Publications

TitleAbstractYear
Filter
PMID
Filter
effect of heparin on infection of cells by equine arteritis virus.the number of plaques formed by equine arteritis virus (eav) and aujesky's disease virus (adv) was reduced to 14% and 5% of the untreated control (100%), respectively, by 10 u/ml of heparin, but could not be reduced below to 13 and 4%, respectively, by use of concentration up to 100 u/ml. an inhibitory effect of heparin, at concentration up to 100 u/ml, was not observed on parainfluenza virus 3 (piv-3). heparinase treatment of rk13 cells reduced the number of eav-, as well as adv-induced plaques ...19979300374
effect of the south african asinine-94 strain of equine arteritis virus (eav) in pregnant donkey mares and duration of maternal immunity in foals.clinical, virological and serological responses were investigated in five pregnant donkey mares after experimental exposure to the south african asinine-94 strain of equine arteritis virus (eav), and the duration of maternal immunity to eav was studied in their foals. in four intranasally inoculated mares, fever with maximum rectal temperatures of 39.1-40.7 degrees c was recorded 2-11 d after challenge. all the inoculated mares developed mild depression, and a serous ocular and nasal discharge; ...19979352564
hemagglutination with equine arteritis virus.equine arteritis virus (eav) grown on rk13 cell cultures was tested for hemagglutination (ha) with erythrocytes from a variety of species at 4 degrees c, room temperature and 37 degrees c. ha was observed at all temperatures with erythrocytes from mouse and chicken but not with those of cattle, horse, rabbit, guinea pig, mongolian gerbil, goose or chick embryo. chickens showed an individual variation in agglutinability of their erythrocytes, requiring selection of birds to obtain erythrocytes fo ...19979362047
alternative proteolytic processing of the arterivirus replicase orf1a polyprotein: evidence that nsp2 acts as a cofactor for the nsp4 serine protease.the c-terminal half of the replicase orf1a polyprotein of the arterivirus equine arteritis virus is processed by a chymotrypsinlike serine protease (sp) (e. j. snijder et al., j. biol. chem. 271:4864-4871, 1996) located in nonstructural protein 4 (nsp4). three probable sp cleavage sites had previously been identified in the orf1a protein. their proteolysis explained the main processing products generated from the c-terminal part of the orf1a protein in infected cells (e. j. snijder et al., j. vi ...19979371590
expression cloning and humoral immune response to the nucleocapsid and membrane proteins of equine arteritis virus.to provide a convenient and sensitive method for the detection of equine arteritis virus (eav)-specific serum antibodies, we developed an immunoblot assay employing the eav nucleocapsid (n) and membrane (m) proteins expressed in a procaryotic expression vector (pmal-c2) for the production of recombinant maltose-binding (mbp) fusion proteins (mbp-n and mbp-m). the antigenic reactivity of the recombinant fusion proteins and their xa factor cleavage eav products was confirmed by immunoblot using ho ...19979384283
comparison of nucleic and amino acid sequences and phylogenetic analysis of open reading frames 3 and 4 of various equine arteritis virus isolates.the genetic variation in equine arteritis virus (eav) protein-encoding open reading frames (orfs) 3 and 4 genes was investigated. nucleic and deduced amino acid sequences from seven different eav isolates (one european, one american and five canadian isolates) and the arvac vaccine strain were compared with those of bucyrus reference strain. orf 3 nucleotide and amino acid sequence identities between these isolates (including the arvac vaccine strain) and the bucyrus reference strain ranged from ...19979428144
venereal infection of mares by equine arteritis virus and use of killed vaccine against the infection.venereal infection with equine arteritis virus (eav) was established in each of seven mares by inoculation via the cervix with 20 ml of viral suspension (> or = 8 x 10(6) plaque-forming units; pfu), following treatment with prostaglandin and oestradiol. a dose of < or = 8 x 10(5) pfu produced infection in only five of eight mares. serum neutralizing antibody developed in mares manifesting clinical signs of equine viral arteritis (eva), and a weak antibody was detectable in one apparently healthy ...19979447481
a 68-nucleotide sequence within the 3' noncoding region of simian hemorrhagic fever virus negative-strand rna binds to four ma104 cell proteins.the 3' noncoding region (ncr) of the negative-strand rna [3'(-)ncr rna] of the arterivirus simian hemorrhagic fever virus (shfv) is 209 nucleotides (nt) in length. since this 3' region, designated 3'(-)209, is the site of initiation of full-length positive-strand rna and is the template for the synthesis of the 5' leader sequence, which is found on both full-length and subgenomic mrnas, it is likely to contain cis-acting signals for rna synthesis and to interact with cellular and viral proteins ...19989557724
antigenic variants of j subgroup avian leukosis virus: sequence analysis reveals multiple changes in the env gene.hprs-103, the prototype of avian leukosis virus (alv) subgroup j, was isolated in 1989 from meat-type chickens from commercial flocks where it induces myelocytic myeloid leukosis (ml). the hprs-103 env gene differs considerably from other alv subgroups but shows high identity (75-97%) to env-like sequences of the different members of the eav family of endogenous avian retroviruses. recently, we have isolated several viruses related to hprs-103 from cases of ml. although these isolates showed pro ...19989568971
effect of heparin on hemagglutination by equine arteritis virus.heparin inhibited hemagglutination (ha) by equine arteritis virus (eav) as well as did ha by aujeszky's disease virus (adv), but failed to inhibit ha by parainfluenza virus type 3 (piv-3). the minimal concentration of heparin required to inhibit 8 ha u of eav was 0.1 u/ml. in addition, most eav hemagglutinin was retained by heparin acrylic beads, as was adv hemagglutinin, but was not piv-3 hemagglutinin. mouse erythrocytes failed to combine with the ha inhibitory factor of heparin. however, mous ...19989592716
orf1a-encoded replicase subunits are involved in the membrane association of the arterivirus replication complex.among the functions of the replicase of equine arteritis virus (eav; family arteriviridae, order nidovirales) are important viral enzyme activities such as proteases and the putative rna polymerase and rna helicase functions. the replicase is expressed in the form of two polyproteins (open reading frame 1a [orf1a] and orf1ab), which are processed into 12 nonstructural proteins by three viral proteases. in immunofluorescence assays, the majority of these cleavage products localized to the perinuc ...19989658116
molecular variation in the nucleoprotein gene (orf7) of the porcine reproductive and respiratory syndrome virus (prrsv).the nucleoprotein gene (orf7) of 15 european isolates of porcine reproductive and respiratory syndrome virus (prrsv) was sequenced and compared with corresponding sequences of other prrsv isolates (2 european and 13 american) and one isolate each of other arteriviruses (the lactate dehydrogenase elevating virus (ldv), the simian haemorrhagic fever virus (shfv) and the equine arteritis virus (eav)). their phylogenetic relationships were established using neighbour-joining and parsimony methods. f ...19989660067
development and application of polymerase chain reaction (pcr) tests for the detection of subgroup j avian leukosis virus.subgroup j avian leukosis virus (alv) is a recently identified avian retrovirus associated with myeloid leukosis in meat-type chickens. the env gene of the hprs-103 strain of alv, the prototype of this subgroup, differs considerably from that of other subgroups, but shows close homology to the env-like sequences of members of the eav family of endogenous retroviruses. polymerase chain reaction (pcr) tests using two sets of primers were developed for the specific detection of the members of this ...19989660074
serologic response of horses to the structural proteins of equine arteritis virus.equine arteritis virus (eav) is the causative agent of equine viral arteritis, an apparently emerging disease of equids. in this study, the antibody response of horses to the structural proteins of eav was evaluated using gradient-purified eav virions and baculovirus-expressed recombinant eav structural proteins (g(l), g(s), m, n) as antigens in a western immunoblotting assay. thirty-three sera from horses that previously had been naturally or experimentally infected with eav were evaluated, inc ...19989683071
nucleotide sequence and genetic analysis of the leader region of canadian, american and european equine arteritis virus isolates.the extreme 5' end, the entire leader sequence of the arvac vaccine strain, and 10 equine arteritis virus (eav) isolates, including the atcc bucyrus reference strain and 5 canadian field isolates, were determined and compared at the primary nucleotide and secondary structure levels. the leader sequence of eight eav isolates, including the bucyrus reference strain, and the leader sequence of the arvac vaccine strain was determined to be 206 nt in length (not including the putative 5' cap structur ...19989684053
retrovirus-induced disease in poultry.three species of avian retrovirus cause disease in poultry: the avian leukosis/sarcoma virus (alsv), reticuloendotheliosis virus (rev), and lymphoproliferative disease virus (lpdv) of turkeys. the alsv can be classified as slowly transforming viruses, which lack a viral oncogene, and acutely transforming viruses, which possess a viral oncogene. slowly transforming viruses induce late onset leukoses of the b cell lymphoid, erythroid, and myeloid cell lineages, and other tumors, by viral promoter ...19989706091
passive transfer, rate of decay, and protein specificity of antibodies against equine arteritis virus in horses from a standardbred herd with high seroprevalence.to determine rate of decay of passively acquired antibodies in standardbred foals on a farm with a high seroprevalence to equine arteritis virus (eav) and to determine whether vertical or horizontal transmission of the virus was responsible for infection on the farm.19989743724
screening of horse polyclonal antibodies with a random peptide library displayed on phage: identification of ligands used as antigens in an elisa test to detect the presence of antibodies to equine arteritis virus.a random hexapeptide fusion-phage library was screened to isolate phages that bind to antibodies present in horse sera positive for equine arteritis virus (eav). analysis of the peptide sequences displayed by isolated phages identified seven groups. 25% of the isolated phages used as antigens in an elisa test were specifically recognised by a pool of sera which was positive for eav in virus neutralisation test (vn). five of these, when used as antigen in elisa, detected greater than 50% of sera ...19989766888
the arterivirus replicase. the road from rna to protein(s), and back again. 19989782270
equine viral arteritis. current status in finland.a serological study for antibodies against equine arteritis virus (eav) in finland was performed during 1996. all equine sera delivered to the virology unit at the national veterinary and food research institute were tested with a micro-neutralization test, using the arvac strain as antigen. the study also included imported horses to evaluate eav circulation in the countries of origin. nucleocapsid gene sequences of 2 finnish equine semen isolates were amplified with rt-pcr and sequenced. the ge ...19989782341
sequence determination and genetic analysis of the leader region of various equine arteritis virus isolates.the entire leader sequence of ten equine arteritis virus (eav) isolates including the bucyrus reference strain was determined and analyzed at the primary nucleotide and secondary structure levels. the leader sequence of eight eav isolates was determined to be 206 nucleotides (nt) in length, whereas those of the 86ab-a1 and 86ny-a1 isolates were found to be 205 and 207 nt in length, respectively. the sequence identity of the leader sequences between the different isolates and the bucyrus referenc ...19989782362
genetic variation and phylogenetic analysis of open reading frames 3 and 4 of various equine arteritis virus isolates.the genetic variation in equine arteritis virus (eav) nonstructural (ns) protein-encoding open reading frames (orf) 3 and 4 genes was investigated. nucleotide and deduced amino acid sequences from seven different eav isolates (one european, one american and five canadian isolates) and the arvac vaccine strain were compared with those of the bucyrus reference strain. orf 3 nucleotide and amino acid sequence identities amongst these isolates (including the arvac vaccine strain) and the bucyrus ref ...19989782363
the reverse transcriptase activity in cell-free medium of chicken embryo fibroblast cultures is not associated with a replication-competent retrovirus.reverse transcriptase (rt) activity has previously been reported in concentrated medium of primary chicken embryo cell cultures using the traditional rt assay. recently, using the newly-developed and highly-sensitive product-enhanced reverse transcriptase (pert) assay, rt activity has been detected in live, attenuated vaccines grown in chicken cell substrates. furthermore, this activity has been associated with particles that contain rna related to an ancient, endogenous avian retrovirus family ...19989784139
enzyme-linked immunosorbent assay for serological survey of equine arteritis virus in racehorses.to examine antibodies against equine arteritis virus (eav), an enzyme-linked immunosorbent assay (elisa) using purified virus antigen was developed. the results of elisa were compared with those of serum neutralization (sn) tests. the elisa absorbance values and the sn titers in sera collected weekly from eav-infected horses showed a similar pattern. the elisa could detect antibody to eav in horses experimentally infected with not only a homologous virus strain, which was used as the elisa antig ...19989795910
the unique envelope gene of the subgroup j avian leukosis virus derives from ev/j proviruses, a novel family of avian endogenous viruses.a new subgroup of avian leukosis virus (alv), designated subgroup j, was identified recently. viruses of this subgroup do not cross-interfere with viruses of the avian a, b, c, d, and e subgroups, are not neutralized by antisera raised against the other virus subgroups, and have a broader host range than the a to e subgroups. sequence comparisons reveal that while the subgroup j envelope gene includes some regions that are related to those found in env genes of the a to e subgroups, the majority ...19989811756
serologic and molecular characterization of an abortigenic strain of equine arteritis virus isolated from infective frozen semen and an aborted equine fetus.a virus isolated from an aborted equine fetus was determined to be antigenically distinct from several other strains of equine arteritis virus (eav) by use of a neutralization assay with a large panel of neutralizing monoclonal antibodies. the virus was readily neutralized by polyclonal equine anti-eav serum. comparative nucleotide and amino acid sequence analyses indicated that the virus (wa97) isolated from the aborted fetus was virtually identical to a virus (s1971) isolated from imported sem ...19989838958
equine viral arteritis risk from imported semen. 19989921633
detection of antibodies to equine arteritis virus by enzyme linked immunosorbant assays utilizing g(l), m and n proteins expressed from recombinant baculoviruses.indirect enzyme linked immunosorbant assays (elisas) utilizing the three major structural proteins (m, n, and g(l)) of equine arteritis virus (eav) expressed from recombinant baculoviruses were developed. a large panel of sera collected from uninfected horses, and from animals experimentally and naturally infected with eav or vaccinated with the modified live virus vaccine against equine viral arteritis, were used to characterize the humoral immune response of horses to the three major eav struc ...19989923747
novel endogenous retroviral sequences in the chicken genome closely related to hprs-103 (subgroup j) avian leukosis virus.hprs-103, the prototype of avian leukosis virus (alv) subgroup j, is a recently identified retrovirus associated with myeloid leukosis in meat-type chickens. although this virus shows high sequence identity to other alv subgroups within the gag and pol genes, its env gene is highly diverged (with only about 40% sequence identity) from other alv subgroups. on the other hand, the sequence of the env gene of hprs-103 was 75% identical to that of e51, a member of the eav family of endogenous avian r ...19999934710
open reading frame 1a-encoded subunits of the arterivirus replicase induce endoplasmic reticulum-derived double-membrane vesicles which carry the viral replication complex.the replicase of equine arteritis virus (eav; family arteriviridae, order nidovirales) is expressed in the form of two polyproteins (the open reading frame 1a [orf1a] and orf1ab proteins). three viral proteases cleave these precursors into 12 nonstructural proteins, which direct both genome replication and subgenomic mrna transcription. immunofluorescence assays showed that most eav replicase subunits localize to membranes in the perinuclear region of the infected cell. using replicase-specific ...19999971782
proteolytic processing of the open reading frame 1b-encoded part of arterivirus replicase is mediated by nsp4 serine protease and is essential for virus replication.the open reading frame (orf) 1b-encoded part of the equine arteritis virus (eav) replicase is expressed by ribosomal frameshifting during genome translation, which results in the production of an orf1ab fusion protein (345 kda). four orf1b-encoded processing products, nsp9 (p80), nsp10 (p50), nsp11 (p26), and nsp12 (p12), have previously been identified in eav-infected cells (l. c. van dinten, a. l. m. wassenaar, a. e. gorbalenya, w. j. m. spaan, and e. j. snijder, j. virol. 70:6625-6633, 1996). ...19999971783
[detection of equine arteritis virus (eav) in stallions--a contribution to the improvement of eav diagnosis].serum samples from 72 stallions were examined for the occurrence of antibodies against equine arteritis virus, of which 41 animals (57%) were found to be positive. 32 of the seropositive stallions were then screened for persistent eav infection, before and after the breeding season. semen samples were investigated by rt-pcr followed by dot blot hybridization and nested pcr, and by virus isolation on cell cultures as well. the carrier state was virologically confirmed in 11 of 32 stallions (34%) ...199910028725
[veterinary recommendations for the handling of equine virus arteritis (eva) in practical breeding care].the equine virus arteritis (eva) consistently epidemically varying throughout the different breeds of the horse breeding countries is up to now only of lower significance by means of the typical clinical manifestation as well as an abortion causing factor. the susceptibility of the sexual mature stallions against the equine arteritis virus (eav) causes different infection response which may lead to some restrictions in their use in natural breeding especially in the artificial insemination. in a ...199910077817
genetic diversity of equine arteritis virus.equine arteritis viruses (eav) from europe and america were compared by phylogenetic analysis of 43 isolates obtained over four decades. an additional 22 virus sequences were retrieved from genbank. fragments of the glycoprotein g(l) and the replicase genes were amplified by rt-pcr, prior to sequencing and construction of phylogenetic trees. the trees revealed many distinctive lineages, consistent with prolonged diversification within geographically separated host populations. two large groups a ...199910092009
control of equine viral arteritis. 199910097333
genetic divergence with emergence of novel phenotypic variants of equine arteritis virus during persistent infection of stallions.the persistently infected carrier stallion is the critical natural reservoir of equine arteritis virus (eav), as venereal infection of mares frequently occurs after breeding to such stallions. two thoroughbred stallions that were infected during the 1984 outbreak of equine viral arteritis in central kentucky subsequently became long-term eav carriers. eav genomes amplified from the semen of these two stallions were compared by sequence analysis of the six 3' open reading frames (orfs 2 through 7 ...199910196259
rapid and sensitive detection of equine arteritis virus in semen and tissue samples by reverse transcription-polymerase chain reaction, dot blot hybridisation and nested polymerase chain reaction.a reverse transcription-polymerase chain reaction (rt-pcr) assay using four different primer pairs for the detection of equine arteritis virus (eav) rna in semen and tissue samples was evaluated. a fragment encoding the leader sequence of the eav genome was most successfully amplified. the specificity and sensitivity of rt-pcr was assessed by virus isolation in cell culture, restriction analysis, dot blot hybridisation and nested pcr. to this end, 23 semen samples from seropositive stallions and ...199810358735
characterization of an equine arteritis virus replicase mutant defective in subgenomic mrna synthesis.equine arteritis virus (eav) is a positive-stranded rna virus that synthesizes a 5'- and 3'-coterminal nested set of six subgenomic mrnas. these mrnas all contain a common leader sequence which is derived from the 5' end of the genome. subgenomic mrna transcription and genome replication are directed by the viral replicase, which is expressed in the form of two polyproteins and subsequently processed into smaller nonstructural proteins (nsps). during the recent construction of an eav infectious ...199910364273
evidence of avian leukosis virus subgroup e and endogenous avian virus in measles and mumps vaccines derived from chicken cells: investigation of transmission to vaccine recipients.reverse transcriptase (rt) activity has been detected recently in all chicken cell-derived measles and mumps vaccines. a study of a vaccine manufactured in europe indicated that the rt is associated with particles containing endogenous avian retrovirus (eav-0) rna and originates from the chicken embryonic fibroblasts (cef) used as a substrate for propagation of the vaccine. we investigated the origin of rt in measles and mumps vaccines from a u.s. manufacturer and confirm the presence of rt and ...199910364336
phylogenetic characterization of a highly attenuated strain of equine arteritis virus from the semen of a persistently infected standardbred stallion.an avirulent, novel variant of equine arteritis virus (eav; ca95g) was isolated from the semen of a persistently infected standardbred stallion. the ca95g virus caused subclinical infection and seroconversion in susceptible horses, and virus was isolated only once from blood and nasal secretions collected from 6 experimentally infected horses. sequence analysis of genes encoding the known eav structural proteins shows that this highly attenuated strain of eav is genetically similar to virulent f ...199910365172
detection of equine arteritis virus in semen by reverse transcriptase polymerase chain reaction-elisa.the reverse transcriptase polymerase chain reaction (rt-pcr) assay was used to detect equine arteritis virus (eav) in the semen of 88 horses and 2 donkeys, with neutralising antibodies against eav, on the basis of the amplification of a 279 bp long fragment located in the viral polymerase gene. the rt-pcr assay revealed the virus at 4 tcid50/ml in cell culture and showed a greater sensitivity (54.4%) than cell culture isolation (33.3%). moreover, the two samples of donkey semen were found positi ...199910391506
identification of a novel structural protein of arteriviruses.arteriviruses are positive-stranded rna viruses with an efficiently organized, polycistronic genome. a short region between the replicase gene and open reading frame (orf) 2 of the equine arteritis virus (eav) genome was previously assumed to be untranslated. however, here we report that this segment of the eav genome contains the 5' part of a novel gene (orf 2a) which is conserved in all arteriviruses. the 3' part of eav orf 2a overlaps with the 5' part of the former orf 2 (now renamed orf 2b), ...199910400725
equine arteritis virus derived from an infectious cdna clone is attenuated and genetically stable in infected stallions.virus derived from an infectious cdna clone of equine arteritis virus (eav030h) was intranasally inoculated into two stallions, neither of which subsequently developed clinical manifestations of equine viral arteritis (eva). virus was isolated from nasal swabs and mononuclear cells collected from both stallions </=14 days p.i. and from the semen of one stallion only at 7 days p.i. similarly, viral rna was detected by rt nested-pcr in nasal swabs and mononuclear cells for </=14 days p.i. and at 7 ...199910405372
equine viral arteritis in a gelding in the uk. 199910458581
genetic stability of equine arteritis virus during horizontal and vertical transmission in an outbreak of equine viral arteritis.an imported carrier stallion (a) from europe was implicated in causing an extensive outbreak of equine viral arteritis (eva) on a warmblood breeding farm in pennsylvania, usa. strains of equine arteritis virus (eav) present in the semen of two carrier stallions (a and g) on the farm were compared to those in tissues of foals born during the outbreak, as well as viruses present in the semen of two other stallions that became persistently infected carriers of eav following infection during the out ...199910466790
avian leukosis virus subgroup j: a rapidly evolving group of oncogenic retroviruses.a strain of avian leukosis virus (alv) belonging to a new envelope subgroup j was isolated in the uk in 1988 from meat-type chickens. the disease caused by the members of this subgroup has since spread very rapidly worldwide and has become one of the major problems facing the broiler meat industry. molecular characterisation of hprs -103, the prototype of subgroup j, has shown that it has a structure of a typical alv with gag, pol and env genes. however the env gene was distinct from that of oth ...199910502478
arterivirus discontinuous mrna transcription is guided by base pairing between sense and antisense transcription-regulating sequences.to generate an extensive set of subgenomic (sg) mrnas, nidoviruses (arteriviruses and coronaviruses) use a mechanism of discontinuous transcription. during this process, mrnas are generated that represent the genomic 5' sequence, the so-called leader rna, fused at specific positions to different 3' regions of the genome. the fusion of the leader to the mrna bodies occurs at a short, conserved sequence element, the transcription-regulating sequence (trs), which precedes every transcription unit i ...199910518575
the open reading frame 3 of equine arteritis virus encodes an immunogenic glycosylated, integral membrane protein.open reading frame 3 (orf 3) of equine arteritis virus (eav) is predicted to encode a glycosylated membrane protein (gp3) that is uncharacterized. orf 3 of the american type culture collection strain of eav was in vitro transcribed and the encoded gp3 protein was in vitro translated with and without canine microsomal membranes. the gp3 protein was approximately 17 kda after in vitro translation without canine microsomal membranes whereas the glycosylated form, after translation with microsomal m ...199910544133
serological surveillance of equine viral arteritis in the united kingdom since the outbreak in 1993.serological analysis of blood samples submitted to the animal health trust showed that during 1995, 185 of 9203 unvaccinated horses (2.0 per cent) tested positive for antibodies to equine arteritis virus (eav), and that during 1996, 46 of 8851 unvaccinated horses (0.52 per cent) tested positive. during both years thoroughbreds were the predominant breed tested and only a small proportion of these (<0.3 per cent), consisting predominantly of imported mares, were seropositive. in contrast, among s ...199910576624
avian endogenous retrovirus eav-hp shares regions of identity with avian leukosis virus subgroup j and the avian retrotransposon art-ch.the existence of novel endogenous retrovirus elements in the chicken genome, designated eav-hp, with close sequence identity to the env gene of avian leukosis virus (alv) subgroup j has been reported (l. m. smith, a. a. toye, k. howes, n. bumstead, l. n. payne, and k. venugopal, j. gen. virol. 80:261-268, 1999). to resolve the genome structure of these retroviral elements, we have determined the complete sequence of two proviral clones of eav-hp from a line n chicken genomic dna yeast artificial ...200010627540
effects of chlorine, iodine, and quaternary ammonium compound disinfectants on several exotic disease viruses.the effects of three representative disinfectants, chlorine (sodium hypochlorite), iodine (potassium tetraglicine triiodide), and quaternary ammonium compound (didecyldimethylammonium chloride), on several exotic disease viruses were examined. the viruses used were four enveloped viruses (vesicular stomatitis virus, african swine fever virus, equine viral arteritis virus, and porcine reproductive and respiratory syndrome virus) and two non-enveloped viruses (swine vesicular disease virus (svdv) ...200010676896
detection of antibodies to equine arteritis virus by a monoclonal antibody-based blocking elisa.a potent elisa antigen was prepared from equine arteritis virus (eav) by differential centrifugation of eav-infected cell culture fluid, followed by solubilization of the preparation by triton x-100 treatment. using this antigen and a mouse monoclonal antibody against the g(l) protein of eav, a reliable blocking elisa (belisa) was developed for the detection of eav antibodies in equine sera. the belisa was evaluated using a total of 837 test serum samples. the relative sensitivity (n = 320) of t ...200010680655
analysis of the effect of endogenous viral genes in the smyth line chicken model for autoimmune vitiligo.the smyth line (sl) chicken, an animal model for autoimmune human vitiligo, is characterized by a spontaneous posthatch pigment loss, determined to be the result of an autoimmune phenomenon. because endogenous virus (ev) genes have been reported to be associated with a number of autoimmune diseases of human and animal models, we designed this experiment to investigate the role of ev in the sl vitiligo by using the complete sequence of rous-associated virus-2 as a probe for ev. an f(2) resource p ...200010702426
isolation and characterization of an arterivirus defective interfering rna genome.equine arteritis virus (eav), the type member of the family arteriviridae, is a single-stranded rna virus with a positive-stranded genome of approximately 13 kb. eav uses a discontinuous transcription mechanism to produce a nested set of six subgenomic mrnas from which its structural genes are expressed. we have generated the first documented arterivirus defective interfering (di) rnas by serial undiluted passaging of a wild-type eav stock in bhk-21 cells. a cdna copy of the smallest di rna (5.6 ...200010708432
equine immunity to viruses.the identification of some of the adaptive immune responses to infection with equine viruses has been the first step toward rational immunoprophylactic design. sufficient knowledge of infection-induced immunity and informed estimates of the requirements for long-term immunity for eiv have now been obtained. thus, the future for inactivated eiv vaccines is promising now that new adjuvants have been applied to induce cellular immunity and safe methods have been designed to stimulate virus-neutrali ...200010752138
genetic manipulation of equine arteritis virus using full-length cdna clones: separation of overlapping genes and expression of a foreign epitope.equine arteritis virus (eav) is an enveloped, positive-stranded rna virus belonging to the family arteriviridae of the order nidovirales. the unsegmented, infectious genome of eav is 12,704 nt in length [exclusive of the poly(a) tail] and contains eight overlapping genes that are expressed from a 3'-coterminal nested set of seven leader-containing mrnas. to investigate the importance of the overlapping gene arrangement in the viral life-cycle and to facilitate the genetic manipulation of the vir ...200010772982
assembly of the coronavirus envelope: homotypic interactions between the m proteins.the viral membrane proteins m and e are the minimal requirements for the budding of coronavirus particles. since the e protein occurs in particles only in trace amounts, the lateral interactions between the m proteins apparently generate the major driving force for envelope formation. by using coimmunoprecipitation and envelope incorporation assays, we provide extensive evidence for the existence of such m-m interactions. in addition, we determined which domains of the m protein are involved in ...200010799570
the predicted metal-binding region of the arterivirus helicase protein is involved in subgenomic mrna synthesis, genome replication, and virion biogenesis.equine arteritis virus (eav), the prototype arterivirus, is a positive-stranded rna virus that expresses its replicase in the form of two large polyproteins of 1,727 and 3,175 amino acids. the functional replicase subunits (nonstructural proteins), which drive eav genome replication and subgenomic mrna transcription, are generated by extensive proteolytic processing. subgenomic mrna transcription involves an unusual discontinuous step and generates the mrnas for structural protein expression. pr ...200010799597
monoclonal antibodies directed against conserved epitopes on the nucleocapsid protein and the major envelope glycoprotein of equine arteritis virus.we recently developed a highly effective immunization procedure for the generation of monoclonal antibodies (mabs) directed against the porcine reproductive and respiratory syndrome virus (e. weiland, m. wieczorek-krohmer, d. kohl, k. k. conzelmann, and f. weiland, vet. microbiol. 66:171-186, 1999). the same method was used to produce a panel of 16 mabs specific for the equine arteritis virus (eav). ten mabs were directed against the eav nucleocapsid (n) protein, and five mabs recognized the maj ...200010834955
bluetongue and equine viral arteritis viruses as models of virus-induced fetal injury and abortion.a number of viruses have the capacity to cross the placenta and infect the fetus to cause, among other potential outcomes, developmental defects (teratogenesis), fetal death and abortion. bluetongue virus (btv) infection of fetal ruminants provides an excellent model for the study of virus-induced teratogenesis. this model has shown that only viruses modified by passage in cell culture, such as modified live virus vaccine strains, readily cross the ruminant placenta, and that the timing of fetal ...200010844231
induction of apoptosis by equine arteritis virus infection.equine arteritis virus (eav) is the etiological agent of equine viral arteritis, a contagious viral disease of equids. eav is the prototype virus of the arteriviruses, a group of small enveloped viruses with positive single-stranded rna genomes. because apoptosis or programmed cell death is believed to play an important role in the biogenesis of several cytopathogenic viruses, we examined whether eav was able to induce cell apoptosis in vitro. to do this, vero cells were infected with eav at a m ...200010872876
current knowledge on the structural proteins of porcine reproductive and respiratory syndrome (prrs) virus: comparison of the north american and european isolates.porcine reproductive and respiratory syndrome virus (prrsv) belongs to the recently recognized arteriviridae family within the genus arterivirus, order nidovirales, which also includes equine arteritis virus (eav), lactate dehydrogenase-elevating virus (ldv), and simian hemorrhagic fever virus (shfv). mature viral particles are composed of an envelope 50-72 nm in diameter, with an isometric core about 20-30 nm enclosing a linear positive-stranded rna genome of approximately 15 kb. the virions ar ...200010893147
equine viral arteritis.equine viral arteritis (eva) can cause prominent economic losses for the equine industry. the purpose of this review is to provide the pathologist some familiarity with the clinical history, lesions, pathogenesis, and diagnosis of eva. eva is caused by an arterivirus (equine arteritis virus, eav), and the vascular system is the principal but not unique viral target. eva has variable presentations, including interstitial pneumonia, panvasculitis with edema, thrombosis and hemorrhage, lymphoid nec ...200010896389
in vitro detection of equine arteritis virus from seminal plasma for identification of carrier stallions.equine arteritis virus (eav) was readily isolated in rk-13 cell monolayers by plaque assay from seminal plasma of experimental carrier stallions when they contained high titers of virus regardless of the presence of non-viral cytotoxicity in the seminal plasma. the cytotoxicity interfered with virus isolation from seminal plasma which contained virus at titers less than 10 pfu/ml. however, it was possible to detect the virus in seminal plasma pretreated with peg (#6000). eav was consistently ide ...200010907693
efficient homologous rna recombination and requirement for an open reading frame during replication of equine arteritis virus defective interfering rnas.equine arteritis virus (eav), the prototype arterivirus, is an enveloped plus-strand rna virus with a genome of approximately 13 kb. based on similarities in genome organization and protein expression, the arteriviruses have recently been grouped together with the coronaviruses and toroviruses in the newly established order nidovirales. previously, we reported the construction of pedi, a full-length cdna copy of eav di-b, a natural defective interfering (di) rna of 5.6 kb (r. molenkamp et al., j ...200010982351
the arterivirus replicase is the only viral protein required for genome replication and subgenomic mrna transcription.equine arteritis virus (eav) (arteriviridae:) encodes several structural proteins. whether any of these also function in viral rna synthesis is unknown. for the related mouse hepatitis coronavirus (mhv), it has been suggested that the nucleocapsid protein (n) is involved in viral rna synthesis. as described for mhv, we established that the eav n protein colocalizes with the viral replication complex, suggesting a role in rna synthesis. using an infectious cdna clone, point mutations and deletion ...200010993938
biochemical characterization of the equine arteritis virus helicase suggests a close functional relationship between arterivirus and coronavirus helicases.the arterivirus equine arteritis virus nonstructural protein 10 (nsp10) has previously been predicted to contain a zn finger structure linked to a superfamily 1 (sf1) helicase domain. a recombinant form of nsp10, mbp-nsp10, was produced in escherichia coli as a fusion protein with the maltose-binding protein. the protein was partially purified by affinity chromatography and shown to have atpase activity that was strongly stimulated by poly(dt), poly(u), and poly(da) but not by poly(g). the prote ...200011000230
expression of the two major envelope proteins of equine arteritis virus as a heterodimer is necessary for induction of neutralizing antibodies in mice immunized with recombinant venezuelan equine encephalitis virus replicon particles.rna replicon particles derived from a vaccine strain of venezuelan equine encephalitis virus (vee) were used as a vector for expression of the major envelope proteins (g(l) and m) of equine arteritis virus (eav), both individually and in heterodimer form (g(l)/m). open reading frame 5 (orf5) encodes the g(l) protein, which expresses the known neutralizing determinants of eav (u. b. r. balasuriya, j. f. patton, p. v. rossitto, p. j. timoney, w. h. mccollum, and n. j. maclachlan, virology 232:114- ...200011044106
diagnosis of equine arteritis virus infection in two horses by using monoclonal antibody immunoperoxidase histochemistry on skin biopsies.two 5-year-old grade male horses presented with epiphora, rhinorrhea, conjunctival and nasal mucosal hyperemia, and dorsal and thoracic macropapular rash. skin biopsies were collected from the affected areas, and serial sections were evaluated following hematoxylin and eosin and immunoperoxidase histochemistry staining by using a murine monoclonal antibody of the immunoglobulin g2a isotype recognizing the 30-kda membrane protein of equine arteritis virus (eav). in both horses, lesions consisted ...200011055877
development and evaluation of elisa procedures to detect antibodies against the major envelope protein (g(l)) of equine arteritis virus.enzyme-linked immunosorbant assays (elisas) were developed for the detection of antibodies against the major envelope glycoprotein (g(l)) of equine arteritis virus (eav). a 6-histidine tagged recombinant protein expressing the complete g(l) ectodomain (g(l)-6his), a glutathione-s-transferase recombinant protein expressing amino acids 55-98 of g(l) (g(l)-gst) and an ovalbumin-conjugated synthetic peptide representing amino acids 81-106 of g(l) (g(l)-ova) were used as diagnostic antigens. an elisa ...200011064117
genetic manipulation of arterivirus alternative mrna leader-body junction sites reveals tight regulation of structural protein expression.to express its structural proteins, the arterivirus equine arteritis virus (eav) produces a nested set of six subgenomic (sg) rna species. these rna molecules are generated by a mechanism of discontinuous transcription, during which a common leader sequence, representing the 5' end of the genomic rna, is attached to the bodies of the sg rnas. the connection between the leader and body parts of an mrna is formed by a short, conserved sequence element termed the transcription-regulating sequence ( ...200011090163
no evidence of infectious retroviruses in measles virus vaccines produced in chicken embryo cell cultures.all vaccines that are prepared in chicken embryo fibroblasts (cefs) contain a low level of particle-associated reverse transcriptase (rt) activity, which is produced from the avian cell substrate. the rnas present in the particles have sequence homology to viral dnas belonging to the ancient endogenous avian virus (eav) family or to the avian sarcoma-leukosis virus (alv)-related subgroup e endogenous virus loci. although no replication-competent retrovirus has been associated with the rt activit ...200111158127
intact eav-hp endogenous retrovirus in sonnerat's jungle fowl.the eav-hp group of chicken endogenous retrovirus elements was previously shown to be defective, with large deletions of the pol gene. in this report, we demonstrate that genomes of other gallus species also maintain eav-hp elements with similar deletions. the chicken eav-hp1 locus was detected in both red (gallus gallus gallus) and sonnerat's (gallus sonneratii) jungle fowl with identical integration sites, indicating that these elements had integrated before separation of the gallus species. f ...200111160706
a zinc finger-containing papain-like protease couples subgenomic mrna synthesis to genome translation in a positive-stranded rna virus.the genome expression of positive-stranded rna viruses starts with translation rather than transcription. for some viruses, the genome is the only viral mrna and expression is regulated primarily at the translational level and by limited proteolysis of polyproteins. other virus groups also generate subgenomic mrnas later in the reproductive cycle. for nidoviruses, subgenomic mrna synthesis (transcription) is discontinuous and yields a 5' and 3' coterminal nested set of mrnas. nidovirus transcrip ...200111172046
an orf-2a protein is not present at a significant level in virions of the arterivirus lactate dehydrogenase-elevating virus.mrna2 of the arteriviruses lactate dehydrogenase-elevating virus (ldv) and equine arteritis virus (eav) encodes two proteins that are read in different frames, an about 26 kda minor envelope glycoprotein and an about 8 kda protein that lacks n-glycosylation sites and a signal peptide, but possesses a central hydrophobic segment. recent studies have shown that both proteins of eav are translated from mrna 2 in eav infected bhk cells, that the 8 kda protein is membrane associated and that small am ...200111226573
elisa and direct immunofluorescence test to detect equine arteritis virus (eav) using a monoclonal antibody directed to the eav-n protein.a monoclonal antibody (mab) directed against the equine arteritis virus (eav) nucleocapsid (n) protein was used for indirect enzyme-linked immunosorbent assays (elisas) using viral antigen from different sources. the same mab was labelled with fluorescein isothiocyanate for direct immunofluorescence tests (difts). the n-specific mab appeared to be suitable for the detection in both elisa and dift of different eav strains and field isolates from semen and tissue samples after passage in lines of ...200111254093
characterization of endogenous avian leukosis viruses in chicken embryonic fibroblast substrates used in production of measles and mumps vaccines.previous findings of low levels of reverse transcriptase (rt) activity in chick cell-derived measles and mumps vaccines showed this activity to be associated with virus particles containing rna of both subgroup e endogenous avian leukosis viruses (alv-e) and endogenous avian viruses (eav). these particles originate from chicken embryonic fibroblast (cef) substrates used for propagating vaccine strains. to better characterize vaccine-associated alv-e, we examined the endogenous alv proviruses (ev ...200111264350
lack of evidence of endogenous avian leukosis virus and endogenous avian retrovirus transmission to measles, mumps, and rubella vaccine recipients.the identification of endogenous avian leukosis virus (alv) and endogenous avian retrovirus (eav) in chick cell-derived measles and mumps vaccines in current use has raised concern about transmission of these retroviruses to vaccine recipients. we used serologic and molecular methods to analyze specimens from 206 recipients of measles, mumps, and rubella (mmr) vaccine for evidence of infection with alv and eav. a western blot assay for detecting antibodies to endogenous alv was developed and val ...200111266296
non-structural proteins 2 and 3 interact to modify host cell membranes during the formation of the arterivirus replication complex.the replicase polyproteins of equine arteritis virus (eav; family arteriviridae, order nidovirales) are processed by three viral proteases to yield 12 non-structural proteins (nsps). the nsp2 and nsp3 cleavage products have previously been found to interact, a property that allows nsp2 to act as a co-factor in the processing of the downstream part of the polyprotein by the nsp4 protease. remarkably, upon infection of vero cells, but not of bhk-21 or rk-13 cells, eav nsp2 is now shown to be subje ...200111297673
large envelope glycoprotein and nucleocapsid protein of equine arteritis virus (eav) induce an immune response in balb/c mice by dna vaccination; strategy for developing a dna-vaccine against eav-infection.equine arteritis virus (eav) is a member of the arteriviridae family, that includes lactate dehydrogenase-elevating virus (ldv), porcine reproductive and respiratory syndrome virus (prrsv), and simian haemorrhagic fever virus (shfv). equine arteritis is a contagious disease of horses and is spread via respiratory or reproductive tract. the objective of the present study is to evaluate the possibility for developing a model system for prevention horses against an eav infection by dnavaccination. ...200111324756
phylogenetic characterisation of the g(l) sequences of equine arteritis virus isolated from semen of asymptomatic stallions and fatal cases of equine viral arteritis in denmark.the study describes for the first time the phylogenetic relationship between equine arteritis virus (eav) isolated from asymptomatic virus-shedding stallions and fatal cases of equine viral arteritis (eva) in an european country. eav was isolated from three dead foals and an aborted foetus during three different outbreaks of eva. from these fatalities, the complete open reading frame 5, encoding the eav g(l) protein, was amplified by reverse transcription-polymerase chain reaction and subjected ...200111348770
recombinant equine arteritis virus as an expression vector.equine arteritis virus (eav) is the prototypic member of the family arteriviridae, which together with the corona- and toroviridae constitutes the order nidovirales. a common trait of these positive-stranded rna viruses is the 3'-coterminal nested set of six to eight leader-containing subgenomic mrnas which are generated by a discontinuous transcription mechanism and from which the viral open reading frames downstream of the polymerase gene are expressed. in this study, we investigated whether t ...200111384225
evaluation of a prototype sub-unit vaccine against equine arteritis virus comprising the entire ectodomain of the virus large envelope glycoprotein (g(l)): induction of virus-neutralizing antibody and assessment of protection in ponies.an escherichia coli-expressed recombinant protein (6hisg(l)ecto) comprising the entire ectodomain (aa 18-122) of equine arteritis virus (eav) glycoprotein g(l), the immunodominant viral antigen, induced higher neutralizing antibody titres than other g(l)-derived polypeptides when compared in an immunization study in ponies. the potential of the recombinant g(l) ectodomain to act as a sub-unit vaccine against eav was evaluated further in three groups of four ponies vaccinated with doses of 35, 70 ...200111562536
seroprevalence of antibodies against equine arteritis virus in horses residing in the united states and imported horses.to compare seroprevalence of antibodies against equine arteritis virus (eav) in horses residing in the united states with that of imported horses.200111601790
construction of chimeric arteriviruses reveals that the ectodomain of the major glycoprotein is not the main determinant of equine arteritis virus tropism in cell culture.the recent development of arterivirus full-length cdna clones makes possible the construction of chimeric arteriviruses for fundamental and applied studies. using an equine arteritis virus (eav) infectious cdna clone, we have engineered chimeras in which the ectodomains of the two major envelope proteins, the glycoprotein gp(5) and the membrane protein m, were replaced by sequences from envelope proteins of related and unrelated rna viruses. using immunofluorescence microscopy, we monitored the ...200111601900
segregation of eav-hp ancient endogenous retroviruses within the chicken population.avian leukosis virus subgroup j (alv-j), an exogenous avian retrovirus, is thought to have evolved by recombination with the highly identical env gene of the endogenous avian retrovirus eav-hp. embryonic expression of eav-hp env has been suggested to be associated with the induction of immunological tolerance, a feature observed in a significant proportion of meat-type chickens infected with alv-j. in support of this hypothesis, we demonstrate that eav-hp loci, some of which could be associated ...200111689680
identification of equine herpesvirus 3 (equine coital exanthema virus), equine gammaherpesviruses 2 and 5, equine adenoviruses 1 and 2, equine arteritis virus and equine rhinitis a virus by polymerase chain reaction.to develop rapid (< 8 hour) tests using polymerase chain reaction (pcr) for the diagnosis of equine herpesvirus 3 (ehv3; equine coital exanthema virus), equine gammaherpesviruses 2 (ehv2) and ehv5, equine adenovirus 1 (eadv1), eadv2, equine arteritis virus (eav), equine rhinitis a virus (erav; formerly equine rhinovirus 1)200111712710
sequence requirements for rna strand transfer during nidovirus discontinuous subgenomic rna synthesis.nidovirus subgenomic mrnas contain a leader sequence derived from the 5' end of the genome fused to different sequences ('bodies') derived from the 3' end. their generation involves a unique mechanism of discontinuous subgenomic rna synthesis that resembles copy-choice rna recombination. during this process, the nascent rna strand is transferred from one site in the template to another, during either plus or minus strand synthesis, to yield subgenomic rna molecules. central to this process are t ...200111742998
the role of international transport of equine semen on disease transmission.despite the numerous benefits of having the capability to transport semen internationally, there are serious potential ramifications if that semen is contaminated with a communicable disease. bacteria: many commensal bacteria colonize the exterior of the stallion penis and are not regarded as pathogenic. they may be cultured from an ejaculate. alterations of the normal bacterial flora on the exterior genitalia may cause the growth of opportunistic bacteria such as klebsiella pneumonia, pseudomon ...200111744267
molecular epidemiology and evolution of equine arteritis virus. 200111774467
characterization of an arterivirus defective interfering rna. replication and homologous recombination. 200111774517
genetic variation of orfs 3 and 4 of equine arteritis virus. 200111774546
detection of equine arteritis virus by real-time taqman reverse transcription-pcr assay.a one-tube real-time taqman reverse transcription-polymerase chain reaction (rt-pcr) assay was developed for the detection of equine arteritis virus (eav). the test was validated using the seminal plasma and nasal secretions of infected horses that were proven to contain eav by traditional virus isolation in rabbit kidney thirteen (rk-13) cells, as well as a variety of cell culture-propagated european and north american strains of eav. the primers and a fluorogenic taqman probe were designed to ...200211849680
alphavirus replicon particles expressing the two major envelope proteins of equine arteritis virus induce high level protection against challenge with virulent virus in vaccinated horses.replicon particles derived from a vaccine strain of venezuelan equine encephalitis (vee) virus were used as vectors for expression in vivo of the major envelope proteins (g(l) and m) of equine arteritis virus (eav), both individually and in heterodimer form (g(l)/m). the immunogenicity of the different replicons was evaluated in horses, as was their ability to protectively immunize horses against intranasal and intrauterine challenge with a virulent strain of eav (eav ky84). horses immunized wit ...200211858869
a replication-competent chimera of plant and animal viruses.human, animal, fungal, and plant viruses encode papain-like proteinases that function in polyprotein processing, rna synthesis, and virus-host interactions. to compare the functional profiles of diverse papain-like proteinases, we replaced a proteinase gene of the beet yellows virus (byv) with those derived from equine arteritis virus (eav), foot-and-mouth disease virus (fmdv), and the fungal virus chv1. we found that, although each of the foreign proteinases efficiently processed the viral poly ...200211886267
nuclear localization of non-structural protein 1 and nucleocapsid protein of equine arteritis virus.rna synthesis (genome replication and subgenomic mrna transcription) directed by equine arteritis virus (eav; family arteriviridae, order nidovirales) occurs on modified cytoplasmic membranes to which most viral replicase subunits localize. remarkably, a fraction of non-structural protein 1 (nsp1), a protein essential for transcription but dispensable for genome replication, is present in the host cell nucleus, in particular during the earlier stages of infection. expression of gfp-tagged fusion ...200211907328
importance of m-protein c terminus as substrate antigen for serodetection of equine arteritis virus infection.equine arteritis virus (eav), an enveloped positive-stranded rna virus, is the prototype of the arterivirus group. in a previous paper (a. kheyar, s. martin, g. st.-laurent, p. j. timoney, w. h. mccollum, and d. archambault, clin. diagn. lab. immunol. 4:648-652, 1997), we have shown that the unglycosylated membrane (m) protein, which is composed of 162 amino acids (aa), is a major target of equine antibody to eav. in order to determine the antigenic regions of the m protein, the cdna encoding th ...200211986280
autoantibodies against golgi apparatus induced by arteriviruses.members of the genus arterivirus within the monogeneric family arteriviridae are lactate dehydrogenase-elvating virus (ldv), porcine reproductive and respiratory syndrome virus (prrsv), equine arteritis virus (eav) and simian hemorrhagic fever virus. in ldv-infected mice the appearance of autoantibodies against golgi-antigen dominated the early immune response. shared antigenicity between ldv and golgi-antigen of normal cells could not be demonstrated. monoclonal antibodies (mabs) reacted either ...200212030432
growth characteristics of a highly virulent, a moderately virulent, and an avirulent strain of equine arteritis virus in primary equine endothelial cells are predictive of their virulence to horses.equine viral arteritis (eva) is an endotheliotropic viral disease of horses caused by equine arteritis virus (eav). although there is only one serotype of eav, there is marked variation in the virulence of different strains of the virus. the replication and cytopathogenicity of three well-characterized strains of eav of different virulence to horses were compared in rabbit kidney (rk-13) and primary equine pulmonary artery endothelial cells (ecs). viral protein expression, plaque size, and cytop ...200212093171
equine viral arteritis in the uk. 200212120929
Displaying items 201 - 300 of 529