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functional properties of the predicted helicase of porcine reproductive and respiratory syndrome virus.porcine reproductive and respiratory syndrome virus (prrsv) is a member of the positive-strand rna virus family arteriviridae. although considerable research has focused on this important pathogen, little is known about the function of most prrsv proteins. to examine characteristics of putative nonstructural proteins (nsp) encoded in orf1b, which have been identified by nucleotide similarity to domains of equine arteritis virus, defined genomic regions were cloned and expressed in the prset expr ...200212127789
structure of arterivirus nsp4. the smallest chymotrypsin-like proteinase with an alpha/beta c-terminal extension and alternate conformations of the oxyanion hole.arteriviruses are enveloped, positive-stranded rna viruses and include pathogens of major economic concern to the swine- and horse-breeding industries. the arterivirus replicase gene encodes two large precursor polyproteins that are processed by the viral main proteinase nonstructural protein 4 (nsp4). the three-dimensional structure of the 21-kda nsp4 from the arterivirus prototype equine arteritis virus has been determined to 2.0 a resolution. nsp4 adopts the smallest known chymotrypsin-like f ...200212163505
characterization of two new structural glycoproteins, gp(3) and gp(4), of equine arteritis virus.equine arteritis virus (eav) is an enveloped, positive-stranded rna virus belonging to the family arteriviridae of the order nidovirales. four envelope proteins have hitherto been identified in eav particles: the predominant membrane proteins m and g(l), the unglycosylated small envelope protein e, and the nonabundant membrane glycoprotein g(s). in this study, we established that the products of eav open reading frame 3 (orf3) and orf4 (designated gp(3) and gp(4), respectively) are also minor st ...200212368326
stable and long-lasting immune response in horses after dna vaccination against equine arteritis virus.equine arteritis virus (eav) is the causative agent of the equine viral arteritis. it is a small rna virus with a linear, non-segmented plus rna genome. eav is a member of the arteriviridae family that includes porcine reproductive and respiratory syndrome virus (prssv), simian haemorrhagic fever virus (shfv) and lactate dehydrogenase virus (ldv). the viral transmission is via respiratory and reproductive routes. clinical signs in horses vary, and severe infection can lead to abortions in pregna ...200212418451
heterodimerization of the two major envelope proteins is essential for arterivirus infectivity.the two major envelope proteins of arteriviruses, the membrane protein (m) and the major glycoprotein (gp(5)), associate into a disulfide-linked heterodimer that is incorporated into the virion and has been assumed to be a prerequisite for virus assembly. using an equine arteritis virus (eav) infectious cdna clone, we have analyzed the requirement for gp(5)-m heterodimerization and have identified the cys residues involved in the formation of the gp(5)-m disulfide bond. the single cys residue (c ...200312477814
chimeric arteriviruses generated by swapping of the m protein ectodomain rule out a role of this domain in viral targeting.arteriviruses are enveloped, positive-strand rna viruses for which the two major envelope proteins gp(5) and m occur as disulfide-linked heterodimers. these were assumed to serve the viral targeting functions, but recent ectodomain swapping studies with equine arteritis virus (eav) indicate that the gp(5) protein does not determine arteriviral tropism. here, we focused on the short, 13- to 18-residue ectodomain of the m protein. using an infectious cdna clone of the lelystad virus isolate of por ...200212490397
identification and characterization of avian retroviruses in chicken embryo-derived yellow fever vaccines: investigation of transmission to vaccine recipients.all currently licensed yellow fever (yf) vaccines are propagated in chicken embryos. recent studies of chick cell-derived measles and mumps vaccines show evidence of two types of retrovirus particles, the endogenous avian retrovirus (eav) and the endogenous avian leukosis virus (alv-e), which originate from the chicken embryonic fibroblast substrates. in this study, we investigated substrate-derived avian retrovirus contamination in yf vaccines currently produced by three manufacturers (yf-vax [ ...200312502826
the stability of the duplex between sense and antisense transcription-regulating sequences is a crucial factor in arterivirus subgenomic mrna synthesis.subgenomic mrnas of nidoviruses (arteriviruses and coronaviruses) are composed of a common leader sequence and a "body" part of variable size, which are derived from the 5'- and 3'-proximal part of the genome, respectively. leader-to-body joining has been proposed to occur during minus-strand rna synthesis and to involve transfer of the nascent rna strand from one site in the template to another. this discontinuous step in subgenomic rna synthesis is guided by short transcription-regulating sequ ...200312502834
use of an internal standard in a closed one-tube rt-pcr for the detection of equine arteritis virus rna with fluorescent probes.routine detection of equine arteritis virus (eav) can be achieved by virus isolation (vi) in cell culture, or by the amplification of viral genome by molecular methods. to simplify molecular diagnosis, a number of different reverse transcriptase polymerase chain reaction (rt-pcr) and rt-nested pcr (rt-npcr) assays were compared, and a one-tube method was developed and optimised utilizing a fluorogenic probe (taqman). an artificial rna template (mimic) and associated probe were also constructed t ...200312657208
the serologic response of horses to equine arteritis virus as determined by competitive enzyme-linked immunosorbent assays (c-elisas) to structural and non-structural viral proteins.in an effort to further characterize the humoral immune response of horses to equine arteritis virus (eav), direct and competitive enzyme-linked immunosorbent assays (c-elisas) were developed using monoclonal and polyclonal anti-sera to structural (g(l), n and m) and non-structural (nsp1) viral proteins. a nsp1-specific monoclonal antibody was produced to facilitate development of a c-elisa to this protein. data obtained using the various c-elisas confirm that the m protein is a major target of ...200312676125
testing for equine arteritis virus. 200312723636
formation of disulfide-linked complexes between the three minor envelope glycoproteins (gp2b, gp3, and gp4) of equine arteritis virus.equine arteritis virus (eav) is an enveloped, positive-stranded rna virus belonging to the family arteriviridae of the order nidovirales: six transmembrane proteins have been identified in eav particles: the nonglycosylated membrane protein m and the glycoprotein gp(5) (previously named g(l)), which occur as disulfide-bonded heterodimers and are the major viral envelope proteins; the unglycosylated small envelope protein e; and the minor glycoproteins gp(2b) (formerly designated g(s)), gp(3), an ...200312743278
testing for equine arteritis virus. 200312790176
differentiation of strains of equine arteritis virus of differing virulence to horses by growth in equine endothelial cells.to compare growth characteristics of strains of equine arteritis virus (eav) of differing virulence to horses in rabbit kidney (rk)-13 cells and equine endothelial cells (eecs) cultured from the pulmonary artery of a foal.200312828265
testing for equine arteritis virus. 200312833939
generation of a candidate live marker vaccine for equine arteritis virus by deletion of the major virus neutralization domain.equine arteritis virus (eav) is an enveloped plus-strand rna virus of the family arteriviridae (order nidovirales) that causes respiratory and reproductive disease in equids. protective, virus-neutralizing antibodies (vnab) elicited by infection are directed predominantly against an immunodominant region in the membrane-proximal domain of the viral envelope glycoprotein g(l), allowing recently the establishment of a sensitive peptide enzyme-linked immunosorbent assay (elisa) based on this partic ...200312857916
equine arteritis virus non-structural protein 1, an essential factor for viral subgenomic mrna synthesis, interacts with the cellular transcription co-factor p100.non-structural protein 1 (nsp1), the n-terminal subunit of the replicase polyprotein of the arterivirus equine arteritis virus (eav), is essential for viral subgenomic mrna synthesis, but fully dispensable for genome replication. however, at the molecular level, the role of nsp1 in eav subgenomic mrna synthesis is poorly understood. a yeast two-hybrid screen did not reveal interactions between eav nsp1 and other viral non-structural proteins or the nucleocapsid protein, although both nsp1 and th ...200312917451
expression of a recombinant gag protein from endogenous avian virus and its use in screening for antibody reactivity in recipients of chick-derived vaccines.virions incorporating endogenous avian virus (eav) rna have been identified in chick-derived biological products, including the vaccines used to protect against measles, mumps, and yellow fever. the presence of eav in these vaccines raises safety concerns regarding transmission to vaccine recipients. development of a serologic assay to detect antibodies to eav required the discovery of a diagnostic eav antigen and reactive antiserum. for this purpose, we have identified and expressed an eav caps ...200312922106
an outbreak of abortion caused by the equine arteritis virus. 195713397180
detection of equine arteritis virus (eav)-specific cytotoxic cd8+ t lymphocyte precursors from eav-infected ponies.equine arteritis virus (eav) causes a systemic infection in equids with variable outcome, ranging from subclinical infections to severe disease, and also has the capacity to induce abortion in pregnant mares and persistent infections in stallions. the serum virus-neutralizing antibody response that invariably develops in the infected animal lasts for many months or years and is believed to play an important role in virus clearance. however, very little is known about cellular immunity against ea ...200313679609
composition of rna and dna of citric acid-isolated liver nuclei from hamsters infected with equine abortion virus (eav). 196013827336
propagation of equine arteritis virus previously adapted to cell cultures of equine kidney in monolayer cultures of hamster kidney. 196214007366
degradation of deoxyribonucleic acid and alteration nucleic acid metabolism in suspension cultures of l-m cells infected with equine abortion virus.randall, charles c. (university of mississippi school of medicine, jackson) and barbara m. walker. degradation of deoxyribonucleic acid and alteration of nucleic acid metabolism in suspension cultures of l-m cells infected with equine abortion virus. j. bacteriol. 86:138-146. 1963.-metabolic alterations in log-phase suspension cultures infected with equine abortion virus (eav) were determined in l-m cells simultaneously labeled or prelabeled with h(3)- or c(14)-thymidine. although infection prod ...196314051805
replication of a deoxyribonucleic acid virus in thymine-deficient mammalian cells.gentry, glenn a. (university of mississippi school of medicine, jackson), lucy a. lawson, and charles c. randall. replication of a deoxyribonucleic acid virus in thymine-deficient mammalian cells. j. bacteriol. 88:1324-1328. 1964.-equine abortion virus (eav), a deoxyribonucleic acid (dna) virus, causes the degradation of host cell dna to acid-soluble components in the l-m cell. it was hypothesized that inhibitors of dna synthesis such as 5-fluorodeoxyuridine (fudr) and amethopterin, which act by ...196414234788
lateral transmission of equine arteritis virus among lipizzaner stallions in south africa.a serological study conducted in 1995 revealed that 7 stallions at the lipizzaner centre, gauteng, south africa, were seropositive for antibody to equine arteritis virus (eav). a lipizzaner stallion imported into south africa from yugoslavia in 1981 had previously (1988) been confirmed to be an eav carrier. despite being placed under life-long breeding quarantine, eav had been transmitted between stallions at the lipizzaner centre.200314515961
virulent and avirulent strains of equine arteritis virus induce different quantities of tnf-alpha and other proinflammatory cytokines in alveolar and blood-derived equine macrophages.equine arteritis virus (eav) infects endothelial cells (ecs) and macrophages in horses, and many of the clinical manifestations of equine viral arteritis (eva) reflect vascular injury. to further evaluate the potential role of eav-induced, macrophage-derived cytokines in the pathogenesis of eva, we infected cultured equine alveolar macrophages (amphi), blood monocyte-derived macrophages (bmphi), and pulmonary artery ecs with either a virulent (ky84) or an avirulent (ca95) strain of eav. eav infe ...200314554093
equine arteritis virus in irish thoroughbreds. 200314627241
equine viral arteritis in a newborn foal: parallel detection of the virus by immunohistochemistry, polymerase chain reaction and virus isolation.a 4-days-old foal died after a short course of respiratory syndrome and fever. large areas of the alveoli, bronchioles and bronchi were partly or completely filled by hyaline membranes. pronounced oedema and mild interstitial pneumonia were present and, in the small muscular arteries, fibrinoid necrosis and vasculitis or perivasculitis could be seen. vasculitis was found in several other organs, and it was most severe in the thymus. the virus was detected in the lung, kidney and spleen using vir ...200314628997
intra- and intermolecular disulfide bonds of the gp2b glycoprotein of equine arteritis virus: relevance for virus assembly and infectivity.equine arteritis virus (eav) is an enveloped, positive-strand rna virus belonging to the family arteriviridae of the order nidovirales: eav virions contain six different envelope proteins. the glycoprotein gp(5) (previously named g(l)) and the unglycosylated membrane protein m are the major envelope proteins, while the glycoproteins gp(2b) (previously named g(s)), gp(3), and gp(4) are minor structural proteins. the unglycosylated small hydrophobic envelope protein e is present in virus particles ...200314645556
interference between avian endogenous ev/j 4.1 and exogenous alv-j retroviral envelopes.a new family of avian retroviral endogenous sequences designated ev/j or eav-hp has been identified recently. here an additional avian ev/j 4.1 endogenous sequence, ev/j 4.1 rb, is reported. ev/j 4.1 rb has the most extensive amino acid identity ever described for an endogenous envelope protein with the alv-j avian leukosis virus. here, we also demonstrate that ev/j 4.1 rb functionally pseudotypes murine leukaemia virions and leads to a complete reciprocal interference with alv-j envelopes. this ...200314645905
investigation of neospora sp. antibodies in aborted mares from normandy, france.neospora caninum, an apicomplexan protozoan parasite, is recognized as a major cause of abortion in cattle while limited information is presently available on association between equine neospora infections and abortions. the aim of the present study was to document prevalence of antibodies against neospora sp. in aborted mares as a clue to the role of n. caninum in mare reproductive failure in normandy, france. using an agglutination test, the number of animals with elevated (>80) anti-neospora ...200314651869
volumetric ultrasound imaging using 2-d cmut arrays.recently, capacitive micromachined ultrasonic transducers (cmuts) have emerged as a candidate to overcome the difficulties in the realization of 2-d arrays for real-time 3-d imaging. in this paper, we present the first volumetric images obtained using a 2-d cmut array. we have fabricated a 128 x 128-element 2-d cmut array with through-wafer via interconnects and a 420-microm element pitch. as an experimental prototype, a 32 x 64-element portion of the 128 x 128-element array was diced and flip-c ...200314682642
genetic characterization of equine arteritis virus during persistent infection of stallions.equine arteritis virus (eav) causes a persistent infection of the reproductive tract of carrier stallions. the authors determined the complete genome sequences of viruses (cw96 and cw01) that were present 5 years apart in the semen of a carrier stallion (cw). the cw96 and cw01 viruses respectively had only 85.6 % and 85.7 % nucleotide identity to the published sequence of eav (eav030). the cw96 and cw01 viruses had two 1 nt insertions and a single 1 nt deletion in the leader sequence, and a 3 nt ...200414769895
secondary structure and function of the 5'-proximal region of the equine arteritis virus rna genome.nidoviruses produce an extensive 3'-coterminal nested set of subgenomic mrnas, which are used to express their structural proteins. in addition, arterivirus and coronavirus mrnas contain a common 5' leader sequence, derived from the genomic 5' end. the joining of this leader sequence to different segments (mrna bodies) from the genomic 3'-proximal region presumably involves a unique mechanism of discontinuous minus-strand rna synthesis. key elements in this process are the so-called transcriptio ...200414970388
the first isolation of equine arteritis virus in argentina.this paper describes the first isolation of equine arteritis virus (eav) in argentina. the virus was isolated from the semen of an imported seropositive stallion held in isolation at a breeding farm in tandil in the buenos aires province. in addition, viral nucleic acid was detected in seminal plasma using the reverse-transcription polymerase chain reaction. the isolated virus was propagated in cell cultures and confirmed as eav by indirect immunofluorescence and virus neutralisation, using a se ...200315005559
characterization of the neutralization determinants of equine arteritis virus using recombinant chimeric viruses and site-specific mutagenesis of an infectious cdna clone.we have used an infectious cdna clone of equine arteritis virus (eav) and reverse genetics technology to further characterize the neutralization determinants in the gp5 envelope glycoprotein of the virus. we generated a panel of 20 recombinant viruses, including 10 chimeric viruses that each contained the orf5 (which encodes gp5) of different laboratory, field, and vaccine strains of eav, a chimeric virus containing the n-terminal ectodomain of gp5 of a european strain of porcine reproductive an ...200415051384
exploring the binding mechanism of the main proteinase in sars-associated coronavirus and its implication to anti-sars drug design.the main proteinase of sars-associated coronavirus (sars-cov) plays an important role in viral transcription and replication, and is an attractive target for anti-sars drug development. the important thing is to understand its binding mechanism with possible ligands. in this study, we investigated possible noncanonical interactions, potential inhibitors, and binding pockets in the main proteinase of sars-cov based on its recently determined crystal structure. these findings provide a wide clue t ...200415080921
phage display of the equine arteritis virus nsp1 zf domain and examination of its metal interactions.a putative zinc finger (zf) domain in the equine arteritis virus (eav) nsp1 protein was described recently to be required for viral transcription. the nsp1 zf (50 aa) was expressed on the surface of m13ke giii phage, fused to the n terminus of the phage piii protein. to evaluate the functionality of the zf domain, a binding assay was developed, based on the use of immobilized ni(2+) ions (ni-nta). phages displaying zf bound significantly better to ni-nta than did phages displaying negative-contr ...200415158598
regulation of relative abundance of arterivirus subgenomic mrnas.the subgenomic (sg) mrnas of arteriviruses (order nidovirales) form a 5'- and 3'-coterminal nested set with the viral genome. their 5' common leader sequence is derived from the genomic 5'-proximal region. fusion of sg rna leader and "body" segments involves a discontinuous transcription step. presumably during minus-strand synthesis, the nascent rna strand is transferred from one site in the genomic template to another, a process guided by conserved transcription-regulating sequences (trss) at ...200415254182
evidence that use of an inactivated equine herpesvirus vaccine induces serum cytotoxicity affecting the equine arteritis virus neutralisation test.several laboratories worldwide have recently experienced problems related to serum cytotoxicity with the equine arteritis virus (eav) neutralisation test (vn) when using office international des epizooties (oie) reference laboratory prescribed rabbit kidney (rk-13) indicator cells. cytotoxicity can be mistaken for viral cytopathic effect and has led to increasing difficulties in test interpretation, consequently causing disruption to both equine breeding and disease surveillance. results from ex ...200415364465
assessing the roles of endogenous retrovirus eav-hp in avian leukosis virus subgroup j emergence and tolerance.avian leukosis virus (alv) subgroup j is thought to have emerged through a recombination event between an unknown exogenous alv and the endogenous retrovirus elements designated eav-hp. all eav-hp elements identified to date in the chicken genome show large deletions, including that of the entire pol gene. here we report the identification of four segregating chicken eav-hp proviruses with complete pol genes, one of which shows exceptionally high sequence identity and a close phylogenetic relati ...200415367619
the immune response to equine arteritis virus: potential lessons for other arteriviruses.the members of the family arteriviridae, genus arterivirus, include equine arteritis virus (eav), porcine reproductive and respiratory syndrome virus (prrsv), lactate dehydrogenase-elevating virus (ldv) of mice, and simian hemorrhagic fever virus (shfv). prrsv is the newest member of the family (first isolated in north america and europe in the early 1990s), whereas the other three viruses were recognized earlier (eav in 1953, ldv in 1960, and shfv in 1964). although arterivirus infections are s ...200415507299
structural protein requirements in equine arteritis virus assembly.equine arteritis virus (eav) is an enveloped, positive-stranded rna virus belonging to the family arteriviridae of the order nidovirales. eav particles contain seven structural proteins: the nucleocapsid protein n, the unglycosylated envelope proteins m and e, and the n-glycosylated membrane proteins gp(2b) (previously named g(s)), gp(3), gp(4), and gp(5) (previously named g(l)). proteins n, m, and gp(5) are major virion components, e occurs in virus particles in intermediate amounts, and gp(4), ...200415542653
rescue of disabled infectious single-cycle (disc) equine arteritis virus by using complementing cell lines that express minor structural glycoproteins.equine arteritis virus (eav) contains seven structural proteins that are all required to produce infectious progeny. alphavirus-based expression vectors have been generated for each of these proteins to explore the possibilities for their constitutive expression in cell lines. this approach was successful for minor glycoproteins gp(2b), gp(3) and gp(4) and for the e protein. subsequently, it was demonstrated that cell lines expressing these proteins could rescue eav mutants that were disabled in ...200415557244
testing for equine arteritis virus. 200415573796
a complex zinc finger controls the enzymatic activities of nidovirus helicases.nidoviruses (coronaviridae, arteriviridae, and roniviridae) encode a nonstructural protein, called nsp10 in arteriviruses and nsp13 in coronaviruses, that is comprised of a c-terminal superfamily 1 helicase domain and an n-terminal, putative zinc-binding domain (zbd). previously, mutations in the equine arteritis virus (eav) nsp10 zbd were shown to block arterivirus reproduction by disrupting rna synthesis and possibly virion biogenesis. here, we characterized the atpase and helicase activities ...200515613297
equine viral arteritis in a stallion. 200515658568
diagnostic application of immunoperoxidase monolayer assay using monoclonal antibodies produced against equine arteritis virus 14-kda nucleocapsid protein.two monoclonal antibodies against the bucyrus strain of equine arteritis virus (eav) were produced, and according to immunoperoxidase reaction following western blot of electrophoresed eav structural proteins, they recognized the nucleocapsid (n) protein antigen (14-kda protein). besides reacting with the blotted polypeptide, the antibodies of the two clones (designated 1h1 and 4g6) selected from 576 have shown high affinity and specificity to intracellular virus antigen as well. both antibodies ...200415684664
binding of cellular proteins to the leader rna of equine arteritis virus.the genome of equine arteritis virus (eav) produces a 3' coterminal-nested set of six subgenomic (sg) viral rnas during virus replication cycle, and each set possesses a common leader sequence of 206 nucleotides (nt) in length derived from the 5' end of the viral genome. given the presence of the leader region within both genomic and sg mrnas, it is likely to contain cis-acting signals that may interact with cellular or viral proteins for rna synthesis. gel mobility shift assays indicated that p ...200515744570
equine viral arteritis control scheme: a brief review with emphasis on laboratory aspects of the scheme in new zealand.to review laboratory aspects of the equine viral arteritis (eva) control scheme in new zealand between 1989 and 2002.200415768101
antibodies against equine herpesviruses and equine arteritis virus in burchell's zebras (equus burchelli ) from the serengeti ecosystem.a total of 51 sera from a migratory population of burchell's zebras (equus burchelli) were collected in the serengeti national park (tanzania) between 1999 and 2001 to assess levels of exposure to equine herpesvirus types 1, 2, 4, 9 (ehv-1, -2, -4, -9), ehv-1 zebra isolate t965, and equine arteritis virus (eav). using virus-specific neutralizing antibody tests, seroprevalence was high for ehv-9 (60% of 45), moderate for eav (24% of 51), and lower for the ehv-1-related zebra isolate (17% of 41), ...200515827213
discontinuous subgenomic rna synthesis in arteriviruses is guided by an rna hairpin structure located in the genomic leader region.nidoviruses produce an extensive 3'-coterminal nested set of subgenomic (sg) mrnas, which are used to express structural proteins and sometimes accessory proteins. in arteriviruses and coronaviruses, these mrnas contain a common 5' leader sequence, derived from the genomic 5' end. the joining of the leader sequence to different segments derived from the 3'-proximal part of the genome (mrna bodies) presumably involves a unique mechanism of discontinuous minus-strand rna synthesis in which base pa ...200515858015
a novel subgroup among genotypes of equine arteritis virus: genetic comparison of 40 strains.the authors determined partial nucleic sequences of the variable regions of open-reading frame (orf5) from 151 nucleotide to 668 nucleotide and deduced amino acid sequences of 518 nucleotide respectively of 20 equine arteritis virus (eav) isolates. about 19 hungarian and one austrian eav strains were subjected to sequence analysis, the further data of 20 eav strains: six north american and 14 european were obtained from the genbank. comparative sequence analysis of the hungarian eav strains indi ...200515876222
study on the epidemiology of equine arteritis virus infection with different diagnostic techniques by investigating 96 cases of equine abortion in hungary.the occurrence of equine arteritis virus (eav) induced equine abortions was studied with different laboratory methods during a 3-year period. tissue samples from 96 aborted equine foetuses or newborn foals were collected from 57 farms located in different parts of hungary. virus isolation, polymerase chain reaction (pcr), immunohistochemistry and serology were used for the detection of eav infection. the overall seroprevalence of eav infection in mares was 65%. eav induced abortion was diagnosed ...200515925460
viruses associated with outbreaks of equine respiratory disease in new zealand.to identify viruses associated with respiratory disease in young horses in new zealand.200216032259
equine respiratory viruses in foals in new zealand.to identify the respiratory viruses that are present among foals in new zealand and to establish the age at which foals first become infected with these viruses.200216032260
modulating reproductive activity in stallions: a review.situations in which suppression or stimulation of reproductive activity in stallions has been attempted, or is desired, include resolution of the equine arteritis virus 'shedding' state, induction of testicular descent in inguinal cryptorchids, and the improvement of sperm production capacity and/or semen quality in sub-fertile stallions. however, the most common reason for wanting to modulate reproductive activity in a stallion is to alter the expression of sexual behaviour. in the case of inta ...200516061332
the 2b protein as a minor structural component of prrsv.porcine reproductive and respiratory syndrome virus (prrsv) orf2 contains an internal orf that codes for a small non-glycosylated protein known as 2b. previous work had identified the presence of a 10kda 2b protein in virus-infected cells and the induction of an anti-2b response in prrsv-infected pigs, as well as a possible association of 2b with the virion (, virology 287:183-191). in this study, we utilized two experimental approaches, including the use of a 2b peptide-specific monoclonal anti ...200516095746
testing for antibodies to equine arteritis virus. 200516170008
antiviral activity of morpholino oligomers designed to block various aspects of equine arteritis virus amplification in cell culture.the antiviral efficacy of ten antisense phosphorodiamidate morpholino oligomers (pmos) directed against equine arteritis virus (eav), a nidovirus belonging to the family arteriviridae, was evaluated in mammalian (vero-e6) cells. peptide-conjugated pmos (p-pmos) supplied in cell culture medium at micromolar concentrations were efficiently taken up by vero-e6 cells and were minimally cytotoxic. the p-pmos were designed to base pair to rna sequences involved in different aspects of eav amplificatio ...200516227231
testing for antibodies to equine arteritis virus. 200516244241
recovery of swedish equine arteritis viruses from semen by cell culture isolation and rna transfection.recovery of infectious equine arteritis virus (eav) from the semen of persistently infected swedish stallions was attempted by classical cell culture isolation and by transfection of extracted total rna. whereas virus from semen samples stored for several months at -20 degrees c or from extended semen could only be recovered by transfection of extracted rna, isolation in cell culture was achieved readily with fresh, unextended semen stored at -70 degrees c or directly used after sampling. in par ...200616297456
site-directed mutagenesis of the nidovirus replicative endoribonuclease nendou exerts pleiotropic effects on the arterivirus life cycle.the highly conserved nendou replicative domain of nidoviruses (arteriviruses, coronaviruses, and roniviruses) belongs to a small protein family whose cellular branch is prototyped by xendou, a xenopus laevis endoribonuclease involved in nucleolar rna processing. recently, sequence-specific in vitro endoribonuclease activity was demonstrated for the nendou-containing nonstructural protein (nsp) 15 of several coronaviruses. to investigate the biological role of this novel enzymatic activity, we ha ...200616439522
expression, purification, and in vitro activity of an arterivirus main proteinase.to allow the biochemical and structural characterization of the chymotrypsin-like "main proteinase" (non-structural protein 4; nsp4) of the arterivirus prototype equine arteritis virus (eav), we developed protocols for the large-scale production of recombinant nsp4 in escherichia coli. the nsp4 proteinase was expressed either fused to maltose binding protein or carrying a c-terminal hexahistidine tag. following purification, the nsp4 moiety of mbp-nsp4 was successfully used for structural studie ...200616527369
mutagenesis analysis of the nsp4 main proteinase reveals determinants of arterivirus replicase polyprotein autoprocessing.nonstructural protein 4 (nsp4; 204 amino acids) is the chymotrypsin-like serine main proteinase of the arterivirus equine arteritis virus (order nidovirales), which controls the maturation of the replicase complex. nsp4 includes a unique c-terminal domain (ctd) connected to the catalytic two-beta-barrel structure by the poorly conserved residues 155 and 156. this dipeptide might be part of a hinge region (hr) that facilitates interdomain movements and thereby regulates (in time and space) autopr ...200616537610
equine viral arteritis. 200616582004
extended phylogeny of equine arteritis virus: division into new subgroups.to determine a conclusive phylogeny, equine arteritis viruses from italy, austria, hungary, sweden, south africa and other parts of the world were analysed by reverse-transcription polymerase chain reaction amplification and direct sequencing. the nucleotide sequences corresponding to the variable part of the large glycoprotein gp5, specified by open reading frame 5, were compared and added to a previously published phylogenetic tree in which a clear division between 'european' and 'american' ty ...200616626399
effective removal of equine arteritis virus from stallion semen.a method of removing equine arteritis virus (eav) from equine semen used for artificial insemination is urgently needed. recent medical studies suggest that a double semen processing technique of density gradient centrifugation followed by a 'swim-up' can provide virus-free sperm preparations for assisted reproduction.200616706276
[case report: equine arteritis virus (eav) as the cause of abortion in alpacas?].here we report a case of a late abortion of a primiparous alpaca where genome fragments of the equine viral arteritis virus (eav) could be detected in fetal tissues using reverse transcription polymerase chain reaction (rt-pcr). all five alpacas of the herd had virus neutralizing antibodies against eav. eav thus must be regarded as a potential agent for abortions in alpacas. possible routes of introduction of the virus are discussed.200616716054
equine arteritis virus.equine arteritis virus (eav) is a small, enveloped, positive-stranded rna virus, in the family arteriviridae , w.h.ich can infect both horses and donkeys. while the majority of eav infections are asymptomatic, acutely infected animals may develop a wide range of clinical signs, including pyrexia, limb and ventral edema, depression, rhinitis, and conjunctivitis. the virus may cause abortion and has caused mortality in neonates. after natural eav infection, most horses develop a solid, long-term i ...199716728076
rna signals in the 3' terminus of the genome of equine arteritis virus are required for viral rna synthesis.rna virus genomes contain cis-acting sequences and structural elements involved in virus replication. both full-length and subgenomic negative-strand rna synthesis are initiated at the 3' terminus of the positive-strand genomic rna of equine arteritis virus (eav). to investigate the molecular mechanism of eav rna synthesis, the rna secondary structure of the 3'-proximal region of the genome was analysed by chemical and enzymic probing. based on the rna secondary structure model derived from this ...200616760399
the intraleader aug nucleotide sequence context is important for equine arteritis virus replication.the 5(-terminal leader sequence of the equine arteritis virus (eav) genome contains an open reading frame (orf) with an aug codon in a suboptimal context for initiation of protein synthesis. to investigate the significance of this intraleader orf (ilo), an expression plasmid was generated carrying a dna copy of the subgenomic mrna7 behind a t7 promoter. capped rna transcribed from this construct was shown to direct, in an in vitro translation system, the synthesis of leader peptide as well as n ...200616791420
highly diverse type of equine arteritis virus (eav) from the semen of a south african donkey: short communication.equine arteritis virus (eav) was detected by rt-nested pcr in semen samples from a naturally infected south african donkey. sequence analysis of the amplified orf5 fragment revealed only 60 to 70% nucleotide identity to a panel of eav reference sequences. the unique donkey eav sequence was also found to be stable during passage in horses. the sequence data reported in this study indicate that the south african donkey variant might represent a new genotype of eav. the distinct genetic properties ...200616841763
application of polymerase chain reaction and virus isolation techniques for the detection of viruses in aborted and newborn foals.the occurrence of two important pathogens, equine herpesvirus 1 (ehv1) and equine arteritis virus (eav) causing abortions, perinatal foal mortality and respiratory disease, was investigated by polymerase chain reaction (pcr) and virus isolation to demonstrate the presence of abortigenic viruses in samples from 248 horse fetuses in hungary. we found 26 ehv1- and 4 eav-positive aborted or prematurely born foals from 16 and 4 outbreaks, respectively, proving that despite the widely applied vaccinat ...200616841764
[prokaryotic expression of the major antigenic domain of equine arteritis virus gl protein and the establishment of putative indirect elisa assay].according to the antigenic analysis of equine arteritis virus (eav) gl protein, one pair of primers were designed, with which the gene fragment coding the high antigenic domain of eav gl protein was amplified from the eav genome. the cloned gene was digested with bamh i and xho i and then inserted into pet-32a and resulted pet-gl1. the pet-gl1 was transformed into the host cell bl21(de3) and the expression was optimized including cultivation temperature and concentration of iptg. the aim protein ...200616933616
equine viral arteritis.eva is an important if uncommon disease of horses. potential economic losses attributable to eva include direct losses from abortion, pneumonia in neonates, and febrile disease in performance horses. indirect losses are those associated with national and international trade/animal movement regulations, particularly those pertaining to persistently infected carrier stallions and their semen. however, eav infection and eva are readily prevented through serological and virological screening of hors ...200617037573
proteolytic maturation of replicase polyprotein pp1a by the nsp4 main proteinase is essential for equine arteritis virus replication and includes internal cleavage of nsp7.the positive-stranded rna genome of the arterivirus equine arteritis virus (order nidovirales) encodes the partially overlapping replicase polyproteins pp1a (1727 aa) and pp1ab (3175 aa). previously, three viral proteinases were reported to cleave these large polyproteins into 12 non-structural proteins (nsps). the chymotrypsin-like viral main proteinase residing in nsp4 is responsible for eight of these cleavages. processing of the c-terminal half of pp1a (the nsp3-8 region) was postulated to o ...200617098961
experiences with new generation vaccines against equine viral arteritis, west nile disease and african horse sickness.viral diseases constitute an ever growing threat to the horse industry worldwide because of the rapid movement of large numbers of horses for competition and breeding. a number of different types of vaccines are available for protective immunization of horses against viral diseases. traditional inactivated and live-attenuated (modified live virus, mlv) virus vaccines remain popular and efficacious but recombinant vaccines are increasingly being developed and used, in part because of the perceive ...200717267078
genetic typing of equine arteritis virus isolates from argentina.we report the nucleotide sequence and genetic diversity of four equine arteritis virus (eav) orf 5 and 6 from argentina isolates, obtained from asymptomatic virus-shedding stallions. nucleic acid recovered from the isolates were amplified by rt-pcr and sequenced. nucleotide and deduced amino acid sequences from the argentine isolates were compared with 17 sequences available from the genbank. phylogenetic analysis revealed that the argentine isolates grouped together in a definite cluster near e ...200717294142
development and characterization of an infectious cdna clone of the virulent bucyrus strain of equine arteritis virus.strains of equine arteritis virus (eav) differ in the severity of the disease that they induce in horses. infectious cdna clones are potentially useful for identification of genetic determinants of eav virulence; to date, two clones have been derived from a cell culture-adapted variant of the original (bucyrus) isolate of eav, and it has previously been shown that recombinant virus derived from one of these (reav030) is attenuated in horses. a complete cdna copy of the genome of the virulent buc ...200717325365
an infectious recombinant equine arteritis virus expressing green fluorescent protein from its replicase gene.thus far, systems developed for heterologous gene expression from the genomes of nidoviruses (arteriviruses and coronaviruses) have relied mainly on the translation of foreign genes from subgenomic mrnas, whose synthesis is a key feature of the nidovirus life cycle. in general, such expression vectors often suffered from relatively low and unpredictable expression levels, as well as genome instability. in an attempt to circumvent these disadvantages, the possibility to express a foreign gene [en ...200717374763
equine viral arteritis.equine viral arteritis is reviewed with specific reference to clinical features, etiology, transmission, diagnosis, epidemiology, and current methods for the control of this disease. there is evidence of variation in pathogenicity among strains of equine arteritis virus. virus transmission occurs primarily by the respiratory and venereal routes during the acute phase of the infection. the long-term carrier stallion appears to play a major epidemiological role in dissemination and perpetuation of ...198717422919
ontario. equine arteritis virus isolated from a standardbred foal with pneumonia. 198817423174
structure of the equine arteritis virus nucleocapsid protein reveals a dimer-dimer arrangement.equine arteritis virus (eav) is an enveloped positive-sense rna virus belonging to the arteriviridae family, which also includes the porcine pathogen prrsv and is genetically and structurally related to the coronaviruses. eav is an important equine pathogen that has caused significant economic losses to the horse-breeding industry and has been difficult to control. the eav virion consists of a genome-containing nucleocapsid core made of nucleocapsid (n) protein surrounded by a lipid envelope con ...200717452783
de novo initiation of rna synthesis by the arterivirus rna-dependent rna polymerase.all plus-strand rna viruses encode an rna-dependent rna polymerase (rdrp) that functions as the catalytic subunit of the viral replication/transcription complex, directing viral rna synthesis in concert with other viral proteins and, sometimes, host proteins. rna synthesis essentially can be initiated by two different mechanisms, de novo initiation and primer-dependent initiation. most viral rdrps have been identified solely on the basis of comparative sequence analysis, and for many viruses the ...200717537850
antiviral activity of carbohydrate-binding agents against nidovirales in cell culture.coronaviruses are important human and animal pathogens, the relevance of which increased due to the emergence of new human coronaviruses like sars-cov, hku1 and nl63. together with toroviruses, arteriviruses, and roniviruses the coronaviruses belong to the order nidovirales. so far antivirals are hardly available to combat infections with viruses of this order. therefore, various antiviral strategies to counter nidoviral infections are under evaluation. lectins, which bind to n-linked oligosacch ...200717560666
an rna pseudoknot in the 3' end of the arterivirus genome has a critical role in regulating viral rna synthesis.in the life cycle of plus-strand rna viruses, the genome initially serves as the template for both translation of the viral replicase gene and synthesis of minus-strand rna and is ultimately packaged into progeny virions. these various processes must be properly balanced to ensure efficient viral proliferation. to achieve this, higher-order rna structures near the termini of a variety of rna virus genomes are thought to play a key role in regulating the specificity and efficiency of viral rna sy ...200717581985
the equine arteritis virus induces apoptosis via caspase-8 and mitochondria-dependent caspase-9 activation.we have previously showed that equine arteritis virus (eav), an arterivirus, induces apoptosis in vitro. to determine the caspase activation pathways involved in eav-induced apoptosis, target cells were treated with peptide inhibitors of apoptosis z-vad-fmk (pan-caspase inhibitor), z-ietd-fmk (caspase-8-specific inhibitor) or z-lehd-fmk (caspase-9-specific inhibitor) 4 h prior to infection with the eav t1329 canadian isolate. significant inhibition of apoptosis was obtained with all peptide inhi ...200717583760
arterivirus subgenomic mrna synthesis and virion biogenesis depend on the multifunctional nsp1 autoprotease.many groups of plus-stranded rna viruses produce additional, subgenomic mrnas to regulate the expression of part of their genome. arteriviruses and coronaviruses (order nidovirales) are unique among plus-stranded rna viruses for using a mechanism of discontinuous rna synthesis to produce a nested set of 5'- and 3'-coterminal subgenomic mrnas, which serve to express the viral structural protein genes. the discontinuous step presumably occurs during minus-strand synthesis and joins noncontiguous s ...200717626105
genetic variation and phylogenetic analysis of 22 french isolates of equine arteritis virus.genetic variation and phylogenetic relationships among 22 french isolates of equine arteritis virus (eav) obtained over four breeding seasons (2001-2004) were determined by sequencing open reading frames (orfs) 2a-7. the orfs 2a-7 of 22 isolates differed from the prototype virulent bucyrus strain of eav by between 14 (99.5% identity) and 328 (88.7% identity) nucleotides, and differed from each other by between 0 (100% identity) and 346 (88.1% identity) nucleotides, confirming genetic diversity a ...200717680321
detection of antibodies to equine arteritis virus in horse sera using recombinant chimaeric n/g(l) protein. 200717827478
comparison of different molecular methods for assessment of equine arteritis virus (eav) infection: a novel one-step mgb real-time rt-pcr assay, pcr-elisa and classical rt-pcr for detection of highly diverse sequences of slovenian eav variants.in the present study, a new one-step real-time reverse transcription-polymerase chain reaction (rt-pcr) strategy with minor-groove-binder (mgb) technology for the detection of eav from 40 semen samples of slovenian carrier stallions was tested. a novel mgb probe (eavmgbpr) and a reverse primer (eav-r) based on the multiple sequence alignment of 49 different eav strain sequences of the highly conserved orf7 (nucleocapsid gene) were designed. the performance of the assay was compared with differen ...200717854913
[european biologists versus rome and berlin]. 200717892151
molecular epizootiology of equine arteritis virus isolates from poland.phylogenetic analysis was performed on the sequences of 44 polish isolates of equine arteritis virus that were isolated from the semen of stallions from national and private studs, collected during 2001--2005. these sequences were also compared with 41 reference strains previously described and commonly used in phylogenesis. on the basis of the nucleotide sequence analysis of the orf5 gene, encoding the glycoprotein gp5, it was demonstrated that the polish eav isolates belonged to two subgroups ...200817964086
testing for antibodies to equine arteritis virus. 200717965374
development of a fluorescent-microsphere immunoassay for detection of antibodies specific to equine arteritis virus and comparison with the virus neutralization test.the development and validation of a microsphere immunoassay (mia) to detect equine antibodies to the major structural proteins of equine arteritis virus (eav) are described. the assay development process was based on the cloning and expression of genes for full-length individual major structural proteins (gp5 amino acids 1 to 255 [gp5(1-255)], m(1-162), and n(1-110)), as well as partial sequences of these structural proteins (gp5(1-116), gp5(75-112), gp5(55-98), m(88-162), and n(1-69)) that cons ...200818032597
analysis of orfs 2b, 3, 4, and partial orf5 of sequential isolates of equine arteritis virus shows genetic variation following experimental infection of horses.samples from horses experimentally infected with the "large plaque variant (lp3a+)" of equine arteritis virus were analysed. these included 182 nasal swabs collected from day 1 to 14 post-infection (p.i.), and 21 virus isolates obtained from white blood cells of animals that showed a prolonged viraemia between days 30 to 72 p.i. in order to determine the genetic stability of the virus and particularly to characterise the genetic variants found during the prolonged viraemia, partial sequences of ...200818191505
characterization of equine arteritis virus particles and demonstration of their hemolytic activity.equine arteritis virus (eav), a member of the newly established family arteriviridae, is a small, positive-stranded rna virus. it carries two protein complexes in its envelope, gp5/m and the recently described gp2b/gp3/gp4 complex. we report here on several basic features of eav replication in cell culture and on the protein composition of virus particles. we have also characterized gp2b, gp3, and gp4 expressed using a baculovirus system in insect cells. finally, we provide evidence that eav pos ...200818219439
molecular analysis of endogenous avian leukosis/sarcoma virus genomes in korean chicken embryos.since the status of endogenous avian leucosis/sarcoma virus (alsv) infections in korean broiler chickens is unclear, this study examined embryonated eggs obtained from broiler farms and korean native chicken breeds in korea using pcr with the primer sets specific for endogenous alsvs. the pcr assays detected the genomes of eav, ev, ev/j and art-ch belonging to the endogenous alsv from all embryos tested. phylogenetically, the korean eav genomes were more closely related to the prototype eav-0 th ...200818250567
the efficacy of a commercial elisa as an alternative to virus neutralisation test for the detection of antibodies to eav.infection with equine arteritis virus is a notifiable disease with sporadic occurrence in the uk. as stallions may harbour the virus after infection, horses are screened for exposure by serological testing prior to breeding. the virus neutralisation test is considered the 'gold standard' serological screening test, but it is time-consuming and labour intensive; consequently there is a move towards more rapid screening methodology. in this study, a commercially available eva antibody elisa is ass ...200818267889
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