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
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
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
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
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
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
evidence for absence of equine arteritis virus in the horse population of new 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
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
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
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
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
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
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
nf-κb activation by equine arteritis virus is myd88 dependent and promotes viralκb, 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
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
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
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
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
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
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
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
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
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
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
equine infectious anemia prevalence in feral donkeys from northeast brazil.equine infectious anemia virus (eiav) is an important cause of morbidity and mortality throughout the world. although the virus infects all members of the equidae the vast majority of studies have been conducted in horses (equus caballus) with comparatively little information available for other equid species. brazil has one of the most abundant donkey (e. asinus) populations of any nation although the economic importance of these animals is declining as transportation becomes increasingly mecha ...201728460747
epidemiology and molecular detection of equine herpesviruses in western algeria in episode of acute equine respiratory infection was reported in western algeria (tiaret province) between february and march 2011, affecting a large population of horses. nasal swabs (n=100) were taken from horses aged between 1 and 27 years, presenting with cough and mucopurulent nasal discharge. the prevalence of equine respiratory virus infections was examined using quantitative polymerase chain reaction (qpcr). one, or more, of four equine respiratory viruses were detected in the nasal swab ...201728757025
equine arteritis virus elicits a mucosal antibody response in the reproductive tract of persistently infected stallions.equine arteritis virus (eav) has the ability to establish persistent infection in the reproductive tract of the stallion (carrier) and is continuously shed in its semen. we have recently demonstrated that eav persists within stromal cells and a subset of lymphocytes in the stallion accessory sex glands in the presence of a significant local inflammatory response. in the present study, we demonstrated that eav elicits a mucosal antibody response in the reproductive tract during persistent infecti ...201728814389
development and characterization of an infectious cdna clone of equine arteritis virus.development and characterization of several infectious cdna clones of equine arteritis virus (eav) have been described in the literature. here we describe the assembly of the full-length infectious cdna clone of the virulent bucyrus strain (vbs; atcc vr-796) of eav in a plasmid vector. this system allows generation of infectious in vitro-transcribed (ivt) rna from the linearized plasmid that can be transfected or electroporated into mammalian cells to produce infectious recombinant progeny virus ...201728508211
equine arteritis virus has specific tropism for stromal cells and cd8(+) t and cd21(+) b lymphocytes but not for glandular epithelium at the primary site of persistent infection in the stallion reproductive tract.equine arteritis virus (eav) has a global impact on the equine industry as the causative agent of equine viral arteritis (eva), a respiratory, systemic, and reproductive disease of equids. a distinctive feature of eav infection is that it establishes long-term persistent infection in 10 to 70% of infected stallions (carriers). in these stallions, eav is detectable only in the reproductive tract, and viral persistence occurs despite the presence of high serum neutralizing antibody titers. carrier ...201728424285
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