Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 24
Filter
Add more filters










Publication year range
1.
Molecules ; 27(1)2021 Dec 22.
Article in English | MEDLINE | ID: mdl-35011264

ABSTRACT

The aquatic infectious pancreatic necrosis virus (IPNV) causes a severe disease in farmed salmonid fish that generates great economic losses in the aquaculture industry. In the search for new tools to control the disease, in this paper we show the results obtained from the evaluation of the antiviral effect of [Cu(NN1)2](ClO4) Cu(I) complex, synthesized in our laboratory, where the NN1 ligand is a synthetic derivate of the natural compound coumarin. This complex demonstrated antiviral activity against IPNV at 5.0 and 15.0 µg/mL causing a decrease viral load 99.0% and 99.5%, respectively. The Molecular Docking studies carried out showed that the copper complex would interact with the VP2 protein, specifically in the S domain, altering the process of entry of the virus into the host cell.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Coordination Complexes/chemistry , Coordination Complexes/pharmacology , Copper/chemistry , Coumarins/chemistry , Infectious pancreatic necrosis virus/drug effects , Ligands , Models, Molecular , Structure-Activity Relationship , Virus Replication
2.
Drug Des Devel Ther ; 12: 2337-2359, 2018.
Article in English | MEDLINE | ID: mdl-30104863

ABSTRACT

INTRODUCTION: Infectious pancreatic necrosis virus (IPNV) causes serious losses in several fish species of commercial interest. IPNV is a non-enveloped double-stranded RNA virus with a genome consisting of two segments A and B. Segment B codes for the VP1 protein, a non-canonical RNA-dependent RNA polymerase that can be found both in its free form and linked to the end of genomic RNA, an essential enzyme for IPNV replication. MATERIALS AND METHODS: We take advantage of the knowledge over the allosteric binding site described on the surface of the thumb domain of Hepatitis C virus (HCV) polymerase to design new non-nucleoside inhibitors against the IPNV VP1 polymerase. RESULTS: Molecular docking techniques have been used to screen a chemical library of 23,760 compounds over a defined cavity in the surface of the thumb domain. Additional ADMET (absorption, distribution, metabolism, excretion, and toxicity) filter criteria has been applied. CONCLUSION: We select two sets of 9 and 50 inhibitor candidates against the polymerases of HCV and IPNV, respectively. Two non-toxic compounds have been tested in vitro with antiviral capacity against IPNV Sp and LWVRT60 strains in the low µM range with different activity depending on the IPNV strain used.


Subject(s)
Antiviral Agents/pharmacology , Drug Discovery , Infectious pancreatic necrosis virus/drug effects , RNA-Dependent RNA Polymerase/antagonists & inhibitors , Cell Survival/drug effects , Cells, Cultured , Hepacivirus/drug effects , Infectious pancreatic necrosis virus/enzymology , Molecular Docking Simulation , RNA-Dependent RNA Polymerase/chemistry
3.
J Fish Dis ; 41(11): 1625-1630, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30091241

ABSTRACT

Disease poses a major threat to aquaculture and commercial and recreational fisheries globally. Biosecurity measures have been implemented; however, empirical evidence of their efficacy in situ is lacking. Here, we present the results from a study conducted to examine the effectiveness of disinfectant net dips. Samples were collected from disinfectant net dips at 25 recreational fisheries in south-west England and assessed to determine (a) the level of bacterial contamination and (b) the reduction in titre of a target virus (infectious pancreatic necrosis virus, IPNV) following a contact time of 2 and 5 min. In addition, the study examined the reduction in target virus titre following exposure to laboratory prepared Virkon® , representing "clean," "dirty" and "diluted and dirty" conditions, for 2 and 5 min. Bacterial contamination was high in 64% of disinfectant samples, and, 76% of disinfectant samples did not effectively reduce the target virus titre in 2 or 5 min. Virus titre was successfully reduced following exposure to laboratory prepared Virkon® for 2 or 5 min, although dilution and contamination reduced the effectiveness. These results suggest that disinfectant net dips may not be working effectively on a high proportion of fishery sites. We provide recommendations for improving biosecurity.


Subject(s)
Bacterial Infections/veterinary , Birnaviridae Infections/veterinary , Disinfectants/standards , Equipment and Supplies/veterinary , Fish Diseases/prevention & control , Fisheries , Animals , Bacteria/drug effects , Bacterial Infections/microbiology , Bacterial Infections/prevention & control , Birnaviridae Infections/prevention & control , Birnaviridae Infections/virology , Disinfectants/pharmacology , England , Equipment and Supplies/microbiology , Fish Diseases/microbiology , Fish Diseases/virology , Infectious pancreatic necrosis virus/drug effects
4.
Carbohydr Polym ; 124: 292-301, 2015 Jun 25.
Article in English | MEDLINE | ID: mdl-25839823

ABSTRACT

Viral infections in the aquaculture of salmonids can lead to high mortality and substantial economic losses. Thus, there is industrial interest in new molecules active against these viruses. Here we describe the production, purification, and the physicochemical and structural characterization of high molecular weight dextrans synthesized by Lactobacillus sakei MN1 and Leuconostoc mesenteroides RTF10. The purified dextrans, and commercial dextrans with molecular weights ranging from 10 to 2000kDa, were assayed in infected BF-2 and EPC fish cell-line monolayers for antiviral activity. Only T2000 and dextrans from MN1 and RTF10 had significant antiviral activity. This was similar to results obtained against infectious pancreatic necrosis virus. However the dextran from MN1 showed ten-fold higher activity against hematopoietic necrosis virus than T2000. In vivo assays using the MN1 polymer confirmed the in vitro results and revealed immunomodulatory activity. These results together with the high levels of dextran production (2gL(-1)) by Lb. sakei MN1, indicate the compounds potential utility as an antiviral agent in aquaculture.


Subject(s)
Antiviral Agents/pharmacology , Dextrans/pharmacology , Infectious pancreatic necrosis virus/drug effects , Lactobacillus/chemistry , Salmonidae/virology , Animals , Antiviral Agents/chemistry , Antiviral Agents/isolation & purification , Aquaculture , Cell Line , Dextrans/chemistry , Dextrans/isolation & purification , Immunologic Factors/chemistry , Immunologic Factors/isolation & purification , Immunologic Factors/pharmacology , Infectious hematopoietic necrosis virus/drug effects , Interferon Type I/genetics , Interferon Type I/metabolism , Interferon-gamma/genetics , Interferon-gamma/metabolism , Lactobacillus/metabolism , Molecular Weight , Spectrophotometry, Infrared , Trout/metabolism
5.
J Fish Dis ; 37(4): 349-55, 2014 Apr.
Article in English | MEDLINE | ID: mdl-23617746

ABSTRACT

The aquaculture industry needs a simple, inexpensive and safe method for the treatment of fish waste without heat. Microbial inactivation by inorganic acid (HCl) or base (KOH) was determined using infectious pancreatic necrosis virus (IPNV) as a model organism for fish pathogens. Salmonella and spores of Clostridium perfringens were general hygiene indicators in supplementary examinations. IPNV, which is considered to be among the most chemical- and heat-resistant fish pathogens, was reduced by more than 3 log in 4 h at pH 1.0 and pH 12.0. Salmonella was rapidly inactivated by the same treatment, whereas spores of C. perfringens were hardly affected. The results indicate that low and high pH treatment could be particularly suitable for fish waste destined for biogas production. pH treatment at aquaculture production sites could reduce the spread of fish pathogens during storage and transportation without disturbing the anaerobic digestion process. The treatment could also be an alternative to the current energy-intensive steam pressure sterilization of fish waste to be used by the bioenergy, fertilizer and soil improver industries.


Subject(s)
Aquaculture/methods , Fish Products/virology , Hydrochloric Acid/pharmacology , Infectious pancreatic necrosis virus/drug effects , Sodium Hydroxide/pharmacology , Virus Inactivation/drug effects , Aquaculture/economics , Clostridium perfringens/drug effects , Clostridium perfringens/physiology , Fish Products/microbiology , Hydrogen-Ion Concentration , Infectious pancreatic necrosis virus/physiology , Microbial Viability/drug effects , Salmonella enterica/drug effects , Salmonella enterica/physiology , Spores, Bacterial/drug effects , Spores, Bacterial/physiology
6.
Mar Biotechnol (NY) ; 15(2): 125-32, 2013 Apr.
Article in English | MEDLINE | ID: mdl-22886190

ABSTRACT

Interferons play a key role in fish resistance to viral infections by inducing the expression of antiviral proteins, such as Mx. The aim of the present study was to test the antiviral activity of the Senegalese sole Mx protein (SsMx) against RNA and DNA viruses pathogenic to fish, i.e. the infectious pancreatic necrosis virus (IPNV, dsRNA), the viral haemorrhagic septicaemia virus (VHSV, ssRNA), and the European sheatfish virus (ESV, dsDNA), using a CHSE-214 cell clone expressing this antiviral protein. A strong inhibition of IPNV and VHSV replication was recorded in SsMx-expressing cells, as has been shown by the virus yield reduction and the decrease in the synthesis of the viral RNA encoding the polyprotein (for IPNV) and the nucleoprotein (for VHSV). The titres of these viruses replicating on SsMx-expressing cells were 100 times lower than those recorded on non-transfected cells. In contrast, SsMx did not inhibit ESV replication since no significant differences were observed regarding the virus yield or the major capsid protein gene transcription in transfected and non-transfected cells.


Subject(s)
Flatfishes/metabolism , GTP-Binding Proteins/pharmacology , Infectious pancreatic necrosis virus/drug effects , Novirhabdovirus/drug effects , Ranavirus/drug effects , Virus Replication/drug effects , Animals , Cell Line , DNA Primers/genetics , DNA, Complementary/biosynthesis , GTP-Binding Proteins/metabolism , Myxovirus Resistance Proteins , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Salmon , Transfection
7.
Langmuir ; 28(9): 4548-58, 2012 Mar 06.
Article in English | MEDLINE | ID: mdl-22313053

ABSTRACT

Polycationic superparamagnetic nanoparticles (∼150-250 nm) were evaluated as virucidal agents. The particles possess a core-shell structure, with cores consisting of magnetite clusters and shells of functional silica covalently bound to poly(hexamethylene biguanide) (PHMBG), polyethyleneimine (PEI), or PEI terminated with aziridine moieties. Aziridine was conjugated to the PEI shell through cationic ring-opening polymerization. The nanometric core-shell particles functionalized with biguanide or aziridine moieties are able to bind and inactivate bacteriophage MS2, herpes simplex virus HSV-1, nonenveloped infectious pancreatic necrosis virus (IPNV), and enveloped viral hemorrhagic septicaemia virus (VHSV). The virus-particle complexes can be efficiently removed from the aqueous milieu by simple magnetocollection.


Subject(s)
Antiviral Agents/chemistry , Magnetics , Nanoparticles/chemistry , Polymers/chemistry , Antiviral Agents/pharmacology , Aziridines/chemistry , Biguanides/chemistry , Infectious pancreatic necrosis virus/drug effects , Polyethyleneimine/chemistry
8.
J Virol ; 85(17): 9188-98, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21697489

ABSTRACT

We investigated the antiviral activity and gene induction properties of interferon gamma (IFN-γ) compared to type I IFN (IFNa1) in Atlantic salmon. IFN-γ protected salmon cells against infectious pancreatic necrosis virus (IPNV)-induced cytopathic effect (CPE), reduced virus titers, and inhibited the synthesis of the viral structural protein VP3. Moreover, IFN-γ showed potent antiviral activity against salmonid alphavirus 3 (SAV3) measured as a reduction in virus nsP1 transcripts. IFN-γ (a type II IFN) had less specific antiviral activity against IPNV than IFNa1, showing a half-maximal effective concentration of 1.6 ng/ml versus 31 pg/ml determined in the CPE reduction assay. Compared to IFNa1, IFN-γ was a more effective inducer of the antiviral protein GBP, several interferon regulatory transcription factors (IRFs), and the chemokine IP-10. The antiviral activity of IFN-γ may also in part be ascribed to upregulation of Mx, ISG15, and viperin. These are typical type I IFN-induced genes in mammals and were also more strongly induced by IFNa1 than by IFN-γ in salmon cells. Fish and mammalian IFN-γ thus show strikingly similar gene induction properties. Interestingly, the antiviral activity of IFN-γ against IPNV and SAV3 and its ability to induce Mx and ISG15 markedly decreased in the presence of neutralizing antiserum against IFNa1. In contrast, antiIFNa1 had no effect on the induction of IRF-1 and IP-10 by IFN-γ. This suggests that the antiviral activity of IFN-γ is partially dependent on IFNa induction. However, because antiIFNa1 could not abolish the IFN-γ-mediated induction of Mx and ISG15 completely, IFN-γ may possibly also induce such genes directly.


Subject(s)
Antiviral Agents/pharmacology , Infectious pancreatic necrosis virus/drug effects , Interferon Type I/pharmacology , Interferon-gamma/pharmacology , Alphavirus/drug effects , Animals , Cell Line , Cytopathogenic Effect, Viral/drug effects , Gene Expression Profiling , Microbial Sensitivity Tests , Salmo salar , Viral Load/drug effects , Viral Proteins/biosynthesis , Virus Replication/drug effects
9.
J Microbiol ; 49(1): 102-6, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21369986

ABSTRACT

Our previous investigation revealed that 80% methanolic extract of the red alga Polysiphonia morrowii has significant antiviral activities against fish pathogenic viruses, infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV). The present study was conducted to identify compounds attributed for its antiviral activities and investigate their antiviral activities against IHNV and IPNV. Activity-guided fractionation for 80% methanolic extract of Polysiphonia morrowii using a cell-based assay measuring virus-induced cytopathic effect (CPE) on cells yielded a 90% methanolic fraction, which showed the highest antiviral activity against both viruses among fractions yielded from the extract. From the fraction, two bromophenols were isolated and identified as 3-bromo-4,5-dihydroxybenzyl methyl ether (1) and 3-bromo-4,5-dihydroxybenzaldehyde (2) based on spectroscopic analyses. For both compounds, the concentrations to inhibit 50% of flounder spleen cell (FSP cell) proliferation (CC(50)) and each viral replication (EC(50)) were measured. In the pretreatment test, 3-bromo-4,5-dihydroxybenzyl methyl ether (1) and 3-bromo-4,5-dihy-droxybenzaldehyde (2) exhibited significant antiviral activities showing selective index values (SI = CC(50)/EC(50)) of 20 to 42 against both IHNV and IPNV. In direct virucidal test, 3-bromo-4,5-dihydroxybenzyl methyl ether (1) showed significant antiviral activités against both viruses while 3-bromo-4,5-dihydroxybenzaldehyde (2) was significantly effective against only IHNV. Although antiviral efficacies of both compounds against IHNV and IPNV were lower than those of ribavirin used as a positive control, our findings suggested that the red alga Polysiphonia morrowii and isolated two bromophenols may have potential as a therapeutic agent against fish viral diseases.


Subject(s)
Antiviral Agents/pharmacology , Complex Mixtures/pharmacology , Infectious hematopoietic necrosis virus/drug effects , Infectious pancreatic necrosis virus/drug effects , Phenols/pharmacology , Rhodophyta/chemistry , Animals , Antiviral Agents/chemistry , Antiviral Agents/isolation & purification , Antiviral Agents/toxicity , Cell Line , Cell Survival/drug effects , Chemical Fractionation , Complex Mixtures/chemistry , Complex Mixtures/isolation & purification , Complex Mixtures/toxicity , Cytopathogenic Effect, Viral/drug effects , Fishes/virology , Microbial Sensitivity Tests , Phenols/chemistry , Phenols/isolation & purification , Phenols/toxicity , Virus Replication/drug effects
10.
J Virol Methods ; 169(2): 412-5, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20691211

ABSTRACT

Development of rapid antiviral assays can expedite the process of screening potential agents against viral pathogens. In the present study, fluorescent quantum dots (QDs) incorporated with infectious pancreatic necrosis virus (IPNV) were used as imaging nanoprobes to detect the threshold amount of poly I:C (an interferon inducer) required to induce zebrafish cells into an antiviral state against IPNV. QD-IPNV hybrids were formed by colloidal clustering of negatively charged QDs and IPNV, using the cationic polymer polybrene (50 µg/mL). To test the screening potential of the QD-IPNV hybrids for anti-IPNV drug candidates, zebrafish ZF4 cells primed with the immunostimulant poly I:C at concentrations of 1, 5, and 10 µg/mL for 6h were used as a model system. After poly I:C treatment, cells were exposed to the QD-IPNV hybrids for 6h at a multiplicity of infection (MOI) of 5. The anti-IPNV effectiveness of poly I:C was assessed via fluorescence intensity of the QDs. Our results showed that ZF4 cells primed with poly I:C at 10 µg/mL were highly protected from IPNV challenge (i.e., no detection of QD fluorescence). In summary, a rapid and efficient cell-based imaging platform has been developed for assessing the anti-IPNV activity of poly I:C on ZF4 cells using QD-IPNV hybrids. This approach may be applied to a wider range of fish species and fish pathogenic viruses.


Subject(s)
Antiviral Agents/pharmacology , Image Processing, Computer-Assisted/methods , Infectious pancreatic necrosis virus/drug effects , Quantum Dots , Animals , Cell Line , Immunologic Factors/pharmacology , Microbial Sensitivity Tests/methods , Poly I-C/pharmacology , Zebrafish
11.
Fish Shellfish Immunol ; 29(2): 293-7, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20420921

ABSTRACT

Vitellogenin is a phosphoglycoprotein which represents the main precursor of the egg yolk in teleost fish. This reproductive protein was also demonstrated to play an important role in innate immunity by acting as a pattern recognition molecule capable of binding to bacteria, fungi and enhancing macrophage phagocytosis. The presented results demonstrate that, egg homogenate, ovarian fluid and serum of mature female Atlantic salmon have high neutralising ability for infectious pancreatic necrosis virus (IPNV). Vitellogenin from mature female Atlantic salmon serum, purified by immuno-affinity on a column matrix coated with monoclonal anti-Atlantic salmon vitellogenin antibody, was able to neutralise between 9.1 x 10(4) and 3.09 x 10(5) TCID(50) IPNV mg(-1) of protein. To the author's knowledge, this is the first time that the neutralising activity of vitellogenin on a teleost virus has been demonstrated. The results may explain why IPNV is difficult to detect by culture methods in ovarian fluid and egg homogenates from carrier mature females and suggest a possible means of vertical transmission via the egg.


Subject(s)
Infectious pancreatic necrosis virus/drug effects , Salmo salar , Vitellogenins/pharmacology , Animals , Antiviral Agents/isolation & purification , Antiviral Agents/pharmacology , Birnaviridae Infections/veterinary , Birnaviridae Infections/virology , Cell Line , Female , Fish Diseases/virology , Vitellogenins/isolation & purification
12.
Mol Immunol ; 47(9): 1757-64, 2010 May.
Article in English | MEDLINE | ID: mdl-20356627

ABSTRACT

Immune responses in the ovary are tightly regulated to provide protection for the developing germ cells, which are very sensitive to inflammatory responses. This characteristic immune response is often used by viral pathogens to evade the immune system, replicate and be transmitted to other specimens through the ovary. Taking into account that in teleost fish, the innate immune system is considered crucial to the outcome of viral infections and the interferon (IFN) system is considered as the first line of defence against viruses, we have studied the IFN response in rainbow trout (Oncorhynchus mykiss) ovary using two viruses with different replicative capacity in this organ, namely viral haemorrhagic septicaemia virus (VHSV) and infectious pancreatic necrosis virus (IPNV). Both VHSV and IPNV are shed from the ovary, but while VHSV actively replicates at this site, IPNV remains silent. In this context, we have determined the levels of expression of IFNs and the IFN-induced Mx genes in the ovary upon in vivo and in vitro infections with VHSV and IPNV, and compared to the effects provoked by the viral mimic poly I:C in vivo. We have demonstrated that while VHSV strongly up-regulates all the IFN genes studied, IPNV in vivo exposure either has no effect or even provokes strong suppression of IFN gene expression. These differences are not observed in vitro, even though IPNV does not replicate actively in this case either. Finally, to better understand the role that the production of type I IFN plays in the ovary, we have studied the effects of two type I recombinant rainbow trout IFNs (rtIFN1 and rtIFN2) to modulate both the expression of immune genes and to establish an antiviral state in the ovary. Interestingly, the ovary was able to respond to both rtIFN1 and 2, despite the fact that the IFN1 gene was not expressed here. Moreover, rtIFN1 and rtIFN2 not only modulated the expression of genes related to the IFN response, but also modulated inflammatory genes and significantly suppressed VHSV replication.


Subject(s)
Fish Proteins/immunology , Interferons/immunology , Oncorhynchus mykiss/immunology , Ovary/immunology , Animals , Antiviral Agents/pharmacology , Female , Fish Diseases/genetics , Fish Diseases/immunology , Fish Diseases/virology , Fish Proteins/genetics , Fish Proteins/pharmacology , GTP-Binding Proteins/genetics , Gene Expression/drug effects , Host-Pathogen Interactions , Infectious pancreatic necrosis virus/drug effects , Infectious pancreatic necrosis virus/physiology , Interferon Type I/genetics , Interferon Type I/immunology , Interferon Type I/pharmacology , Interferon-gamma/genetics , Interferon-gamma/immunology , Interferon-gamma/pharmacology , Interferons/genetics , Interferons/pharmacology , Myxovirus Resistance Proteins , Novirhabdovirus/drug effects , Novirhabdovirus/physiology , Oncorhynchus mykiss/genetics , Oncorhynchus mykiss/virology , Ovary/drug effects , Ovary/virology , Poly I-C/pharmacology , Reverse Transcriptase Polymerase Chain Reaction
13.
Vet Microbiol ; 141(1-2): 53-8, 2010 Feb 24.
Article in English | MEDLINE | ID: mdl-19818567

ABSTRACT

Infectious pancreatic necrosis is a disease caused by a birnavirus affecting several wild and commercial aquatic organisms. This infectious disease results in significant losses in the farming industry and therefore effective therapeutic agents are needed to control outbreaks caused by this pathogen. Our goal was to evaluate in vitro antiviral effect of a group of natural compounds (geranyl aromatic derivatives) isolated from the resinous exudate of the plant Heliotropium filifolium (Heliotropiaceae), semi-synthetics compounds obtained from them, and the resinous exudate, on CHSE-214 cell line infected with infectious pancreatic necrosis virus (IPNV) using a virus plaque inhibition assay at various concentrations. The compound ester filifolinyl senecionate was the best antiviral with EC(50) 160 microg/mL and a cytotoxic concentration required to reduce cell viability by 50% up to 400 microg/mL. In order to obtain information about the mechanism of the antiviral action, was evaluated the influence of ester filifolinyl senecionate on the viral RNA synthesis. This compound produced inhibition of the synthesis of viral genomic RNA, suggesting that the ester could be interacting with the viral RNA during the viral cycle. Additionally, a preliminary study of the interaction between ester and a sample of single-stranded RNA was studied at the level of theory Restricted Hartree Fock PM3 method. The results showed that the ester formed hydrogen bonds mainly with nitrogenous bases but not with ribose and phosphate. These results allow propose that the ester filifolinyl senecionate is a good candidate for used as antiviral therapy for IPN virus in salmon fry.


Subject(s)
Antiviral Agents/pharmacology , Heliotropium/chemistry , Infectious pancreatic necrosis virus/drug effects , Infectious pancreatic necrosis virus/physiology , Plant Exudates/pharmacology , Virus Replication/drug effects , Animals , Antiviral Agents/chemical synthesis , Antiviral Agents/chemistry , Cell Line , Cell Proliferation/drug effects , Cell Survival/drug effects , DNA/metabolism , Plant Exudates/chemistry , RNA/metabolism , Salmon
14.
Virus Res ; 143(1): 53-60, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19463721

ABSTRACT

Infectious pancreatic necrosis virus (IPNV) is a major pathogen in the aquaculture industry worldwide. Factors contributing to IPNV pathogenicity are yet poorly understood. Indications of IPNV being able to evade or counteract innate host defense come from its lack of ability to induce strong type I interferon (IFN) responses in cell culture. We show here that addition of salmon rIFN-alpha1 to cells prior to IPNV infection halts the viral protein synthesis and prevents processing of pVP2 into mature VP2. Furthermore, compared to pre-treatment with IFN-alpha1 the antiviral state in cells infected with IPNV prior to IFN-treatment, was antagonized by IPNV, as detected by higher viral titers, faster viral protein synthesis and also by reduced Mx expression. The longer headstart the virus gets, the more prominent is the weakening of IFN signaling. IPNV VP4 and VP5 inhibit IFN-induced expression from the Mx promoter, indicating that these proteins contribute to the antagonistic effect.


Subject(s)
Birnaviridae Infections/veterinary , Fish Diseases/drug therapy , Fish Diseases/virology , Infectious pancreatic necrosis virus/drug effects , Interferon-alpha/pharmacology , Signal Transduction , Animals , Antiviral Agents/pharmacology , Birnaviridae Infections/drug therapy , Birnaviridae Infections/metabolism , Birnaviridae Infections/virology , Cell Line , Fish Diseases/metabolism , GTP-Binding Proteins/biosynthesis , GTP-Binding Proteins/genetics , Gene Expression Regulation , Host-Pathogen Interactions , Infectious pancreatic necrosis virus/pathogenicity , Infectious pancreatic necrosis virus/physiology , Myxovirus Resistance Proteins , Salmon , Serine Endopeptidases/metabolism , Viral Nonstructural Proteins/metabolism , Viral Structural Proteins/metabolism , Virulence , Virus Replication/drug effects
15.
Antiviral Res ; 80(3): 332-8, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18721827

ABSTRACT

Infectious pancreatic necrosis virus (IPNV) and viral hemorrhagic septicemia virus (VHSV) remain two of the most important pathogens of farmed trout worldwide. Mycophenolic acid (MPA) is an inhibitor of cellular inosine monophosphate dehydrogenase (IMPDH), an enzyme that catalyzes an essential step in the biosynthesis of GTP. In this report, the antiviral activity of MPA against IPNV and VHSV in cell culture was assessed. Cell viability, virus yield, protein and RNA synthesis determinations were used to evaluate the inhibitory effect of MPA. MPA caused a dose-dependent inhibition of IPNV and VHSV replication. It was found that MPA had a particularly potent effect against IPNV, inhibiting the production of infectious virus more than 10(5)-fold. MPA was also highly effective in preventing viral protein synthesis. Quantitative real-time RT-PCR was used to measure viral RNA in cells infected by IPNV or VHSV to evaluate the inhibitory capacity of MPA as well as to compare MPA to the established antiviral drug ribavirin. MPA showed a good efficacy in decreasing accumulation of viral RNA at low concentrations. Finally, time of addition and wash out experiments suggested that MPA may have a dual mechanism of action, targeting both a cell and a viral function. This study provides evidence that MPA can function as a broad-spectrum antiviral drug for use in therapy of rainbow trout diseases.


Subject(s)
Antiviral Agents/pharmacology , Birnaviridae Infections/veterinary , Fish Diseases/drug therapy , Infectious pancreatic necrosis virus/drug effects , Mycophenolic Acid/pharmacology , Novirhabdovirus/drug effects , Rhabdoviridae Infections/veterinary , Virus Replication/drug effects , Animals , Birnaviridae Infections/drug therapy , Birnaviridae Infections/virology , Cell Line , Fish Diseases/virology , Infectious pancreatic necrosis virus/physiology , Novirhabdovirus/physiology , Protein Biosynthesis/drug effects , Rhabdoviridae Infections/drug therapy , Rhabdoviridae Infections/virology , Salmonidae
16.
J Fish Dis ; 31(7): 535-46, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18482382

ABSTRACT

A flow cytometric virus-binding assay that directly visualizes the binding and entry of infectious pancreatic necrosis virus (IPNV), infectious haematopoietic necrosis virus (IHNV) and virus haemorrhagic septicaemia virus (VHSV) to several cell lines was established. The highest efficiency of binding was shown by the BF-2 cell line and this was used to study, at the attachment level, the interactions of these cells with salmonid fish viruses in coinfections, and to further determine if the earliest stage of the viral growth cycle could explain the previously described loss of infectivity of IHNV when IPNV is present. Our results demonstrated that IPNV binds to around 88% of cells either in single or dual infections, whereas IHNV attachment always decreased in the presence of any of the other viruses. VHSV binding was not affected by IPNV, but coinfection with IHNV reduced the percentage of virus-binding cells, which suggests competition for viral receptors or co-receptors. Internalization of the adsorbed IHNV was not decreased by coinfection with IPNV, so the hypothetical competence could be restricted to the binding step. Treatment of the cells with antiviral agents, such as amantadine or chloroquine, did not affect the binding of IPNV and VHSV, but reduced IHNV binding by more than 30%. Tributylamine affected viral binding of the three viruses to different degrees and inhibited IPNV or IHNV entry in a large percentage of cells treated for 30 min. Tributylamine also inhibited IHNV cytopathic effects in a dose-dependent manner, decreasing the virus yield by 4 log of the 50% endpoint titre, at 10 mm concentration. IPNV was also inhibited, but at a lower level. The results of this study support the hypothesis that IHNV, in contrast to VHSV or IPNV, is less efficient at completing its growth cycle in cells with a simultaneous infection with IPNV. It can be affected at several stages of viral infection and is more sensitive to the action of antiviral compounds.


Subject(s)
RNA Virus Infections/veterinary , RNA Viruses/physiology , Salmonidae/virology , Animals , Cell Line , Hydrolases/pharmacology , Infectious hematopoietic necrosis virus/drug effects , Infectious hematopoietic necrosis virus/physiology , Infectious pancreatic necrosis virus/drug effects , Infectious pancreatic necrosis virus/physiology , Novirhabdovirus/drug effects , Novirhabdovirus/physiology , RNA Virus Infections/pathology , RNA Virus Infections/virology , RNA Viruses/drug effects , Virus Attachment/drug effects
17.
Fish Shellfish Immunol ; 24(5): 506-13, 2008 May.
Article in English | MEDLINE | ID: mdl-18329900

ABSTRACT

Type I (alpha/beta) interferons (IFNs) are a family of cytokines that stimulate the expression of numerous proteins that mediate an antiviral state in uninfected cells. Two Atlantic salmon (Salmo salar) IFN-alpha (SasaIFN-alpha1 & 2) genes have previously been cloned and both were found to contain a putative N-linked glycosylation site. Recombinant SasaIFN-alpha1 (rSasaIFN-alpha1) produced in eukaryotic systems has repeatedly been shown to confer antiviral properties. However, different IFN-alpha subtypes may exhibit differential antiviral activities and be subject to glycosylation. To evaluate the potential therapeutic impact of a rSasaIFN-alpha, the mature form of the SasaIFN-alpha2 protein was produced in a high-level Escherichia coli expression system. Expression of the rSasaIFN-alpha2 was detected by SDS-PAGE and Western blot, and its identity was confirmed by mass spectrometry. In the homologous Chinook salmon embryonic (CHSE-214) cell line, the rSasaIFN-alpha2 incited early expression of the IFN-induced Mx protein and exhibited high antiviral activity of about 2.8 x 10(6) U mg(-1) against infectious pancreatic necrosis virus (IPNV). Conversely, antiviral protection by rSasaIFN-alpha2 was not observed in a heterologous Japanese flounder embryo (HINAE) cell line. Hence, a biologically active form of rSasaIFN-alpha2 was successfully produced using a glycosylation-deficient prokaryotic system and purified to homogeneity, suggesting that glycosylation is not required for its antiviral activity.


Subject(s)
Escherichia coli/genetics , Fish Proteins/metabolism , GTP-Binding Proteins/metabolism , Interferon Type I/genetics , Interferon Type I/metabolism , Recombinant Proteins/metabolism , Salmo salar/metabolism , Animals , Antiviral Agents/pharmacology , Cell Line , Fish Proteins/genetics , Fish Proteins/immunology , Fish Proteins/pharmacology , GTP-Binding Proteins/genetics , Gene Expression Regulation , Infectious pancreatic necrosis virus/drug effects , Interferon Type I/biosynthesis , Interferon-alpha/genetics , Interferon-alpha/immunology , Interferon-alpha/pharmacology , Myxovirus Resistance Proteins , Recombinant Proteins/genetics , Recombinant Proteins/immunology , Recombinant Proteins/pharmacology , Salmo salar/genetics , Salmo salar/immunology
18.
J Virol ; 78(15): 7938-44, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15254166

ABSTRACT

Mx proteins form a family of interferon (IFN)-induced GTPases with potent antiviral activity against various single-stranded RNA viruses in mammals and chickens. In fish, alpha/beta IFN has been reported to inhibit the replication of infectious pancreatic necrosis virus (IPNV), but the mode of action has not been elucidated. A correlation between the inhibition of IPNV and Mx protein expression has, however, been observed. To examine whether Atlantic salmon Mx1 protein (ASMx1) possesses antiviral activity against IPNV, CHSE-214 cells constitutively expressing ASMx1 were established. ASMx1 appeared to be localized in the cytoplasm. The ASMx1-expressing clone selected showed a severely reduced IPNV-induced cytopathic effect, which was confirmed by a 500-fold reduction in virus yield. The antiviral activity against IPNV was further confirmed by the inhibition of virus protein synthesis and the reduced accumulation of virus transcripts. The present work further adds to the body of evidence which suggests that antiviral activity is a major functional role of vertebrate Mx proteins. Moreover, the list of viruses inhibited by Mx proteins is extended to include double-stranded RNA viruses.


Subject(s)
Antiviral Agents/pharmacology , GTP-Binding Proteins/pharmacology , Infectious pancreatic necrosis virus/drug effects , Salmo salar/metabolism , Virus Replication/drug effects , Animals , Cells, Cultured , Cytopathogenic Effect, Viral , Infectious pancreatic necrosis virus/pathogenicity , Myxovirus Resistance Proteins , RNA, Viral/biosynthesis , Viral Proteins/biosynthesis
19.
Dev Comp Immunol ; 25(4): 313-21, 2001 May.
Article in English | MEDLINE | ID: mdl-11246071

ABSTRACT

Unmethylated CpG dinucleotides are more frequent in the genomes of bacteria and viruses than of vertebrates. We report herein that plasmid DNA and synthetic oliogodeoxynucleotides (ODNs) containing unmethylated CpG induce production of antiviral cytokine activity in Atlantic salmon leucocytes, whereas ODNs with an inverted motif (GpC) or with methylated cytosines have nearly no stimulatory effect. The adherent cell population, representing mainly macrophages, is directly activated by CpG-ODN, while the effect on the non-adherent population is weak. Since the peak antiviral activity in ODN-stimulated leucocytes is seen after 48h, this might indicate that the unmethylated DNA stimulates the adherent cells to produce co-stimulatory molecules, which in turn stimulates production of antiviral cytokines in the non-adherent cell population. The potent immune activation by CpG ODNs points to possible new applications as adjuvant in fish vaccines.


Subject(s)
Antiviral Agents/pharmacology , CpG Islands , Cytokines/biosynthesis , DNA, Bacterial/pharmacology , Leukocytes/drug effects , Macrophage Activation/drug effects , Macrophages/drug effects , Oligodeoxyribonucleotides/pharmacology , Salmo salar/immunology , Adjuvants, Immunologic , Animals , Bacterial Vaccines , Culture Media, Conditioned/pharmacology , Cytokines/pharmacology , DNA Methylation , Fish Diseases/immunology , Fish Diseases/prevention & control , Infectious pancreatic necrosis virus/drug effects , Infectious pancreatic necrosis virus/physiology , Leukocytes/metabolism , Macrophages/metabolism , Plasmids/genetics , Poly I-C/pharmacology , Species Specificity , Viral Vaccines , Virus Replication/drug effects
20.
Antiviral Res ; 48(2): 125-30, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11114414

ABSTRACT

The in vivo antiviral effect of 5-ethynyl-1-beta-D-ribofuranosylimidazole-carboxamide (EICAR) was evaluated in coho salmon and rainbow trout fry, experimentally infected with infectious pancreatic necrosis virus (IPNV). Treatment consisted of a daily bath of 2 h in 0.4 microg ml(-1) or 0.8 microg ml(-1) of EICAR, for approximately 20 days. The behavior of the fish was studied for 45 days post-infection. The survival of the infected treated groups was compared with the survival of non-infected and infected untreated control groups. The results showed that the survival of coho salmon and rainbow trout fry in the infected group treated with both doses of EICAR was similar to the survival observed in the healthy control group (approximately 94%). While, the survival of the infected and untreated control fish was 56% for salmon and 28% for trout, there were no significant difference in the weight of coho salmon fry between those treated with EICAR and non-infected and infected untreated control groups. However, in rainbow trout there was a statistically significant weight decrease in infected untreated group. Finally, the analysis of tissue samples of the fish by reverse transcription associated with the polymerase chain reaction (RT-PCR) suggest that EICAR have decreased the viral load in infected treated fry. Consequently, the results indicate that EICAR is an effective inhibitor of IPNV replication in vivo and could be a promissory antiviral compound for the treatment of IPNV disease.


Subject(s)
Antiviral Agents/therapeutic use , Birnaviridae Infections/veterinary , Infectious pancreatic necrosis virus , Oncorhynchus kisutch/virology , Oncorhynchus mykiss/virology , Ribonucleosides/therapeutic use , Animals , Antiviral Agents/pharmacology , Birnaviridae Infections/drug therapy , Birnaviridae Infections/virology , Fish Diseases/drug therapy , Fish Diseases/virology , Infectious pancreatic necrosis virus/drug effects , Infectious pancreatic necrosis virus/isolation & purification , Infectious pancreatic necrosis virus/pathogenicity , Ribonucleosides/pharmacology
SELECTION OF CITATIONS
SEARCH DETAIL
...