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At least 1,063 records · Page 59Linked to original sources
PubMed1995

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 achieved by passaging them in the presence of polyvalent immune serum. The absence of virus in cured cells was confirmed by infectivity assay and immunocytochemistry. This finding, together with the low percentage of infected cells in cultures confirms that persistently infected BHK-21 cells satisfy the definitions of a carrier culture. The characteristics of the in vitro system and its relevance to the study of FMD carrier state in vivo are discussed.

Animals↗
PubMed1994

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% homology with the P1 gene segment of type O1k. The deduced amino acid sequence shares 79% homology with that of the P1 region of serotype O1k.

Amino Acid Sequence↗
PubMed1988

Prediction of three-dimensional models for foot-and-mouth disease virus and hepatitis A virus.

Atomic models of foot-and-mouth disease virus and hepatitis A virus have been predicted using amino acid sequence alignments with the known structures of Mengo virus and human rhinovirus 14. The structural models are consistent with results of biochemical and immunological studies. The two viruses appear to have surface features exceedingly different than those of other picornaviruses. They also have large hydrophobic cavities within VP1 suggesting that it may be possible to inhibit their infectivity with suitably designed antiviral agents that block uncoating.

Amino Acid Sequence↗
PubMed1987

Safety and efficacy of foot-and-mouth disease vaccines containing endonuclease-inactivated virions.

Inactivation of foot-and-mouth disease virus (FMDV) by means of virion-associated endonuclease was found to be suited to the production of safe and potent vaccines, which proved to be equal or better than those containing formaldehyde or ethyleneimine in guinea-pig potency tests. First order inactivation kinetics were regularly shown, with half life values which varied according to the different temperatures used. Inactivation brought about extensive degradation of FMDV RNA, while it did not adversely influence the integrity of critical viral epitopes on FMDV VP1.

Animals↗
PubMed1988

Genetic and immunogenic variations among closely related isolates of foot-and-mouth disease virus.

Genetic heterogeneity among closely related isolates of foot-and-mouth disease virus (FMDV) has been measured by direct sequencing of the VP1-coding-region RNA for three new FMDVs of serotype C1 and by additional sequences of RNA from previously reported isolates, all belonging to a single episode of disease [Sobrino et al., Gene 50 (1986) 149-159]. In the ten viruses compared, eight different VP1 are represented. The changes include amino acid substitutions at a critical antigenic determinant of VP1. We document that variations present in such natural isolates result in changes of the immunogenic properties of the viruses. Vaccines prepared with two of the FMDV C1 analyzed induce complete protection against an homologous virus but only partial protection against an heterologous virus in swine, the host from which these viruses were isolated.

Animals↗
PubMed1999

Surface plasmon resonance screening of synthetic peptides mimicking the immunodominant region of C-S8c1 foot-and-mouth disease virus.

The main antigenic site (site A) of foot-and-mouth disease virus (FMDV, strain C-S8c1) may be adequately reproduced by a 15-peptide with the amino acid sequence H-YTASARGDLAHLTTT-NH(2) (A15), corresponding to the residues 136-150 of the viral protein VP1. The effect of amino acid substitutions within A15 on its antigenicity towards monoclonal antibodies (MAb) raised against antigenic site A, has been studied by means of BIAcore technology, based on surface plasmon resonance (SPR). Although these antigenicities have previously been determined from enzyme-linked immunosorbent assays (ELISA), the SPR-based technique is superior in that it allows a fast and straightforward screening of antigens while simultaneously providing kinetic data of the antigen-antibody interaction. With a view to screening fairly large libraries of individual peptides, we have inverted the typical SPR experiment by immobilizing the MAb on the sensor surface and using peptides as soluble analytes. We report the validation of this approach through the screening of 44 site A peptides, with results generally in good agreement with the relative antigenicities previously determined by competition ELISA.

Amino Acid Sequence↗
PubMed1978

Dose-response relationships in a microneutralization test for foot-and-mouth disease viruses.

Two-dimensional quantal microneutralization tests on foot-and-mouth disease viruses, in which neutralizing antibody activity was titrated against a serial range of virus doses, demonstrated a variety of dose-response curves some of which were rectilinear, others clearly curvilinear. Moreover, in the case of the non-linear responses obtained with some antisera, the shape of the curve was such that antibody titres recorded with doses of virus ranging from 10(3)-10(5) TCD50 were closely similar. Studies were carried out on the effect of varying the conditions of the test on the shape of the dose-response curve: significant differences were obtained after treatment of the antiserum-virus mixtures with anti-species globulin, and when the test was assayed in cells of differing susceptibility to infection.

Aphthovirus↗
PubMed1999

Characterization of the structural-protein-coding region of SAT 2 type foot-and-mouth disease virus.

The South African Territories (SAT) types of foot-and-mouth disease (FMD) virus show marked genomic and antigenic variation in sub-Saharan Africa that is to a large extent geographically determined. This has implications for selection of appropriate vaccine strains as well as the accuracy of laboratory diagnosis. However, adaptation of field isolates as vaccine strains is cumbersome, time consuming and expensive. We propose the construction of recombinant viruses in which specific antigenic determinants can be manipulated. To achieve this goal, the structural-protein-coding region of a SAT 2 vaccine strain, ZIM 7/83/2, was determined and compared with two other known SAT 2 P1 regions. Five hypervariable regions were identified of which four are situated within VP1. The cleavage sites for proteolytic processing differs from serotype A, while the junction between P1/2A is variable within the SAT 2 serotype. These differences could influence the construction of recombinant vaccines.

Amino Acid Sequence↗
PubMed1989

The three-dimensional structure of foot-and-mouth disease virus at 2.9 A resolution.

The structure of foot-and-mouth disease virus has been determined at close to atomic resolution by X-ray diffraction without experimental phase information. The virus shows similarities with other picornaviruses but also several unique features. The canyon or pit found in other picornaviruses is absent; this has important implications for cell attachment. The most immunogenic portion of the capsid, which acts as a potent peptide vaccine, forms a disordered protrusion on the virus surface.

Algorithms↗
PubMed1992

Identification and characterization of foot-and-mouth disease virus O1 Burgwedel/1987 as an intertypic recombinant.

The foot-and-mouth disease virus field isolate Burgwedel/1987 subtype O1 was found to differ genetically from the antigenically related strain O1 Kaufbeuren within the region encoding the non-structural proteins. This genetic difference was indicated by the RNase mismatch cleavage method and confirmed by nucleotide sequencing. An alignment of sequences encoding proteinase 3C of the Burgwedel isolate and several other virus strains identified this isolate as an intertypic recombinant; the parent strains were O1 Kaufbeuren and a subtype C1 strain. Recombination occurred between nucleotide positions 5493 and 5521, within the region encoding peptide 3B1. Thus, the 5' three-quarters of the O1 genome were fused to the 3'-terminal quarter of the C1 genome. Other contemporary isolates from the same district are not recombinants. Sequence alignment distinguished four patterns of proteinase 3C-coding sequences among the virus strains analysed: subtypes A12, C1 and O1 exhibit one pattern each, and another pattern is common to subtypes A5, A10 and O2.

Aphthovirus↗
PubMed2003

In vitro and in vivo studies of the Yrp1 protease from Yersinia ruckeri and its role in protective immunity against enteric red mouth disease of salmonids.

Yersinia ruckeri, the etiological agent of the enteric red mouth disease (ERM) of salmonids, produces Yrp1, a serralysin metalloprotease involved in pathogenesis. We describe here the hydrolytic and immunogenic properties of Yrp1. The protease was able to hydrolyze different matrix and muscle proteins as laminin, fibrinogen, gelatine, actin, and myosin but not type II and IV collagens. In addition, the Yrp1 protein, when inactivated by heat and used as an immunogen, was able to elicit a strong protection against the development of ERM. The analysis of different Y. ruckeri strains with (Azo+) or without (Azo-) Yrp1 activity showed that all of them contained the yrp1 operon. By using yrp1::lacZ operon fusions, protease production analysis, and complementation studies, it was possible to show that an Azo- strain was blocked at the transcription level. The transcriptional study of the yrp1 operon under different environmental conditions showed that it was regulated by osmolarity and temperature, without pH influence. Finally, when beta-galactosidase activity was used as a probe in vivo, the progression of the disease in the fish could be visualized, and the tropism of the bacterium and affected organs could be defined. This system opens a vast field of study not only with regard to fish disease progression but also in pathogen interactions, temporal gene expression, carrier stages, antibiotic resistance selection, etc.

Animals↗
PubMed1978

More precise location of the polycytidylic acid tract in foot and mouth disease virus RNA.

The polycytidylic acid [poly(C)] tract in foot and mouth disease virus RNA has been located about 400 nucleotides from the 5' end of the RNA by analysis of the products from the digestion of the RNA with RNase H in the presence of oligodeoxyguanylic acid [oligo(dG)]. This treatment produces a small fragment (S) containing the small protein covalently linked to the RNA and a large fragment (L) that migrates faster than untreated RNA on low-percentage polyacrylamide gels, lacks the poly(C) tract as shown by RNase T1 digestion and oligo(dG)-cellulose binding, and is no longer infective. Polyacrylamide gel electrophoresis of fragment S suggests that it is about 400 nucleotides long, in agreement with the size estimated from the proportion of radioactivity in the fragment. Analysis of the RNase T1 digestion products of S shows that it contains only those oligonucleotides mapping close to the poly(C) tract that is situated near the 5' end of the virus RNA.

Aphthovirus↗
PubMed1976

Effect of methyl glyoxal on infectivity and antigenicity of foot-and-mouth disease virus.

The inactivating effect of methyl glyoxal on foot-and-mouth disease (FMD) virus was studied. The rate of inactivation depended upon the drug concentration, incubation temperature and pH of the medium. RNA recovered from the inactivated virus was not infectious. The complement-fixing activity of the virus was not reduced by methyl glyoxal treatment. The antigenicity of inactivated virus preparations determined by levels of virus neutralizing antibody in the blood sera of immunized white rats and rabbits was not inferior to that of the initial uninactivated virus.

Aldehydes↗
PubMed1976

A foot-and-mouth disease vaccine for swine.

An inactivated vaccine containing purified foot-and-mouth disease virus type O1, strain Brugge, emulsified with incomplete Freund's adjuvant was studied in swine. The antigen mass ranged from 0.02 to 416 mug in 0.25 ml of vaccine. At 90 days postinoculation (DPI) 33 to 100% of the swine which had been inoculated with 0.72% mug or larger amounts of antigen were protected against challenge. There was little protection at 182 DPI although the neutralizing titers obtained with 2.9, 34.6 and 416 mug doses of antigen were similar to those observed at 90 DPI. The 50% protective dose for swine was approximately 2.3 mug of antigen whether used in a freshly prepared state or after storage at 4 degrees C for 105 or 259 days. Significant protection was afforded when small volumes (0.1 and 0.5 ml) of vaccine were applied with a jet injector gun to the ear or neck of swine. Initial tissue reactions at the site of inoculation were minimal with these small doses of vaccine and generally disappeared ny 90 DPI.

Animals↗
PubMed1990

cDNA-cloning and expression of VP1-specific sequences of foot-and-mouth disease virus types A5 and O1.

The RNA genome of foot- and mouth disease virus strains A5 Westerwald and O1 Lausanne has been reverse-transcribed and cloned in lambdaphages or plasmids. Identification of cDNA-clones containing VP1-specific sequences was achieved by hybridization, restriction mapping, and sequence analysis. VP1-coding cDNA-fragments were subcloned into the expression vector pEX which led to synthesis of fusion proteins with beta-galactosidase. These fusion proteins reacted with anti-VP1 antibodies on a Western blot, but were not capable of inducing neutralizing antibodies to mice. This seemed to suggest a tertiary structure of the VP1-epitopes unlike those of native VP1. Other attempts are discussed to construct VP1-fusion proteins folding similarly to the native viral protein structure.

Amino Acid Sequence↗
PubMed1980

The potential of recombination for the production of foot-and-mouth disease virus vaccine strains.

Biological proof of recombination in foot-and-mouth disease virus has been provided by studies on a large suite of conditional lethal mutants and a recombination map of approximately 70 mutations has been produced. However, recombination is a highly variable phenomenon and this has cast doubt on its validity and certainly on its applicability to such practical purposes as the production of good vaccine strains. Evidence is presented to demonstrate (1) that the genetic map has a good correlation with the biochemical map of polypeptide coding sequence for the genome and (2) that recombinants can be isolated bearing biochemical and biological markers from both parents. Finally, the analysis of 36 recombinants from a cross involving a cattle-attenuated and a cattle-virulent virus is described. These results have enabled us to identify the location of biological properties such as a mouse virulence and good growth in BHK cells on the genome of these two parent viruses.

Animals↗
PubMed1981

Observations and implications of proteolysis in preparations of foot-and-mouth disease virus.

The integrity of the VP1 protein of foot-and-mouth disease virus was assessed by polyacrylamide gel electrophoresis (following storage at 4 degrees C of conventional tissue culture preparations and concentrated preparations of the virus. There was little evidence of VP1 degradation in tissue culture filtrates whereas considerable degradation was observed throughout a range of different concentrates. The use of the proteolytic enzyme inhibitor 'Trasylol' appeared to inhibit VP1 degradation in some virus preparations. Vaccination experiments with guinea pigs indicate that cleavage of O BFS 1860 virus by a range of proteolytic enzymes was always associated with a lowered stimulation of neutralising antibody and total antibody. Experiments with six other strains treated with trypsin gave similar results to those obtained with O BFS 1860.

Aphthovirus↗