Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1981-6-13
pubmed:abstractText
The plaques formed by wild-type (WT) populations of strain K485 visna (V-K485) virus, strain K796 visna (V-K796) virus, and of progressive pneumonia virus in sheep choroid plexus (SCP) cell cultures are heterogeneous in size. Plaque purification procedures showed that this heterogeneity was due to the presence of two biologically different viruses, large plaque-forming (Lpf) virus and small plaque-forming (Spf) virus. The V-K796 Lpf virus, the V-K796 Spf virus, and the V-K796 WT virus are antigenically similar to each other. Although the V-K796 Spf virus is less cytopathic than the V-K796 Lpf virus, both viruses have a 14- to 16-hour latent period in SCP cells and have similar rates of synthesis for the initial 24 to 30 hours after infection. The V-K796 Spf virus is considered a temperature-sensitive visna virus since, unlike the V-K796 Lpf virus, it does not produce plaques at 41 degrees C and it is more thermosensitive than the V-K796 Lpf variant. Population analyses of two strains of wild-type visna virus and one strain of progressive pneumonia virus demonstrated that these populations contain variants with the phenotypes of V-K796 Spf virus and V-K796 Lpf virus, that the Spf virus was not selected against in sheep, and that cultivation of the wild type visna viruses at 37 degrees C selected against the temperature-sensitive variants. The existence of the temperature-sensitive Spf viruses in these wild-type virus populations suggests that the Spf variants maintain the persistent visna virus infection in sheep and delay the development of the host's cell-mediated immune response to the viral proteins.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0304-8608
pubmed:author
pubmed:issnType
Print
pubmed:volume
67
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
229-40
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Wild-type temperature-sensitive and -resistant visna viruses: isolation and biological comparison.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.