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
ultrastructural and replicative features of foot-and-mouth disease virus in persistently infected bhk-21 cells.persistent foot-and-mouth disease (fmd) virus infection in vitro has been studied in a chronically infected cloned bhk-21 cell line. virus growth during serial cell passages was followed by infectivity assay and immunocytochemical staining. only a small percentage of cells (0.006-6%) was found to harbour virus during persistence. light and electron microscopy showed the presence of cytoplasmic protuberances ("blebs") at the surface of persistently infected cells. the curing of cell cultures was ...19957646338
mapping of functional domains in eukaryotic protein synthesis initiation factor 4g (eif4g) with picornaviral proteases. implications for cap-dependent and cap-independent translational initiation.cap-dependent binding of mrna to the 40 s ribosomal subunit during translational initiation requires the association of eukaryotic initiation factor 4g (eif4g; formerly eif-4 gamma and p220) with other initiation factors, notably eif4e, eif4a, and eif3. infection of cells by picornaviruses results in proteolytic cleavage of eif4g and generation of a cap-independent translational state. rhinovirus 2a protease and foot-and-mouth-disease virus l protease were used to analyze the association of eif4 ...19957665619
enhanced immunogenicity and cross-reactivity of retro-inverso peptidomimetics of the major antigenic site of foot-and-mouth disease virus.retro-inverso analogues of peptides corresponding to the major antigenic site 141-159 of vp1 from two foot-and-mouth disease virus variants have been synthesized and tested for their antigenic and immunogenic properties. antibodies to the l- and retro-inverso peptides were produced by injecting rabbits with peptides covalently coupled to small unilamellar liposomes containing monophosphoryl lipid a as adjuvant. when compared to the antibody response raised against the l-peptides, the duration of ...19957670228
effect of cleavage of the p220 subunit of eukaryotic translation initiation factor eif-4f on protein synthesis in vitro. 19957672346
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
effect of expression of the aphthovirus protease 3c on viral infection and gene expression.cells transformed with specific regions of the foot-and-mouth disease virus (fmdv) genome have been constructed and analyzed with respect to viability and susceptibility to fmdv infection. constitutive expression of an active protease 3c under the control of the tk promoter has been documented by the ability of transformed cells to catalyze the processing of a p1 capsid precursor. high-level, transient expression but not low-level, constitutive expression, of 3c caused a 10-fold reduction in the ...19957676620
topology of phoe porin: the 'eyelet' region.a model for the topology of the phoe porin has been proposed according to which the polypeptide traverses the outer membrane sixteen times mostly as amphipathic beta-sheets, thereby exposing eight loops at the cell surface. until now, no evidence has been obtained for the surface exposure of the third loop. recently, the structure of porin of rhodobacter capsulatus has been determined. the proposed model of phoe is very similar to the structure of the r. capsulatus porin, which has an 'eyelet' r ...19937679770
amino acid changes outside the g-h loop of capsid protein vp1 of type o foot-and-mouth disease virus confer resistance to neutralization by antipeptide g-h serum.antiserum to a peptide corresponding to the 135-154 sequence of capsid protein vp1 of the foot-and-mouth disease virus o1 kaufbeuren was raised in a pig. although this serum contained neutralizing antibodies, the pig showed clinical symptoms after challenge. virus isolated from this pig was identified as a mutant, with changes at positions 50, 198 and 211 of vp1 and at position 209 of vp2. this mutant, as well as a plaque isolate of it, differing from the challenge virus at positions 198 on vp1 ...19937680514
genotypic and phenotypic changes of bhk-21 cells grown in suspension cultures.the propagation of foot-and-mouth disease virus on bhk-21 suspension cells, although economically convenient, may yield a scarcely immunizing antigen. helpful insights were obtained by investigating a few genotypic and phenotypic features of the cell cultures. the appearance of polyploid populations, higher cell concentrations at the end of culturing, the progressive reduction of spreading on surfaces and an abnormal expression of the alpha 5 beta 1 integrin were found to be correlated with the ...19937686770
cyclic disulfide model of the major antigenic site of serotype-c foot-and-mouth disease virus. synthetic, conformational and immunochemical studies.a cyclic disulfide peptide representing antigenic site a of foot-and-mouth disease virus (fmdv) strain c-s8c1 (residues 134 to 155 of viral protein 1 (vp1) with tyr136 and arg153 replaced by cystine; ttctasargdlahlttthachl) was synthesized by solid phase methods. formation of the cyclic disulfide was carried out by air oxidation of the fully deprotected and reduced bis-cysteine precursor, under high dilution conditions. the identity of the cyclic peptide was confirmed by both physical and enzyma ...19937688321
use of the enterobacterial outer membrane protein phoe in the development of new vaccines and dna probes.phoe protein is a major outer membrane protein of escherichia coli. the polypeptide spans the membrane 16 times, thereby exposing 8 regions at the cell surface. insertions in these regions did not affect the biogenesis of the protein. therefore, we considered the possibility of using phoe as a vector for the exposure of foreign antigenic determinants at the cell surface, with the ultimate goal of constructing new (live oral) vaccines. via recombinant dna techniques, b-cell epitopes of vp1 protei ...19937688607
distinct repertoire of antigenic variants of foot-and-mouth disease virus in the presence or absence of immune selection.antigenic variants of foot-and-mouth disease virus (fmdv) were generated and frequently became dominant in clonal populations of fmdv (clone c-s8c1) grown in the absence of anti-fmdv antibodies. we have now passaged eight samples of the same fmdv clone in the presence of a limited amount of neutralizing polyclonal antibodies directed to the major antigenic site a of capsid protein vp1. complex populations of variants showing increased resistance to polyclonal sera and to site a-specific monoclon ...19937690417
use of substituted and tandem-repeated peptides to probe the relevance of the highly conserved rgd tripeptide in the immune response against foot-and-mouth disease virus.antigenic site a of foot-and-mouth disease virus (fmdv) is an exposed, mobile loop which includes a central, highly conserved arg-gly-asp tripeptide (rgd, vp1 residues 141-143 in serotype c) thought to be part of the cell attachment site. we have analyzed the contribution of rgd to the interaction of site a with antibodies by incorporating selected amino acid replacements at rgd into synthetic peptides representing site a, and analyzing the reactivity of substituted peptides with site a-specific ...19937690714
the use of monoclonal antibodies in the molecular typing of animal viruses.monoclonal antibodies (mabs) are biological reagents which have a definite structure. they identify epitopes with total specificity. such specificity is based on the exact physico-chemical structure of antigens. thus mabs provide a unique link between chemical structure and antigenic properties and can give great insight into the functional properties of biological agents. the author describes a number of applications of mabs in the characterisation of foot and mouth disease viruses for diagnost ...19937691272
characterization of monoclonal antibodies against a type sat 2 foot-and-mouth disease virus.this paper is the first to describe characterization of monoclonal antibodies (mabs) against a south african territories 2 (sat 2) foot-and-mouth disease virus (isolate rho 1/48). twelve mabs which neutralized homologous virus were characterized in indirect and sandwich elisa using purified rho 1/48 virus particles, subunits, trypsin-treated, and chemically denatured virus. all the mabs inhibited haemagglutination by parental virus. binding of the mabs to 73 sat 2 field isolates was measured in ...19937691630
new observations on antigenic diversification of rna viruses. antigenic variation is not dependent on immune selection.recent results have revealed novel features in the process of antigenic diversification of fmdv. (i) antigenic variation is not necessarily the result of immune selection. (ii) single, critical amino acid replacements may either have a minor effect on antigenic specificity or cause a drastic antigenic change affecting many epitopes on an antigenic site. (iii) the effect of such a critical replacement may be suppressed by additional substitutions at neighbouring sites. (iv) antigenic diversificat ...19937691985
expression of an animal virus antigenic site on the surface of a plant virus investigate if cowpea mosaic virus (cpmv) particles can be used to express foreign protein sequences, oligonucleotides encoding an epitope derived from vp1 of foot-and-mouth disease virus (fmdv) were cloned into the region of the cpmv genome encoding the small (s) coat protein. the chimeras were designed so that the foreign sequence was expressed either as an insertion or as a replacement for part of the wild-type sequence. while rna from both chimeras was able to replicate in cowpea protopla ...19937692669
new virus-specific t-helper epitopes of foot-and-mouth disease viral vp1 protein.immunogenicity studies of synthetic peptides from different regions of vp1 protein of foot-and-mouth disease virus strain a22 revealed the following active fragments: 39-61, 50-69, 135-159, 175-189, 170-189 and 197-213. testing of virus neutralizing antibody production in rabbits primed by peptides and then inoculated by the virus showed that only peptides 135-159 and 170-189 were able to induce the functional t-cell helper activity. localization of virus-specific t-cell recognition sites in seq ...19937693508
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
interaction of eukaryotic initiation factor eif-4b with a picornavirus internal translation initiation site.we studied the interaction of cellular proteins with the internal ribosome entry site (ires) of foot-and-mouth disease virus by uv cross-linking and observed specific binding of a 80-kda protein contained in cytosolic hela cell extract and in rabbit reticulocyte lysate. binding of the protein was dependent on the presence of atp. immunoprecipitation with eif-4b antiserum revealed that the protein is identical to the initiation factor eif-4b. deletions in the 3' part, but not in the 5' part, of t ...19957707504
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
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
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 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
cleavage of transcripts of foot and mouth disease virus (fmdv), asia1 serotype, by ribozymes targeted to the vp3 and vp4 genes.two ribozyme genes were designed to cut within the vp4 and vp3 sequences of foot and mouth disease virus (fmdv) asia1 serotype genome. the two genes were synthesized and cloned into pbluescript under the control of the t3 promoter. the ribozyme designed to cut the vp4 gene contained two catalytic sequences targeted to two guc triplets that are 16 bases apart. the second ribozyme, intended to cut vp3, contained one catalytic sequence. ribozymes obtained from run-off transcription from both plasmi ...19957732660
foot-and-mouth disease virus lb proteinase can stimulate rhinovirus and enterovirus ires-driven translation and cleave several proteins of cellular and viral origin.rhinovirus and enterovirus 2a proteinases stimulate translation initiation driven from the cognate internal ribosome entry segment (ires) (s. j. hambidge and p. sarnow, proc. natl. acad. sci. usa 89:10272-10276, 1992; h.-d. liebig, e. ziegler, r. yan, k. hartmuth, h. klump, h. kowalski, d. blaas, w. sommergruber, l. frasel, b. lamphear, r. rhoads, e. kuechler, and t. skern, biochemistry 32:7581-7588, 1993). given the functional similarities between the foot-and-mouth disease virus (fmdv) l prote ...19957745693
large deletions in the 5'-untranslated region of foot-and-mouth disease virus of serotype c.nucleotide sequences of the 5'-untranslated region (5'-utr), at the 3'-side of the poly c tract, have been compared for 21 isolates of foot-and-mouth disease virus (fmdv) of serotype c from europe, south america and the philippines. a deletion of 43 nucleotides is present in the european isolates as compared with most american isolates. a larger deletion of 86 nucleotides is present in some viruses from south america and the philippines. these deletions include the loss of one or two pseudoknot ...19957762289
uses of beta-galactosidase tag in on-line monitoring production of fusion proteins and gene expression in escherichia coli.a simple method for monitoring and quantifying automatically the production by fermentation of beta-galactosidase fusion proteins, making use of the remaining activity of the beta-galactosidase part, is considered. a hybrid protein carrying the major antigenic domain of foot-and-mouth disease virus c1 joined at the n-terminus of beta-galactosidase has been expressed in escherichia coli. the yield of the chimeric protein has been monitored by flow injection analysis (fia) during batch fermentatio ...19937764038
enhanced production of pl-controlled recombinant proteins and plasmid stability in escherichia coli reca+ strains.overexpression of pl-controlled foot-and-mouth disease virus recombinant proteins was studied in escherichia coli reca+ strains and in a reca mutant. higher protein yield and extractable plasmid dna amounts were found in wild type cells, in absence of detectable reca proteolytic activity. minor but still significant differences in pbr322 dna amounts were also detected between reca+ and its reca13 and lexa1 derivatives. these data should be seriously considered to select expression systems and to ...19937764065
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
neutralizing activity in bovine secretions against foot-and-mouth disease virus. 19957779950
african swine fever interference with foot-and-mouth disease infection and seroconversion in pigs.initial oral infection of pigs with either highly virulent (l-60) or moderately virulent (dr-2) african swine fever virus (asfv), followed in 3 days with exposure to foot-and-mouth disease virus (fmdv) (tongue inoculation and contact), failed to cause fmdv infection or seroconversion in 18 of 22 l-60-infected pigs and 13 of 34 dr-2-infected pigs. of the 13 dr-2-infected pigs remaining free of foot-and-mouth disease (fmd), 2 pigs survived to 24 days without antibody to fmdv, despite constant cont ...19957779962
african swine fever virus infection of skin-derived dendritic cells in vitro causes interference with subsequent foot-and-mouth disease virus infection.highly purified skin-derived dendritic cells (sddcs) isolated from swine skin by a simple novel method were cultured for 24 hours before independent or sequential inoculation with african swine fever virus (asfv) and foot-and-mouth disease virus (fmdv). by avidin-biotin immunohistochemical staining, asfv antigen was detected in 50% of sddcs as early as 1.5 hours postinfection (hpi) and in 80% by 3 hpi when cytopathic effect was noted. cell lysis was detected with fmdv infection as early as 8 hpi ...19957779963
detection and subtyping of foot-and-mouth disease virus in infected cattle by polymerase chain reaction and amplified vp1 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
expression in escherichia coli and purification of biologically active l proteinase of foot-and-mouth disease virus.the foot-and-mouth disease virus (fmdv) lb gene was cloned into bacterial expression vectors under the control of a t7 rna polymerase promoter. the lb protein was expressed in both an in vitro transcription-translation system and in escherichia coli. in vitro expression of a construct containing the lb gene fused to a portion of the vp4 and 3d genes demonstrated cis cleavage activity that could be blocked by the thiol protease inhibitor e-64. lb expressed in e. coli was purified from the soluble ...19957785315
antibodies raised in a natural host and monoclonal antibodies recognize similar antigenic features of foot-and-mouth disease virus.swine polyclonal antibodies directed against a major antigenic site (site a) of foot-and-mouth disease virus (fmdv) of serotype c, and monoclonal antibodies (mabs) which recognize different epitopes within this site, have been compared with regard to reactivity with a panel of synthetic peptides. the peptides used represent different segments or variant sequences of site a, and their reactivities reflect differences in antigenic specificity. the results indicate a remarkable immunochemical simil ...19957793064
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
ompa fusion proteins for presentation of foreign antigens on the bacterial outer membrane.the ompa genes of escherichia coli and shigella dysenteriae have been used to construct a group of enterobacterial surface expression vectors for foreign genes. linker oligonucleotides were inserted into the sequence corresponding to the third or fourth outer domain to allow in-frame sandwich fusion of foreign genes or epitopes into ompa. influenza haemagglutinin was inserted without its leader peptide and anchor sequences and shown to be transferred as an ompa fusion protein to the bacterial su ...19957796962
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
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
direct evaluation of the immunodominance of a major antigenic site of foot-and-mouth disease virus in a natural host.the immunodominance of a major antigenic site of foot-to-mouth disease virus (fmdv) (serotype c; clone c-s8c1) in a natural host has been evaluated by serum immunoglobulin fractionation. nineteen sera from either convalescent or vaccinated swine were fractionated by affinity chromatography using a synthetic peptide representing antigenic site a (the g-h loop of capsid protein vp1) coupled to a sepharose matrix. antigen-binding and neutralizing activities of serum fractions were quantitated. on a ...19957831785
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
genetic variation of foot-and-mouth disease virus during persistent infection in cattle.genetic variation of foot-and-mouth disease virus o1 campos has been analyzed in consecutive isolates recovered over a one- or two-year period from four cattle with experimental persistent infection. comparisons of rnase t1 two-dimensional maps and nucleotide sequences of the vp1-coding region revealed a continual, although irregular, increase in the fixation of mutations as the infection progressed. most changes were not conserved in consecutive isolates. these results, together with the substa ...19947831963
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
validation of an inhibition elisa using a monoclonal antibody for foot-and-mouth disease (fmd) primary inhibition elisa (ih-elisa) test for foot-and-mouth disease virus (fmdv) was validated using 106 epithelial samples from suspected cases of fmd in argentina submitted to the argentine national diagnostics laboratory (gelab) over a period of 12 months and examined in parallel with the complement fixation test (cft). ih-elisa was found to be more sensitive, detecting 25% (26 samples) more fmdv positives than the cft in original suspensions of field samples. the effect of storage conditions on 1 ...19947839753
a review of the possible mechanisms for the persistence of foot-and-mouth disease virus. 19957867727
genome variation in the sat types of foot-and-mouth disease viruses prevalent in buffalo (syncerus caffer) in the kruger national park and other regions of southern africa, 1986-93.dideoxy nucleotide sequencing of a portion of the 1d gene of sat-type foot-and-mouth disease viruses (fmdv) was used to derive phylogenetic relationships between viruses recovered from the oesophageo-pharyngeal secretions of buffalo in the kruger national park as well as several other wildlife areas in southern africa. the three serotypes differed from one another by more than 40% while intratypic variation did not exceed 29%. within each type, isolates from particular countries were more closel ...19957867739
proteolytic cleavage of initiation factor eif-4 gamma in the reticulocyte lysate inhibits translation of capped mrnas but enhances that of uncapped mrnas.infection of cells with the foot-and-mouth-disease virus, a member of the picornavirus family, results in the shut-off of host protein synthesis. a major contributory mechanism is the proteolytic destruction of the gamma subunit of the complex eif-4, which functions in translation to promote the binding of the 43s ribosomal preinitiation complex to the 5' end of the cellular mrna molecules bearing a 5' terminal cap structure. picornavirus rna molecules, which are uncapped, use a distinct mechani ...19957885827
foot-and-mouth disease virus undergoes restricted replication in macrophage cell cultures following fc receptor-mediated adsorption.we have previously reported that foot-and-mouth disease virus (fmdv) can enter an fc receptor (fcr)-expressing cell line by antibody-dependent enhancement. since fmdv can establish a persistent infection in animals in the presence of high levels of neutralizing antibodies (carrier state), we examined macrophages for their ability to be infected by the virus in the presence of antibody. the murine macrophage cell line p388d1 or porcine macrophage-monocytes isolated from peripheral blood were incu ...19957886954
function of minor polypeptides in foot-and-mouth disease virus and poliovirus.foot-and-mouth disease virus and poliovirus each contain several minor polypeptides, in addition to the four structural proteins. one of these, the viral rna polymerase, can also act as a nuclease, hydrolysing the rna and thus destroying viral infectivity. it is tightly bound to the rna and may be the packaging signal for assembly of the particle.19947889327
t-lymphocyte responses in guinea pigs vaccinated with foot-and-mouth disease virus.the guinea pig provides an alternative experimental model for analysis of the immune response against foot-and-mouth disease virus (fmdv). the cellular immune response against fmdv in this experimental animal is unknown and was analyzed by in vivo and in vitro studies. in guinea pigs immunized with an fmdv a5 vaccine, a marked change in t-lymphocyte count appeared. for analyzing which functional t-cell compartment was affected, immunofluorescence studies, using monoclonal antibodies directed aga ...19947909182
specific inhibition of aphthovirus infection by rnas transcribed from both the 5' and the 3' noncoding regions.rna molecules containing the 3' terminal region of foot-and-mouth disease virus (fmdv) rna in both antisense and sense orientations were able to inhibit viral fmdv translation and infective particle formation in bhk-21 cells following comicroinjection or cotransfection with infectious viral rna. antisense, but not sense, transcripts from the 5' noncoding region including the proximal element of the internal ribosome entry site and the two functional initiation augs were also inhibitory, both in ...19947933126
construction and use of integrative vectors to express foreign genes in mycobacteria.we have constructed a mycobacterial integrative vector by placing two copies of the insertion sequence is900 flanking a kanamycin-resistance gene into a 'suicide' vector unable to replicate in mycobacteria. the mycobacterium leprae gene encoding the m. leprae 18 kda protein was cloned between the two copies of is900 to provide expression signals. constructs were introduced into mycobacterium species smegmatis, vaccae and bovis bcg by electroporation and selection for kanamycin resistance. the ex ...19937934874
use of combined shewhart-cusum control charts in internal quality control of enzyme-linked immunosorbent assays for the typing of foot and mouth disease virus enzyme-linked immunosorbent assay (elisa) for the typing of foot and mouth disease virus (fmdv) antigen was employed for the routine laboratory diagnosis of fmd at a regional veterinary laboratory in northern thailand. an objective procedure was developed to monitor the test performance of the elisa, using absolute test control limits in a shewhart-cusum (cumulative sum) control chart method. the procedure detected significant data trends and 'beyond control limit' situations for each antigen ...19947949345
establishment of a typing enzyme-linked immunosorbent assay for foot and mouth disease antigen, using reagents against viruses endemic in thailand.antisera were produced at a central laboratory in thailand against the endemic serotypes (o, a and asia 1) of foot and mouth disease (fmd) virus. at a regional veterinary laboratory, these antisera were used in an indirect sandwich enzyme-linked immunosorbent assay (elisa) for the detection and serotyping of fmd virus (fmdv) antigen. elisa readings of < 0.10 optical density (od) units were considered negative. this was verified using fifty tissue samples which were known to be negative for fmdv. ...19947949346
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
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
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
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
viral rna modulates the acid sensitivity of foot-and-mouth disease virus capsids.foot-and-mouth disease virus (fmdv) manifests an extreme sensitivity to acid, which is thought to be important for entry of the rna genome into the cell. we have compared the low-ph-induced disassembly in vitro of virions and natural empty capsids of three subtypes of serotype a fmdv by enzyme-linked immunosorbent assay and sucrose gradient sedimentation analysis. for all three subtypes (a22 iraq 24/64, a10(61), and a24 cruzeiro), the empty capsid was more stable by 0.5 ph unit on average than t ...19957983739
functional analysis of the two alternative translation initiation sites of foot-and-mouth disease virus.the effect of deletion of each of the two authentic polyprotein translation initiation sites of foot-and-mouth disease virus on viral protein synthesis and replication was analyzed. deletion of either the first or the second initiation site led to the expression of only one form of the leader protein, l or l', respectively, but in vitro processing of the viral polyprotein and cleavage of eif-4 gamma were not affected by either deletion. whereas rna in which the first translation initiation site ...19957983755
effect of adjuvant formulations on the induction of virus-neutralizing and virus-binding antibodies by chemosynthetic peptides of vp1 of foot-and-mouth-disease virus.synthetic peptides corresponding to the 141-160 amino acid sequence of the protein vp1 of virus type o1 kaufbeuren (o1k) and a5 riems (a5r) were conjugated to thyroglobulin and mixed with complete freund's adjuvant (cfa) or incomplete freund's adjuvant (ifa) together with quil a. although the peptide of a5r, together with ifa and quil a, or with cfa, elicited a high antibody response to the virus in the elisa, formula containing both ifa and quil a induced only high titres of virus-neutralizing ...19947985430
insertion of a 27 amino acid viral peptide in different zones of escherichia coli beta-galactosidase: effects on the enzyme internal, putatively exposed regions of escherichia coli beta-galactosidase have been explored regarding their tolerance to insertions of large foreign peptides. small sequence modifications, including amino acid substitutions and small deletions, were introduced into the lacz gene to generate unique bamhi restriction sites. by using these mutant genes, a 27 amino acid stretch reproducing the hypervariable loop of foot-and-mouth disease virus vp1 protein (site a) was further inserted in pr ...19947988875
immunogenicity of non-structural proteins of foot-and-mouth disease virus: differences between infected and vaccinated swine.non-structural as well as vp1 recombinant proteins of foot-and-mouth disease virus (fmdv) produced in e. coli, have been used to study the specific antibody response of infected or vaccinated swine. an analysis of sera from infected pigs, using a direct elisa, showed that polypeptide 3abc (spanning non-structural proteins 3a, 3b and 3c) was the most antigenic among the recombinant proteins studied and allowed specific detection of fmdv infected swine from the second week after the infection. the ...19948002780
[synthesis of new fragments of vp1 protein fragments from foot and mouth disease virus type a22. synthesis of fragments 134-139, 134-145, 140-145, 150-155, and 150-159].fragments 134-145 and 150-159 of the antigenic-region of the vp1 protein of the a22 foot-and-mouth disease virus were synthesized by classic methods of peptide chemistry with isobutyl chloroformate as a coupling reagent. after purification by hplg and amino acid analysis, the free peptides h-gly-lys-tyr-ser-ala-gly-gly-leu-gly-arg-arg-gly-oh and h-leu-ala-ala-arg-val-ala-lys-gln-leu-pro-oh were conjugated with bsa by means of n,n-dicyclohexylcarbodiimide. the conjugates were used, with complete ...19948003043
efficient use of lactose for the lac promoter-controlled overexpression of the main antigenic protein of the foot and mouth disease virus in escherichia coli under fed-batch fermentation conditions.derivatives of the lac promoter (tac, pac, rac) belong to the strongest bacterial promoters which are frequently used for the induced overexpression of foreign genes in escherichia coli. however, their use in fermentation processes is strongly restricted because of the high cost of the inducer iso-propyl-beta-d-thiogalactopyranoside (iptg). the aim of this work was to investigate the possibility of using lac-derived promoters in high cell density processes resulting in a high yield of the induce ...19948011364
development of cowpea mosaic virus as a high-yielding system for the presentation of foreign has recently been shown that cowpea plants can be infected with a cowpea mosaic virus (cpmv) chimera containing an antigenic site from foot-and-mouth disease virus (usha et al., virology 197, 366-374, 1993). analysis of progeny rna produced during such an infection has revealed that the inserted sequence is rapidly lost during serial passaging, probably by a process of homologous recombination. using the information gained from this analysis, we have redesigned the chimeras in such a way that ...19948030255
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
the structure of an immunodominant loop on foot and mouth disease virus, serotype o1, determined under reducing conditions.residues 136-159 of vpi of foot and mouth disease virus (fmdv) comprise the g-h loop of the protein and form a prominent feature on the surface of virus particles. this sequence contains an immunodominant neutralizing epitope, which can be mimicked with synthetic peptides, and includes an arg, gly, asp motif which has been implicated in the binding of the virus to cellular receptors. crystallographic analysis of native virus particles failed to resolve the structure of this region due to its dis ...19948032279
comparison of liquid-phase and mab-blocking elisa for assessment of the reactivity of monoclonal antibodies to foot-and-mouth disease virus. 19948034975
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
ompa-fmdv vp1 fusion proteins: production, cell surface exposure and immune responses to the major antigenic domain of foot-and-mouth disease virus.exposure at the bacterial outer surface of the major antigenic epitope of the foot-and-mouth disease (fmdv) viral protein vp1 was studied using protein fusion with outer membrane protein a (ompa) of shigella dysenteriae for production and transport of the foreign polypeptide to the outer membrane of escherichia coli. fusion constructs with vp1 peptide insertions of up to 56 amino acids in the third outer domain of ompa could be demonstrated on the bacterial surface by indirect immunofluorescence ...19948036821
modelling the spread of foot-and-mouth disease virus.foot-and-mouth disease is an economically important viral disease in animals. it is shown that airborne diffusion is one of the main sources of contamination between animals and between herds. epidemiological data linked to viral particle excretion can thus be used in a predictive model, added to meteorological data related to the few days before the slaughter of animals. the model computes, on a 10 km radius around the outbreak and in every space direction, the quantity of viral particles that ...19948038801
a comparative study of serological and biochemical methods for strain differentiation of foot-and-mouth disease type a viruses.three serological and three biochemical methods were used to compare five field isolates of foot-and-mouth disease virus (fmdv) from western india with nine reference vaccine strains and five field isolates from other countries. the serological tests (liquid-phase elisa and virus neutralization) were able to distinguish between the three reference vaccine strains examined, but the five indian field isolates reacted poorly with antisera produced against these vaccine strains. analysis of monoclon ...19948042276
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
foot-and-mouth disease virus leader proteinase: purification of the lb form and determination of its cleavage site on eif-4 gamma.many picornaviruses cause a dramatic decrease in the translation of cellular mrnas in the infected cell, without affecting the translation of their own rna. specific proteolysis of protein synthesis initiation factor eif-4 gamma occurs during infection with rhinoviruses, enteroviruses, and aphthoviruses, apparently leading to an inability of the ribosomes to bind capped mrnas. cleavage of eif-4 gamma in human rhinoviruses and enteroviruses is carried out by the viral 2a proteinase; in aphthoviru ...19948057448
dituftsin and polytuftsin induce an anti-peptide igg response to non-immunogenic peptides in mice.the effect of covalently attaching multiple forms of the immunomodulating tetrapeptide tuftsin to normally non-immunogenic peptides was studied in balb/c and c57bl/6 mice. the peptides: (nanp)3 from the plasmodium falciparum circumsporozoite protein and peptides 136-152 and 205-213 derived from the capsid protein of foot-and-mouth disease virus were coupled to polytuftsin or dituftsin. anti-peptide igg titers were determined after two immunizations. all of these three non-immunogenic peptides co ...19948070848
direct pcr detection of foot-and-mouth disease virus.a pcr assay for the detection and characterization of foot-and-mouth disease virus was developed. the procedure allows rt-pcr amplification following direct adsorption of viral suspensions to microtiter plates, avoiding previous steps of phenol-extraction or heating. using this procedure, fmdv-specific (based on 3d gene sequences), as well as serotype-specific (based on vp1 gene sequences) amplification were achieved for viral samples of serotypes a, o and c, either from cell culture supernatant ...19948071421
sequence of the s fragment of foot-and-mouth disease virus type a12.the foot-and-mouth disease virus (fmdv) genome contains a 5' untranslated region (s fragment) capable of forming a stem-loop structure of over 350 bases, which is separated from the remainder of the genome by a homopolymeric cytidylic acid tract (poly(c)) of variable length. the sequence of the s fragment of serotype a12 appears more similar to those of type o1 or type c3 than to subtype a10. the relatively large difference between the s fragment sequences of two type a viruses suggests that the ...19948073639
circular dichroism, molecular modeling, and serology indicate that the structural basis of antigenic variation in foot-and-mouth disease virus is alpha-helix antigenic variants obtained from a single field isolate of foot-and-mouth disease virus, serotype a12, differ only at residues 148 and 153 in the immunodominant loop of viral protein vp1. synthetic peptides corresponding to the region 141-160 are highly immunogenic. uv circular dichroism shows that (i) in aqueous solution the peptides are nearly identical, but in 100% trifluoroethanol they display helix-forming properties which correlate well with their serological crossreactivities for an ...19948078900
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
the structure and antigenicity of a type c foot-and-mouth disease virus.picornaviruses are responsible for a wide range of mammalian diseases and, in common with other rna viruses, show considerable antigenic variation. foot-and-mouth disease viruses (fmdvs) constitute one genus of the picornavirus family and are classified into seven serotypes, each of which shows considerable intratypic variation. this antigenic variation leads to continuing difficulties in controlling the disease. to date the structure of only one serotype, o, has been reported.19948081743
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
experiments on an early protection against foot-and-mouth disease virus.the influence of the peptide diacetylsplenopentin (sp5) on an early protection of guinea pigs against foot-and-mouth disease (fmd) was investigated. 80% protection was achieved if sp5 was applied in a dose of 2 mg one day before challenge with fmd virus (fmdv) type o1 lausanne strain. in comparison with this a conventional commercial adsorbate vaccine protected guinea pigs about 7 days after vaccination. an earlier protection can be obtained in general by vaccination with a higher content of the ...19938105663
antigenic heterogeneity of a foot-and-mouth disease virus serotype in the field is mediated by very limited sequence variation at several antigenic sites.antigenic variation in a major discontinuous site (site d) of foot-and-mouth disease virus (fmdv) of serotype c has been evaluated with neutralizing monoclonal antibodies. isolates representing the major evolutionary sublines previously defined for serotype c were compared. extensive variation, comparable to that of continuous epitopes within the hypervariable immunodominant site a (the vp1 g-h loop), was found. the amino acid sequences of the complete capsids of three antigenically highly diver ...19948107204
foot-and-mouth disease virus 2a oligopeptide mediated cleavage of an artificial polyprotein.we describe the construction of a plasmid (pcat2agus) encoding a polyprotein in which a 19 amino acid sequence spanning the 2a region of the foot-and-mouth disease virus (fmdv) polyprotein was inserted between the reporter genes chloramphenicol acetyl transferase (cat) and beta-glucuronidase (gus) maintaining a single, long open reading frame. analysis of translation reactions programmed by this construct showed that the inserted fmdv sequence functioned in a manner similar to that observed in f ...19948112307
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
rgd sequence of foot-and-mouth disease virus is essential for infecting cells via the natural receptor but can be bypassed by an antibody-dependent enhancement pathway.foot-and-mouth disease virus appears to initiate infection by binding to cells at an arg-gly-asp (rgd) sequence found in the flexible beta g-beta h loop of the viral capsid protein vp1. the role of the rgd sequence in attachment of virus to cells was tested by using synthetic full-length viral rnas mutated within or near the rgd sequence. baby hamster kidney (bhk) cells transfected with three different rnas carrying mutations bordering the rgd sequence produced infectious viruses with wild-type ...19948127909
a rapid and sensitive chemiluminescence dot-immunobinding assay for screening hybridoma supernatants.the present report describes a simple and rapid dot-immunobinding assay combined with a chemiluminescence detection system for screening hybridoma supernatants for specific monoclonal antibodies (mabs). small rectangular nitrocellulose filters dotted with either crude mixtures of antigens, or with control samples, were placed in six well plates, incubated with hybridoma supernatants, then stained with peroxidase-conjugated anti-mouse igg. the reaction was performed with a chemiluminescence detec ...19948157996
crystallization and preliminary x-ray diffraction studies of a monoclonal antibody fab fragment against foot-and-mouth disease virus and of its complex with the main antigenic site peptide.the fab fragment of the neutralizing monoclonal antibody sd6 elicited against foot-and-mouth disease virus (fmdv) c-s8c1 and its complex with a peptide, corresponding to the major antigenic site of fmdv (vp1 residues 136-150, ytasargdlahlttt), have been crystallized using the hanging drop vapor diffusion techniques. for the isolated fab, crystals diffracting to 2.5 a resolution were obtained at room temperature using ammonium sulfate as precipitant. these crystals are monoclinic, space group c2, ...19948159669
picornaviral 3c cysteine proteinases have a fold similar to chymotrypsin-like serine proteinases.the picornavirus family includes several pathogens such as poliovirus, rhinovirus (the major cause of the common cold), hepatitis a virus and the foot-and-mouth disease virus. picornaviral proteins are expressed by direct translation of the genomic rna into a single, large polyprotein precursor. proteolysis of the viral polyprotein into the mature proteins is assured by the viral 3c enzymes, which are cysteine proteinases. here we report the x-ray crystal structure at 2.3 a resolution of the 3c ...19948164744
rapid cell variation can determine the establishment of a persistent viral infection.evidence for a mechanism of initiation of viral persistence in which the cell, and not the virus, plays a critical role has been obtained using the important animal pathogen foot-and-mouth disease virus (fmdv). we have developed a virulence assay consisting of quantification of the ability of virus to kill cells and of cells to divide in the presence of virus and to initiate a carrier state. cells were cured of fmdv at early times following a cytolytic infection of bhk-21 monolayers with fmdv. w ...19948170973
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 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
antibody response to 146s particle, 12s protein subunit and isolated vp1 polypeptide of foot-and-mouth disease virus type asia-1.the antibody response to foot-and-mouth disease virus (fmdv) antigens of type asia-1 in guinea-pigs was studied by micro-serum neutralization test (msnt) and enzyme-linked immunosorbent assay (elisa). one inoculation of as little as 1 microgram of binary ethyleneimine (bei)-inactivated 146s virus particles in guinea-pigs elicited enough neutralizing antibodies to protect them against challenge with virulent virus. however, one inoculation of live 146s virus particles elicited higher levels of ne ...19948203119
expression of a foreign protein by influenza a this report we describe the rescue of a transfectant influenza a virus which stably expresses a heterologous protein, bacterial chloramphenicol acetyltransferase (cat). the foreign sequences encoding cat are expressed as part of an essential influenza virus segment, that coding for the neuraminidase (na) protein. the novel way by which this was achieved involved inserting in frame the 16-amino-acid self-cleaving 2a protease of foot-and-mouth disease virus between the cat and the na coding seq ...19948207822
characterization of the foot-and-mouth disease virus 3c protease expressed in escherichia coli.we have constructed a clone encoding the foot-and-mouth disease virus (fmdv) 3c protease gene (p3c) using the polymerase chain reaction. the construct was engineered to contain initiation and termination codons and cloned into a plasmid under the control of the bacteriophage t7 promoter. the p3c gene was expressed both in an in vitro transcription-translation system and in vivo in an escherichia coli system containing an inducible t7 rna polymerase gene. in both systems the expressed products we ...19938212567
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