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t cell-stimulatory fragments of foot-and-mouth disease virus released by mild treatment with cathepsin d.cathepsin d and cathepsin b are endosomal/lysosomal proteases that are thought to play a role during in vivo antigen processing, releasing fragments for binding to major histocompatibility complex class ii products and subsequent presentation to t cells. here we treated purified foot-and-mouth disease virus (fmdv) strain a10holland with both enzymes. cathepsin d, but not cathepsin b, was shown to release fragments from reduced or non-reduced fmdv under mild conditions in vitro. twenty-eight pred ...19947964603
need for cellular and humoral immune responses in bovines to ensure protection from foot-and-mouth disease virus (fmdv)--a point of view.the published studies on immunization of experimental animals, cattle, and sheep with synthetic peptides containing the antigenic domains in fmdv structural protein vp1 were analyzed. the results obtained with various fmdv synthetic peptides designed to stimulate the humoral immune response in bovines were compared to the current knowledge on mhc class i and class ii, and the properties of the peptide binding grooves in each of them. x-ray crystallography of mhc class i proteins provided the thr ...19947975267
induction of effective cross-reactive immunity by fmdv peptides is critically dependent upon specific mhc-peptide-t cell interactions.bocd4+ t-cell clones specific for a peptide derived from foot-and-mouth disease virus envelope protein, vp1 (fmdv15) were generated from two responder cattle. one animal was a high and the other was an intermediate responder in terms of both t-cell and antibody responses. however both animals had identical major histocompatibility complex (mhc) class ii dr-like types (drbf3,6) according to a one-dimensional isoelectric focusing method which distinguishes dr-like alleles. in contrast, mixed lymph ...19948045586
animal-derived antigenic variants of foot-and-mouth disease virus type a12 have low affinity for cells in culture.we recently have shown that binding of foot-and-mouth disease virus (fmdv) to cells in culture requires an arginine-glycine-aspartic acid (rgd) sequence in the g-h loop of the capsid protein vp1 (p. w. mason, e. rieder, and b. baxt, proc. natl. acad. sci. usa 91:1932-1936, 1994). in this report, we show that fmdv type a12 viruses found in infected bovine tongue tissue (btt) differ from their tissue culture-grown derivatives at amino acid residues near the rgd. viruses genetically engineered to c ...19948035529
demonstration of antibodies against foot and mouth disease virus (fmdv) type o and asia-1 in non-descriptive crossbred calves.sera from non-descriptive crossbred calves were screened for the presence of neutralizing antibodies against fmdv type o and asia-1 for a period up to 215 days. the antibody titer of 16 remained constant up to 215 days against type o and up to 190 days against type asia-1 virus in some animals. in majority of the animals the antibody titers remained constant up to three months. the possible reason for a frequent breakdown of immunity in the vaccinated animals even 3-4 months after vaccination co ...19947817899
application of monoclonal antibodies to quality control of foot-and-mouth disease vaccines.panels of monoclonal antibodies (mabs) produced against foot-and-mouth disease (fmd) virus types o, a and c were selected for cell culture neutralization titre (nt), mouse protection index (mpi), trypsin sensitivity (ts) and avidity to different epitopes. the selected sets were used to assay the antigen concentration and the fit between fmdv vaccine and challenge strains. it was observed that fmd vaccines protect more than 75% of vaccinated cattle when manufactured with antigens characterized by ...19948091844
analysis of mixed foot-and-mouth disease virus infections in saudi arabia: prolonged circulation of an exotic serotype.plaque purification of foot-and-mouth disease (fmd) type o viruses isolated from cattle in saudi arabia showed the presence of mixed serotype infections. sixteen out of 31 samples collected between 1985 and 1991 also contained asia 1 virus, a serotype which had previously only been isolated from a single outbreak in that country in 1980. nucleotide sequences of the asia 1 component of all these samples revealed little variation and showed that they were closely related to both a russian lapinize ...19948119359
genetic relationships between foot-and-mouth disease type asia 1 viruses.the sequence of 165 nucleotides at the 3' end of the 1d (vp1) gene of foot-and-mouth disease (fmd) virus was determined for 44 type asia 1 strains isolated from throughout asia between 1954-92. analysis of the relationships between the virus genomes showed epidemiological links not previously evident. the possible origin of the only outbreak of fmd asia 1 to have occurred in europe, in greece in 1984, was identified because the nucleotide sequence of this virus was closely-related to the sequenc ...19948119360
experimental transmission of foot-and-mouth disease virus from carrier african buffalo (syncerus caffer) to cattle in zimbabwe.four female cattle and three male african buffalo (syncerus caffer) which were free of foot-and-mouth disease (fmd) virus were held together on an island in lake kariba, zimbabwe. the buffalo were experimentally infected with fmd virus type sat2, developed generalised disease and became virus carriers. while the buffalo were in the acute phase of the disease the susceptible contact cattle did not show lesions, no virus was recovered from them and they did not develop serum antibodies. however, f ...19948171808
recognition of b and t cell epitopes by cattle immunized with a synthetic peptide containing the major immunogenic site of vp1 fmdv 01 campos.the precise location of b and t cell epitopes have been established in a peptide containing the major immunogenic site (residues 135-160) of fmdv strain 01 campos (01c) vp1. the peptide (p135-160), administered free or conjugated to bovine serum albumin, induced complete protection in guinea pigs and a strong neutralizing antibody (nab) response in cattle. using a set of partially overlapping peptides it was shown that although several b cell epitopes were distributed along the p135-160, the res ...19948184548
natural transmission of foot-and-mouth disease virus from african buffalo (syncerus caffer) to cattle in a wildlife area of zimbabwe.an outbreak of foot-and-mouth disease (fmd) occurred during april 1991 in a trypanosomiasis sentinel cattle herd by the rifa river to the east of lake kariba, zimbabwe. despite the cattle having been vaccinated biannually for the previous five years the disease was severe. the viruses isolated from the affected animals were typed as fmd virus type sat 1. free-living african buffalo (syncerus caffer) which had been using the same watering place as the affected cattle were sampled and fmd type sat ...19948197679
haptoglobin response of cattle infected with foot-and-mouth disease virus.haptoglobin, a major bovine acute phase protein, was evaluated as a marker of the primary replication of foot-and-mouth disease virus in 12 naturally infected cattle from which blood was collected daily. an acute phase response, as measured by an increase in serum haptoglobin concentration and the presence of fever, was not detected during the previraemic stage of disease, but there was a significant increase in serum haptoglobin after the onset of viraemia. it occurred on the same day as the fi ...19947973086
nucleotide sequence of the p1 region of serotype asia1 foot-and-mouth disease virus.differences in the amino acid sequence of foot-and-mouth disease virus (fmdv) virion proteins (vp) among the various fmdv serotypes, particularly in the vp1 polypeptide, are the basis for antigenic diversity of this virus group. this phenomenon provides the basis for type diagnosis of fmdv by the polymerase chain reaction (pcr). in order to specifically identify the asia1 fmdv serotype by pcr, the nucleotide sequence of its p1-coding region was determined. the sequence exhibited over 70% homolog ...19947975273
genetic variation of foot-and-mouth disease virus from field outbreaks to laboratory isolation.foot-and-mouth disease virus (fmdv), by nature of its rna genome, possesses a high rate of mutation during replication. this results in extensive genetic polymorphism of virus populations in nature. the emergence of fmdv variants during replication has been reported. genetic changes in the viral capsid protein (vp1) gene can result in amino acid changes affecting the immunodominant epitopes of fmdv. the genetic heterogeneity of fmdv in the field and the antigenic variants observed after cell cul ...19948079512
analysis of sites of foot and mouth disease virus persistence in carrier cattle via the polymerase chain reaction.this study was undertaken in order to explore possible sites of foot-and-mouth disease virus (fmdv) persistence during the carrier state. tissue samples taken from experimentally infected animals at different times post-infection (p.i.) were examined by conventional viral isolation and the polymerase chain reaction (pcr) technique. the analysis of samples from several organs taken from 17 bovines between 3 and 270 days p.i. allowed the following conclusions: 1) virus present in oesophageal-phary ...19948031235
foot-and-mouth disease in ethiopia from 1988 to 1991.during the period 1988 to 1991 samples from 16 foot-and-mouth disease outbreaks in ethiopia were examined at the national veterinary institute, ethiopia, and at the fao world reference laboratory for foot-and-mouth disease, uk. typing of the virus responsible was possible in 13 of these outbreaks representing 10 separate disease events; 8 of these were caused by serotype o and 2 by serotype sat2. this is the first record of the presence of serotype sat2 foot-and-mouth disease virus in ethiopia. ...19947809989
rapid coagglutination test for the detection and typing of foot and mouth disease virus.protein a containing staphylococcus aureus was used to develop a coagglutination (coa) test for the detection and typing of foot and mouth disease virus (fmdv) o, a and c serotypes in infected cells and tissues. different batches and amounts of guinea pig anti-fmdv sera were assessed to optimize the preparation of coa conjugates. the sensitivity and specificity of the coa test for the detection of fmdv o, a and c serotypes and heterologous viruses was also characterized. comparison between the c ...19947714052
a modified liquid phase (lp) blocking elisa used to assess type o foot-and-mouth disease virus antigenic variation in thailand.a selection of type o foot-and-mouth disease (fmd) viruses isolated in thailand between 1986 and 1989 were compared to the reference viruses o1 thailand 1960 (o bkk/60) and o nakorn pathom 1965 (o npt/65) using a liquid-phase blocking elisa (lp elisa) to derive serum titres and associated r values. interpolation techniques were used to increase the precision for estimation of r values through a more accurate estimation of serum titres at predicted equivalent levels of antigen input. mean r value ...19947839587
the influence of mhc polymorphism on the selection of t-cell determinants of fmdv in cattle.there is a quest for the development of a new generation of vaccines consisting of well-defined subunit antigens. for a number of practical reasons it is attractive to develop vaccines on the basis of synthetic peptides. however, their efficacy may be limited by genetic restrictions imposed on t-cell recognition via major histocompatibility complex (mhc) polymorphism, as shown by many studies using inbred animal species. to study the effect of mhc polymorphism in an outbred species, we selected ...19957534267
immune response of calves to foot-and-mouth disease virus vaccine emulsified with oil adjuvant. strategies of vaccination.calves born to vaccinated cows under the regular annual vaccination programme were vaccinated at different ages using commercial quadrivalent (01, a79, a87 and c85 fmdv strains) vaccine emulsified in oil adjuvant. the antibody responses of vaccinated calves were evaluated using liquid-phase blocking sandwich elisa. all calves 20, 30 and 40 days old having high maternal antibody titres responded well to vaccination. moreover, 25-57% of vaccinated calves showed protective antibody titres both at 9 ...19957483763
sequences derived from the highly antigenic vp1 region 140 to 160 of foot-and-mouth disease virus do not prime for a bovine t-cell response against intact virus.although vp1 region 140 to 160 of foot-and-mouth disease virus (fmdv) is able to elicit neutralizing antibody in cattle, the protection against virus challenge that is conferred by peptide immunization is often poor. here, we show that bovine t cells primed with peptides derived from this region generally show no reactivity to intact fmdv. in contrast, t-cell epitope vp4[20-34] is able to prime for a virus-specific response.19957769713
foot and mouth disease virus replication in bovine skin langerhans cells under in vitro conditions detected by rt-pcr.the replication of foot and mouth disease virus (fmdv) was studied in isolated bovine skin langerhans cells (lc), in keratinocytes from epidermal cell suspension, and in migrating lc obtained from cultured bovine epidermal sheets in vitro. viral rna replication in infected cells was determined by the reverse transcriptase-polymerase chain reaction (rt-pcr) of the negative fmdv rna strand and by the plaque forming assay of fmdv. it was established that bovine skin lc, keratinocytes, and migratory ...19957483289
receptor binding site-deleted foot-and-mouth disease (fmd) virus protects cattle from fmd.binding of foot-and-mouth disease virus (fmdv) to cells requires an arginine-glycine-aspartic acid (rgd) sequence in the capsid protein vp1. we have genetically engineered an fmdv in which these three amino acids have been deleted, producing a virus particle which is unable to bind to cells. cattle vaccinated with these receptor binding site-deleted virions were protected from disease when challenged with a virulent virus, demonstrating that these rgd-deleted viruses could serve as the basis for ...19957637023
identification of native foot-and-mouth disease virus non-structural protein 2c as a serological indicator to differentiate infected from vaccinated livestock.cattle and pigs which have been vaccinated against foot-and-mouth disease can be distinguished from convalescent animals by radio-immunoprecipitation and sodium dodecyl sulphate polyacrylamide gel electrophoresis of the virus-induced proteins reacting with the respective sera. baby hamster kidney cells infected with foot-and-mouth disease virus (fmdv) (serotype a24) were labelled with 35s-methionine and the virus-induced proteins were precipitated with sera from vaccinated and subsequently chall ...19958525090
the persistence of foot-and-mouth disease virus on wool.five suffolk sheep, held in a high-security isolation room, were exposed for 2 hours to the aerosol of 3 mature pigs that had been infected with foot-and-mouth disease virus (fmdv), strain o1-bfs. the fleeces of 3 of the sheep were contaminated with fmdv at 2 days post exposure (dpe), while at 5 dpe the fleeces of all 5 sheep were more extensively, and more heavily, contaminated. the persistence of fmdv on contaminated wool was examined in vitro using multiple 0.5 g samples of merino wool that w ...19958579558
assessment of foot and mouth disease vaccine potency by liquid-phase blocking elisa: a proposal for an alternative to the challenge procedure in argentina.the lowest expected protection (lep) at a 95% confidence of 245 foot and mouth disease (fmd) commercial vaccines was calculated from the titres of liquid-phase blocking sandwich elisa (lpelisa) of cattle sera obtained from 3920 animals at 60 days post-vaccination (d.p.v.) and challenged with live virus at 90 d.p.v. it was found that lep evaluation is highly specific (i.e. it is able to predict the failure in 100% of the cases) although its ability to predict the challenge (pg test) approval (i.e ...19958585292
detection of foot-and-mouth disease virus-infected cattle by assessment of antibody response in oropharyngeal fluids.the detection of foot-and-mouth disease virus (fmdv)-persistent carriers among convalescent ruminants is of paramount importance in the aftermath of a field outbreak. to this purpose, fmdv-specific antibody should be investigated first, since virus isolation procedures from such carriers are seriously constrained. the complexity of the overall picture may be compounded by possible emergency vaccinations in the affected areas at the beginning of the outbreak. in this case, it is suggested that mu ...19957699071
serological comparison of type a foot and mouth disease virus isolates from thailand.antigenic variation of type a foot and mouth disease (fmd) virus in thailand was examined using a total of 82 field viruses isolated between 1986 and 1989. a two-dimensional serum microneutralisation test was used to compare these isolates to a reference strain, a15 bangkok 1960 (a bkk/60). viruses regarded as unrelated to a bkk/60 were compared to another reference strain, a22 nakhon pathom 1986 (a npt/86). this approach divided the viruses into two groups. most of the viruses shared a close an ...19958593389
susceptibility of llamas (lama glama) to infection with foot-and-mouth-disease virus.an experimental trial was conducted to evaluate the ability of foot-and-mouth-disease (fmd) virus (serotypes a79, c3, o1) to infect susceptible llamas exposed either directly to affected livestock, or indirectly to llamas that had been directly exposed to affected livestock. in addition, susceptible livestock species (cattle, pigs, goats, and sheep) were exposed to those llamas that had been both directly and indirectly exposed to the fmd virus to further look at potential transmission possibili ...19958594845
comparative between-laboratory trials of the liquid-phase blocking sandwich elisa for the detection of antibodies to foot-and-mouth disease virus.fifty bovine serum samples were tested for the presence or amounts of antibodies to foot-and-mouth disease (fmd) virus serotypes a, o and c by the liquid-phase blocking sandwich elisa (lpb-elisa) using reagents prepared by the world reference laboratory for foot-and-mouth disease (wrl) in pirbright, u.k. twenty of the sera had been collected before extensive vaccination with a commercial inactivated trivalent fmd vaccine was ceased and the remaining thirty originated from animals which had not b ...19957716862
optimization of an in situ hybridization technique for the detection of foot-and-mouth disease virus in bovine tissues using the digoxigenin system.an in situ hybridization technique has been optimised for use on paraffin-embedded sections of tissues collected from cattle infected experimentally with foot-and-mouth disease virus type o1bfs. tissue was collected 5 days after infection by direct contact. in situ hybridization was carried out using an rna probe corresponding to a region of the 3d gene which codes for the rna polymerase, and labelled with digoxigenin. consistent, reproducible signal was detected within the epithelial layers of ...19957730440
characterization of an acid-resistant mutant of foot-and-mouth disease virus.a foot-and-mouth disease virus mutant which is stable at ph 6.4 has been isolated from a virus of serotype a. in contrast to the parent (p) virus, which gave a mixture of large and small plaques in bhk21 cells and in a bovine kidney cell line, the acid-resistant (ar) virus gave small plaques which did not increase markedly in size after 24 hr. the infectivity titer of the acid-resistant virus was about 100-fold lower in suckling mice than in bhk21 cells, whether the inoculation was made intraper ...19957831827
detection and subtyping of foot-and-mouth disease virus in infected cattle by polymerase chain reaction and amplified vp1 sequencing.fast and accurate detection of foot-and-mouth disease (fmd) outbreaks is needed to limit spread of the disease by proper vaccination. the use of the polymerase chain reaction (pcr) has revolutionized the way in which viral diseases are diagnosed. sequence analysis of the amplified vp1 sequence can enable the classification of fmd virus detected in the morbid animal. pcr assays were carried out to identify the virus and its serotype in suspect animals from 2 outbreaks of fmd type o virus. sequenc ...19957779964
serial passage in tissue culture of mixed foot-and-mouth disease virus serotypes.the foot-and-mouth disease (fmd) virus field specimen sau/8/88 was previously shown to consist of a mixture of o and asia 1 serotypes [15]. in this study, plaques representing the o and asia 1 components isolated from the original epithelial virus suspension were used to construct mixtures of known ratios, and these were serially passaged in tissue culture. after each passage, the ratio of o to asia 1 virus was calculated. the two virus populations were shown to be cycling through time. this cyc ...19957794118
serological comparison of type asia 1 foot and mouth disease virus isolates from thailand.antigenic variation of type asia 1 foot and mouth disease (fmd) virus in thailand was examined using a total of 50 field viruses isolated between 1986 and 1992. a two-dimensional serum neutralisation test was used to calculate r values for comparison of these isolates with a reference vaccine strain, asia 1 bangkok 1960 (bkk/60). viruses were also compared to two field isolates, asia 1 36-2/88 and asia 1 45/88, and some were compared to another vaccine strain, asia 1 nakhon pathom 1984 (npt/84). ...19958593388
rapid detection and characterization of foot-and-mouth disease virus by restriction enzyme and nucleotide sequence analysis of pcr products.reverse transcription coupled with pcr was used for the detection of foot-and-mouth disease virus serotypes a, c, and o in organ extracts from experimentally infected cattle. primers were selected from conserved sequences flanking the genome region coding for the major antigenic site of the capsid located in the c-terminal part of viral protein 1 (vp1). because this region of the capsid is highly variable its coding sequence is considered to be the most appropriate for the characterization of vi ...19957714205
response of foot-and-mouth disease virus c3 resende to immunological pressure exerted in vitro by antiviral polyclonal sera.the foot-and-mouth disease virus (fmdv) shows a remarkable antigenic variability. like other rna viruses, fmdv has a high mutation rate and it has been proposed that selection exerted by antibodies of the host could play a major role in its evolution. in this work, antiserum-resistant variants of fmdv (nr variants) were selected upon 25 serial passages of a cloned c3 resende strain on secondary monolayers of fetal bovine kidney (fbk-2) cells in the presence of subneutralizing levels of antiviral ...19957542827
serological study of type a indian foot-and-mouth disease virus isolates.the antigenic relationship of sixty type a foot-and-mouth disease (fmd) viruses isolated between 1968 and 1993 has been determined with reference to a post-vaccinal bovine serum produced against type a ind 17/82. a micro-neutralization test and elisa were used to compare isolates. analysis of the results indicated that there was a positive correlation between the data from the two methods. the study indicated that type a ind 17/82 had a broad immunogenic spectrum and could be considered as a can ...19958825299
antigenic analysis of sat 2 serotype foot-and-mouth disease virus isolates from zimbabwe using monoclonal antibodies.this paper compares strains of foot-and-mouth disease (fmd) serotype sat (south african territories) 2 viruses isolated from zimbabwe and other african countries using monoclonal antibodies (mab). a sandwich-elisa was used to examine the relative binding of anti-sat 2 mab to the various viruses. the mab-binding profiles of viruses isolated from field samples were compared using hierarchical cluster analysis. viruses were obtained from game animals, mainly african buffalo (syncerus caffer) which ...19957543860
a 10-amino-acid linear sequence of vp1 of foot and mouth disease virus containing b- and t-cell epitopes induces protection in mice.the area of foot and mouth disease virus (fmdv) comprising residues 140 and 160 of capsid protein vp1 has been used extensively as an immunogen in natural and experimental hosts. a detailed epitope mapping of this region, however, has not been reported. for this purpose a synthetic peptide containing the residues 135 to 160 (p135-160) of vp1 of fmdv o1 campos was analyzed for its t- and b-cell epitopes. the p135-160 is highly immunogenic, either by itself or coupled to a carrier protein (bsa), e ...19957571431
bovine t cells preferentially recognize non-viral spacer epitopes in a putative fmdv vaccinal peptide.in a group of immunized cattle with a variety of mhc class ii types, t-cell responses were detected to a synthetic peptide (fmdv15) proposed as a basis for a vaccine against foot-and-mouth disease. this peptide combines the loop region of vp1 with the c-terminal sequence connected by a spacer (pps). two major immunodominant regions of fmdv15 for bovine t cells were detected, one within the loop region and the other around the spacer. a substantial proportion of the t-cell response to fmdv15 was ...19957625121
detection of foot-and-mouth disease virus in nasal swabs of asymptomatic cattle by rt-pcr within 24 hours.a method for extracting rna from animal-derived materials that provides foot-and-mouth disease viral template suitable for tth polymerase-dependent synthesis of cdna and subsequent pcr is described. viral genomes were detected in less than 24 h. nasal swabs that can be easily and repeatedly collected, proved suitable for virus detection by pcr, even during the asymptomatic stages of infection.19957673392
the foot-and-mouth disease virus leader proteinase gene is not required for viral replication.the foot-and-mouth disease virus (fmdv) leader (l) proteinase has only two known functions: (i) autocatalytic removal from the n terminus of the viral polyprotein and (ii) cleavage of the p220 subunit of the eukaryotic initiation factor 4f complex, which helps to shut off host protein synthesis. cleavage of p220 appears to be important for picornavirus replication, since rhinoviruses and enteroviruses utilize a different proteinase (2a) to cleave p220. to explore the role of l in fmdv replicatio ...19957636982
inactivation of viruses in liquid manure.the stability of some viruses and methods of virus inactivation in liquid manure are reviewed. the authors discuss experimental data on the stability of foot and mouth disease virus, classical swine fever virus, aujeszky's disease virus, african swine fever virus, swine influenza virus, porcine paramyxovirus, bovine virus diarrhoea virus and transmissible gastroenteritis of pigs virus. recommendations and practical advice are given for the choice and application of chemical disinfectants for slu ...19957579641
increase of murine splenic natural antibody-secreting cells after cyclophosphamide treatment.administration of a low sub-immunosuppressive dose of cyclophosphamide (cy) to naive mice induced a marked increase in the number of splenic cells forming natural antibodies against unrelated antigens such as foot-and-mouth disease virus, keyhole limpet hemocyanin, horseradish peroxidase, or bovine serum albumin, as determined by an enzyme-linked immunosorbent assay spot technique. these results suggest that in mice there exists a repertoire of b cells forming natural antibodies which is restrai ...19968906754
serological and molecular analysis of serotype o foot-and-mouth disease virus isolated from disease outbreaks in india during 1987-91.foot-and-mouth disease virus (fmdv) type o outbreaks have been reported frequently in vaccinated cattle in india. twenty-five field isolates, recovered from outbreaks in vaccinated and unvaccinated cattle between 1987 and 1991, were analyzed in relation to the vaccine strain (r2/75) by complement fixation, serum neutralization and partial nucleotide sequencing of the vp1 gene. these sequences were compared with the viral sequences in genembl database. although the indian type o viruses were clos ...19968822633
recognition of foot-and-mouth disease virus and its capsid protein vp1 by bovine peripheral t lymphocytes.the role of t cells in immunity to foot-and-mouth disease virus is still poorly defined compared to that of the humoral response. in this paper we describe a systematic, longitudinal study on the cellular recognition of fmdv and its subunit protein vp1 by bovine peripheral blood t lymphocytes. multiple vaccination with a single virus serotype induced a serotype cross-reactive proliferative t cell repertoire that varied in magnitude between individual animals and with the serotype of the vaccine ...19968627261
[nucleotide sequence of the rna polymerase gene attenuated by a variant of foot-and-mouth disease virus and its comparison with the virulence of related variants of subtype a22].the nucleotide sequence of rna-polymerase gene and 3'-terminal untranslated genome region of attenuated foot-and-mouth disease virus (fmdv) strain a(22)645 has been determined. rna-polymerase gene and predicted amino acid sequences of attenuated fmdv strain a(22)645 were compared with those of the original virulent fmdv strain a(22)550. the examined genome region of strain a(22)645 differed from that of strain a(22)550 by 22 nucleotides and 3 amino acids. three mutations occurred within nucleoti ...19968786750
[mechanisms involved in the prolonged humoral immune response: behavior of aphthous fever virus].foot and mouth disease (fmd) is a widespread infectious disease affecting cloven-hoofed animals with severe economic consequences. animals infected with fmd virus (fmdv) develop an immunological status of immunity characterized by high titers of virus serotype-specific neutralizing antibodies (nab) which persist for at least 18 months. in contrast, currently inactivated virus vaccines elicit lower antibody response for shorter periods. protection against fmdv infection has been commonly related ...19968815460
detection of antibodies against foot-and-mouth disease virus using a liquid-phase blocking sandwich elisa (lpbe) with a bioengineered 3d protein.a liquid-phase blocking sandwich enzyme-linked immunosorbent assay (elisa-3d) was developed to detect specific antibodies to the 3d protein in sera from foot-and-mouth disease (fmd) virus (fmdv)-infected animals. the assay uses a nonstructural 3d recombinant protein and two polyclonal antisera, one for capture (bovine) and the other for detector (guinea pig). the specificity of the assay was demonstrated by negative results with 101 sera of cattle from the fmd-free zone in argentina and with bov ...19968744733
antiviral activity of crude extracts of guarea guidona.crude extracts of leaves and fruits of guarea guidona were tested for antiviral activity against pseudorabies virus and foot-and-mouth disease virus in the ib-rs-2 pig cell line and against bovine herpesvirus-1 (bhv-1) in the gbk bovine cell line. the highest nontoxic doses of extracts from fruits and leaves were 125 micrograms/ml and 500 micrograms/ml. respectively. crude extracts presented antiviral activity against pseudorabies virus with a decrease in virus titer of 3.0 log units at 500 micr ...19969033817
efficient infection of cells in culture by type o foot-and-mouth disease virus requires binding to cell surface heparan sulfate.foot-and-mouth disease virus (fmdv) enters cells by attaching to cellular receptor molecules of the integrin family, one of which has been identified as the rgd-binding integrin alpha(v)beta3. here we report that, in addition to an integrin binding site, type o strains of fmdv share with natural ligands of alpha(v)beta3 (i.e., vitronectin and fibronectin) a specific affinity for heparin and that binding to the cellular form of this sulfated glycan, heparan sulfate, is required for efficient infe ...19968764038
pathogenesis of wild-type and leaderless foot-and-mouth disease virus in cattle.four calves were experimentally infected via aerosol with foot-and-mouth disease virus. two were infected with a wild-type virus derived from a full-length infectious clone (a12-ic), and two were infected with a clone-derived virus lacking the leader gene (a12-llv2), with euthanasia and tissue collection at 24 and 72 h postexposure (hpe). clinical disease was apparent only in the animal given a12-ic and euthanized at 72 hpe. in situ hybridization revealed that the animal infected with a12-ic and ...19968764079
a protective anti-peptide antibody against the immunodominant site of the a24 cruzeiro strain of foot-and-mouth disease virus and its reactivity with other subtype viruses containing the same minimum binding sequence.a synthetic peptide vaccine of the general sequence cys-cys-(200-213)-pro-pro-ser-(l41-158)-pro-cys-gly(peptide a40), where the numbered residues refer to the vp1 sequence of foot-and-mouth disease virus (fmdv) strain a24 cruzeiro, has previously been shown to elicit neutralizing and protective antibodies in guinea-pigs and cattle. to examine this immunogenic tract in more detail monoclonal antibodies (mabs) were raised to this peptide. one such mab c1.1, which recognized the homologous peptide, ...19968609466
the use of cyclophosphamide as an enhancer of the vaccine against foot-and-mouth disease.the immunization of biungulate animals with killed foot-and-mouth disease virus (fmdv) requires periodic vaccinations due to a low vaccine immunogenicity. therefore, fmdv antigens need to be combined with adjuvants such as aluminium hydroxide, saponin or oil emulsions. animal handling for periodic inoculations, and the repeated doses of vaccines that have to be administered increase the commercialization costs. moreover, the use of adjuvants may induce adverse effects. in the present work we sho ...19968698098
strategy for producing new foot-and-mouth disease vaccines that display complex epitopes.widely used inactivated vaccines for foot-and-mouth disease (fmd) induce protective immunity, but vaccine production plants and residual virus in the vaccine itself have been implicated in disease outbreaks. the structure of the fmd virion has been determined, and although much of the surface of the viral particle is produced by complex folding of the three surface-exposed capsid proteins (vp1-3), some surface regions representing important linear epitopes can be mimicked by recombinant proteins ...19968717390
emerging foot-and-mouth disease virus variants with antigenically critical amino acid substitutions predicted by model studies using reference viruses.one of the major obstacles to the design of effective antiviral vaccines is the frequent generation of antigenic viral variants in the field. the types of variants that will become dominant during disease outbreaks is often unpredictable. however, here we report the genetic and antigenic characterization of emerging foot-and-mouth disease virus (fmdv) variants with antigenically critical amino acid substitutions predicted by model studies using reference viruses and monoclonal antibodies. the ne ...19968852403
identification of foot-and-mouth disease virus-free regions by use of a standardized enzyme-linked immunoelectrotransfer blot assay.to assess the potential of a highly sensitive enzyme-linked immunoelectrotransfer blot (eitb) assay to monitor persistent foot-and-mouth disease (fmd) viral activity in a livestock population.19968807005
preparation of virus-infection-associated (via) antigen of foot-and-mouth disease (fmd) virus from inactivated vaccine.virus-infection-associated (via) antigen of foot-and-mouth disease (fmd) virus was prepared from an inactivated fmd vaccine. the via antigen coupled with an adjuvant of aluminium hydroxide gel supplemented vaccine was efficiently eluted by suspending and stirring in high concentration of phosphate buffer solution (0.3m, ph 7.6). the final elute purified by deae-sephadex a50 from the vaccine was concentrated in 1/500-1/1,000 of the original volume. via antigens prepared from two kinds of vaccine ...19968811637
antigenic analysis of type o foot-and-mouth disease virus in the persistently infected bovine.the antigenic profiles of serotype o strains of fmdv collected from the oropharynx of persistently infected cattle were defined with a panel of monoclonal antibodies (mab's) in an indirect antigen-trapping elisa. the mab profiling showed no significant loss of reactivity in two neutralising antigenic sites of persistent fmdv isolates collected over a period of eight months. early and late serum taken from a carrier animal showed similar neutralising activity against early and late carrier isolat ...19968856023
isotype-specific antibody responses to foot-and-mouth disease virus in sera and secretions of "carrier' and "non-carrier' cattle.isotype-specific antibody responses to foot-and-mouth disease virus (fmdv) were measured in the sera and upper respiratory tract secretions of vaccinated and susceptible cattle challenged with fmdv by direct contact or by intranasal inoculation. a comparison was made between cattle that eliminated fmdv and those that developed and maintained a persistent infection. serological and mucosal antibody responses were detected in all animals after challenge. iga and igm were detected before the develo ...19968870633
prevalence of foot-and-mouth disease antibodies in dairy herds in the netherlands four years after vaccination.a total of 298 serum samples were collected from dutch cattle born in 1988 or before, and examined in the virus neutralisation test for antibodies against foot-and-mouth disease virus types a10 holland. o bfs, and c1detmold. all the cattle had been vaccinated at least twice during the annual vaccination programme, which stopped in 1991. antibody titres equal to or higher than the titre at which 95 per cent of the cattle would be expected to be protected against challenge, were found in 57 to 73 ...19968819202
[the use of synthetic peptides for detection of antibodies against foot-and-mouth disease virus in the blood from convalescent animals].peptides were synthesized, which, according to theoretical analysis of the antigenic structure of protein vp1 of foot-and-mouth disease (fmd) virus types a, 0, and asia 1, corresponded to potential immunodominant protein sites. activities of the peptides were studied by solid-phase indirect radioimmunoassay on polyethylene film with purified immunoglobulins against intact fmd virus. virtually no cross reactions were observed. blood sera of cattle convalescent after fmd were tested with the fmd v ...19968999315
absence of protein 2c from clarified foot-and-mouth disease virus vaccines provides the basis for distinguishing convalescent from vaccinated animals.we have recently reported that cattle and pigs which have been vaccinated against foot-and-mouth disease can be distinguished from convalescent animals by the absence of antibodies to viral non-structural protein 2c (lubroth and brown, res. vet. sci., 1995, 59, 70-78(1)). in this study, we show that the absence of 2c antibodies from the sera of vaccinated animals can be explained by the association of this viral protein with cellular debris which is separated from the virus harvest prior to inac ...19968735554
evaluation of the presence and risk of foot and mouth disease virus by commodity in international trade.potential sources of foot and mouth disease (fmd) virus include semen from bulls, rams, goats and boars; embryos and ova from ruminants and pigs; meat and meat products and milk and milk products. the author discusses precautions to prevent the transmission of fmd via these commodities.19969025152
detection of foot-and-mouth disease viral sequences in various fluids and tissues during persistence of the virus in cattle.to assess whether foot-and-mouth disease virus (fmdv)-specific sequences could be identified in tissues from persistently virus-infected animals.19968633795
rapid and sensitive polymerase chain reaction based detection and typing of foot-and-mouth disease virus in clinical samples and cell culture isolates, combined with a simultaneous differentiation with other genomically and/or symptomatically related viruses.reverse transcription followed by the polymerase chain reaction method (pcr) allowed the detection of foot-and-mouth disease virus (fmdv), regardless of the serotype. a primer set corresponding to highly conserved regions of the 2b sequence was selected. by combining in a single reaction tube specific primer pairs for fmdv, swine vesicular disease virus, (svdv), encephalomyocarditis virus (emcv) and bovine viral diarrhea virus (bvdv), all four viruses could be identified and differentiated in on ...19968634024
persistent infection of african buffalo (syncerus caffer) with sat-type foot-and-mouth disease viruses: rate of fixation of mutations, antigenic change and interspecies transmission.transmission of a plaque-purified sat-2 foot-and-mouth disease virus (fmdv) occurred erratically from artificially infected african buffaloes in captivity to susceptible buffaloes and cattle in the same enclosure; in some instances transmission occurred only after contact between persistently infected carriers and susceptible animals lasting a number of months. because the rate at which fmdv mutations accumulated in persistently infected buffaloes was approximately linear (1.64 percent nucleotid ...19968757987
the performance of southern african territories serotypes of foot and mouth disease antigen in oil-adjuvanted vaccines.the performance of selected oil adjuvants containing southern african territories (sat) serotypes of foot and mouth disease virus was assayed by testing antibody levels elicited in cattle, sheep and goats, and by testing protection of cattle on challenge. various oil adjuvant formulations were tested initially in cattle and guinea pigs, and compared with a standard alhydrogel and saponin-based (as) vaccine. a commercial double oil emulsion vaccine elicited higher antibody titres and a more prolo ...19969025141
functional expression of a cattle mhc class ii dr-like antigen on mouse l cells.cattle dra and drb genes, cloned by reverse-transcription polymerase chain reaction, were transfected into mouse l cells. the cattle dr-expressing l-cell transfectant generated was analyzed serologically, biochemically, and functionally. sequence analysis of the transfected drb gene clearly showed showed that it was drb3 allele drb3(*)0101 , which corresponds to the 1d-ief-determined allele drbf3. 1d-ief analysis of the transfectant confirmed that the expressed dr product was drbf3. functional i ...19969110933
synthetic peptides.efforts to produce more stable and defined vaccines have concentrated on studying, in detail, the immune response to many infectious diseases in order to identify the antigenic sites on the pathogens that are involved in stimulating protective immumty. armed with this knowledge, it is possible to mimic such sites by producing short chains of amino acids (peptides) and to use these as the basis for novel vaccines. the earliest documented work on peptide immunization is actually for a plant virus, ...199621359696
a large-scale evaluation of peptide vaccines against foot-and-mouth disease: lack of solid protection in cattle and isolation of escape mutants.a large-scale vaccination experiment involving a total of 138 cattle was carried out to evaluate the potential of synthetic peptides as vaccines against foot-and-mouth disease. four types of peptides representing sequences of foot-and-mouth disease virus (fmdv) c3 argentina 85 were tested: a, which includes the g-h loop of capsid protein vp1 (site a); at, in which a t-cell epitope has been added to site a; ac, composed of site a and the carboxy-terminal region of vp1 (site c); and act, in which ...19979060612
escape mutants of foot-and-mouth disease virus selected by monoclonal antibodies directed to a trypsin-sensitive neutralization epitope.five monoclonal antibodies (moabs) against indian reference/vaccine strain of foot-and-mouth disease (fmd) virus subtype a22 (ind17/77) and a guinea pig antibody against a synthetic peptide representing amino acids (aa) 136-151 of vp1 polypeptide of a22 virus were used in the study. all the antibodies either failed to react or showed a reduced reactivity with trypsin-treated (tt)-146 s virus particles in enzyme-linked immunosorbent assay (elisa), and could neutralize the infectivity of the refer ...19979385400
dexamethasone inhibits virus production and the secretory iga response in oesophageal-pharyngeal fluid in cattle persistently infected with foot-and-mouth disease virus.cattle persistently infected with foot-and-mouth disease virus were treated with dexamethasone to suppress the immune system in an attempt to influence the level of virus recovery from oesophageal pharyngeal (probang) samples. twelve carrier cattle were assigned to one of three groups: control; 0.1 mg/kg dexamethasone; and 0.5 mg/kg dexamethasone. groups 2 and 3 were injected intramuscularly three times weekly for 3 weeks with dexamethasone between days 33 and 56 post-infection with foot-and-mou ...19979129595
development of tests for antibodies against foot-and-mouth disease virus in cattle milk.the liquid-phase blocking elisa (lpbe) and a specific isotype assay (sia) for bovine igg1 were modified to detect antibodies against fmdv isolate o1 manisa in cattle milk. samples from vaccinated animals were mostly indistinguishable from negative control cattle in the lpbe but 90% of milks from convalescent animals (which had also been vaccinated several times previously) gave positive results. the sia was able to detect 95% of cattle vaccinated up to 12 months previously, and 100% of the recov ...19979015288
the non-structural polyprotein 3abc of foot-and-mouth disease virus as a diagnostic antigen in elisa to differentiate infected from vaccinated cattle.a diagnostic assay to differentiate antibodies induced by foot-and-mouth disease virus (fmdv) infection from those induced by vaccination was developed. the test is an indirect-trapping elisa which uses a monoclonal antibody to trap the non-structural 3abc-fmdv polypeptide expressed in e. coli. experimental and field sera from naive, vaccinated and infected cattle were examined. using the established threshold of 0.20 optical density units, the sensitivity of the assay was 100%, as all the exper ...19979413510
nucleotide sequence of the p1 region of foot-and-mouth disease virus strain o1 caseros.it has been shown that variation of antigenic site i in vp1 of foot-and-mouth disease virus (fmdv) plays an important role in the antigenic diversification of this virus. however, the o1 campos strain is able to efficiently cross-protect cattle against the o1 caseros strain, despite having a different sequence in the site i. in this paper we report and compare the p1 coding region for the capsid proteins of fmdv o1 caseros and o1 campos. the deduced amino acid sequence showed a total of 31 amino ...19979311571
[seroprevalence of viral infections in llamas (lama glama) in the republic of argentina].this study reports the seroprevalence of bovine viral infections in llamas (lama glama) in argentina. this is the first study made in the country including 390 llamas and testing antibodies against eight viruses. samples were collected from nine farms distributed in three different provinces: buenos aires, córdoba and jujuy. the samples were tested for antibodies against eight viruses known to infect cattle: bovine herpesvirus type 1 (bhv-1), bovine viral diarrhea virus (bvdv), bovine adenovirus ...19979229724
foot-and-mouth disease virus-infected but not vaccinated cattle develop antibodies against recombinant 3ab1 nonstructural protein.foot-and-mouth disease (fmd) vaccines induce antibodies against structural and some nonstructural proteins present in vaccine preparations. to differentiate between fmdv-infected and vaccinated animals, we developed immunochemical assays capable of detecting antibodies against a fmdv nonstructural protein. recombinant nonstructural 3ab1 protein was expressed in e.coli and in insect cells and used to detect anti-3ab1 antibodies. elisa and western blot analysis showed that sera from cattle infecte ...19979170505
characteristic in vitro evolution pattern of foot and mouth disease virus a81/castellanos/arg/87.the in vitro evolution of foot and mouth disease virus (fmdv) a/81/castellanos/arg/87 (a/castellanos/87) was studied by partial biological and biochemical characterization of viral populations selected after 25 passages on secondary fetal bovine kidney cell monolayers. these passages were performed in the presence or absence of immune pressure exerted in the form of antiviral polyclonal serum. while the viral populations passaged in the absence of immune pressure acquired characteristics such as ...19979175254
an analysis of foot-and-mouth-disease epidemics in the uk.there was a major epidemic of the foot-and-mouth-disease virus among cattle herds in the uk in 1967-68 which showed a very rapid early spread, a much slower later spread, and eventually infected 12% of herds in the core epidemic area. a simple discrete-time version of a susceptible-latent-infectious-removed epidemiological model is used to generate a set of estimates of the transmission rate. this parameter has high values over the first few days, then the values are lower and they subsequently ...19979080685
infectivity assays of foot-and-mouth disease virus: contact transmission between cattle and buffalo (bubalus bubalis) in the early stages of infection.no differences were observed between cattle and indian buffalo (bubalus bubalis) in terms of temperature, viraemia or virus replication in the pharyngeal area, during the acute phase of foot-and-mouth disease. like cattle, the indian buffalo became infected and excreted virus before any clinical signs of foot-and-mouth disease developed. the disease was transmitted from cattle to buffalo and vice versa, during the acute stage of infection, as if the animals had been of the same species, presumab ...19979123797
plasmid dna encoding replicating foot-and-mouth disease virus genomes induces antiviral immune responses in swine.dna vaccine candidates for foot-and-mouth disease (fmd) were engineered to produce fmd virus (fmdv) particles that were noninfectious in cell culture or animals. the prototype plasmid, pwrm, contains a cytomegalovirus immediate-early promoter-driven genome-length type a12 cdna followed by the bovine growth hormone polyadenylation site. bhk cells transfected with this plasmid produced virus, but the specific infectivity of pwrm was much lower than that achieved with in vitro-generated rna genomes ...19979311823
tissue culture adaptation of foot-and-mouth disease virus selects viruses that bind to heparin and are attenuated in cattle.isolates of foot-and-mouth disease virus (fmdv) exist as complex mixtures of variants. two different serotype o1 campos preparations that we examined contained two variants with distinct plaque morphologies on bhk cells: a small, clear-plaque virus that replicates in bhk and cho cells, and a large, turbid-plaque virus that only grows in bhk cells. cdnas encoding the capsids of these two variants were inserted into a genome-length fmdv type a12 infectious cdna and used to produce chimeric viruses ...19979188578
antigenic features of foot-and-mouth disease virus serotype asia1 as revealed by monoclonal antibodies and neutralization-escape mutants.neutralizable antigenic sites/epitopes of serotype asial foot-and-mouth disease virus (strain ind63/72) were identified using monoclonal antibodies (mabs) and their neutralization-escape mutants. relative affinity/reactivity of the mabs for viral (both native and trypsin-cleaved) and subviral antigens in enzyme-linked immunosorbent assay (elisa) showed dominance of trypsin-sensitive and conformation-dependent neutralizable antigenic sites. characterization of neutralization escape mutants identi ...19979282776
total and isotype humoral responses in cattle vaccinated with foot and mouth disease virus (fmdv) immunogen produced either in bovine tongue tissue or in bhk-21 cell suspension cultures.the anti-foot and mouth disease virus (fmdv) serum antibody activity of protected and non protected animals immunized with inactivated fmdv originated in either bovine tongue tissue (bttv vaccines) or bhk-21 cell suspension cultures (bhkv vaccines) was evaluated. the results show that 80-100% of the bttv immunized and only 40-60% of the bhkv immunized animals with liquid-phase blocking sandwich elisa (lp elisa) serum titres of 1.5-1.7 u, were protected against the challenge with any of the four ...19979178462
computer simulations to identify in polyproteins of fmdv ok1 and a12 strains putative nonapeptides with amino acid motifs for binding to bola class i a11 and a20 haplotype molecules.the computer program "findpatterns" was used to search fmdv- (ok1 and a12 strains) coded structural and nonstructural proteins for the availability of putative proteasome-generated nonapeptides with motifs reported for bola class i a11 and a20 haplotypes. these bola class i a11 and a20 nonapeptide motifs are identical to motifs of nonapeptides that interact with the peptide binding grooves of hla class i b35 and b27 haplotypes, respectively. the computer findpattern program was used to analyze t ...19979237351
baculovirus expressed 2c of foot-and-mouth disease virus has the potential for differentiating convalescent from vaccinated animals.determining whether animals have been infected with foot-and-mouth disease virus or vaccinated is important because infected animals frequently become carriers of the virus, shed it intermittently and thus may be the source of new outbreaks of the disease. we had shown previously that the sera of convalescent animals contain antibodies to 2c, a highly conserved non-structural protein, whereas the sera of vaccinated animals do not. this is explained by observation that 2c is retained on the membr ...19979128860
evaluation of a live-attenuated foot-and-mouth disease virus as a vaccine candidate.a variant of foot-and-mouth disease virus (fmdv) lacking the leader (l) coding region (a12-llv2) was previously constructed and shown to be less virulent in cattle than its wild-type parent (a12-ic). in this study, cattle were tested for their clinical and immunological responses to subcutaneous inoculation with a12-llv2 or a12-ic or to intramuscular vaccination with chemically inactivated a12-ic. five weeks postinoculation animals were challenged by intradermal inoculation in the tongue with a ...19979007062
antiviral activity of an extract from leaves of the tropical plant acanthospermum hispidum.incubation of the alphaherpesviruses pseudorabiesvirus (prv) and bovine herpesvirus 1 during infection of cell cultures with an extract prepared from the leaves of acanthospermum hispidum impaired productive replication of these viruses in a concentration-dependent manner whereas propagation of classical swine fever virus, foot-and-mouth disease virus and vaccinia virus was not affected. the 50% inhibitory concentration for cell growth (ic50) was 107 +/- 5 microliters/ml, and the concentration r ...19979330761
induction of anti foot and mouth disease virus t and b cell responses in cattle immunized with a peptide representing ten amino acids of vp1.we previously demonstrated that the immunization of cattle with a synthetic peptide representing the amino acid sequence of foot and mouth disease virus (fmdv) type o1 campos vp1 residues 135-160 (p135-160), containing immunodominant t and b epitopes, was able to induce a strong neutralizing antibody (na) response. the epitope mapping of p135-160 identified t and b epitopes in the area restricted to amino acid residues 135-144 (zamorano et al. 1994, virology 201; 1995, virology 212). we are now ...19989569465
cattle response to foot-and-mouth disease virus nonstructural proteins as antigens within vaccines produced using different concentrations.four groups of ten nine-month-old nelore heifers were used for this study. each group received one of four foot-and-mouth disease (fmd) trivalent vaccines for the duration of the experiment. the four vaccine formulations (normal, 2x, 4x and 8x) differed in 140s content to determine the serological reactivities to fmd virus (fmdv) nonstructural proteins 2c, 3abc and 3d. vaccination was by the intramuscular administration of vaccine on day 0, 180 and 360. bleedings were done at 30 days post vaccin ...19989652056
diagnostic potential of mab-based elisas for antibodies to non-structural proteins of foot-and-mouth disease virus to differentiate infection from vaccination.this paper summarises the development of monoclonal antibody (mab)-based immunoassays measuring antibodies to non-structural proteins of fmdv to differentiate infection from vaccination. of the three non-structural proteins 2c, 3c and 3abc evaluated in this study, the polypeptide 3abc was the most immunogenic. three elisas for the detection of antibodies to 3abc were developed. two assays rely on the competition of test sera against either a anti-3a mab or against antisera to 3abc raised in rabb ...19989652058
influence of il-12 on interferon-gamma production by bovine leucocyte subsets in response to bovine respiratory syncytial virus.the cytokine il-12 is a key molecule in the regulation of cd4+ t cell development and specifically potentiates the development of t helper 1 responses in mouse and man. however the biological effects mediated by bovine il-12 have not been defined in cattle. to produce the expression of the two mature proteins a polyprotein approach was used. this system is employed by positive strand viruses and encodes both products from a single open reading frame (orf). the 2a region of foot-and-mouth disease ...19989656442
monoclonal antibodies, against o1 serotype foot-and-mouth disease virus, from a natural bovine host, recognize similar antigenic features to those defined by the mouse.eight neutralizing and two non-neutralizing anti-foot-and-mouth disease virus (fmdv) bovine igg1 and igg2 monoclonal antibodies (bmabs) recognize conformationally dependent epitopes. the majority of those shown to neutralize virus passively protected mice from virus challenge, regardless of isotype. well-characterized anti-fmdv mouse mabs, representing five independent neutralizing epitopes on o1 serotype virus, were examined with each of the ten bmabs in a competition-based elisa. five of the n ...19989680132
host factors affecting the homologous and heterologous immune response of cattle to fmdv: genetic background, age, virus strains and route of administration.sixty bulls were tested for antibodies to the heterologous serotype c1 of fmdv following repeatable vaccinations with a commercial trivalent vaccine (o1, a22, asia1). six (10%) bulls were found to possess rather high levels of heterologous neutralizing antibodies which showed accumulative trend with age. two high positive and two negative bulls for the heterologous serotype c1 were selected for progeny test involving ten daughters of each bull. the four bulls, either positive or negative for the ...19989607052
quantitation of foot-and-mouth disease virus genomes in bovine tissue by competitive rt-pcr.the sensitivity of a reverse transcription-dependent polymerase chain reaction (rt-pcr) for detecting foot-and-mouth disease virus (fmdv) genomes was quantified by use of rna transcribed in vitro from fmdv-specific cdna. previously, the cdna had been elongated by 228 base pairs. the minimum number of template molecules required to obtain the specific rt-pcr product was determined to be 10(4). this was achieved by use of 1 microg of primer for cdna synthesis and by undertaking of at least 30 cycl ...19989694331
protection of swine by live and inactivated vaccines prepared from a leader proteinase-deficient serotype a12 foot-and-mouth disease virus.previously, we demonstrated that a genetically engineered variant of foot-and-mouth disease virus (fmdv) serotype a12 lacking the leader proteinase-coding region (a12-llv2) was attenuated and induced an immune response that partially protected cattle from fmd. in this study, a12-llv2 was tested in swine as a live or chemically inactivated vaccine. animals vaccinated with chemically inactivated a12-llv2 or wild-type (wt) virus in oil adjuvant developed high levels of neutralizing antibodies and w ...19989711798
differentiating foot-and-mouth disease virus-infected from vaccinated animals with baculovirus-expressed specific proteins.we had shown in preliminary studies with a small number of animals that antibodies against 2c could be detected in cattle and pigs which had been infected with fmdv but not in animals which had been vaccinated against the disease. to determine whether this test was generally applicable, sera from several hundred animals which had been vaccinated with different products in many countries have been tested in an elisa using baculovirus expressed 2c. our results show that only 1-2% of the sera gave ...19989652055
genetic heterogeneity of indian field isolates of foot-and-mouth disease virus serotype o as revealed by partial sequencing of 1d gene.the sequence of 165 nucleotides at the 3' end of the 1d gene, determined from rt pcr amplified cdna fragments, of 25 type o strains isolated from different parts/regions of india during 1987 1995 and the vaccine strain (r2/75) currently in use in india were subjected to phylogenetic analysis. one isolate from the neighbouring country nepal was also included in the study. the virus/ field strains showed high degree of genetic heterogeneity among themselves with % divergence in nucleotide sequence ...19989725665
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