Biomedical subjects

A Bridgen

Publications and source records attributed to A Bridgen.

6 recordsLinked to original sources

PubMed2001

Bunyamwera bunyavirus nonstructural protein NSs is a nonessential gene product that contributes to viral pathogenesis.

Bunyamwera virus (family Bunyaviridae, genus Bunyavirus) contains a tripartite negative-sense RNA genome. The smallest RNA segment, S, encodes the nucleocapsid protein N and a nonstructural protein, NSs, in overlapping reading frames. We have generated a mutant virus lacking NSs, called BUNdelNSs, by reverse genetics. Compared with the wild-type (wt) virus, BUNdelNSs exhibited a smaller plaque size and generated titers of virus approximately 1 log lower. In mammalian cells, the mutant expressed greatly increased levels of N protein; significantly, the marked inhibition of host cell protein synthesis shown by wt virus was considerably impaired by BUNdelNSs. When inoculated by the intracerebral route BUNdelNSs killed BALB/c mice with a slower time course than wt and exhibited a reduced cell-to-cell spread, and titers of virus in the brain were lower. In addition, the abrogation of NSs expression changed Bunyamwera virus from a noninducer to an inducer of an interferon-beta promoter. These results suggest that, although not essential for growth in tissue culture or in mice, the bunyavirus NSs protein has several functions in the virus life cycle and contributes to viral pathogenesis.

Aedes↗

PubMed1992

The detection of Alcelaphine herpesvirus-1 DNA by in situ hybridization of tissues from rabbits affected with malignant catarrhal fever.

Tissue sections and cultured lymphocytes from rabbits clinically affected following experimental infection with Alcelaphine herpesvirus-1 (AHV-1) were assessed for the presence of viral DNA by in situ hybridization with the cloned major HindII repeat sequence of this virus. Small numbers of virus-infected cells were consistently detected only in submandibular lymph nodes, while other tissues showed no evidence of viral DNA. Virus titration in culture suggested that there were higher titres of virus in the lymph nodes, spleen and lung of infected animals than in the kidney or peripheral blood lymphocytes and confirmed the low level of virus in these animals. Substantially more viral DNA was detected by in situ hybridization in lymphocytes following at least 24 h of culture, suggesting that viral replication is normally repressed by the host.

Animals↗

PubMed1991

Recovery of a herpesvirus from a roan antelope (Hippotragus equinus).

A herpesvirus was recovered in culture from the cells of a roan antelope (Hippotragus equinus) following cryopreservation in DMSO and it is thought that the DMSO may have been involved in reactivation. The virus was shown to be antigenically related to alcelaphine herpesvirus-1 (AHV-1) of wildebeest and ovine herpesvirus-2 (OHV-2) of domestic sheep (formerly designated the sheep-associated agent of malignant catarrhal fever (MCF]. Cloned DNA fragments of AHV-1 and OHV-2 cross hybridised with DNA prepared from cells infected with the roan antelope virus and the intensity of reaction suggested that this virus was more closely related to AHV-1 than is OHV-2. The virus represents the third gamma herpesvirus isolated from large African antelope and should be provisionally designated hippotragine herpesvirus-1. On inoculation into rabbits the virus induced malignant catarrhal fever indicating that roan antelope should be considered as a possible source of infection.

Animals↗

PubMed1991

The derivation of a restriction endonuclease map for Alcelaphine herpesvirus 1 DNA.

The gammaherpesvirus Alcelaphine herpesvirus 1 (AHV-1), indigenous to the wildebeest (Connochaetes species), is a causative agent of the fatal lymphoproliferative disease malignant catarrhal fever in cattle and deer. The genome of the attenuated WC11 isolate of AHV-1 has previously been shown to possess a region of unique DNA together with multiple direct repeat sequences. Approximately 70% of the genome of WC11 has now been cloned into plasmid or bacteriophage vectors and these clones have been used in hybridisation experiments to construct a restriction endonuclease map of the WC11 unique DNA with respect to BamHI. EcoRI, SalI, SmaI and XhoI. The map allows the size of the unique region of the WC11 genome to be estimated as 130 kbp and thus the entire genome as 155-160 kbp. The results confirm a terminal location for the repeat sequences.

Bacteriophage lambda↗

PubMed1991

Derivation of a DNA clone corresponding to the viral agent of sheep-associated malignant catarrhal fever.

Malignant catarrhal fever is a fatal lymphoproliferative and degenerative disease of ruminants. One causative agent is the gammaherpesvirus alcelaphine herpesvirus 1 (AHV-1), which produces no disease in its natural host, the wildebeest (Connochaetes species). Epidemiological evidence implicates sheep as the carrier of a similar virus. However, attempts to culture this virus from sheep or from animals affected with sheep-associated malignant catarrhal fever (SA-MCF) have failed. Lymphoblastoid cells have been propagated from cattle, deer and rabbits with SA-MCF. Although these cells show no evidence of viral particles or antigens, hybridisation experiments now show that they contain DNA sequences homologous to those of AHV-1. A genomic library was constructed from one of these lymphoblastoid cell lines and a clone identified which hybridised to cloned AHV-1 DNA. The authors believe that this clone contains part of the SA-MCF viral genome, and that the SA-MCF virus and AHV-1 are closely related gammaherpesviruses.

Animals↗

PubMed1989

Preliminary characterization of the alcelaphine herpesvirus 1 genome.

Alcelaphine herpesvirus type 1 (AHV-1) is a causative agent of the fatal lymphoproliferative disease malignant catarrhal fever in deer and cattle. The genomes of the attenuated WC11 isolate and the virulent C500 isolate have been studied. The genome of WC11 comprises a region of unique DNA of approximately 130 kbp, which has a G + C content of 50%, and approximately 30 kbp of additional tandem direct repeat sequences with G + C content of 72%. WC11 possesses a major repeat sequence of 950 bp interspersed with a small number of related sequences of different length; these sequences are probably terminal in location. DNA from the C500 isolate has a similar restriction profile to that of WC11 in the unique region, but only one repeat sequence of 1050 bp is present. We propose, on the basis of biological and structural properties, that AHV-1 be included within the gamma 2 group of herpesviruses of which herpesvirus ateles is the prototype.

Animals↗