118 PMCID: PMC5904571 DOI: 10.1016/j.ijpara.2017.12.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/05/2017] [Accepted: 12/19/2017] [Indexed: 12/24/2022]
Abstract
We recently reported the discovery of a new parasite-derived protein that functionally mimics the immunosuppressive cytokine transforming growth factor (TGF)-β. The Heligmosomoides polygyrus TGF-β Mimic (Hp-TGM) shares no homology to any TGF-β family member, however it binds the mammalian TGF-β receptor and induces expression of Foxp3, the canonical transcription factor of both mouse and human regulatory T cells. Hp-TGM consists of five atypical Complement Control Protein (CCP, Pfam 00084) domains, each lacking certain conserved residues and 12-15 amino acids longer than the 60-70 amino acids consensus domain, but with a recognizable 3-cysteine, tryptophan, cysteine motif. We now report on the identification of a family of nine related Hp-TGM homologues represented in the secreted proteome and transcriptome of H. polygyrus. Recombinant proteins from five of the nine new TGM members were tested for TGF-β activity, but only two were functionally active in an MFB-F11 reporter assay, and by the induction of T cell Foxp3 expression. Sequence comparisons reveal that proteins with functional activity are similar or identical to Hp-TGM across the first three CCP domains, but more variable in domains 4 and 5. Inactive proteins diverged in all domains, or lacked some domains entirely. Testing truncated versions of Hp-TGM confirmed that domains 1-3 are essential for full activity in vitro, while domains 4 and 5 are not required. Further studies will elucidate whether these latter domains fulfill other functions in promoting host immune regulation during infection and if the more divergent family members play other roles in immunomodulation.
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Affiliation(s)
- Danielle J Smyth
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, UK
| | - Yvonne Harcus
- Institute of Infection and Immunology Research and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, UK
| | - Madeleine P J White
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, UK
| | - William F Gregory
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, UK
| | - Janina Nahler
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, UK
| | - Ian Stephens
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, UK
| | - Edward Toke-Bjolgerud
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, UK
| | - James P Hewitson
- Centre for Infection and Immunology, Department of Biology, University of York, UK
| | - Alasdair Ivens
- Institute of Infection and Immunology Research and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, UK
| | - Henry J McSorley
- Institute of Infection and Immunology Research and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, UK; MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, UK
| | - Rick M Maizels
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, UK; Institute of Infection and Immunology Research and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, UK.
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8
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A structurally distinct TGF-β mimic from an intestinal helminth parasite potently induces regulatory T cells. Nat Commun 2017; 8:1741. [PMID: 29170498 PMCID: PMC5701006 DOI: 10.1038/s41467-017-01886-6] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 10/23/2017] [Indexed: 01/06/2023] Open
Abstract
Helminth parasites defy immune exclusion through sophisticated evasion mechanisms, including activation of host immunosuppressive regulatory T (Treg) cells. The mouse parasite Heligmosomoides polygyrus can expand the host Treg population by secreting products that activate TGF-β signalling, but the identity of the active molecule is unknown. Here we identify an H. polygyrus TGF-β mimic (Hp-TGM) that replicates the biological and functional properties of TGF-β, including binding to mammalian TGF-β receptors and inducing mouse and human Foxp3+ Treg cells. Hp-TGM has no homology with mammalian TGF-β or other members of the TGF-β family, but is a member of the complement control protein superfamily. Thus, our data indicate that through convergent evolution, the parasite has acquired a protein with cytokine-like function that is able to exploit an endogenous pathway of immunoregulation in the host. Heligmosomoides polygyrus can activate mammalian TGF-β signalling pathways, but how it does so is not known. Here the authors identify and isolate a H. polygyrus TFG-β mimic that can bind both mammalian TGF-β receptor subunits, activate Smad signalling and generate inducible regulatory T cells.
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9
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Aberrant immune response with consequent vascular and connective tissue remodeling - causal to scleroderma and associated syndromes such as Raynaud phenomenon and other fibrosing syndromes? Curr Opin Rheumatol 2016; 28:571-6. [PMID: 27548652 DOI: 10.1097/bor.0000000000000333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE OF REVIEW Scleroderma and other autoimmune-induced connective tissue diseases are characterized by dysfunctions in the immune system, connective tissue and the vasculature. We are focusing on systemic sclerosis (SSc)-associated pulmonary hypertension, which remains a leading cause of death with only a 50-60% of 2-year survival rate. RECENT FINDINGS Much research and translational efforts have been directed at understanding the immune response that causes SSc and the networked interactions with the connective tissue and the vasculature. One of the unexpected findings was that in some cases the pathogenic immune response in SSc resembles the immune response to helminth parasites. During coevolution, means of communication were developed which protect the host from over-colonization with parasites and which protect the parasite from excessive host responses. One explanation for the geographically clustered occurrence of SSc is that environmental exposures combined with genetic predisposition turn on triggers of molecular and cellular modules that were once initiated by parasites. SUMMARY Future research is needed to further understand the parasite-derived signals that dampen the host response. Therapeutic helminth infection or treatment with parasite-derived response modifiers could be promising new management tools for autoimmune connective tissue diseases.
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10
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Coakley G, Buck AH, Maizels RM. Host parasite communications-Messages from helminths for the immune system: Parasite communication and cell-cell interactions. Mol Biochem Parasitol 2016; 208:33-40. [PMID: 27297184 PMCID: PMC5008435 DOI: 10.1016/j.molbiopara.2016.06.003] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 06/03/2016] [Accepted: 06/09/2016] [Indexed: 12/27/2022]
Abstract
Helminth parasites release a spectrum of mediators to dampen host immunity. Secreted proteins can act on host receptors and intracellular signalling. Parasites also produce exosome-like extracellular vesicles containing microRNAs. Exosomes can enter host cells and modulate host gene expression. Extracellular vesicles may be a more general mode of host-parasite interaction.
Helminths are metazoan organisms many of which have evolved parasitic life styles dependent on sophisticated manipulation of the host environment. Most notably, they down-regulate host immune responses to ensure their own survival, by exporting a range of immuno-modulatory mediators that interact with host cells and tissues. While a number of secreted immunoregulatory parasite proteins have been defined, new work also points to the release of extracellular vesicles, or exosomes, that interact with and manipulate host gene expression. These recent results are discussed in the overall context of how helminths communicate effectively with the host organism.
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Affiliation(s)
- Gillian Coakley
- Institute for Immunology and Infection Research, and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, UK
| | - Amy H Buck
- Institute for Immunology and Infection Research, and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, UK
| | - Rick M Maizels
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunology and Inflammation, University of Glasgow, 120 University Place, Glasgow, G12 8TA, UK.
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11
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Johnston CJC, Smyth DJ, Dresser DW, Maizels RM. TGF-β in tolerance, development and regulation of immunity. Cell Immunol 2015; 299:14-22. [PMID: 26617281 PMCID: PMC4711336 DOI: 10.1016/j.cellimm.2015.10.006] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 10/20/2015] [Accepted: 10/21/2015] [Indexed: 12/20/2022]
Abstract
The broader superfamily of TGF-β-like proteins is reviewed, and signaling pathways summarised. The role of TGF-β in the immune tolerance and control of infectious disease is discussed. The superfamily member AMH is involved in embryonic sexual differentiation. Helminth parasites appear to exploit the TGF-β pathway to suppress host immunity. TGF-β homologues and mimics from parasites offer a new route for therapeutic tolerance induction.
The TGF-β superfamily is an ancient metazoan protein class which cuts across cell and tissue differentiation, developmental biology and immunology. Its many members are regulated at multiple levels from intricate control of gene transcription, post-translational processing and activation, and signaling through overlapping receptor structures and downstream intracellular messengers. We have been interested in TGF-β homologues firstly as key players in the induction of immunological tolerance, the topic so closely associated with Ray Owen. Secondly, our interests in how parasites may manipulate the immune system of their host has also brought us to study the TGF-β pathway in infections with longlived, essentially tolerogenic, helminth parasites. Finally, within the spectrum of mammalian TGF-β proteins is an exquisitely tightly-regulated gene, anti-Müllerian hormone (AMH), whose role in sex determination underpins the phenotype of freemartin calves that formed the focus of Ray’s seminal work on immunological tolerance.
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Affiliation(s)
- Chris J C Johnston
- Institute of Immunology and Infection Research, University of Edinburgh, UK
| | - Danielle J Smyth
- Institute of Immunology and Infection Research, University of Edinburgh, UK
| | - David W Dresser
- Institute of Immunology and Infection Research, University of Edinburgh, UK
| | - Rick M Maizels
- Institute of Immunology and Infection Research, University of Edinburgh, UK.
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12
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Morel M, Vanderstraete M, Hahnel S, Grevelding CG, Dissous C. Receptor tyrosine kinases and schistosome reproduction: new targets for chemotherapy. Front Genet 2014; 5:238. [PMID: 25101117 PMCID: PMC4102852 DOI: 10.3389/fgene.2014.00238] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 07/03/2014] [Indexed: 12/31/2022] Open
Abstract
Schistosome parasites still represent a serious public health concern and a major economic problem in developing countries. Pathology of schistosomiasis is mainly due to massive egg production by these parasites and to inflammatory responses raised against the eggs which are trapped in host tissues. Tyrosine kinases (TKs) are key molecules that control cell differentiation and proliferation and they already represent important targets in cancer therapy. During recent years, it has been shown that receptor tyrosine kinases (RTK) signaling was active in reproductive organs and that it could regulate sexual maturation of schistosomes and egg production. This opens interesting perspectives for the control of transmission and pathogenesis of schistosomiasis based on new therapies targeting schistosome RTKs. This review relates the numerous data showing the major roles of kinase signaling in schistosome reproduction. It describes the conserved and particular features of schistosome RTKs, their implication in gametogenesis and reproduction processes and summarizes recent works indicating that RTKs and their signaling partners are interesting chemotherapeutical targets in new programs of control.
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Affiliation(s)
- Marion Morel
- Center for Infection and Immunity of Lille, INSERM U1019, CNRS-UMR 8204, Institut Pasteur de Lille, University Lille Nord de France Lille Cedex, France
| | - Mathieu Vanderstraete
- Center for Infection and Immunity of Lille, INSERM U1019, CNRS-UMR 8204, Institut Pasteur de Lille, University Lille Nord de France Lille Cedex, France
| | - Steffen Hahnel
- Biomedical Centre for Research Seltersberg, Institute of Parasitology, Justus-Liebig-University Giessen Giessen, Germany
| | - Christoph G Grevelding
- Biomedical Centre for Research Seltersberg, Institute of Parasitology, Justus-Liebig-University Giessen Giessen, Germany
| | - Colette Dissous
- Center for Infection and Immunity of Lille, INSERM U1019, CNRS-UMR 8204, Institut Pasteur de Lille, University Lille Nord de France Lille Cedex, France
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13
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Buro C, Oliveira KC, Lu Z, Leutner S, Beckmann S, Dissous C, Cailliau K, Verjovski-Almeida S, Grevelding CG. Transcriptome analyses of inhibitor-treated schistosome females provide evidence for cooperating Src-kinase and TGFβ receptor pathways controlling mitosis and eggshell formation. PLoS Pathog 2013; 9:e1003448. [PMID: 23785292 PMCID: PMC3681755 DOI: 10.1371/journal.ppat.1003448] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 05/07/2013] [Indexed: 11/18/2022] Open
Abstract
Schistosome parasites cause schistosomiasis, one of the most prevalent parasitemias worldwide affecting humans and animals. Constant pairing of schistosomes is essential for female sexual maturation and egg production, which causes pathogenesis. Female maturation involves signaling pathways controlling mitosis and differentiation within the gonads. In vitro studies had shown before that a Src-specific inhibitor, Herbimycin A (Herb A), and a TGFβ receptor (TβR) inhibitor (TRIKI) have physiological effects such as suppressed mitoses and egg production in paired females. As one Herb A target, the gonad-specifically expressed Src kinase SmTK3 was identified. Here, we comparatively analyzed the transcriptome profiles of Herb A- and TRIKI-treated females identifying transcriptional targets of Src-kinase and TβRI pathways. After demonstrating that TRIKI inhibits the schistosome TGFβreceptor SmTβRI by kinase assays in Xenopus oocytes, couples were treated with Herb A, TRIKI, or both inhibitors simultaneously in vitro. RNA was isolated from females for microarray hybridizations and transcription analyses. The obtained data were evaluated by Gene Ontology (GO) and Ingenuity Pathway Analysis (IPA), but also by manual classification and intersection analyses. Finally, extensive qPCR experiments were done to verify differential transcription of candidate genes under inhibitor influence but also to functionally reinforce specific physiological effects. A number of genes found to be differentially regulated are associated with mitosis and differentiation. Among these were calcium-associated genes and eggshell-forming genes. In situ hybridization confirmed transcription of genes coding for the calcium sensor hippocalcin, the calcium transporter ORAI-1, and the calcium-binding protein calmodulin-4 in the reproductive system pointing to a role of calcium in parasite reproduction. Functional qPCR results confirmed an inhibitor-influenced, varying dependence of the transcriptional activities of Smp14, Smp48, fs800, a predicted eggshell precursor protein and SmTYR1. The results show that eggshell-formation is regulated by at least two pathways cooperatively operating in a balanced manner to control egg production. As one of the most prevalent parasitic infections worldwide, schistosomiasis is caused by blood-flukes of the genus Schistosoma. Pathology coincides with egg production, which is started upon pairing of the dioeciously living adults. A constant pairing contact is required to induce mitoses and differentiation processes in the female leading to the development of the gonads. Although long known, the molecular processes controlling gonad development or egg-production in schistosomes or other platyhelminths are largely unknown. Using an established in vitro-culture system and specific, chemical inhibitors we have obtained first evidence in previous studies for the participation of signal transduction processes playing essential roles in controlling mitoses, differentiation and egg production. In the present study we applied combinatory inhibitor treatments combined with subsequent microarray and qPCR analyses and demonstrate for the first time that cooperating Src-Kinase- und TGFβ-signaling pathways control mitoses and egg formation processes. Besides direct evidence for managing transcription of eggshell-forming genes, new target molecules of these pathways were identified. Among these are calcium-associated genes providing a first hint towards a role of this ion for reproduction. Our finding shed first light on the signaling mechanisms controlling egg formation, which is important for life-cycling and pathology.
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Affiliation(s)
- Christin Buro
- Institute of Parasitology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Katia C. Oliveira
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brasil
| | - Zhigang Lu
- Institute of Parasitology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Silke Leutner
- Institute of Parasitology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Svenja Beckmann
- Institute of Parasitology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Colette Dissous
- CIIL - Center of Infection and Immunity of Lille, Université Lille Nord de France, Inserm U1019, CNRS-UMR 8204, Institut Pasteur de Lille, Lille, France
| | - Katia Cailliau
- Laboratoire de Régulation des Signaux de Division, Université Lille 1 Sciences et Technology, EA 4479, IFR 147, Villeneuve d'Ascq, France
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Abstract
The increasing incidence of type 1 diabetes (T1D) and autoimmune diseases in industrialized countries cannot be exclusively explained by genetic factors. Human epidemiological studies and animal experimental data provide accumulating evidence for the role of environmental factors, such as infections, in the regulation of allergy and autoimmune diseases. The hygiene hypothesis has formally provided a rationale for these observations, suggesting that our co-evolution with pathogens has contributed to the shaping of the present-day human immune system. Therefore, improved sanitation, together with infection control, has removed immunoregulatory mechanisms on which our immune system may depend. Helminths are multicellular organisms that have developed a wide range of strategies to manipulate the host immune system to survive and complete their reproductive cycles successfully. Immunity to helminths involves profound changes in both the innate and adaptive immune compartments, which can have a protective effect in inflammation and autoimmunity. Recently, helminth-derived antigens and molecules have been tested in vitro and in vivo to explore possible applications in the treatment of inflammatory and autoimmune diseases, including T1D. This exciting approach presents numerous challenges that will need to be addressed before it can reach safe clinical application. This review outlines basic insight into the ability of helminths to modulate the onset and progression of T1D, and frames some of the challenges that helminth-derived therapies may face in the context of clinical translation.
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Affiliation(s)
- Paola Zaccone
- Department of Pathology, University of Cambridge, Tennis Court Rd, Cambridge CB2 1QP, UK
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Correale J, Farez MF. Does helminth activation of toll-like receptors modulate immune response in multiple sclerosis patients? Front Cell Infect Microbiol 2012; 2:112. [PMID: 22937527 PMCID: PMC3426839 DOI: 10.3389/fcimb.2012.00112] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Accepted: 08/03/2012] [Indexed: 12/15/2022] Open
Abstract
Multiple sclerosis (MS) is an inflammatory autoimmune demyelinating disease affecting the Central Nervous System (CNS), in which Th1 and Th17 cells appear to recognize and react against certain myelin sheath components. Epidemiological evidence has accumulated indicating steady increase in autoimmune disease incidence in developed countries. Reduced infectious disease prevalence in particular has been proposed as the cause. In agreement with this hypothesis, we recently demonstrated significantly better clinical and radiological outcome in helminth-infected MS patients, compared to uninfected ones. Parasite-driven protection was associated with regulatory T cell induction and anti-inflammatory cytokine secretion, including increased TGF-β and IL-10 levels. Interestingly, surface expression of TLR2, on both B cells and dendritic cells (DC) was significantly higher in infected MS patients. Moreover, stimulation of myelin-specific T cell lines with a TLR2 agonist induced inhibition of T cell proliferation, suppression of IFN-γ, IL-12, and IL-17 secretion, as well as increase in IL-10 production, suggesting the functional responses observed correlate with TLR2 expression patterns. Furthermore, parasite antigens were able to induce TLR2 expression on both B cells and DCs. All functional effects mediated by TLR2 were abrogated when MyD88 gene expression was silenced; indicating helminth-mediated signaling induced changes in cytokine secretion in a MyD88-dependent manner. In addition, helminth antigens significantly enhanced co-stimulatory molecule expression, effects not mediated by MyD88. Parasite antigens acting on MyD88 induced significant ERK kinase phosphorylation in DC. Addition of the ERK inhibitor U0126 was associated with dose-dependent IL-10 inhibition and reciprocal enhancement in IL-12, both correlating with ERK inhibition. Finally, cytokine effects and changes observed in co-stimulatory DC molecules after helminth antigen exposure were lost when TLR2 was silenced. Overall, the data described indicate that helminth molecules exert potent regulatory effects on both DCs and B cells from MS patients through TLR2 regulation.
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Affiliation(s)
- Jorge Correale
- Department of Neurology, Institute for Neurological Research Dr. Raúl Carrea, FLENI Buenos Aires, Argentina. ;
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Modulation of specific and allergy-related immune responses by helminths. J Biomed Biotechnol 2011; 2011:821578. [PMID: 22219659 PMCID: PMC3248237 DOI: 10.1155/2011/821578] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 09/09/2011] [Indexed: 01/10/2023] Open
Abstract
Helminths are master regulators of host immune responses utilising complex mechanisms to dampen host protective Th2-type responses and favour long-term persistence. Such evasion mechanisms ensure mutual survival of both the parasite and the host. In this paper, we present recent findings on the cells that are targeted by helminths and the molecules and mechanisms that are induced during infection. We discuss the impact of these factors on the host response as well as their effect in preventing the development of aberrant allergic inflammation. We also examine recent findings on helminth-derived molecules that can be used as tools to pinpoint the underlying mechanisms of immune regulation or to determine new anti-inflammatory therapeutics.
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Epping K, Brehm K. Echinococcus multilocularis: molecular characterization of EmSmadE, a novel BR-Smad involved in TGF-β and BMP signaling. Exp Parasitol 2011; 129:85-94. [PMID: 21802416 DOI: 10.1016/j.exppara.2011.07.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 07/08/2011] [Accepted: 07/14/2011] [Indexed: 12/11/2022]
Abstract
Smad transcription factors are central components of transforming growth factor-β (TGF-β)/bone morphogenetic protein (BMP) signaling pathways in metazoans, and regulate key developmental processes such as body axis formation or regeneration. In the present study, we have identified and characterized a novel member of this protein family, EmSmadE, in the human parasitic cestode Echinococcus multilocularis, the causative agent of alveolar echinococcosis. The cDNA of the corresponding gene, emsmadE, was fully sequenced and shown to encode a protein with considerable homologies to known members of the receptor regulated Smad (R-Smad) family of a wide variety of organisms. EmSmadE contains highly conserved MH1- and MH2-domains and, on the basis of sequence features around the L3 loop region, could be assigned to the BR-Smad subfamily that typically transmits BMP signals. RT-PCR analyses indicated expression of emsmadE in all larval stages that are involved in the infection of the intermediate host. Yeast two-hybrid interaction studies demonstrated that EmSmadE can form homodimers, and is capable of heterodimer formation with the previously identified common Smad (Co-Smad) EmSmadD and the R-Smads, EmSmadA, and EmSmadB. In a heterologous expression system, EmSmadE was specifically phosphorylated at a conserved C-terminal SSVS motif by the human BMP type I receptor and, despite being structurally a BR-Smad, also by the human TGF-β type I receptor. Taken together, these data indicate that EmSmadE is a functionally active R-Smad that is involved in larval Echinococcus development. The data presented herein will be important for further analyses on the role of TGF-β/BMP signaling pathways in Echinococcus pattern formation and differentiation.
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Affiliation(s)
- Kerstin Epping
- University of Würzburg, Institute of Hygiene and Microbiology, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
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18
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Andrade LF, Nahum LA, Avelar LGA, Silva LL, Zerlotini A, Ruiz JC, Oliveira G. Eukaryotic protein kinases (ePKs) of the helminth parasite Schistosoma mansoni. BMC Genomics 2011; 12:215. [PMID: 21548963 PMCID: PMC3117856 DOI: 10.1186/1471-2164-12-215] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 05/06/2011] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Schistosomiasis remains an important parasitic disease and a major economic problem in many countries. The Schistosoma mansoni genome and predicted proteome sequences were recently published providing the opportunity to identify new drug candidates. Eukaryotic protein kinases (ePKs) play a central role in mediating signal transduction through complex networks and are considered druggable targets from the medical and chemical viewpoints. Our work aimed at analyzing the S. mansoni predicted proteome in order to identify and classify all ePKs of this parasite through combined computational approaches. Functional annotation was performed mainly to yield insights into the parasite signaling processes relevant to its complex lifestyle and to select some ePKs as potential drug targets. RESULTS We have identified 252 ePKs, which corresponds to 1.9% of the S. mansoni predicted proteome, through sequence similarity searches using HMMs (Hidden Markov Models). Amino acid sequences corresponding to the conserved catalytic domain of ePKs were aligned by MAFFT and further used in distance-based phylogenetic analysis as implemented in PHYLIP. Our analysis also included the ePK homologs from six other eukaryotes. The results show that S. mansoni has proteins in all ePK groups. Most of them are clearly clustered with known ePKs in other eukaryotes according to the phylogenetic analysis. None of the ePKs are exclusively found in S. mansoni or belong to an expanded family in this parasite. Only 16 S. mansoni ePKs were experimentally studied, 12 proteins are predicted to be catalytically inactive and approximately 2% of the parasite ePKs remain unclassified. Some proteins were mentioned as good target for drug development since they have a predicted essential function for the parasite. CONCLUSIONS Our approach has improved the functional annotation of 40% of S. mansoni ePKs through combined similarity and phylogenetic-based approaches. As we continue this work, we will highlight the biochemical and physiological adaptations of S. mansoni in response to diverse environments during the parasite development, vector interaction, and host infection.
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Affiliation(s)
- Luiza F Andrade
- Genomics and Computational Biology Group, Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz - FIOCRUZ, Belo Horizonte, MG- 30190-002, Brazil
| | - Laila A Nahum
- Genomics and Computational Biology Group, Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz - FIOCRUZ, Belo Horizonte, MG- 30190-002, Brazil
- Centro de Excelência em Bioinformática, Fundação Oswaldo Cruz - FIOCRUZ, Belo Horizonte, MG- 30190-110, Brazil
| | - Lívia GA Avelar
- Genomics and Computational Biology Group, Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz - FIOCRUZ, Belo Horizonte, MG- 30190-002, Brazil
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais - UFMG, Belo Horizonte, MG- 31270-910, Brazil
| | - Larissa L Silva
- Genomics and Computational Biology Group, Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz - FIOCRUZ, Belo Horizonte, MG- 30190-002, Brazil
- Centro de Excelência em Bioinformática, Fundação Oswaldo Cruz - FIOCRUZ, Belo Horizonte, MG- 30190-110, Brazil
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais - UFMG, Belo Horizonte, MG- 31270-910, Brazil
| | - Adhemar Zerlotini
- Centro de Excelência em Bioinformática, Fundação Oswaldo Cruz - FIOCRUZ, Belo Horizonte, MG- 30190-110, Brazil
| | - Jerônimo C Ruiz
- Genomics and Computational Biology Group, Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz - FIOCRUZ, Belo Horizonte, MG- 30190-002, Brazil
| | - Guilherme Oliveira
- Genomics and Computational Biology Group, Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz - FIOCRUZ, Belo Horizonte, MG- 30190-002, Brazil
- Centro de Excelência em Bioinformática, Fundação Oswaldo Cruz - FIOCRUZ, Belo Horizonte, MG- 30190-110, Brazil
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19
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Brehm K. The role of evolutionarily conserved signalling systems in Echinococcus multilocularis development and host–parasite interaction. Med Microbiol Immunol 2010. [DOI: 78495111110.1007/s00430-010-0154-1' target='_blank'>'"<>78495111110.1007/s00430-010-0154-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [78495111110.1007/s00430-010-0154-1','', '10.1074/jbc.m104685200')">Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
78495111110.1007/s00430-010-0154-1" />
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20
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The role of evolutionarily conserved signalling systems in Echinococcus multilocularis development and host-parasite interaction. Med Microbiol Immunol 2010; 199:247-59. [PMID: 20376483 DOI: 10.1007/s00430-010-0154-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Indexed: 12/15/2022]
Abstract
Alveolar echinococcosis, one of the most serious and life-threatening zoonoses in the world, is caused by the metacestode larval stage of the fox-tapeworm Echinococcus multilocularis. Mostly due to its accessibility to in vitro cultivation, this parasite has recently evolved into an experimental model system to study larval cestode development and associated host-parasite interaction mechanisms. Respective advances include the establishment of axenic in vitro cultivation systems for parasite larvae as well as culture systems by which the early development of metacestode vesicles from totipotent parasite stem cells can be reconstituted under controlled laboratory conditions. A series of evolutionarily conserved signalling molecules of the insulin, epidermal growth factor and transforming growth factor-beta pathways that are able to functionally interact with corresponding host cytokines have been described in E. multilocularis and most likely play a crucial role in parasite development within the liver of the intermediate host. Furthermore, a whole genome sequencing project has been initiated by which a comprehensive picture on E. multilocularis cell-cell communication systems will be available in due time, including information on parasite cytokines that are secreted towards host tissue and thus might affect the immune response. In this article, an overview of our current picture on Echinococcus signalling systems will be given, and the potential to exploit these pathways as targets for anti-parasitic chemotherapy will be discussed.
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21
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Growth factors and chemotactic factors from parasitic helminths: molecular evidence for roles in host-parasite interactions versus parasite development. Int J Parasitol 2010; 40:761-73. [PMID: 20359480 DOI: 10.1016/j.ijpara.2010.02.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2010] [Revised: 02/25/2010] [Accepted: 02/25/2010] [Indexed: 01/04/2023]
Abstract
For decades molecular helminthologists have been interested in identifying proteins expressed by the parasite that have roles in modulating the host immune response. In some cases, the aim was targeting parasite-derived orthologues of mammalian cytokines and growth factors known to have functions in immune modulation. In others, novel proteins without homology to mammalian cytokines were isolated by investigating effects of purified worm extracts on various immunological processes. Often, the role parasite-derived growth factors play in worm development was ignored. Here, we review growth factors and chemotactic factors expressed by parasitic helminths and discuss their recognised and potential roles in immunomodulation and/or parasite development.
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22
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Echinococcus multilocularis as an experimental model in stem cell research and molecular host-parasite interaction. Parasitology 2009; 137:537-55. [PMID: 19961652 DOI: 10.1017/s0031182009991727] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Totipotent somatic stem cells (neoblasts) are key players in the biology of flatworms and account for their amazing regenerative capability and developmental plasticity. During recent years, considerable progress has been made in elucidating molecular features of neoblasts from free-living flatworms, whereas their role in parasitic species has so far merely been addressed by descriptive studies. Very recently, however, significant advances have been made in the in vitro culture of neoblasts from the cestode Echinococcus multilocularis. The isolated cells proved capable of generating mature metacestode vesicles under laboratory conditions in a manner that closely resembles the oncosphere-metacestode transition during natural infections. Using the established neoblast cultivation protocols, combined with targeted manipulation of Echinococcus genes by RNA-interference, several fundamental questions of host-dependent parasite development can now be addressed. Here, I give an overview of current cultivation techniques for E. multilocularis neoblasts and present experimental approaches to study their function. Furthermore, I introduce the E. multilocularis genome sequencing project that is presently in an advanced stage. The combined input of data from the E. multilocularis sequencing project, stem cell cultivation, and recently initiated attempts to genetically manipulate Echinococcus will provide an ideal platform for hypothesis-driven research into cestode development in the next years.
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LoVerde PT, Andrade LF, Oliveira G. Signal transduction regulates schistosome reproductive biology. Curr Opin Microbiol 2009; 12:422-8. [PMID: 19577949 DOI: 10.1016/j.mib.2009.06.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Revised: 05/15/2009] [Accepted: 06/01/2009] [Indexed: 10/20/2022]
Abstract
Schistosome parasites exhibit separate sexes and with the evolution of sex they have developed an intricate relationship between the male and female worms such that signals between the male and female that are initiated at the time of mating, regulate female reproductive development and subsequent egg production. As the egg stage is responsible for pathogenesis and transmission, understanding the molecular mechanisms of female reproductive development may identify novel targets for the control of transmission and morbidity of this major world public health problem. Recent data have demonstrated that the pairing process, proliferation, and differentiation of vitelline cells, expression of female-specific genes and egg embryogenesis are regulated by the TGFbeta pathway and protein tyrosine kinases.
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Affiliation(s)
- Philip T LoVerde
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78229, USA.
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Adisakwattana P, Saunders SP, Nel HJ, Fallon PG. Helminth-Derived Immunomodulatory Molecules. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 666:95-107. [DOI: 10.1007/978-1-4419-1601-3_8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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25
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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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26
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Bahia D, Andrade LF, Ludolf F, Mortara RA, Oliveira G. Protein tyrosine kinases in Schistosoma mansoni. Mem Inst Oswaldo Cruz 2008; 101 Suppl 1:137-43. [PMID: 17308761 DOI: 10.1590/s0074-02762006000900022] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Accepted: 06/26/2006] [Indexed: 11/22/2022] Open
Abstract
The identification and description of signal transduction molecules and mechanisms are essential to elucidate Schistosoma mansoni host-parasite interactions and parasite biology. This mini review focuses on recent advancements in the study of signalling molecules and transduction mechanisms in S. mansoni, drawing special attention to the recently identified and characterised protein tyrosine kinases of S. mansoni.
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Affiliation(s)
- Diana Bahia
- Centro de Pesquisas René Rachou-Fiocruz, Av. Augusto de Lima 1715, Barro Preto, 31190-002 Belo Horizonte, MG, Brazil.
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Carlo JM, Osman A, Niles EG, Wu W, Fantappie MR, Oliveira FMB, LoVerde PT. Identification and characterization of an R-Smad ortholog (SmSmad1B) fromSchistosoma mansoni. FEBS J 2007; 274:4075-93. [PMID: 17635586 DOI: 10.1111/j.1742-4658.2007.05930.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Smad proteins are the cellular mediators of the transforming growth factor-beta superfamily signals. Herein, we describe the isolation of a fourth Smad gene from the helminth Schistosoma mansoni, a receptor-regulated Smad (R-Smad) gene termed SmSmad1B. The SmSmad1B protein is composed of 380 amino acids, and contains conserved MH1 and MH2 domains separated by a short 42 amino acid linker region. The SmSmad1B gene (> 10.7 kb) is composed of five exons separated by four introns. On the basis of phylogenetic analysis, SmSmad1B demonstrates homology to Smad proteins involved in the bone morphogenetic protein pathway. SmSmad1B transcript is expressed in all stages of schistosome development, and exhibits the highest expression level in the cercariae stage. By immunolocalization experiments, the SmSmad1B protein was detected in the cells of the parenchyma of adult schistosomes as well as in female reproductive tissues. Yeast two-hybrid experiments revealed an interaction between SmSmad1B and the common Smad, SmSmad4. As determined by yeast three-hybrid assays and pull-down assays, the presence of the wild-type or mutated SmTbetaRI receptor resulted in a decreased interaction between SmSmad1B and SmSmad4. These results suggest the presence of a nonfunctional interaction between SmSmad1B and SmTbetaRI that does not give rise to the phosphorylation and the release of SmSmad1B to form a heterodimer with SmSmad4. SmSmad1B, as well as the schistosome bone morphogenetic protein-related Smad SmSmad1 and the transforming growth factor-beta-related SmSmad2, interacted with the schistosome coactivator proteins SmGCN5 and SmCBP1 in pull-down assays. In all, these data suggest the involvement of SmSmad1B in critical biological processes such as schistosome reproductive development.
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Affiliation(s)
- Joelle M Carlo
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, State University of New York, NY, USA
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Gene discovery for the carcinogenic human liver fluke, Opisthorchis viverrini. BMC Genomics 2007; 8:189. [PMID: 17587442 PMCID: PMC1913519 DOI: 10.1186/1471-2164-8-189] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2007] [Accepted: 06/22/2007] [Indexed: 12/30/2022] Open
Abstract
Background Cholangiocarcinoma (CCA) – cancer of the bile ducts – is associated with chronic infection with the liver fluke, Opisthorchis viverrini. Despite being the only eukaryote that is designated as a 'class I carcinogen' by the International Agency for Research on Cancer, little is known about its genome. Results Approximately 5,000 randomly selected cDNAs from the adult stage of O. viverrini were characterized and accounted for 1,932 contigs, representing ~14% of the entire transcriptome, and, presently, the largest sequence dataset for any species of liver fluke. Twenty percent of contigs were assigned GO classifications. Abundantly represented protein families included those involved in physiological functions that are essential to parasitism, such as anaerobic respiration, reproduction, detoxification, surface maintenance and feeding. GO assignments were well conserved in relation to other parasitic flukes, however, some categories were over-represented in O. viverrini, such as structural and motor proteins. An assessment of evolutionary relationships showed that O. viverrini was more similar to other parasitic (Clonorchis sinensis and Schistosoma japonicum) than to free-living (Schmidtea mediterranea) flatworms, and 105 sequences had close homologues in both parasitic species but not in S. mediterranea. A total of 164 O. viverrini contigs contained ORFs with signal sequences, many of which were platyhelminth-specific. Examples of convergent evolution between host and parasite secreted/membrane proteins were identified as were homologues of vaccine antigens from other helminths. Finally, ORFs representing secreted proteins with known roles in tumorigenesis were identified, and these might play roles in the pathogenesis of O. viverrini-induced CCA. Conclusion This gene discovery effort for O. viverrini should expedite molecular studies of cholangiocarcinogenesis and accelerate research focused on developing new interventions, drugs and vaccines, to control O. viverrini and related flukes.
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Freitas TC, Jung E, Pearce EJ. TGF-beta signaling controls embryo development in the parasitic flatworm Schistosoma mansoni. PLoS Pathog 2007; 3:e52. [PMID: 17411340 PMCID: PMC1847691 DOI: 10.1371/journal.ppat.0030052] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2006] [Accepted: 02/20/2007] [Indexed: 11/19/2022] Open
Abstract
Over 200 million people have, and another 600 million are at risk of contracting, schistosomiasis, one of the major neglected tropical diseases. Transmission of this infection, which is caused by helminth parasites of the genus Schistosoma, depends upon the release of parasite eggs from the human host. However, approximately 50% of eggs produced by schistosomes fail to reach the external environment, but instead become trapped in host tissues where pathological changes caused by the immune responses to secreted egg antigens precipitate disease. Despite the central importance of egg production in transmission and disease, relatively little is understood of the molecular processes underlying the development of this key life stage in schistosomes. Here, we describe a novel parasite-encoded TGF-β superfamily member, Schistosoma mansoni Inhibin/Activin (SmInAct), which is key to this process. In situ hybridization localizes SmInAct expression to the reproductive tissues of the adult female, and real-time RT-PCR analyses indicate that SmInAct is abundantly expressed in ovipositing females and the eggs they produce. Based on real-time RT-PCR analyses, SmInAct transcription continues, albeit at a reduced level, both in adult worms isolated from single-sex infections, where reproduction is absent, and in parasites from IL-7R−/− mice, in which viable egg production is severely compromised. Nevertheless, Western analyses demonstrate that SmInAct protein is undetectable in parasites from single-sex infections and from infections of IL-7R−/− mice, suggesting that SmInAct expression is tightly linked to the reproductive potential of the worms. A crucial role for SmInAct in successful embryogenesis is indicated by the finding that RNA interference–mediated knockdown of SmInAct expression in eggs aborts their development. Our results demonstrate that TGF-β signaling plays a major role in the embryogenesis of a metazoan parasite, and have implications for the development of new strategies for the treatment and prevention of an important and neglected human disease. Schistosomes are parasitic worms that infect hundreds of millions of people in developing countries. They cause disease by virtue of the fact that the eggs that they produce, which are intended for release from the host in order to allow transmission of infection, can become trapped in target organs such as the liver, where they induce damaging inflammation. Egg production by female schistosomes is critically dependent on the presence of male parasites, without which females never fully develop, and (counterintuitively) on the contribution of signals from the host's immune system. Very little is understood about the molecular basis of these interactions. Here, we describe a newly discovered schistosome gene, which is expressed in the reproductive tract of the female parasite and in parasite eggs. The protein encoded by this gene is made only when females are paired with males in an immunologically competent setting. Using recently developed tools that allow gene function to be inhibited in schistosomes, we show that the product of this gene plays a crucial role in egg development. Examining how the expression of this gene is controlled has the potential to provide insight into the molecular nature of the interactions between male and female parasites and their hosts. Moreover, the pivotal role of this gene in the egg makes it a potential target for blocking transmission and disease development.
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Affiliation(s)
- Tori C Freitas
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Euihye Jung
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Edward J Pearce
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * To whom correspondence should be addressed. E-mail:
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Loverde PT, Osman A, Hinck A. Schistosoma mansoni: TGF-beta signaling pathways. Exp Parasitol 2007; 117:304-17. [PMID: 17643432 PMCID: PMC2149906 DOI: 10.1016/j.exppara.2007.06.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 05/25/2007] [Accepted: 06/05/2007] [Indexed: 10/23/2022]
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. We review the role of the TGF-beta signaling pathway in parasite development, host-parasite interactions and male-female interactions. The data to date support multiple roles for the TGF-beta signaling pathway throughout schistosome development, in particular, in the tegument which is at the interface with the host and between the male and female schistosome, development of vitelline cells in female worms whose genes and development are regulated by a stimulus from the male schistosome and embryogenesis of the egg. The human ligand TGF-beta1 has been demonstrated to regulate the expression of a schistosome target gene that encodes a gynecophoric canal protein in the schistosome worm itself. Studies on signaling in schistosomes opens a new era for investigation of host-parasite and male-female interactions.
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Affiliation(s)
- Philip T Loverde
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA.
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31
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Abstract
The syncytial cytoplasmic layer, termed the tegument, which covers the entire surface of adult schistosomes, is a major interface between the parasite and its host. Since schistosomes can survive for decades within the host bloodstream, they are clearly able to evade host immune responses, and their ability is dependent on the properties of the tegument surface. We review here the molecular organization and biochemical functions of the tegument, combining the extensive literature over the last three decades with recent proteomic studies. We have interpreted the organization of the tegument surface as bounded by a conventional plasma membrane overlain by a membrane-like secretion, the membranocalyx, with which host molecules can associate. The range of parasite proteins, glycans and lipids found in the surface complex is evaluated, together with the host molecules detected. We consider the way in which the tegument surface is formed after cercarial penetration into the skin, and changes that occur as parasites develop to maturity. Lastly, we review the evidence on surface dynamics and turnover.
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Affiliation(s)
- Patrick J Skelly
- Tufts Cummings School of Veterinary Medicine, Department of Biomedical Sciences, 20 Westboro Road, North Grafton, MA 01536, USA
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Osman A, Niles EG, Verjovski-Almeida S, LoVerde PT. Schistosoma mansoni TGF-beta receptor II: role in host ligand-induced regulation of a schistosome target gene. PLoS Pathog 2006; 2:e54. [PMID: 16789838 PMCID: PMC1479047 DOI: 10.1371/journal.ppat.0020054] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2006] [Accepted: 04/26/2006] [Indexed: 11/19/2022] Open
Abstract
Members of transforming growth factor-beta (TGF-β) superfamily play pivotal roles in development in multicellular organisms. We report the functional characterization of the Schistosoma mansoni type II receptor (SmTβRII). Mining of the S. mansoni expressed sequence tag (EST) database identified an EST clone that shows homology to the kinase domain of type II receptors from different species. The amplified EST sequence was used as a probe to isolate a cDNA clone spanning the entire coding region of a type II serine/threonine kinase receptor. The interaction of SmTβRII with SmTβRI was elucidated and shown to be dependent on TGF-β ligand binding. Furthermore, in the presence of human TGF-β1, SmTβRII was able to activate SmTβRI, which in turn activated SmSmad2 and promoted its interaction with SmSmad4, proving the transfer of the signal from the receptor complex to the Smad proteins. Gynaecophoral canal protein (GCP), whose expression in male worms is limited to the gynaecophoric canal, was identified as a potential TGF-β target gene in schistosomes. Knocking down the expression of SmTβRII using short interfering RNA molecules (siRNA) resulted in a concomitant reduction in the expression of GCP. These data provide evidence for the direct involvement of SmTβRII in mediating TGF-β–induced activation of the TGF-β target gene, SmGCP, within schistosome parasites. The results also provide additional evidence for a role for the TGF-β signaling pathway in male-induced female reproductive development. Schistosomes are multicellular parasites that infect 200 million people worldwide. Schistosome development in the human host likely involves host molecules that regulate biological processes of the parasite. Members of transforming growth factor-beta (TGF-β) superfamily play pivotal roles in development in multicellular organisms. TGF-β signaling requires ligand binding to a specific surface receptor, TGF-β type II receptor. The authors isolated the schistosome TGF-β type II receptor (SmTβRII), which was found to be biologically active and responded to stimulation by host TGF-β. The gynaecophoric canal is a ventral groove in the male worm in which the female must reside for sexual maturity. Gynaecophoral canal protein (GCP) is a protein whose expression in male worms is limited to the gynaecophoric canal and is implicated in female reproductive maturation. GCP expression was found to be regulated by human TGF-β. Knocking down the expression of SmTβRII resulted in a concomitant reduction in the expression of GCP, providing evidence for the direct involvement of SmTβRII-mediated, host TGF-β–induced regulation of schistosome gene expression. This study implicates the TGF-β signaling pathway in worm pairing, a prerequisite for female egg production. Because the eggs produced by the worm pairs are responsible for pathogenesis, the authors' research identifies potential targets for intervention.
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Affiliation(s)
- Ahmed Osman
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, United States of America
| | - Edward G Niles
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, United States of America
| | | | - Philip T LoVerde
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, United States of America
- Southwest Foundation for Biomedical Research, San Antonio, Texas, United States of America
- * To whom correspondence should be addressed. E-mail:
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Wang C, Xia C, Bian W, Liu L, Lin W, Chen YG, Ang SL, Jing N. Cell aggregation-induced FGF8 elevation is essential for P19 cell neural differentiation. Mol Biol Cell 2006; 17:3075-84. [PMID: 16641368 PMCID: PMC1483041 DOI: 10.1091/mbc.e05-11-1087] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
FGF8, a member of the fibroblast growth factor (FGF) family, has been shown to play important roles in different developing systems. Mouse embryonic carcinoma P19 cells could be induced by retinoic acid (RA) to differentiate into neuroectodermal cell lineages, and this process is cell aggregation dependent. In this report, we show that FGF8 expression is transiently up-regulated upon P19 cell aggregation, and the aggregation-dependent FGF8 elevation is pluripotent stem cell related. Overexpressing FGF8 promotes RA-induced monolayer P19 cell neural differentiation. Inhibition of FGF8 expression by RNA interference or blocking FGF signaling by the FGF receptor inhibitor, SU5402, attenuates neural differentiation of the P19 cell. Blocking the bone morphogenetic protein (BMP) pathway by overexpressing Smad6 in P19 cells, we also show that FGF signaling plays a BMP inhibition-independent role in P19 cell neural differentiation.
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Affiliation(s)
- Chen Wang
- *Key Laboratory of Stem Cell Biology and Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences and Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Caihong Xia
- *Key Laboratory of Stem Cell Biology and Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences and Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Wei Bian
- *Key Laboratory of Stem Cell Biology and Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences and Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Li Liu
- *Key Laboratory of Stem Cell Biology and Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences and Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Wei Lin
- *Key Laboratory of Stem Cell Biology and Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences and Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- Division of Developmental Neurobiology, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom; and
| | - Ye-Guang Chen
- Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, China
| | - Siew-Lan Ang
- Division of Developmental Neurobiology, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom; and
| | - Naihe Jing
- *Key Laboratory of Stem Cell Biology and Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences and Graduate School of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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Vermeire JJ, Humphries JE, Yoshino TP. Signal transduction in larval trematodes: putative systems associated with regulating larval motility and behaviour. Parasitology 2006; 131 Suppl:S57-70. [PMID: 16569293 DOI: 10.1017/s0031182005008358] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The multi-host lifestyle of parasitic trematodes necessitates their ability to communicate with their external environment in order to invade and navigate within their hosts' internal environment. Through recent EST and genome sequencing efforts, it has become clear that members of the Trematoda possess many of the elaborate signal transduction systems that have been delineated in other invertebrate model systems like Drosophila melanogaster and Caenorhabditis elegans. Gene homologues representing several well-described signal receptor families including receptor tyrosine kinases, receptor serine tyrosine kinases, G protein-coupled receptors and elements of their downstream signalling systems have been identified in larval trematodes. A majority of this work has focused on the blood flukes, Schistosoma spp. and therefore represents a narrow sampling of the diverse digenean helminth taxon. Despite this fact and given the substantial evidence supporting the existence of such signalling systems, the question then becomes, how are these systems employed by larval trematodes to aid them in interpreting signals received from their immediate environment to initiate appropriate responses in cells and tissues comprising the developing parasite stages? High-throughput, genome-wide analysis tools now allow us to begin to functionally characterize genes differentially expressed throughout the development of trematode larvae. Investigation of the systems used by these parasites to receive and transduce external signals may facilitate the creation of technologies for achieving control of intramolluscan schistosome infections and also continue to yield valuable insights into the basic mechanisms regulating motility and behaviour in this important group of helminths.
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Affiliation(s)
- J J Vermeire
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 2115 Observatory Drive, Madison, WI 53706, USA
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35
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Dissous C, Khayath N, Vicogne J, Capron M. Growth factor receptors in helminth parasites: Signalling and host-parasite relationships. FEBS Lett 2006; 580:2968-75. [PMID: 16579990 DOI: 10.1016/j.febslet.2006.03.046] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2006] [Accepted: 03/12/2006] [Indexed: 11/29/2022]
Abstract
Parasitic helminths remain major pathogens of both humans and animals throughout the world. The success of helminth infections depends on the capacity of the parasite to counteract host immune responses but also to exploit host-derived signal molecules for its development. Recent progress has been made in the characterization of growth factor receptors of various nematode and flatworm parasites with the demonstration that transforming growth factor beta (TGF-beta), epidermal growth factor (EGF) and insulin receptor signalling pathways are conserved in helminth parasites and potentially implicated in the host-parasite molecular dialogue and parasite development.
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Affiliation(s)
- Colette Dissous
- Unité Inserm 547, Institut Pasteur de Lille, 1 Rue du Pr. Calmette, 59019 Lille Cedex, France.
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36
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Zavala-Góngora R, Kroner A, Bernthaler P, Knaus P, Brehm K. A member of the transforming growth factor-beta receptor family from Echinococcus multilocularis is activated by human bone morphogenetic protein 2. Mol Biochem Parasitol 2006; 146:265-71. [PMID: 16434111 DOI: 10.1016/j.molbiopara.2005.12.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 12/16/2005] [Accepted: 12/19/2005] [Indexed: 10/25/2022]
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37
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Brehm K, Spiliotis M, Zavala-Góngora R, Konrad C, Frosch M. The molecular mechanisms of larval cestode development: first steps into an unknown world. Parasitol Int 2005; 55 Suppl:S15-21. [PMID: 16343987 DOI: 10.1016/j.parint.2005.11.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Several hundred million years ago, the free-living ancestors of all extant helminth parasites decided to colonize entirely new habitats, the bodies of other metazoan animals. As a consequence of the resulting adaptation processes, they evolved highly complex life-cycles in which many developmental transitions were initiated and controlled by host-derived signals. Understanding the molecular basis of the original developmental mechanisms, and the modifications that occurred during co-evolution with the host, is not only fundamental to our understanding of parasitism but also highly relevant for the design of anti-parasitic drugs and vaccines. In the past several years, molecular investigations on parasitic nematode and trematode development have made considerable progress and, supported by respective genome sequencing projects and emerging methods of genetic manipulation, will be a flourishing field in the years to come. We consider it time that corresponding studies are also pushed for the third large group of parasitic helminths, the cestodes. Here, we review the first experimental steps into that area, which have been undertaken recently. We report on cestode genomics, the identification of signaling factors associated with larval development, and the establishment as well as improvement of in vitro cultivation systems by which cestode life-cycles can be studied in the laboratory.
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Affiliation(s)
- Klaus Brehm
- Institute of Hygiene and Microbiology, University of Würzburg, Germany.
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38
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Waghabi MC, Keramidas M, Bailly S, Degrave W, Mendonça-Lima L, Soeiro MDNC, Meirelles MDNL, Paciornik S, Araújo-Jorge TC, Feige JJ. Uptake of host cell transforming growth factor-beta by Trypanosoma cruzi amastigotes in cardiomyocytes: potential role in parasite cycle completion. THE AMERICAN JOURNAL OF PATHOLOGY 2005; 167:993-1003. [PMID: 16192635 PMCID: PMC1603686 DOI: 10.1016/s0002-9440(10)61189-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The cytokine transforming growth factor-beta (TGF-beta) plays various functions in the control of Trypanosoma cruzi infectivity and in the progression of Chagas' disease. When we immunostained T. cruzi-infected cardiomyocytes (after either in vivo or in vitro infections) for TGF-beta, we observed stronger immunoreactivity in parasites than in host cells. TGF-beta immunoreactivity evolved during parasite cycle progression, with intense staining in amastigotes versus very faint staining in trypomastigotes. TGF-beta was present on the surface of amastigotes, in the flagellar pocket, and in intraparasitic vesicles as revealed by electron microscopy. However, no ortholog TGF-beta gene could be identified in the genome of T. cruzi by in silico analysis or by extensive polymerase chain reaction and reverse transcriptase-polymerase chain reaction studies. Immunoreactive TGF-beta was most probably taken up by the parasite from the host cell cytoplasm because such an internalization process of biotinylated TGF-beta could be observed in axenic amastigotes in vitro. These observations represent the first example of a novel mechanism by which a primitive unicellular protozoan can use host cell TGF-beta to control its own intracellular life cycle.
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Affiliation(s)
- Mariana C Waghabi
- Laboratorios de Biologia Celular, Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
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39
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Wakahara K, Kobayashi H, Yagyu T, Matsuzaki H, Kondo T, Kurita N, Sekino H, Inagaki K, Suzuki M, Kanayama N, Terao T. Bikunin down-regulates heterodimerization between CD44 and growth factor receptors and subsequently suppresses agonist-mediated signaling. J Cell Biochem 2005; 94:995-1009. [PMID: 15597342 DOI: 10.1002/jcb.20364] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We provided evidence previously that bikunin, a Kunitz-type protease inhibitor, can disrupt dimerization of CD44 proteins, which may result in suppression of receptor-mediated MAP kinase signaling. However, to what extent dimerization may alter ligand-induced signaling has not been documented. Given the recent recognition that some growth factor receptors can form heterodimers with CD44, the present study was undertaken to determine whether the CD44 and growth factor receptors (e.g., EGFR, FGFR, HGFR, VEGFR, TGF-betaRI, or TGF-betaRII) can form heterodimers in cancer cells and, if so, to investigate the potential functional consequences of such heterodimerization. We also examined whether bikunin can abrogate these heterodimerizations and inhibit CD44/growth factor-dependent signaling. Here, we show direct evidence for heterodimerization of CD44-FGFR and CD44-TGF-betaRI in human chondrosarcoma HCS-2/8 cells, CD44-EGFR complex in human glioma U87MG cells, and CD44-TGF-betaRI heterodimer in human ovarian cancer HRA cells. Coupling of CD44 and growth factor receptor may be selective, depending on a cell type. Bikunin does not alter the ligand binding, whereas functionally reduces heterodimerization between CD44 and growth factor receptors. The disruption of heterodimerization substantially reduces receptor-induced tyrosine phosphorylation and ERK1/2 activation. Taken together, our data suggest that bikunin-mediated suppression of heterodimerization between CD44 and growth factors may inhibit the agonist-promoted activation of the signaling pathway.
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Affiliation(s)
- Kiyoshi Wakahara
- NetForce Co. Ltd., Taiko 3-1-18, Nakamura, Nagoya, Aichi 453-0801, Japan
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40
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Tarrab-Hazdai R, Hanoch T, Jeon SH, Pauli H, Gold D, Arnon R, Seger R. ECTO- AND EXO-PROTEIN KINASES IN SCHISTOSOMA MANSONI: REGULATION OF SURFACE PHOSPHORYLATION BY ACETYLCHOLINE AND IDENTIFICATION OF THE ALPHA SUBUNIT OF CKII AS A MAJOR SECRETED PROTEIN KINASE. J Parasitol 2005; 91:756-63. [PMID: 17089740 DOI: 10.1645/ge-458r.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The Schistosoma mansoni parasite life cycle involves complex developmental processes that enable it to cause severe hepatic damage. Protein phosphorylation has previously been implicated in the transformation of cercariae to schistosomula of S. mansoni. Here, we studied the possible involvement of surface (ecto) and shed (exo) protein kinases (PKs) in this developmental process. We found that ecto-PKs are indeed located on the surface of the schistosomula and can phosphorylate up to 5 distinct proteins at this location. Surface phosphorylation was sensitive to acetylcholine, which increased phosphorylation of 3 proteins and reduced phosphorylation of the other 2. The ecto-PKs can be shed from the surface into the incubation medium during parasite differentiation. The main exo-PK is CKII, as concluded from the substrate specificity of the PK, its inhibition by heparin, activation by spermin, and recognition by antibody directed to the anti--alpha-subunit of CKII in the incubation medium of the schistosomula. In spite of its similarity to the ecto-PKs, the activity of the exo-PK is not affected by addition of acetylcholine. These results indicate that ecto- and exo-PKs could be involved in the parasite's development or host-parasite interactions.
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Affiliation(s)
- Rebeca Tarrab-Hazdai
- Department of Immunology, The Weizmann Institute of Science 76100 Rehovot, Israel
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41
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Daly R, Hearn MTW. Expression of heterologous proteins in Pichia pastoris: a useful experimental tool in protein engineering and production. J Mol Recognit 2005; 18:119-38. [PMID: 15565717 DOI: 10.1002/jmr.687] [Citation(s) in RCA: 514] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The use of the methylotrophic yeast, Pichia pastoris, as a cellular host for the expression of recombinant proteins has become increasing popular in recent times. P. pastoris is easier to genetically manipulate and culture than mammalian cells and can be grown to high cell densities. Equally important, P. pastoris is also a eukaryote, and thereby provides the potential for producing soluble, correctly folded recombinant proteins that have undergone all the post-translational modifications required for functionality. Additionally, linearized foreign DNA can be inserted in high efficiency via homologous recombination procedures to generate stable cell lines whilst expression vectors can be readily prepared that allow multiple copies of the target protein, multimeric proteins with different subunit structures, or alternatively the target protein and its cognate binding partners, to be expressed. A further benefit of the P. pastoris system is that strong promoters are available to drive the expression of a foreign gene(s) of interest, thus enabling production of large amounts of the target protein(s) with relative technical ease and at a lower cost than most other eukaryotic systems. The purpose of this review is to summarize important developments and features of this expression system and, in particular, to examine from an experimental perspective the genetic engineering, protein chemical and molecular design considerations that have to be taken into account for the successful expression of the target recombinant protein. Included in these considerations are the influences of P. pastoris strain selection; the choice of expression vectors and promoters; procedures for the transformation and integration of the vectors into the P. pastoris genome; the consequences of rare codon usage and truncated transcripts; and techniques employed to achieve multi-copy integration numbers. The impact of the alcohol oxidase (AOX) pathways in terms of the mut+ and mut(s) phenotypes, intracellular expression and folding pathways is examined. The roles of pre-pro signal sequences such as the alpha mating factor (alpha-MF) and the Glu-Ala repeats at the kex2p cleavage site on the processing of the protein translate(s) have also been considered. Protocols for the generation of protein variants and mutants for screening for orphan cognate binding partners and the use of experimental platforms addressing the molecular recognition behaviour of recombinant proteins such as the extracellular domains of transmembrane receptors with their physiological ligands are also described. Finally, the palindromic patterns of glycosylation that can occur with these expression systems, in terms of the role and location of the sequon in the primary structure, the number of mannose units and the types of oligosaccharides incorporated as Asn- or O-linkages and their impact on the thermostability and immunogenicity of the recombinant protein are considered. Procedures to prevent glycosylation through manipulation of cell culture conditions or via enzymatic and site-directed mutagenesis methods are also discussed.
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Affiliation(s)
- Rachel Daly
- ARC Special Research Centre for Green Chemistry, Monash University, Building 23, Wellington Road, Clayton, Victoria 3800, Australia
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42
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Dunne DW, Cooke A. A worm's eye view of the immune system: consequences for evolution of human autoimmune disease. Nat Rev Immunol 2005; 5:420-6. [PMID: 15864275 DOI: 10.1038/nri1601] [Citation(s) in RCA: 184] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Humans and the many parasites that we can host have co-evolved over millions of years. This has been compared to an arms race in which the immune armoury of the human has evolved to deal with potential pathogens and the pathogen has evolved strategies to evade, and in some cases use, the immune system of the human host. Recently, there have been marked changes in the exposure of individuals in the developed world to both microorganisms and metazoan parasites, so the immune stimuli such organisms provide no longer have a role in our lives. As we discuss here, this is a marked perturbation, and the absence of the associated immunomodulation might have led to the increased emergence of autoimmune diseases.
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Affiliation(s)
- David W Dunne
- Department of Pathology, University of Cambridge, Cambridge, UK
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43
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Hirata M, Hirata K, Hara T, Kawabuchi M, Fukuma T. Expression of TGF-?-like molecules in the life cycle of Schistosoma japonicum. Parasitol Res 2005; 95:367-73. [PMID: 15711848 DOI: 10.1007/s00436-004-1296-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Accepted: 11/23/2004] [Indexed: 11/28/2022]
Abstract
The transforming growth factor beta (TGF-beta) family controls an extremely wide range of biological activities, such as the growth and differentiation of cells, and immunological events against infectious agents. Although TGF-beta homologs appear to be widely present in metazoan animals, studies of parasite-derived molecules are relatively few. Using antibodies against anti-mouse TGF-beta1, -beta2, and -beta3, we show the expression of TGF-beta-like molecules in Schistosoma japonicum cercariae, schistosomula, eggs and adult worms. Intense immunoreactivity was found on the surface of free-living cercarial bodies. In transverse sections of cercariae, the molecules were localized in the tegument and subtegumental cells, and the number and distribution of producing cells significantly differed with each antibody. In the skin-migrating stage, the expression in the tegumental surface gradually decreased and became almost negative within 48 h of exposure. In adult worms and eggs, the reactivity was found in subtegumental cells and in cells of a tubular structure, respectively. In western blot analysis, the detection of conventional TGF-beta molecules failed. The expression of TGF-beta-like molecules was distinctly regulated at each developmental stage.
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Affiliation(s)
- M Hirata
- Department of Parasitology, Kurume University School of Medicine, 830-0011, Kurume, Japan.
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Waghabi MC, Keramidas M, Feige JJ, Araujo-Jorge TC, Bailly S. Activation of transforming growth factor β by Trypanosoma cruzi. Cell Microbiol 2004; 7:511-7. [PMID: 15760451 DOI: 10.1111/j.1462-5822.2004.00481.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The anti-inflammatory cytokine, transforming growth factor beta (TGFbeta), plays an important role in Chagas disease, which is caused by the protozoan parasite Trypanosoma cruzi. In the current study, we show that the addition of an anti-TGFbeta antibody inhibited T. cruzi infection of cardiomyocytes, demonstrating the requirement for active endogenous TGFbeta. As TGFbeta is synthesized as a biologically inactive precursor, which is proteolytically processed to yield a mature, active homodimer, we hypothesized that T. cruzi could activate latent TGFbeta. To test this, we added recombinant latent TGFbeta to a TGFbeta-responsive reporter cell line in the presence of T. cruzi. We observed that T. cruzi was able to activate latent recombinant TGFbeta in this cellular model. We then investigated the ability of T. cruzi to activate latent TGFbetain vitro. We found that live T. cruzi, or cytosolic extracts of T. cruzi, activated latent TGFbeta in a dose- and temperature-dependent manner. The agent involved in TGFbeta activation was shown to be thermolabile and hydrophobic. Taken together, our studies demonstrate that T. cruzi directly activates latent TGFbeta. This activation is required for parasite entry into the mammalian cells and is likely to play an important role in modulating the outcome of T. cruzi infection.
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Affiliation(s)
- M C Waghabi
- Lab. de Biologia Celular, Depto. de Ultra-estrutura e Biologia Celular, Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
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Knobloch J, Rossi A, Osman A, LoVerde PT, Klinkert MQ, Grevelding CG. Cytological and biochemical evidence for a gonad-preferential interplay of SmFKBP12 and SmTβR-I in Schistosoma mansoni. Mol Biochem Parasitol 2004; 138:227-36. [PMID: 15555734 DOI: 10.1016/j.molbiopara.2004.09.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2004] [Revised: 09/20/2004] [Accepted: 09/30/2004] [Indexed: 11/19/2022]
Abstract
In eukaryotes, FK506-binding proteins with a molecular weight of 12 kDa (FKBP12s) influence a variety of signal transduction pathways that regulate cell division, differentiation, and ion homeostasis. Amongst these, TGFbeta signaling and calcineurin (CN) phosphatase activity is modulated by FKBP12 via binding to TGFbeta-family type I receptors (TbetaR-Is) or to the CN subunit A, respectively. In this work, we demonstrate the tissue-specific expression of the Schistosoma mansoni FKBP12 homologue (SmFKBP12) in the gonads of female parasites as well as in the tegument of both genders. Components of the TGFbeta pathway have been characterized in schistosomes and their roles in mediating host-parasite or male-female interactions proposed. We show that a schistosome TGFbeta-family type I receptor (SmTbetaR-I, SmRK-1) is expressed in the female gonads, suggesting that SmFKBP12 may regulate its activity in this tissue. This hypothesis is supported by yeast two-hybrid analyses showing a direct binding of SmFKBP12 and SmTbetaR-I, which was specifically inhibited by the drug FK506. Our data provide the first evidence for the activity of a transmembrane receptor in the vitellarium of schistosome females and indicate that FKBP12-meditated regulation of the TGFbeta pathway is evolutionarily conserved in a primitive metazoan such as Schistosoma. Furthermore, we show that the schistosome CN (SmCN) is not expressed in the female gonads, but co-localizes with SmFKBP12 only in the tegument. From these data we conclude an SmFKBP12/SmTbetaR-I, but not an SmCN/SmFKBP12 interplay in the female gonads.
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Affiliation(s)
- Jürgen Knobloch
- Institut für Genetik, Genetische Parasitologie und Biologisch-Medizinisches-Forschungszentrum, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
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Forrester SG, Warfel PW, Pearce EJ. Tegumental expression of a novel type II receptor serine/threonine kinase (SmRK2) in Schistosoma mansoni. Mol Biochem Parasitol 2004; 136:149-56. [PMID: 15478794 DOI: 10.1016/j.molbiopara.2004.03.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The TGF-beta family of receptor serine/threonine kinases (RSTKs) is responsible for a diverse array of functions in metazoans. Here, we describe the isolation of SmRK2, a type II RSTK expressed in schistosomula and adult stages of Schistosoma mansoni. Based on amino acid sequence homology, SmRK2 is most closely related to the Activin type II receptor subset of RSTKs. SmRK2 appears to be expressed as three different transcripts: one encoding a full-length receptor with 5'- and 3'-untranslated regions (UTRs) (SmRK2), a second encoding a longer form containing no 3'-UTR and no stop codon (SmRK2a), and a third truncated variant (SmRK2b), which contains sequence encoding the first 53 amino acids of the N-terminal extracellular domain followed by an inserted 10 residue hydrophobic domain. Using an anti-peptide antibody raised against a partial extracellular domain sequence common to all three isoforms, SmRK2 was localized predominantly to the tegumental surface of the parasites. We hypothesize that SmRK2 is the receptor partner for the previously reported type I RSTK SmRK1 (or SmTbetaR1) and that together these proteins constitute a receptor system for receiving signals from the mammalian host.
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Affiliation(s)
- Sean G Forrester
- Department of Pathobiology, University of Pennsylvania, 202D Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104-6076, USA
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Zavala-Góngora R, Kroner A, Wittek B, Knaus P, Brehm K. Identification and characterisation of two distinct Smad proteins from the fox-tapeworm Echinococcus multilocularis. Int J Parasitol 2004; 33:1665-77. [PMID: 14636682 DOI: 10.1016/s0020-7519(03)00208-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Members of the transforming growth factor-beta (TGF-beta) family of cytokines and their corresponding receptors regulate cellular key processes such as proliferation and differentiation, and could be involved in communication mechanisms between parasitic helminths and their hosts. A pivotal role in intracellular TGF-beta signalling is played by Smad factors which directly transmit incoming signals from the cell surface receptors to the nucleus. In this study, we have identified and characterised two novel members of the Smad family, EmSmadA and EmSmadB, which are expressed by the human parasite Echinococcus multilocularis. Based on amino acid sequence comparisons, both echinococcal Smad homologues could be classified as members of the R-Smad subfamily. EmSmadB showed a typical domain structure consisting of conserved MH1 and MH2 domains separated by a proline-rich linker region. EmSmadA, on the other hand, lacked an MH1 region and merely contained an MH2 domain, a feature which has so far not been described for R-Smads. Based on the structures of the corresponding chromosomal loci and on sequence features of the conserved L3 loop regions, EmSmadA and EmSmadB are most likely involved in the transmission of TGF-beta- and bone morphogenetic protein (BMP) signals, respectively. Yeast two-hybrid analyses revealed that both Echinococcus Smads are capable of homo- and heterodimer formations. However, while the formation of homodimers for EmSmadB required previous activation of the protein at the C-terminal SSVS motif, EmSmadA homodimers were already formed in the basal state of the factor. Upon expression of the Echinococcus Smads in human cells, EmSmadA, but not EmSmadB, was phosphorylated by the human TGF-beta type I receptor. Furthermore, both factors functionally interacted with human BMP receptors. By reverse transcriptase-PCR experiments, the encoding genes, emsmadA and emsmadB, were shown to be expressed in the larval stages metacestode and protoscolex during an infection of the intermediate host. Taken together, our data suggest an involvement of EmSmadA and EmSmadB in echinococcal developmental processes during natural infections and provide a solid basis for further investigations on TGF-beta signalling mechanisms in cestodes.
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Affiliation(s)
- Ricardo Zavala-Góngora
- Institute for Hygiene and Microbiology, University of Würzburg, Josef-Schneider-Strasse 2, D-97080 Würzburg, Germany
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Abstract
Schistosome parasites are muticellular eucaryotic organisms with a complex life cycle that involves mammalian and snail hosts. Unlike other trematode parasites, schistosomes (along with the Didymozoidae) have evolved separate sexes or dioecy. Sex is determined by a chromosomal mechanism. The dioecious state created an opportunity for the sexes to play a role in schistosome evolution that has resulted in an interesting interplay between the sexes. The classical observation, made more than 50 years ago, is that female schistosomes do not develop unless a male worm is present. Studies up through the 1990s focused on dissecting the role of the sexes in mate attraction, mate choice, mating behavior, female growth, female reproductive development, egg production, and other sex-evolved functions. In the mid-1980s, studies began to address the molecular events of male–female interactions. The classic morphological observation that female schistosomes do not complete reproductive development unless a male worm is present has been redefined in molecular terms. The male by an unknown mechanism transduces a signal that regulates female gene expression in a stage-, tissue-, and temporal-specific manner. A number of female-specific genes have been identified, along with signaling pathways and nuclear receptors, that play a role in female reproductive development. In addition, a number of host factors such as cytokines have also been demonstrated to affect adult male and female development and egg production. This review focuses on the biological interactions of the male and female schistosome and the role of parasite and host factors in these interactions as they contribute to the life cycle of Schistosoma mansoni.
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Omer FM, de Souza JB, Corran PH, Sultan AA, Riley EM. Activation of transforming growth factor beta by malaria parasite-derived metalloproteinases and a thrombospondin-like molecule. ACTA ACUST UNITED AC 2004; 198:1817-27. [PMID: 14676296 PMCID: PMC2194152 DOI: 10.1084/jem.20030713] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Much of the pathology of malaria is mediated by inflammatory cytokines (such as interleukin 12, interferon γ, and tumor necrosis factor α), which are part of the immune response that kills the parasite. The antiinflammatory cytokine transforming growth factor (TGF)-β plays a crucial role in preventing the severe pathology of malaria in mice and TGF-β production is associated with reduced risk of clinical malaria in humans. Here we show that serum-free preparations of Plasmodium falciparum, Plasmodium yoelii 17XL, and Plasmodium berghei schizont-infected erythrocytes, but not equivalent preparations of uninfected erythrocytes, are directly able to activate latent TGF-β (LatTGF-β) in vitro. Antibodies to thrombospondin (TSP) and to a P. falciparum TSP-related adhesive protein (PfTRAP), and synthetic peptides from PfTRAP and P. berghei TRAP that represent homologues of TGF-β binding motifs of TSP, all inhibit malaria-mediated TGF-β activation. Importantly, TRAP-deficient P. berghei parasites are less able to activate LatTGF-β than wild-type parasites and their replication is attenuated in vitro. We show that activation of TGF-β by malaria parasites is a two step process involving TSP-like molecules and metalloproteinase activity. Activation of LatTGF-β represents a novel mechanism for direct modulation of the host response by malaria parasites.
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Affiliation(s)
- Fakhreldin M Omer
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
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Osman A, Niles EG, LoVerde PT. Expression of functional Schistosoma mansoni Smad4: role in Erk-mediated transforming growth factor beta (TGF-beta) down-regulation. J Biol Chem 2003; 279:6474-86. [PMID: 14630909 DOI: 10.1074/jbc.m310949200] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Members of the transforming growth factor (TGF)-beta superfamily play pivotal roles in cell migration, differentiation, adhesion, pattern formation, and apoptosis. The family of Smad proteins acts as intracellular signal transducers of TGF-beta and related peptides. Smad4, a common mediator Smad (co-Smad), performs a central role in transmitting signals from TGF-beta, BMP, and activins. Schistosoma mansoni receptor-regulated Smad1 and SmSmad2 were previously identified and shown to act in TGF-beta signaling. Herein, we report the identification and characterization of a Smad4 homologue from S. mansoni and provide details about its role in mediation and down-regulation of TGF-beta signaling in schistosomes. In order to identify the schistosome co-Smad, we designed degenerate primers based on the sequence of the conserved MH1/MH2 domains of Smad4 proteins, which were used in PCR to amplify a 137-bp PCR product. A S. mansoni adult worm pair cDNA library was screened resulting in the isolation of a cDNA clone that encodes a 738 amino acid protein (SmSmad4). SmSmad4 was shown to interact with schistosome R-Smads (SmSmad1 and SmSmad2) in vivo and in vitro. The interaction with SmSmad2 was dependent on the receptor-mediated phosphorylation of SmSmad2. In addition, several potential phosphorylation sites for Erk1/2 kinases were identified in the SmSmad4 linker region and shown to be phosphorylated in vitro by an active mutant of mammalian Erk2. Furthermore, Erk-mediated phosphorylation of SmSmad4 decreased its interaction with the receptor-activated form of SmSmad2, in vitro. SmSmad4 was shown to complement a human Smad4 deficiency through the restoration of TGF-beta-responsiveness in MDA-MB-468 breast cancer cells.
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Affiliation(s)
- Ahmed Osman
- Department of Microbiology and Immunology and Witebsky Center for Microbial Pathogenesis and Immunology, School of Medicine, State University of New York, Buffalo, New York 14214, USA
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