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formation of the arterivirus replication/transcription complex: a key role for nonstructural protein 3 in the remodeling of intracellular membranes.the replication/transcription complex of the arterivirus equine arteritis virus (eav) is associated with paired membranes and/or double-membrane vesicles (dmvs) that are thought to originate from the endoplasmic reticulum. previously, coexpression of two putative transmembrane nonstructural proteins (nsp2 and nsp3) was found to suffice to induce these remarkable membrane structures, which are typical of arterivirus infection. here, site-directed mutagenesis was used to investigate the role of ns ...200818305048
comparison of two real-time reverse transcription polymerase chain reaction assays for the detection of equine arteritis virus nucleic acid in equine semen and tissue culture fluid.two previously developed taqman fluorogenic probe-based 1-tube real-time reverse transcription polymerase chain reaction (real-time rt-pcr) assays (t1 and t2) were compared and validated for the detection of equine arteritis virus (eav) nucleic acid in equine semen and tissue culture fluid (tcf). the specificity and sensitivity of these 2 molecular-based assays were compared to traditional virus isolation (vi) in cell culture. the t1 real-time rt-pcr had a higher sensitivity (93.4%) than the t2 ...200818319426
the in vitro rna synthesizing activity of the isolated arterivirus replication/transcription complex is dependent on a host factor.the cytoplasmic replication of positive-stranded rna viruses is associated with characteristic, virus-induced membrane structures that are derived from host cell organelles. we used the prototype arterivirus, equine arteritis virus (eav), to gain insight into the structure and function of the replication/transcription complex (rtc) of nidoviruses. rtcs were isolated from eav-infected cells, and their activity was studied using a newly developed in vitro assay for viral rna synthesis, which repro ...200818411274
analysis of the eiav rev-responsive element (rre) reveals a conserved rna motif required for high affinity rev binding in both hiv-1 and eiav.a cis-acting rna regulatory element, the rev-responsive element (rre), has essential roles in replication of lentiviruses, including human immunodeficiency virus (hiv-1) and equine infection anemia virus (eiav). the rre binds the viral trans-acting regulatory protein, rev, to mediate nucleocytoplasmic transport of incompletely spliced mrnas encoding viral structural genes and genomic rna. because of its potential as a clinical target, rre-rev interactions have been well studied in hiv-1; however ...200818523581
equine arteritis virus is delivered to an acidic compartment of host cells via clathrin-dependent endocytosis.equine arteritis virus (eav) is an enveloped, positive-stranded rna virus belonging to the family arteriviridae. infection by eav requires the release of the viral genome by fusion with the respective target membrane of the host cell. we have investigated the entry pathway of eav into baby hamster kidney cells (bhk). infection of cells assessed by the plaque reduction assay was strongly inhibited by substances which interfere with clathrin-dependent endocytosis and by lysosomotropic compounds. f ...200818570963
persistent equine arteritis virus infection in hela cells.the horse-adapted virulent bucyrus (vb) strain of equine arteritis virus (eav) established persistent infection in high-passage-number human cervix cells (hela-h cells; passages 170 to 221) but not in low-passage-number human cervix cells (hela-l cells; passages 95 to 115) or in several other cell lines that were evaluated. however, virus recovered from the 80th passage of the persistently infected hela-h cells (hela-h-eavp80) readily established persistent infection in hela-l cells. comparative ...200818579588
amino acid substitutions in the structural or nonstructural proteins of a vaccine strain of equine arteritis virus are associated with its attenuation.comparative sequence analysis of a series of strains of equine arteritis virus (eav) of defined virulence for horses, ranging from the horse-adapted virulent bucyrus (vb) strain to a fully attenuated vaccine strain derived from it, identified 13 amino acid substitutions associated with attenuation. these include 4 substitutions in the replicase proteins and 9 in the structural proteins. using reverse genetic techniques, these amino acid substitutions were introduced into a virulent infectious cd ...200818619638
identification of an additional neutralization determinant of equine arteritis virus.we recently established an in vitro model of equine arteritis virus (eav) persistence in hela cells. the objective of this study was to determine whether viral variants with novel neutralization phenotypes emerged during persistent eav infection of hela cells, as occurs during viral persistence in carrier stallions. viruses recovered from persistently infected hela cells had different neutralization phenotypes than the virus in the original inoculum, as determined by neutralization assays using ...200818851997
equine arteritis virus: a new isolate from the presumable first carrier stallion in argentina and its genetic relationships among the four reported unique argentinean strains.equine arteritis virus (eav) was isolated from a testicle of the presumable first stallion infected with eav in argentina. this virus isolate (named lt-lp-arg) was confirmed by gp5-specific pcr and indirect immunofluorescence assays. the pcr product was sequenced, and the phylogenetic analysis revealed that the lt-lp-arg strain of eav forms a monophyletic group, together with other strains previously isolated in our laboratory (lp02 group). however, all argentinean eav strains belong to a polyph ...200818937029
rna interference protects horse cells in vitro from infection with equine arteritis virus.equine arteritis virus (eav) belongs to the arteriviridae and causes viral arteritis in horses. in an attempt to develop novel and save therapies against the infection it was tested whether eav is susceptible to rna interference (rnai) in an equine in vitro system. horse cells were transfected with chemically synthesized small interfering rna oligonucleotides (sirnas) and challenged with eav. application of these sirnas led to a significant protection of the cells, and virus titers decreased dra ...200919007819
[molecular biological progression of equine arteritis virus]. 200819035332
[examination of biocides for their effectiveness against animal viruses according to european union standards with emphasis on the selection of a suitable test virus].because of the changes to be expected in the methods for testing disinfectants deemed to be used in the veterinary field, candidate viral species were evaluated for their suitability as test virus. considered viral species included different non-enveloped viruses [bovine enterovirus type 1 (ecbo (enteric cytopathogenic bovine orphan) virus), mammalian reovirus type 1, feline calici virus (fcv), and bovine parvovirus (bpv)], as well as enveloped viruses, as equine arteritisvirus (eav), bovine her ...200919226936
biochemical characterization of arterivirus nonstructural protein 11 reveals the nidovirus-wide conservation of a replicative endoribonuclease.nidoviruses (arteriviruses, coronaviruses, and roniviruses) are a phylogenetically compact but diverse group of positive-strand rna viruses that includes important human and animal pathogens. nidovirus rna synthesis is mediated by a cytoplasmic membrane-associated replication/transcription complex that includes up to 16 viral nonstructural proteins (nsps), which carry common enzymatic activities, like the viral rna polymerase, but also unusual and poorly understood rna-processing functions. of t ...200919297500
[use of multiplex pcr method with real-time detection for differential diagnosis of respiratory viral infections].multiplex real-time polymerase chain reaction test-system with fluorescent detection (rt-pcr) for simultaneous identification of main agents of acute respiratory viral infections: influenza a (iav) and b viruses (ibv), parainfluenza viruses types 1, 2, 3, 4 (piv 1 - 4), adenoviruses (adv), respiratory syncitial virus (rsv), rhinoviruses (rv) and enteroviruses (ev), in presence internal positive control (ipc) represented by vaccine strain of rubella virus ra 27/3. using multiplex rt-pcr method, r ...200919338239
novel approach for detection of enteric viruses to enable syndrome surveillance of acute viral gastroenteritis.acute gastroenteritis is one of the most common diseases worldwide, with viruses, particularly noroviruses, being the leading cause in developed countries. in the netherlands, systematic surveillance of gastroenteritis outbreaks of suspected viral etiology was established by the national institute for public health and the environment in 1994. since 2002, the total number of outbreaks reported has been increasing, and with that comes the need for sensitive assays that can be performed quickly. i ...200919339472
testing for antibodies to equine arteritis virus. 200919346547
the lactate dehydrogenase-elevating virus capsid protein is a nuclear-cytoplasmic protein.arteriviruses replicate in the cytoplasm and do not require the nucleus function for virus multiplication in vitro. however, nucleocapsid (n) protein of two arteriviruses, porcine reproductive respiratory syndrome virus and equine arteritis virus, has been observed to localize in the nucleus and nucleolus of virus-infected and n-gene-transfected cells in addition to their normal cytoplasmic distribution. in the present study, the n protein of lactate dehydrogenase-elevating virus (ldv) of mice w ...200919517211
structure and cleavage specificity of the chymotrypsin-like serine protease (3clsp/nsp4) of porcine reproductive and respiratory syndrome virus (prrsv).biogenesis and replication of the porcine reproductive and respiratory syndrome virus (prrsv) include the crucial step of replicative polyprotein processing by self-encoded proteases. whole genome bioinformatics analysis suggests that nonstructural protein 4 (nsp4) is a 3c-like serine protease (3clsp), responsible for most of the nonstructural protein processing. the gene encoding this protease was cloned and expressed in escherichia coli in order to confirm this prediction. the purified protein ...200919646449
myristoylation of the arterivirus e protein: the fatty acid modification is not essential for membrane association but contributes significantly to virus infectivity.the envelope of equine arteritis virus (eav) contains two glycoprotein complexes (gp2b/gp3/gp4 and gp5/m) and the small, non-glycosylated e protein. as e is essential for the production of infectious progeny but dispensable for assembly and release of virus-like particles, it probably mediates virus entry into cells, putatively in concert with the gp2b/gp3/gp4 complex. the e protein contains a central hydrophobic domain and a conserved potential site for n-terminal myristoylation, a hydrophobic ...200919656967
a virus-induced epizootic hemorrhagic disease of the virginia white-tailed deer (odocoileus virginianus).a circumscribed natural outbreak of a highly fatal disease of deer, which we have designated epizootic hemorrhagic disease (ehd), has been studied. the disease has proven readily transmissible in deer but not in other experimental or domestic animals tested, nor in embryonating eggs or deer kidney cell cultures. the causative agent is a virus which is readily filterable and is capable of storage, either frozen or in glycerol, for relatively long periods of time. it produces a solid immunity in t ...196019867168
antiviral effect of recombinant equine interferon-gamma on several equine viruses.recombinant equine interferon-gamma (reifn-gamma) was prepared using a baculovirus expression system and its antiviral activity was investigated using several equine viruses. the reifn-gamma suppressed the replication of all equine viruses used in the present experiment in horse cell cultures, but did not affect the growth of host cells at concentrations of less than 1000 u/ml. a strong antiviral effect was observed, especially against rna viruses. equine picornavirus, equine rhinovirus and equi ...201020004981
arterivirus nsp1 modulates the accumulation of minus-strand templates to control the relative abundance of viral mrnas.the gene expression of plus-strand rna viruses with a polycistronic genome depends on translation and replication of the genomic mrna, as well as synthesis of subgenomic (sg) mrnas. arteriviruses and coronaviruses, distantly related members of the nidovirus order, employ a unique mechanism of discontinuous minus-strand rna synthesis to generate subgenome-length templates for the synthesis of a nested set of sg mrnas. non-structural protein 1 (nsp1) of the arterivirus equine arteritis virus (eav) ...201020174607
curing of hela cells persistently infected with equine arteritis virus by a peptide-conjugated morpholino oligomer.a significant consequence of equine arteritis virus (eav) infection of horses is persistence of the virus in a variable percentage of infected stallions. we recently established an in vitro model of eav persistence in cell culture for the purpose of furthering our understanding of eav biology in general and viral persistence in the stallion in particular. in this study we investigated whether persistently infected hela cells could be cured of eav infection by treatment with an antisense peptide- ...201020206215
complex interactions between the major and minor envelope proteins of equine arteritis virus determine its tropism for equine cd3+ t lymphocytes and cd14+ monocytes.extensive cell culture passage of the virulent bucyrus (vb) strain of equine arteritis virus (eav) to produce the modified live virus (mlv) vaccine strain has altered its tropism for equine cd3(+) t lymphocytes and cd14(+) monocytes. the vb strain primarily infects cd14(+) monocytes and a small subpopulation of cd3(+) t lymphocytes (predominantly cd4(+) t lymphocytes), as determined by dual-color flow cytometry. in contrast, the mlv vaccine strain has a significantly reduced ability to infect cd ...201020219931
molecular epidemiology and genetic characterization of equine arteritis virus isolates associated with the 2006-2007 multi-state disease occurrence in the usa.in 2006-2007, equine viral arteritis (eva) was confirmed for the first time in quarter horses in multiple states in the usa. the entire genome of an equine arteritis virus (eav) isolate from the index premises in new mexico was 12 731 nt in length and possessed a previously unrecorded unique 15 nt insertion in the nsp2-coding region in orf1a and a 12 nt insertion in orf3. sequence analysis of additional isolates made during this disease occurrence revealed that all isolates from new mexico, utah ...201020444993
evaluation of neutralization patterns of the five unique argentine equine arteritis virus field strains reported.equine viral arteritis (eva) is a contagious viral disease that frequently causes mild or subclinical infections in adult horses. only one eav serotype has been described. however, there are differences in antigenicity, pathogenicity and neutralization characteristics of virus field strains. the interaction of two viral proteins, gp5 and m, is critical for infectivity and amino acid changes in the gp5 sequences have an effect on the neutralizing phenotype, regardless the effects of other viral p ...201020461287
autophagy protein atg5 interacts transiently with the hepatitis c virus rna polymerase (ns5b) early during infection.autophagy is an important cellular process by which atg5 initiates the formation of double membrane vesicles (dmvs). upon infection, dmvs have been shown to harbor the replicase complex of positive-strand rna viruses such as mhv, poliovirus, and equine arteritis virus. recently, it has been shown that autophagy proteins are proviral factors that favor initiation of hepatitis c virus (hcv) infection. here, we identified atg5 as an interacting protein for the hcv ns5b. atg5/ns5b interaction was co ...201020580051
equine viral arteritis: further characterization of the carrier state in stallions.further characterization of the carrier state in stallions infected with equine arteritis virus revealed that there is considerable variation in the frequency of its occurrence among breeds. the frequency ranged from 12.5% (holsteiner stallions) to 72.7% (dutch warmblood stallions), with a mean occurrence of 40.8% in the seropositive stallions (n=561) examined. more than 70% of the virus shedders were standardbred stallions. the carrier state was not confirmed in any of the stallions that had be ...200020681110
extended phylogeny of the equine arteritis virus sequences including south american sequences.to perform genetic analysis of the orf5 of equine arteritis virus (eav) may provide new insights into the genetic evolution and origin of the argentinean eav sequences.201120689314
the prrsv replicase: exploring the multifunctionality of an intriguing set of nonstructural proteins.our knowledge about the structure and function of the nonstructural proteins (nsps) encoded by the arterivirus replicase gene has advanced in recent years. the continued characterization of the nsps of the arterivirus prototype equine arteritis virus has not only corroborated several important functional predictions, but also revealed various novel features of arteriviral replication. for porcine reproductive and respiratory syndrome virus (prrsv), based on bioinformatics predictions and experim ...201020696193
resonance assignment of nsp7α from arterivirus.the (1)h, (15)n and (13)c resonance assignment of nsp7α, a non-structural protein of unknown function from the equine arteritis virus, is reported.201120703834
epizotiology and phylogeny of equine arteritis virus in hucul horses.the aim of the study was to determine the situation of equine arteritis virus (eav) infections in hucul horses. a total of 176 horses (154 mares and 22 stallions) from the biggest hucul horse stud in poland were tested. antibodies against eav were detected in 97 (55.1%) horses. the eav seroprevalence among mares was 53.2% while in stallions - 68.2%. the percentage of positive mares increased with their age, thus amongst the mares of less than 2 years of age the percentage was 32.5%, while in the ...201020956062
description of the first recorded major occurrence of equine viral arteritis in france.the vast majority of equine arteritis virus (eav) infections are inapparent or relatively mild, but may occasionally cause outbreaks of equine viral arteritis. the event observed in france during the summer of 2007 was the most important seen in the country, with mortality and disruption of economic activity.201021039801
zn(2+) inhibits coronavirus and arterivirus rna polymerase activity in vitro and zinc ionophores block the replication of these viruses in cell culture.increasing the intracellular zn(2+) concentration with zinc-ionophores like pyrithione (pt) can efficiently impair the replication of a variety of rna viruses, including poliovirus and influenza virus. for some viruses this effect has been attributed to interference with viral polyprotein processing. in this study we demonstrate that the combination of zn(2+) and pt at low concentrations (2 µm zn(2+) and 2 µm pt) inhibits the replication of sars-coronavirus (sars-cov) and equine arteritis virus ...201021079686
characterization of equine humoral antibody response to the nonstructural proteins of equine arteritis virus.equine arteritis virus (eav) replicase consists of two polyproteins (pp1a and pp1ab) that are encoded by open reading frames (orfs) 1a and 1b of the viral genome. these two replicase polyproteins are posttranslationally processed by three orf 1a-encoded proteinases to yield at least 13 nonstructural proteins (nsp1 to nsp12, including nsp7α and 7β). these nsps are expressed in eav-infected cells, but the equine immune response they induce has not been studied. therefore, the primary purpose of th ...201021147938
equine disease surveillance: quarterly summary. 201121257557
discovery of a small arterivirus gene that overlaps the gp5 coding sequence and is important for virus production.the arterivirus family (order nidovirales) of single-stranded, positive-sense rna viruses includes porcine respiratory and reproductive syndrome virus and equine arteritis virus (eav). their replicative enzymes are translated from their genomic rna, while their seven structural proteins are encoded by a set of small, partially overlapping genes in the genomic 3'-proximal region. the latter are expressed via synthesis of a set of subgenomic mrnas that, in general, are functionally monocistronic ( ...201121307223
infection of embryos following insemination of donor mares with equine arteritis virus infective semen.the objective was to evaluate the potential risks associated with embryo transfer from mares bred with equine arteritis virus (eav) infective semen. twenty-six mares were embryo donors, whereas 18 unvaccinated and eav antibody seronegative mares were embryo recipients. of the 26 donor mares, 15 were unvaccinated and seronegative for antibodies to eav and 11 were vaccinated for the first time with a commercially available modified live virus vaccine against eva before breeding and subsequent embr ...201121345485
tenacity of mammalian viruses in the gut of leeches fed with porcine blood.leech therapy is currently considered to be of high therapeutic value in medicine. however, feeding leeches with fresh animal blood during the maintenance and reproduction phase bears the risk of transmission of zoonotic viruses to the patient. we hypothesize that this would be abolished by subjecting leeches to quarantine measures prior to use. the required duration of quarantine would depend on the maximum survival time of pathogens in contaminated leeches. in order to be able to estimate this ...201121372183
evaluation of the safety of vaccinating mares against equine viral arteritis during mid or late gestation or during the immediate postpartum period.to determine whether it is safe to vaccinate pregnant or postpartum mares with a commercial modified-live virus vaccine against equine viral arteritis (eva). design-randomized controlled study. animals-73 mares and their foals.201121401431
serological survey of equine viral diseases in mongolia.three hundred sera were collected from horses in various parts of mongolia in 2007 and seroepidemiological surveys for several equine viruses performed on them. equid herpesvirus 1 and equine rhinitis a virus were prevalent, and equine arteritis virus and equid herpesvirus 3 were detected over a wide area though their rates of antibody-positivity were not high. equine infectious anemia was distributed locally. the rates of horses antibody-positive for japanese encephalitis virus and equine influ ...201121447048
development of an antigen-capture elisa for the detection of equine influenza virus nucleoprotein.an antigen-capture enzyme-linked immunosorbent assay (ac-elisa) was developed for the detection of the equine influenza virus (eiv), employing monoclonal and polyclonal antibodies against the a/equine/xingjiang/2007 (h3n8) nucleoprotein (np). immunoglobulin g antibodies were purified and used as capture or detector antibodies. the specificity of the optimized ac-elisa was evaluated using eiv, equine herpesvirus 1 (ehv-1), equine herpesvirus 4 (ehv-4), equine arteritis virus (eav) and japanese en ...201121536075
structure and genetic analysis of the arterivirus nonstructural protein 7{alpha}arterivirus replicase polyproteins are cleaved into at least 13 mature nonstructural proteins (nsps) and in particular the nsp5-8 region is subject to a complex processing cascade. the function of the largest subunit from this region, nsp7, which is further cleaved into nsp7α and nsp7ß, is unknown. using nmr spectroscopy, we determined the solution structure of nsp7α of equine arteritis virus, revealing an interesting unique fold for this protein but as such providing little clue to its possible ...201121561912
eca20 microsatellite polymorphisms in equine viral arteritis-infected horses from argentina.we investigated the association of equine arteritis virus (eav) infection and three short tandem repeat (str) polymorphisms located within or in close proximity to equine lymphocyte antigen (ela) region. we used a case-control design as a first approach before proceeding to select candidate genes. one hundred and sixty-five silla argentino horses were taken in 2002 from positive serological detections of eav in argentina, to determine whether str genotypes were correlated to genetic susceptibili ...201121812763
evaluation of two magnetic bead-based viral nucleic acid purification kits and three real-time rt-pcr reagent systems in two taqman(r) assays for equine arteritis virus detection in semen.this study showed that under specifically defined conditions with respect to nucleic acid extraction method and testing reagents, a previously described real-time rt-pcr assay (t1 assay) provides sensitivity equal to or higher than virus isolation for the detection of equine arteritis virus in semen.201121832018
validation of an internally controlled one-step real-time multiplex rt-pcr assay for the detection and quantitation of dengue virus rna in plasma.dengue is mosquito-borne virus infection that annually causes ôê+50 million clinically apparent cases worldwide. an internally controlled one-step real-time multiplex rt-pcr assay was developed for detection and quantitation of denv rna in plasma sample by using specific primers and fluorogenic taqman probes. all primers and probes targeted sequences near the 3' end of the ns5 gene. the method comprised two multiplex assays and was validated for sensitivity, specificity, linearity, reproducibili ...201121843553
Genome-wide association study among four horse breeds identifies a common haplotype associated with in vitro CD3+ T cell susceptibility/resistance to equine arteritis virus infection.Previously, we have shown that horses could be divided into susceptible and resistant groups based on an in vitro assay using dual-color flow cytometric analysis of CD3+ T cells infected with equine arteritis virus (EAV). Here, we demonstrate that the differences in in vitro susceptibility of equine CD3+ T lymphocytes to EAV infection have a genetic basis. To investigate the possible hereditary basis for this trait, we conducted a genome-wide association study (GWAS) to compare susceptible and r ...201121994447
prevalence of antibodies to equine viruses in the netherlands.summary the prevalence of antibodies to various viruses was investigated in a series of serum samples collected from horses in the netherlands between 1963 and 1966 and from 1972 onwards. neutralizing antibodies to equine rhinopneumonitis virus, equine arteritis virus and to equine rhinovirus types 1 and 2 were detected in respectively 76%, 14%, 66% and 59% of the equine serum samples tested. the observed incidence of serum samples positive to equine adenovirus in the complement fixation tes ...197922039753
assessment of correlation between in vitro cd3(+) t cell susceptibility to eav infection and clinical outcome following experimental infection.in a recent study, we demonstrated that the virulent bucyrus strain (vbs) of eav could infect in vitro a small population of cd3(+) t lymphocytes from some but not all horses. furthermore, we have shown that a common haplotype is associated with this in vitro cd3(+) t cell susceptibility/resistance phenotype to eav infection. in this study, we investigated whether the differences in the susceptibility or resistance of cd3(+) t cells in vitro correlate with the outcome and severity of clinical si ...201122177968
Ultrastructural characterization of arterivirus replication structures: Reshaping the endoplasmic reticulum to accommodate viral RNA synthesis.Virus-induced membrane structures support the assembly and function of positive-stranded RNA virus replication complexes. The replicase proteins of arteriviruses are associated with double-membrane vesicles (DMVs), which were previously proposed to derive from endoplasmic reticulum (ER). Using electron tomography, we performed an in-depth ultrastructural analysis of cells infected with the prototypic arterivirus equine arteritis virus (EAV). We established that the outer membranes of EAV-induced ...201122190716
Emergence of novel equine arteritis virus (EAV) variants during persistent infection in the stallion: Origin of the 2007 French EAV outbreak was linked to an EAV strain present in the semen of a persistently infected carrier stallion.During the summer of 2007, an outbreak of equine viral arteritis (EVA) occurred in Normandy (France). After investigation, a link was suggested between an EAV carrier stallion (A) and the index premise of the outbreak. The full-length nucleotide sequence analysis of a study reference strain (F27) isolated from the lung of a foal revealed a 12,710 nucleotides EAV genome with unique molecular hallmarks in the 5'UTR leader sequence and the ORF1a sequence encoding the non-structural protein 2. The e ...201122209234
arterivirus minor envelope proteins are a major determinant of viral tropism in cell culture.arteriviruses are enveloped positive-strand rna viruses for which the attachment proteins and cellular receptors have remained largely controversial. arterivirus particles contain at least eight envelope proteins, an unusually large number among rna viruses. these appear to segregate into three groups: major structural components (major glycoprotein gp5 and membrane protein [m]), minor glycoproteins (gp2a, gp3, and gp4), and small hydrophobic proteins (e and the recently discovered orf5a protein ...201222258262
clinical and virological outcome of an infection with the belgian equine arteritis virus strain 08p178.equine viral arteritis (eva) is an infectious disease with variable clinical outcome. outbreaks, causing important economic losses, are becoming more frequent. currently, there is a shortage of pathogenesis studies performed with european strains. in the present study, eight seronegative ponies were experimentally inoculated with the belgian strain of equine arteritis virus (eav) 08p178 (eu-1 clade) and monitored daily for clinical signs of eva. nasopharyngeal swabs, ocular swabs, bronchoalveola ...201222306037
ela-dra polymorphisms are not associated with equine arteritis virus infection in horses from argentina.polymorphisms at major histocompatibility complex (mhc) genes have been associated with resistance/susceptibility to infectious diseases in domestic animals. the aim of this investigation was to evaluate whether polymorphisms of the dra gene the equine lymphocyte antigen is associated with susceptibility to equine arteritis virus (eav) infection in horses in argentina. the equine dra gene was screened for polymorphisms using pyrosequencing® technology which allowed the detection of three ela-dra ...201222534582
folding and oligomerization of the gp2b/gp3/gp4 spike proteins of equine arteritis virus in vitro.equine arteritis virus (eav) is a small, positive-stranded rna virus. the glycoproteins gp2b, gp3 and gp4 form a heterotrimer in the viral envelope, which is required for cell entry of eav. we describe expression of the ectodomains of the proteins in e. coli and their refolding from inclusion bodies. after extraction of inclusion bodies and dialysis, gst-, but not his-tagged proteins, refold into a soluble conformation. however, when dialyzed together with gst-gp3 or with gst-gp4, his-gp2b and h ...201222590679
isolation of equine rhinitis a virus from a horse semen sample.semen from an apparently healthy 4-year-old american quarter horse was submitted to the national veterinary services laboratories for equine arteritis virus isolation. visual inspection of the semen sample upon arrival noted it was unusually yellow in color. the semen sample was inoculated onto cell monolayers, and cytopathic effect was observed 5 days postinoculation. the resultant isolate tested negative for equine arteritis virus, and was subsequently identified as equine rhinitis a virus. eq ...201222621949
chimeric viruses containing the n-terminal ectodomains of gp5 and m proteins of porcine reproductive and respiratory syndrome virus do not change the cellular tropism of equine arteritis virus.equine arteritis virus (eav) and porcine reproductive and respiratory syndrome virus (prrsv) are members of family arteriviridae; they are highly species specific and differ significantly in cellular tropism in cultured cells. in this study we examined the role of the two major envelope proteins (gp5 and m) of eav and prrsv in determining their cellular tropism. we generated three viable eav/prrsv chimeric viruses by swapping the n-terminal ectodomains of these two proteins from prrsv ia1107 str ...201222739441
development and characterization of an infectious cdna clone of the modified live virus vaccine strain of equine arteritis virus.a stable full-length cdna clone of the modified live virus (mlv) vaccine strain of equine arteritis virus (eav) was developed. rna transcripts generated from this plasmid (peavrmlv) were infectious upon transfection into mammalian cells, and the resultant recombinant virus (rmlv) had 100% nucleotide identity to the parental mlv vaccine strain of eav. a single silent nucleotide substitution was introduced into the nucleocapsid gene (peavrmlvb), enabling the cloned vaccine virus (rmlvb) to be dist ...201222739697
evidence that in vitro susceptibility of cd3+ t lymphocytes to equine arteritis virus infection reflects genetic predisposition of naturally infected stallions to become carriers of the virus.we investigated the correlation between in vitro susceptibility of cd3(+) t lymphocytes to equine arteritis virus (eav) infection and establishment of persistent infection among 14 stallions following natural infections. the data showed that carrier stallions with a cd3(+) t lymphocyte susceptibility phenotype to in vitro eav infection may be at higher risk of becoming carriers than those that lack this phenotype (p = 0.0002).201222933293
equine arteritis virus induced cell death is associated with activation of the intrinsic apoptotic signalling pathway.equine arteritis virus (eav) causes a respiratory and reproductive disease in horses, equine viral arteritis. though cell death in infection with eav is considered to occur by apoptosis, the underlying molecular mechanism has not been extensively elucidated. we investigated the expression of mrna of pro-apoptotic and caspase genes during eav infection in bhk21 cells, a well-established cell type for eav replication. using a sybr green real-time pcr, mrna of p53, bax, caspase 3 and caspase 9 were ...201323079113
comparative analysis of orf5 nucleotide sequences and amino acid sequences of the gp5 protein of equine arteritis virus (eav) detected in the semen of stallions from eastern poland.the purpose of this study was to conduct a comparative analysis of the orf5 gene fragment nucleotide sequences and the gp5 protein amino acid sequences formed on this matrix, for the equine arteritis virus (eav) strains isolated from the semen of infected stallions from eastern poland. the study covered 41 stallions whose blood serum tested positive for antigens specific to the eav. the presence of eav genetic material was shown in material from 5 horses, in one of which permanent presence of vi ...201323116636
nf-κb activation by equine arteritis virus is myd88 dependent and promotes viral replication.nf-κb, a family of transcription factors involved in different cell functions and immune responses is targeted by viruses. the mechanism of nf-κb signalling and its role in replication of eav have not been investigated. we demonstrate that eav infection in bhk-21 cells activates nf-κb, and this activation was found to be mediated through the myd88 pathway. infection of ikkβ(-/-) murine embryo fibroblasts (mefs), which are deficient in nf-κb signalling, resulted in lower virus titre, less cytopat ...201323151818
cyclophilin inhibitors block arterivirus replication by interfering with viral rna synthesis.virus replication strongly depends on cellular factors, in particular, on host proteins. here we report that the replication of the arteriviruses equine arteritis virus (eav) and porcine reproductive and respiratory syndrome virus (prrsv) is strongly affected by low-micromolar concentrations of cyclosporine a (csa), an inhibitor of members of the cyclophilin (cyp) family. in infected cells, the expression of a green fluorescent protein (gfp) reporter gene inserted into the prrsv genome was inhib ...201223152531
an autophagy-independent role for lc3 in equine arteritis virus replication.equine arteritis virus (eav) is an enveloped, positive-strand rna virus. genome replication of eav has been associated with modified intracellular membranes that are shaped into double-membrane vesicles (dmvs). we showed by immuno-electron microscopy that the dmvs induced in eav-infected cells contain double-strand (ds)rna molecules, presumed rna replication intermediates, and are decorated with the autophagy marker protein microtubule-associated protein 1 light chain 3 (lc3). replication of eav ...201323182945
single-layer centrifugation reduces equine arteritis virus titre in the semen of shedding stallions.several countries have adopted strategies for preventing and/or controlling equine viral arteritis based on vaccination and restricting the breeding activities of carrier stallions. however, in some cases, carrier stallions are only identified after they have transmitted virus to a mare. therefore, a mechanism for separating virus from spermatozoa in the semen of carrier stallions would facilitate control measures for preventing disease transmission. in this study, the use of several modificatio ...201323190015
deubiquitinase function of arterivirus papain-like protease 2 suppresses the innate immune response in infected host cells.protein ubiquitination regulates important innate immune responses. the discovery of viruses encoding deubiquitinating enzymes (dubs) suggests they remove ubiquitin to evade ubiquitin-dependent antiviral responses; however, this has never been conclusively demonstrated in virus-infected cells. arteriviruses are economically important positive-stranded rna viruses that encode an ovarian tumor (otu) domain dub known as papain-like protease 2 (plp2). this enzyme is essential for arterivirus replica ...201323401522
comparison of an improved competitive enzyme-linked immunosorbent assay with the world organization for animal health-prescribed serum neutralization assay for detection of antibody to equine arteritis virus.equine arteritis virus (eav) causes contagious equine viral arteritis, characterized by fever, anorexia, conjunctivitis, nasal discharge, dependent edema, abortion, infrequent death in foals, and establishment of the carrier state in stallions. the world organization for animal health (oie) defines a horse as seropositive if the serum neutralization (sn) antibody titer is ≥1:4 to eav. however, determining the sn titer is time-consuming and requires specific laboratory facilities, equipment, and ...201323404482
sequence analysis of orfs 5, 6 and 7 of equine arteritis virus during persistent infection of the stallion--a 7-year study.nucleotide and amino acid sequences of orfs 5, 6 and 7 of eav during persistent infection in the stallion of the malopolska breed were analysed in the study. a total of 11 blood and semen samples were collected between 2004 and 2011. the titre of specific eav antibodies in this carrier stallion was maintained at a high level throughout the study and was equal approximately 1:128. the sequence analysis of orf5 showed 16 variable sites including 12 with synonymous substitutions and 4 with non-syno ...201323490558
development and use of a polarized equine upper respiratory tract mucosal explant system to study the early phase of pathogenesis of a european strain of equine arteritis virus.the upper respiratory tract mucosa represents the first line of defense, which has to be overcome by pathogens before invading the host. considering the economic and ethical aspects involved in using experimental animals for pathogenesis studies, respiratory mucosal explants, in which the tissue's three-dimensional architecture is preserved, may be ideal alternatives. different respiratory mucosal explant cultures have been developed. however, none of them could be inoculated with pathogens sole ...201323537375
evidence for absence of equine arteritis virus in the horse population of new zealand.to summarise investigation and laboratory data collected between 2001 and 2011 to provide evidence that equine arteritis virus is not present in the horse population of new zealand.201323611669
identification of a conserved b-cell epitope in the equine arteritis virus (eav) n protein using the pepscan technique.the nucleocapsid (n) gene of equine arteritis virus (eav) is highly conserved between isolates, and the n protein is an important antigen that induces immunity when horses are infected with eav. this study describes the identification of a linear b-cell epitope on the n protein using the pepscan technique with a monoclonal antibody (mab) 2b1 directed against the n protein. the n protein was divided into 11 overlapping peptides, each containing 16 amino acids associated with six overlapping amino ...201323813249
equine arteritis virus.equine arteritis virus (eav) is the causative agent of equine viral arteritis (eva), a respiratory and reproductive disease of equids. there has been significant recent progress in understanding the molecular biology of eav and the pathogenesis of its infection in horses. in particular, the use of contemporary genomic techniques, along with the development and reverse genetic manipulation of infectious cdna clones of several strains of eav, has generated significant novel information regarding t ...201323891306
arterivirus molecular biology and pathogenesis.arteriviruses are positive-stranded rna viruses that infect mammals. they can cause persistent or asymptomatic infections, but also acute disease associated with a respiratory syndrome, abortion or lethal haemorrhagic fever. during the past two decades, porcine reproductive and respiratory syndrome virus (prrsv) and, to a lesser extent, equine arteritis virus (eav) have attracted attention as veterinary pathogens with significant economic impact. particularly noteworthy were the 'porcine high fe ...201323939974
identification of target cells of a european equine arteritis virus strain in experimentally infected ponies.currently, little is known on the cellular pathogenesis of equine arteritis virus (eav). the purpose of the present study was to identify the target cells in ponies experimentally inoculated with eav 08p178 (eu, clade-1). eav-target organs (respiratory tissues with associated lymphoid tissues and large intestines), collected at 3 and 7 days post inoculation (dpi) and with virus titers≥10(5.0) tcid50/g, were processed with double immunofluorescence staining for the simultaneous detection of eav n ...201323993255
co-translational processing of glycoprotein 3 from equine arteritis virus: n-glycosylation adjacent to the signal peptide prevents cleavage.signal peptide cleavage and n-glycosylation of proteins are co-translational processes, but little is known about their interplay if they compete for adjacent sites. here we report two unique findings for processing of glycoprotein 3 of equine arteritis virus. glycoprotein 3 (gp3) contains an n-terminal signal peptide, which is not removed, although bioinformatics predicts cleavage with high probability. there is an overlapping sequon, nntt, adjacent to the signal peptide that we show to be glyc ...201324142700
inhibition of virus replication and induction of human tetherin gene expression by equine ifn-α1.type i interferons (ifns) play important roles in the defense of host cells against viral infection by inducing the expression of a diverse range of antiviral factors. ifns from different animals likely share similar features with human ifns, and some of them have cross-species activities. equine ifn-α was proved effective in both equine and human cells. however, the previous studies mostly focused on the inhibition of virus induced cytopathic effects. in this study, we used virus-specific assay ...201324144682
serological markers of bornavirus infection found in horses in iceland.in a stable of eight horses in northern iceland, six horses presented with clinical signs, such as ataxia and reduced appetite, leading to euthanasia of one severely affected horse. serological investigations revealed no evidence of active equine herpes virus type 1 infection, a common source of central nervous system disease in horses, nor equine arteritis virus and west nile virus. another neurotropic virus, borna disease virus, was therefore included in the differential diagnosis list.201324180621
validation of an improved competitive enzyme-linked immunosorbent assay to detect equine arteritis virus antibody.the objective of the present study was to validate a previously described competitive enzyme-linked immunosorbent assay (celisa) to detect antibody to equine arteritis virus (eav) based on gp5-specific nonneutralizing monoclonal antibody (mab) 17b7(9) using the world organization for animal health (oie)-recommended protocol, which includes the following 5 in-house analyses. 1) the assay was calibrated with the oie-designated reference serum panel for eav; 2) repeatability was evaluated within an ...201324202992
equine arteritis virus gp5 protein induces apoptosis in cultured insect cells.equine arteritis virus (eav) has been shown to induce apoptosis in vitro but the induction of this mechanism has not been previously associated with any viral gene product. in this work, we found a cytotoxicity effect of the eav gp5 protein on baculovirus-insect cells and a low yield of protein recovery. besides, different morphological features by electron transmission microscopy, dna fragmentation in agarose gel, tunel analysis and caspase 3 activity were found. all these findings indicate tha ...201424518298
signal peptide cleavage from gp3 enabled by removal of adjacent glycosylation sites does not impair replication of equine arteritis virus in cell culture, but the hydrophobic c-terminus is essential.the disulphide-linked gp2/3/4 spike of equine arteritis virus (eav) is essential for virus entry. we showed recently that in transfected cells carbohydrates attached adjacent to the signal peptide of gp3 inhibit cleavage. here we confirm this unique phenomenon in recombinant viruses with disabled glycosylation sites. surprisingly, the infectivity of eav containing gp3 with cleaved signal peptide was not impaired and gp3 with cleaved signal peptide associates with gp2/4 in virus particles. in con ...201424556360
development of a peptide elisa for the diagnosis of equine arteritis virus.a peptide-based indirect elisa was developed to detect antibodies against equine arteritis virus (eav). two peptides for epitope c of protein gp5 and fragment e of protein m were designed, synthesized, purified and used as antigens either alone or combined. ninety-two serum samples obtained from the 2010 equine viral arteritis outbreak, analyzed previously by virus neutralization, were evaluated by the elisa here developed. the best resolution was obtained using peptide gp5. the analysis of the ...201424803114
experiences with infectious cdna clones of equine arteritis virus: lessons learned and insights gained.the advent of recombinant dna technology, development of infectious cdna clones of rna viruses, and reverse genetic technologies have revolutionized how viruses are studied. genetic manipulation of full-length cdna clones has become an especially important and widely used tool to study the biology, pathogenesis, and virulence determinants of both positive and negative stranded rna viruses. the first full-length infectious cdna clone of equine arteritis virus (eav) was developed in 1996 and was a ...201424913633
biogenesis of non-structural protein 1 (nsp1) and nsp1-mediated type i interferon modulation in arteriviruses.type i interferons (ifns-α/β) play a key role for the antiviral state of host, and the porcine arterivirus; porcine reproductive and respiratory syndrome virus (prrsv), has been shown to down-regulate the production of ifns during infection. non-structural protein (nsp) 1 of prrsv has been identified as a viral ifn antagonist, and the nsp1α subunit of nsp1 has been shown to degrade the creb-binding protein (cbp) and to inhibit the formation of enhanceosome thus resulting in the suppression of if ...201424928046
equine arteritis virus does not induce interferon production in equine endothelial cells: identification of nonstructural protein 1 as a main interferon antagonist.the objective of this study was to investigate the effect of equine arteritis virus (eav) on type i interferon (ifn) production. equine endothelial cells (eecs) were infected with the virulent bucyrus strain (vbs) of eav and expression of ifn-β was measured at mrna and protein levels by quantitative real-time rt-pcr and ifn bioassay using vesicular stomatitis virus expressing the green fluorescence protein (vsv-gfp), respectively. quantitative rt-pcr results showed that ifn-β mrna levels in eecs ...201424967365
the recent european isolate (08p178) of equine arteritis virus causes inflammation but not arteritis in experimentally infected ponies.in the last two decades, outbreaks of equine viral arteritis (eva) have been reported in europe, but little is known about these european isolates of equine arteritis virus (eav). eav european strain (08p178, eu-1 clade) isolated from one of these recent outbreaks is able to cause clinical signs on experimental infection. the aim of the present study was to investigate the microscopical lesions induced by this isolate after experimental infection of ponies. animals were killed at 3, 7, 14 and 28 ...201424975896
how viruses hijack the erad tuning machinery.an essential step during the intracellular life cycle of many positive-strand rna viruses is the rearrangement of host cell membranes to generate membrane-bound replication platforms. for example, nidovirales and flaviviridae subvert the membrane of the endoplasmic reticulum (er) for their replication. however, the absence of conventional er and secretory pathway markers in virus-induced er-derived membranes has for a long time hampered a thorough understanding of their biogenesis. recent report ...201424990995
semen quality of stallions challenged with the kentucky 84 strain of equine arteritis virus.equine arteritis virus (eav) is the causal agent of equine viral arteritis (eva), a respiratory and reproductive disease of equids. some strains of eav can cause fever, leukopenia, and dependent edema of the limbs, scrotum, and preputium in the acutely infected stallion. we hypothesized that fever and scrotal edema observed during the acute phase of the infection, but not the presence of eav, have an adverse effect on semen quality. a group of seven stallions were intranasally inoculated with th ...201425156969
possible involvement of coaxially stacked double pseudoknots in the regulation of -1 programmed ribosomal frameshifting in rna viruses.-1 programmed ribosomal frameshifting (prf) in viruses is often stimulated by a pseudoknot downstream from the slippery sequence. at the prf junction of hiv-1, transmissible gastroenteritis virus (tgev), barmah forest virus (bfv), fort morgan virus (fmv), and equine arteritis virus (eav), we identified potential double pseudoknots in either a tandem mode or embedded mode. in viruses with tandem pseudoknots (5'pk & 3'pk), the slippery sequence is encompassed in the 5'pk. the ribosome needs to unw ...201525204560
modulation of innate immune signaling by nonstructural protein 1 (nsp1) in the family arteriviridae.arteriviruses infect immune cells and may cause persistence in infected hosts. inefficient induction of pro-inflammatory cytokines and type i ifns are observed during infection of this group of viruses, suggesting that they may have evolved to escape the host immune surveillance for efficient survival. recent studies have identified viral proteins regulating the innate immune signaling, and among these, nsp1 (nonstructural protein 1) is the most potent ifn antagonist. for porcine reproductive an ...201425262851
membrane proteins of arterivirus particles: structure, topology, processing and function.arteriviruses, such as equine arteritis virus (eav) and porcine reproductive and respiratory syndrome virus (prrsv), are important pathogens in veterinary medicine. despite their limited genome size, arterivirus particles contain a multitude of membrane proteins, the gp5/m and the gp2/3/4 complex, the small and hydrophobic e protein and the orf5a protein. their function during virus entry and budding is understood only incompletely. we summarize current knowledge of their primary structure, memb ...201425278143
combination of an unbiased amplification method and a resequencing microarray for detecting and genotyping equine arteritis virus.this study shows that an unbiased amplification method applied to equine arteritis virus rna significantly improves the sensitivity of the real-time reverse transcription-quantitative pcr (rt-qpcr) recommended by the world organization for animal health. twelve viral rnas amplified using this method were hybridized on a high-density resequencing microarray for effective viral characterization.201525339390
[development of pcr methods for detection of eav infection].the goal of this work was the development of suitable (real-time) rt-pcr techniques for fast and sensitive diagnosis of eav and for molecular-epidemiological characterisation of viral strains, as an alternative to virus isolation. to this purpose two conventional rt-pcr methods and one real-time rt-pcr were adapted to detect the broadest possible spectrum of viral strains. several dilutions with bucyrus strain showed a 100-fold higher sensitivity of real-time rt-pcr and heminested rt-pcr compare ...201425359114
equine viral arteritis.equine arteritis virus (eav), the causative agent of equine viral arteritis (eva), is a respiratory and reproductive disease that occurs throughout the world. eav infection is highly species-specific and exclusively limited to members of the family equidae, which includes horses, donkeys, mules, and zebras. eva is an economically important disease and outbreaks could cause significant losses to the equine industry. the primary objective of this article is to summarize current understanding of ev ...201425441113
antiviral activity of a bacillus sp. p34 peptide against pathogenic viruses of domestic animals.p34 is an antimicrobial peptide produced by a bacillus sp. strain isolated from the intestinal contents of a fish in the brazilian amazon basin with reported antibacterial activity. the aim of this work was to evaluate the peptide p34 for its in vitro antiviral properties against canine adenovirus type 2 (cav-2), canine coronavirus (ccov), canine distemper virus (cdv), canine parvovirus type 2 (cpv-2), equine arteritis virus (eav), equine influenza virus (eiv), feline calicivirus (fcv) and felin ...201425477947
re-emergence of a genetic outlier strain of equine arteritis virus: impact on phylogeny.equine arteritis virus (eav) is the causative agent of equine viral arteritis (eva), a respiratory and reproductive disease of equids, which is notifiable in some countries including the great britain (gb) and to the oie. herein, we present the case of a persistently infected stallion and the phylogenetic tracing of the virus strain isolated. discussing eav occurrence and phylogenetic analysis we review features, which may aid to harmonise and enhance the classification of eav.201525527462
proteolytic processing of the porcine reproductive and respiratory syndrome virus replicase.the porcine reproductive and respiratory syndrome virus (prrsv) replicase polyproteins pp1a and pp1ab are proteolytically processed by four proteases encoded in orf1a. in this study, a large set of prrsv replicase cleavage products were identified and pp1a cleavage sites were verified by using a combination of bioinformatics, proteomics, immunoprecipitation, and site-directed mutagenesis. for genotype 1 prrsv (isolate sd01-08), proteomic analysis identified h180/s181, g385/a386, and g1446/a1447 ...201525557977
the equine arteritis virus isolate from the 2010 argentinian outbreak.a semen sample from a stallion infected during the 2010 equine arteritis virus (eav) outbreak was received for viral isolation prior to castration of the animal. the virus was identified using a polyclonal antibody immunofluorescence test. reverse-transcription polymerase chain reaction (rt-pcr) was used to amplify a region of the gp5 gene with primers gl105f and gl673r. the pcr products were purified and sequences of both strands were determined in a megabace™1000 with inner primers cr2 and eav ...201425812217
prevalence of equine viral arteritis in algeria.in order to determine the prevalence of equine viral arteritis in algeria, 268 sera from non-vaccinated horses were collected from the western and eastern regions. serological analysis of the sera, which were collected from 2009 to 2011, was performed using the virus neutralisation test, as described by the world organisation for animal health. overall, 20 sera (7.46%) were seropositive, 152 (56.71%) were negative and 96 sera (35.82%) were cytotoxic. equine arteritis virus (eav) seroprevalence w ...201425812220
in vivo assessment of equine arteritis virus vaccine improvement by disabling the deubiquitinase activity of papain-like protease 2.arteriviruses are a family of positive-stranded rna viruses that includes the prototypic equine arteritis virus (eav) and porcine reproductive and respiratory syndrome virus (prrsv). although several vaccines against these viruses are commercially available there is room for improvement, especially in the case of prrsv. the ability of arteriviruses to counteract the immune response is thought to decrease the efficacy of the current modified live virus vaccines. we have recently shown that the de ...201525975520
arterivirus nsp12 versus the coronavirus nsp16 2'-o-methyltransferase: comparison of the c-terminal cleavage products of two nidovirus pp1ab polyproteins.the 3'-terminal domain of the most conserved orf1b in three of the four families of the order nidovirales (except for the family arteriviridae) encodes a (putative) 2'-o-methyltransferase (2'-o-mtase), known as non structural protein (nsp) 16 in the family coronaviridae and implicated in methylation of the 5' cap structure of nidoviral mrnas. as with coronavirus transcripts, arterivirus mrnas are assumed to possess a 5' cap although no candidate mtases have been identified thus far. to address t ...201526041874
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