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2013
Petrillo Jessica E, Venter Arno P, Short James R, Gopal Radhika, Deddouche Safia, Lamiable Olivier, Imler Jean-Luc, Schneemann Anette
Cytoplasmic granule formation and translational inhibition of nodaviral RNAs in the absence of the double-stranded RNA binding protein B2 Article de journal
Dans: Journal of Virology, vol. 87, non 24, p. 13409–13421, 2013, ISSN: 1098-5514.
Résumé | Liens | BibTeX | Étiquettes: Animals, Capsid Proteins, Cell Line, Cricetinae, Cytoplasmic Granules, Double-Stranded, imler, M3i, Nodaviridae, Protein Biosynthesis, RNA, RNA Virus Infections, RNA-Binding Proteins, Viral, Viral Proteins
@article{petrillo_cytoplasmic_2013,
title = {Cytoplasmic granule formation and translational inhibition of nodaviral RNAs in the absence of the double-stranded RNA binding protein B2},
author = {Jessica E Petrillo and Arno P Venter and James R Short and Radhika Gopal and Safia Deddouche and Olivier Lamiable and Jean-Luc Imler and Anette Schneemann},
doi = {10.1128/JVI.02362-13},
issn = {1098-5514},
year = {2013},
date = {2013-12-01},
journal = {Journal of Virology},
volume = {87},
number = {24},
pages = {13409--13421},
abstract = {Flock House virus (FHV) is a positive-sense RNA insect virus with a bipartite genome. RNA1 encodes the RNA-dependent RNA polymerase, and RNA2 encodes the capsid protein. A third protein, B2, is translated from a subgenomic RNA3 derived from the 3' end of RNA1. B2 is a double-stranded RNA (dsRNA) binding protein that inhibits RNA silencing, a major antiviral defense pathway in insects. FHV is conveniently propagated in Drosophila melanogaster cells but can also be grown in mammalian cells. It was previously reported that B2 is dispensable for FHV RNA replication in BHK21 cells; therefore, we chose this cell line to generate a viral mutant that lacked the ability to produce B2. Consistent with published results, we found that RNA replication was indeed vigorous but the yield of progeny virus was negligible. Closer inspection revealed that infected cells contained very small amounts of coat protein despite an abundance of RNA2. B2 mutants that had reduced affinity for dsRNA produced analogous results, suggesting that the dsRNA binding capacity of B2 somehow played a role in coat protein synthesis. Using fluorescence in situ hybridization of FHV RNAs, we discovered that RNA2 is recruited into large cytoplasmic granules in the absence of B2, whereas the distribution of RNA1 remains largely unaffected. We conclude that B2, by binding to double-stranded regions in progeny RNA2, prevents recruitment of RNA2 into cellular structures, where it is translationally silenced. This represents a novel function of B2 that further contributes to successful completion of the nodaviral life cycle.},
keywords = {Animals, Capsid Proteins, Cell Line, Cricetinae, Cytoplasmic Granules, Double-Stranded, imler, M3i, Nodaviridae, Protein Biosynthesis, RNA, RNA Virus Infections, RNA-Binding Proteins, Viral, Viral Proteins},
pubstate = {published},
tppubtype = {article}
}
Flock House virus (FHV) is a positive-sense RNA insect virus with a bipartite genome. RNA1 encodes the RNA-dependent RNA polymerase, and RNA2 encodes the capsid protein. A third protein, B2, is translated from a subgenomic RNA3 derived from the 3' end of RNA1. B2 is a double-stranded RNA (dsRNA) binding protein that inhibits RNA silencing, a major antiviral defense pathway in insects. FHV is conveniently propagated in Drosophila melanogaster cells but can also be grown in mammalian cells. It was previously reported that B2 is dispensable for FHV RNA replication in BHK21 cells; therefore, we chose this cell line to generate a viral mutant that lacked the ability to produce B2. Consistent with published results, we found that RNA replication was indeed vigorous but the yield of progeny virus was negligible. Closer inspection revealed that infected cells contained very small amounts of coat protein despite an abundance of RNA2. B2 mutants that had reduced affinity for dsRNA produced analogous results, suggesting that the dsRNA binding capacity of B2 somehow played a role in coat protein synthesis. Using fluorescence in situ hybridization of FHV RNAs, we discovered that RNA2 is recruited into large cytoplasmic granules in the absence of B2, whereas the distribution of RNA1 remains largely unaffected. We conclude that B2, by binding to double-stranded regions in progeny RNA2, prevents recruitment of RNA2 into cellular structures, where it is translationally silenced. This represents a novel function of B2 that further contributes to successful completion of the nodaviral life cycle.
2010
Garcia Alvaro Baeza, Pierce Raymond J, Gourbal Benjamin, Werkmeister Elisabeth, Colinet Dominique, Reichhart Jean-Marc, Dissous Colette, Coustau Christine
Involvement of the cytokine MIF in the snail host immune response to the parasite Schistosoma mansoni Article de journal
Dans: PLoS Pathog., vol. 6, non 9, p. e1001115, 2010, ISSN: 1553-7374.
Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Apoptosis, Biomphalaria, Blotting, Cell Proliferation, Cells, Cricetinae, Cultured, Hemocytes, Host-Parasite Interactions, Humans, Liver, M3i, Macrophage Migration-Inhibitory Factors, messenger, Oocysts, Recombinant Proteins, reichhart, Reverse Transcriptase Polymerase Chain Reaction, RNA, Schistosoma mansoni, Schistosomiasis mansoni, Sequence Homology, Small Interfering, Western
@article{baeza_garcia_involvement_2010,
title = {Involvement of the cytokine MIF in the snail host immune response to the parasite Schistosoma mansoni},
author = {Alvaro Baeza Garcia and Raymond J Pierce and Benjamin Gourbal and Elisabeth Werkmeister and Dominique Colinet and Jean-Marc Reichhart and Colette Dissous and Christine Coustau},
doi = {10.1371/journal.ppat.1001115},
issn = {1553-7374},
year = {2010},
date = {2010-01-01},
journal = {PLoS Pathog.},
volume = {6},
number = {9},
pages = {e1001115},
abstract = {We have identified and characterized a Macrophage Migration Inhibitory Factor (MIF) family member in the Lophotrochozoan invertebrate, Biomphalaria glabrata, the snail intermediate host of the human blood fluke Schistosoma mansoni. In mammals, MIF is a widely expressed pleiotropic cytokine with potent pro-inflammatory properties that controls cell functions such as gene expression, proliferation or apoptosis. Here we show that the MIF protein from B. glabrata (BgMIF) is expressed in circulating immune defense cells (hemocytes) of the snail as well as in the B. glabrata embryonic (Bge) cell line that has hemocyte-like features. Recombinant BgMIF (rBgMIF) induced cell proliferation and inhibited NO-dependent p53-mediated apoptosis in Bge cells. Moreover, knock-down of BgMIF expression in Bge cells interfered with the in vitro encapsulation of S. mansoni sporocysts. Furthermore, the in vivo knock-down of BgMIF prevented the changes in circulating hemocyte populations that occur in response to an infection by S. mansoni miracidia and led to a significant increase in the parasite burden of the snails. These results provide the first functional evidence that a MIF ortholog is involved in an invertebrate immune response towards a parasitic infection and highlight the importance of cytokines in invertebrate-parasite interactions.},
keywords = {Amino Acid, Animals, Apoptosis, Biomphalaria, Blotting, Cell Proliferation, Cells, Cricetinae, Cultured, Hemocytes, Host-Parasite Interactions, Humans, Liver, M3i, Macrophage Migration-Inhibitory Factors, messenger, Oocysts, Recombinant Proteins, reichhart, Reverse Transcriptase Polymerase Chain Reaction, RNA, Schistosoma mansoni, Schistosomiasis mansoni, Sequence Homology, Small Interfering, Western},
pubstate = {published},
tppubtype = {article}
}
We have identified and characterized a Macrophage Migration Inhibitory Factor (MIF) family member in the Lophotrochozoan invertebrate, Biomphalaria glabrata, the snail intermediate host of the human blood fluke Schistosoma mansoni. In mammals, MIF is a widely expressed pleiotropic cytokine with potent pro-inflammatory properties that controls cell functions such as gene expression, proliferation or apoptosis. Here we show that the MIF protein from B. glabrata (BgMIF) is expressed in circulating immune defense cells (hemocytes) of the snail as well as in the B. glabrata embryonic (Bge) cell line that has hemocyte-like features. Recombinant BgMIF (rBgMIF) induced cell proliferation and inhibited NO-dependent p53-mediated apoptosis in Bge cells. Moreover, knock-down of BgMIF expression in Bge cells interfered with the in vitro encapsulation of S. mansoni sporocysts. Furthermore, the in vivo knock-down of BgMIF prevented the changes in circulating hemocyte populations that occur in response to an infection by S. mansoni miracidia and led to a significant increase in the parasite burden of the snails. These results provide the first functional evidence that a MIF ortholog is involved in an invertebrate immune response towards a parasitic infection and highlight the importance of cytokines in invertebrate-parasite interactions.
