Adjuvant enhancement of humoral immune response to chemically inactivated bovine viral diarrhea virus.
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Potentiation of the antibody response to inactivated bovine viral diarrhea virus by immunological adjuvants was studied in guinea pigs and cattle. The inactivated bovine viral diarrhea virus alone was demonstrated to be a weak immunogen. Addition of either 2 mg per mL diethylaminoethyl-dextran or 5% alhydrogel to inactivated bovine viral diarrhea virus did not or only slightly stimulated the antibody response; the combined adjuvants induced a significantly higher titer. A higher concentration (20 mg per mL) of diethylaminoethyl-dextran, on the contrary, suppressed the immune potentiation by the dual adjuvants. Combination of Bordetella bronchiseptica and alhydrogel adjuvants stimulated a high titer of antibody. The titer was further elevated upon revaccination and was significantly higher than that induced by alhydrogel alone. In cattle, alhydrogel enhanced the immune response and the additional inclusion of diethylaminoethyl-dextran did not cause a significant potentiation of the immunity. However, the antibody decay rate was significantly slower when stimulated by the combined adjuvants. (+info)
Cell-protective monoclonal antibodies to bovine enterovirus-3 and partial or no activity against other serotypes.
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Preparation of monoclonal antibodies to bovine virus diarrhea virus (BVDV) yielded some hybridoma cells that secreted monoclonal antibodies against the Madin-Darby bovine kidney cells. The anti-cellular monoclonal antibodies reacted with other bovine cells (bovine turbinate and testicle) but not with cell lines derived from other animal species. Subclones derived from one hybridoma partially blocked the infectivity of BVDV, possibly through the binding of the monoclonal antibodies with an epitope close to the receptor site of BVDV and not by way of steric hindrance. Unexpectedly, these same subclones completely blocked the infectivity of bovine enterovirus-3 (BEV-3) strain 240A and partially blocked the infectivity of BEV-2 and BEV-3 (ATCC strain) but not that of other serotypes. Other subclones derived from two other hybridomas, although cell membrane specific, did not have a protective activity against BEV or BVDV. (+info)
Characterization of bovine viral diarrhoea-mucosal disease virus-specific proteins in bovine cells.
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The presence of virus-specific polypeptides in bovine viral diarrhoea-mucosal disease (BVD) virus-infected bovine cells was studied by radiolabelling in the presence of a hypertonic initiation block (HIB) and by analysis by SDS-PAGE. These experiments were complemented by radioimmunoprecipitations with anti-BVD hyperimmune serum of infected cells labelled under isotonic conditions. A total of 12 polypeptides (Mr 165, 135, 118, 80, 75, 62, 56 to 58, 48, 37, 32, 35 and 19, all X 10(-3)) were identified in infected cells. Time course analysis of the induction of the viral polypeptides indicated that they could be detected as early as 4 h post-infection and their synthesis reached a plateau between 12 and 20 h post-infection. The most abundant polypeptides were the ones that could be detected earliest. HIB was found to be an excellent adjunct to existing techniques in the identification of viral polypeptides. Seven of these polypeptides had not been reported previously. This is the first report of the direct detection of BVD virus-induced polypeptides in infected cells without the aid of immunoprecipitation. The sum of the molecular masses of these polypeptides is greater than the coding capacity of the genome; therefore precursor-product relationships must exist between these polypeptides. (+info)
Glycoproteins of bovine viral diarrhoea-mucosal disease virus in infected bovine cells.
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Bovine cell cultures infected with bovine viral diarrhoea-mucosal disease (BVD) virus were radiolabelled with L-[35S]methionine or D-[2-3H]mannose followed by analysis of the labelled polypeptides by radioimmunoprecipitation and polyacrylamide gel electrophoresis in one and two dimensions. Six glycoproteins were detected in infected cells. Two abundant species had Mr of 48K and 56K to 58K while the less abundant species had Mr of 118K, 75K, 65K and 25K. When cells were radiolabelled with L-[35S]methionine in the presence of tunicamycin 56K to 58K migrated with apparent masses of 54K (a minor species) and 48K to 50K (the major molecular species) in PAGE. Endoglycosidase F digestion of virus-induced polypeptides caused a 4K to 6K reduction in the apparent molecular mass of 56K to 58K yielding a single 52K digested product, indicating that the heterogeneity of 56K to 58K was due to differences in the oligosaccharide moieties. Tunicamycin caused a drastic reduction in the yield of infectious virus indicating that the carbohydrate moieties serve a critical role in the infectious cycle of BVD virus. (+info)
Demonstration of bovine viral diarrhoea virus in peripheral blood mononuclear cells of persistently infected, clinically normal cattle.
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Peripheral blood mononuclear cells (PBL) from cattle known to be persistently viraemic with bovine viral diarrhoea virus (BVDV) following a foetal infection, were examined for the presence of viral antigens and cell-associated infectious virus. Using immunocytochemical techniques, physical separations of PBL subsets and virus isolation techniques (directly and by cocultivation) it was found that infection occurred in B and T lymphocytes, monocytes, and a group of cells designated null cells for lack of more specific classification. The latter three groups also supported viral replication, as infectious virus could be isolated from enriched cell populations. BVDV-like particles in cytoplasmic vesicles of PBL subsets were detected by electron microscopy. (+info)
Enzyme-linked immunosorbent assay for the detection of antibodies to bovine virus diarrhea virus in sera from border disease virus-infected sheep.
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An enzyme-linked immunosorbent assay (ELISA) was established for the rapid detection of specific antibodies against the causative agent of border disease in ovine sera. Polyethylene-glycol concentrated, equilibrium density gradient purified bovine virus diarrhea virus was used as test antigen. The optimal amount of antigen was 0.5 microgram/well, and the optimal concentration of conjugate was at 1/4,000 dilution. A total of 20 ovine serum samples, which had been collected from animals with or without border disease, were compared by ELISA and serum neutralization test for the detection of border disease-specific antibodies. ELISA was shown to be equally specific but less time-consuming and easier to perform than serum neutralization test. A positive correlation (r = 0.60) between the two tests was found. (+info)
Cell-free translation of bovine viral diarrhea virus RNA.
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Bovine viral diarrhea virus RNA was translated in a reticulocyte cell-free protein synthesizing system. The purified, 8.2-kilobase, virus-specific RNA species was unable to serve an an efficient message unless it was denatured immediately before translation. In this case, several polypeptides, ranging in molecular weight from 50,000 to 150,000 and most of which were immunoprecipitated by bovine viral diarrhea virus-specific antiserum, were synthesized in vitro. When polyribosomes were used to program cell-free synthesis, mature viral 80,000- and 115,000-molecular-weight proteins were detected; no precursor to the viral 55,000-molecular-weight glycoprotein was noted. The implications of these results with respect to virus-specific protein synthesis are discussed. (+info)
Specific fluorescein-labeled antibodies to bovine viral diarrhea virus prepared from sera of rabbits immunized with purified virus.
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Specific fluorescein-labeled antibody conjugates to three strains of bovine virus diarrhea virus were prepared from hyperimmune rabbit sera. Viruses used to hyperimmunize the rabbits were purified by four different procedures. Conjugates were comparable in quality and specificity to conjugates prepared from serum of a calf hyperimmunized to bovine virus diarrhea virus in our laboratory. The latter conjugate was tested by Biologics Laboratories, National Veterinary Services, U.S.D.A., Ames, Iowa. (+info)