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At least 145 records · Page 8Linked to original sources
PubMed1991

Natural infection of broiler breeder chickens with endemic apathogenic Newcastle disease virus and their subsequent response to vaccination with a live V4 Newcastle disease virus vaccine.

Flocks of broiler breeder chickens housed on a commercial farm were monitored from 13 w of age for natural infection with endemic lentogenic Newcastle disease virus (NDV). Seroconversion was first detected at 17 w. By 24 w, all 8 flocks had achieved peak log2 mean haemagglutination inhibiting antibody titres of up to 4.8. Antibody titres then declined and rose again over several months, suggesting cyclic reinfection with NDV. A lentogenic NDV indistinguishable from V4 was isolated from the cloaca of one bird at 18 weeks of age. At 54 weeks of age, 6 of 8 flocks were vaccinated en masse with live V4 NDV vaccine, 3 flocks by drinking water and 3 flocks by aerosol. All flocks were serologically monitored for a further 8 w. Drinking water vaccination induced an anamnestic response in 3 flocks, showing that flocks with pre-existing active immunity to NDV may be successfully vaccinated with V4. However, in all aerosol vaccinated flocks, the procedures failed to induce a response different to that observed in unvaccinated flocks. The serological response to vaccination was greater in sires than in dams.

Animals↗
PubMed1998

Evolution of the immune response in the central nervous system following infection with Borna disease virus.

Borna disease virus infection of Lewis rats results in an immune-mediated disease associated with transient meningoencephalitis and persistent viral infection. In the acute phase of disease, perivascular immune cell infiltrates consisted of CD4 + and CD8 + T cells, macrophages and NK cells with peak expression of mRNAs encoding the cytokines IL1alpha, IL2, IL6, TNFalpha, and IFNgamma. In the chronic phase of disease, numbers of NK cells, B cells and activated microglia increased in the brain parenchyma with peak expression of IL4 mRNA. These data were consistent with a switch from a Th1-like, cellular immune response to a Th2-like, humoral immune response.

Animals↗
PubMed1995

The multimeric nonstructural NS2 proteins of bluetongue virus, African horsesickness virus, and epizootic hemorrhagic disease virus differ in their single-stranded RNA-binding ability.

The structure and single-stranded (ss) RNA-binding by the nonstructural protein NS2 of three different orbiviruses were studied and compared. African horsesickness virus (AHSV), bluetongue virus (BTV), and epizootic hemorrhagic disease virus (EHDV) were analyzed in recombinant baculovirus-infected cells and in cells infected with BTV and AHSV. Sedimentation analysis and nonreducing SDS-PAGE revealed that NS2 of all three orbiviruses is a 7S multimer with both inter- and intramolecular disulfide bonds, probably consisting of six or more NS2 molecules. The 7S NS2 multimer of all three viruses binds ssRNA but there is a marked disparity in the ssRNA-binding ability between the three proteins. At physiological salt concentration, BTV NS2 binds ssRNA very efficiently, whereas AHSV NS2 shows only a low efficiency for binding ssRNA. EHDV NS2 binds with intermediate efficiency. The result was the same irrespective of whether poly(U)-Sepharose or viral mRNA was used, indicating that ssRNA-binding by NS2 is nonspecific. The difference in RNA-binding ability may be related to the alpha-helix content of the respective proteins. NS2 of BTV has the highest predicted alpha-helix content followed by EHDV and AHSV. The ability of the NS2 proteins to form virus inclusion body-like structures in baculovirus-infected cells is not affected by the ssRNA-binding disparity.

African Horse Sickness Virus↗
PubMed1988

A rapid, quantitative assay for titration of bovine virus diarrhoea-mucosal disease virus.

An end point dilution microtitration assay is described that can be used for the titration of both cytopathic and non-cytopathic isolates of bovine virus diarrhoea-mucosal disease virus. Indirect immunofluorescence is used to detect infected MDBK cells in the wells of Terasaki plates. The virus titre is derived from the number of uninfected wells, using the Poisson distribution. The assay is simple, fast and economical. Titres of cytopathic virus determined by the microtitration assay and standard plaque assay are equivalent.

Animals↗
PubMed2006

Experimental transmission of sleeping disease in one-year-old rainbow trout, Oncorhynchus mykiss (Walbaum), induced by sleeping disease virus.

Sleeping disease (SD) is a serious disease of rainbow trout, Oncorhynchus mykiss, reared in fresh water caused by sleeping disease virus (SDV). In this study a detailed clinical, histological, virological and serological description of the experimental reproduction of SD in 1-year-old rainbow trout exposed to SDV was carried out. Two hundred disease-free fish were intraperitoneally inoculated with a SDV isolate and 100 fish were inoculated with an uninfected cell culture lysate as a negative control. Infected and control fish were randomly removed at days 4, 7, 14, 21, 42 and 70 post-infection. Blood and tissues were collected for virus isolation, histopathological examination and serum neutralization. SDV was detected in serum, kidney and brain of infected fish from 4 to 21 days post-infection (dpi). Characteristic pathological lesions were observed in infected fish as early as 7 dpi. Lesions were first detected in exocrine pancreas and subsequently observed in heart and skeletal muscle. Neutralizing antibodies to SDV were detected in infected fish from 14 to 70 dpi. Infected fish displayed typical signs of SD 1-month pi and the mortality reached 18.7% within 44 days. This study experimentally reproduced all the pathognomonic features of natural outbreaks of SD in 1-year-old rainbow trout.

Alphavirus↗
PubMed2002

[Sequence analysis of the fusion (F) protein genes of four Newcastle disease virus strains causing clinical disease in geese].

Four strains of Newcastle disease virus(NDV), which have proven to be responsible for the disease outbreaks in south and east China regions called "geese paramyxovirus infection" or "avian paramyxovirus infection of geese", were examined for the features of their fusion(F) protein genes. A 1700 nucleotides(nt) fragment of the F gene (1705 nt) of each of the 4 strains were sequenced, the results revealed that the NDV strains of goose origin share common transcriptional sequence and translational start position with the hitherto reported NDV, the F gene homologies among the 4 strains were 97.8%-98.9%, while the corresponding homologies between these strains and the standard challenge strain F48E8 were only 86.0-86.8%. The deduced amino acid sequences near cleavage site of F0 proteins showed a 112RRQKR/F117 motif, comforming well with that of the virulent strains. The cleavage sites distribution of 3 restriction enzymes(Hinf I, Basto I, Rsa I) in 75% region of the F gene(between 334-1682 nt), which is used to group NDV strains into different genotypes, were also analysed with the aid of computer program MegAlign, it is very interesting to find that the 4 strains showed a distinct distribution pattern from all the genotypes so far reported(genotype I-VIII), characterized by the simultaneously presence of a Bsto I site at 752 nt and two Rsa I sites at 872 nt and 973 nt. Additionally, 3 out of the 4 strains, despite their different geographical locations, showed a novel Rsa I site at position 1249 which is absent in all of the other genotypes. The 4 NDV strains of goose origin were essentially virulent ones, and probably belong to a new genotype.

Amino Acid Sequence↗
PubMed1995

Quantitative measurement of paramyxovirus fusion: differences in requirements of glycoproteins between simian virus 5 and human parainfluenza virus 3 or Newcastle disease virus.

To compare the requirements for paramyxovirus-mediated cell fusion, the fusion (F) and hemagglutinin-neuraminidase (HN) glycoproteins of simian virus 5 (SV5), human parainfluenza virus 3 (HPIV-3), and Newcastle disease virus (NDV) were expressed individually or coexpressed in either homologous or heterologous combinations in CV-1 or HeLa-T4 cells, using the vaccinia virus-T7 polymerase transient expression system. The contribution of individual glycoproteins in virus-induced membrane fusion was examined by using a quantitative assay for lipid mixing based on the relief of self-quenching (dequenching) of fluorescence of the lipid probe octadecyl rhodamine (R18) and a quantitative assay for content mixing based on the cytoplasmic activation of a reporter gene, beta-galactosidase. In these assays, expression of the individual F glycoproteins did not induce significant levels of cell fusion and no cell fusion was observed in experiments when cells individually expressing homologous F or HN proteins were mixed. However, coexpression of homologous F and HN glycoproteins resulted in extensive cell fusion. The kinetics of fusion were found to be very similar for all three paramyxoviruses studied. With NDV and HPIV-3, no cell fusion was detected when F proteins were coexpressed with heterologous HN proteins or influenza virus hemagglutinin (HA). In contrast, SV5 F protein exhibited a considerable degree of fusion activity when coexpressed with either NDV or HPIV-3 HN or with influenza virus HA, although the kinetics of fusion were two- to threefold higher when the homologous SV5 F and HN proteins were coexpressed. Thus, these data indicate that among the paramyxoviruses tested, SV5 has different requirements for cell fusion.

Animals↗
PubMed1990

Protection of chickens with a recombinant fowlpox virus expressing the Newcastle disease virus hemagglutinin-neuraminidase gene.

A recombinant fowlpox virus expressing the hemagglutinin-neuraminidase (HN) protein of Newcastle disease virus (NDV) strain Texas was generated. Immunoprecipitation with chicken anti-NDV serum confirmed authentic expression of the HN protein. Protection of chickens from infection with NDV was observed when birds were immunized with the recombinant HN fowlpox virus by the intramuscular route after one or two inoculations. Vaccination by the ocular route with a mixture of fowlpox recombinants expressing the fusion and HN proteins did not show added protection over that seen with the individual viruses.

Animals↗
PubMed1999

High susceptibility of Mongolian gerbil (Meriones unguiculatus) to Borna disease virus.

Borna disease virus (BDV) is a neurotropic enveloped virus with a nonsegmented, single-, negative-stranded RNA genome. This virus induced encephalitis in experimentally infected adult rats, but in newborn rats BDV established a persistent, tolerant infection with no apparent clinical signs. Here, we report evidence that newborn Mongolian gerbils (Meriones unguiculatus) are more susceptible to experimental intracranial inoculation of horse-derived BDV in persistently infected MDCK cells, compared with similar inoculation in newborn rats. All inoculated newborn gerbils, but not rats, died 30 days after infection. Reverse transcriptase-polymerase chain reaction amplified BDV-specific sequences in several regions including the brain. Histopathological analysis revealed apparent inflammatory reactions in the brains of inoculated gerbils but not rats, although similar levels of BDV RNA were detected in both gerbil and rat brains. BDV-specific antigen and RNA were identified predominantly in neurons in the brains by immunohistochemistry with antibodies to BDV and in situ hybridization with BDV-specific riboprobes, respectively. BDV in the gerbil brain was easily rescued by co-cultivation of the brain homogenate with human oligodendroglioma cells. Thus, gerbils seem to be a useful animal model for studying BDV-induced pathogenesis in the brain.

Animals↗