title: Pathogenetic differences after experimental infection of calves with Korean non-cytopathic BVDV-1 and BVDV-2 isolates.
abstract: The purpose of this study was to compare clinical and virological differences between non-cytopathic (ncp) bovine viral diarrhea virus (BVDV)-1 and ncp BVDV-2 isolated from Korean field cases. Each five naïve calves were experimentally infected with Korean ncp BVDV-1 or BVDV-2 isolates. Two additional age-matched animals were used as uninfected controls. Leukocyte, lymphocyte, and platelet counts declined in all infected calves, but were significantly lower and remained decreased longer in calves infected with ncp BVDV-2 isolate. The number of monocytes was greater in calves infected with ncp BVDV-2. Flow cytometric assay showed that lymphocyte apoptosis occurred with an increase of annexin-V positive cells in all infected calves by day 6. Tumor necrosis factor alpha (TNF-α) concentration in all infected calves was lower than in control calves. In ncp BVDV-1 infected calves, interferon gamma (IFN-γ) levels in the serum were increased by day 6 compared to calves infected with ncp BVDV-2. These results demonstrated that the Korean ncp BVDV-2 isolate shows a reduced IFN-γ production, indicating prevention of the antiviral activity, and therefore promotes the development of pathological effects.
authors.affiliation: Department of Animal Biotechnology, College of Animal Science, Kyungpook National University, Sangju 742-711, Republic of Korea.
authors.forename: Giyong
authors.initials: G
authors.lastname: Seong
authors.forename: Jae-Ku
authors.initials: JK
authors.lastname: Oem
authors.forename: Kyoung-Seong
authors.initials: KS
authors.lastname: Choi
mesh_terms: D000818:Animals; D017304:Annexin A5 / Q000032:analysis; D017209:Apoptosis; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000276:immunology* / Q000473:pathology / Q000821:virology; D002417:Cattle; D030241:Diarrhea Virus 1, Bovine Viral / Q000472:pathogenicity*; D030242:Diarrhea Virus 2, Bovine Viral / Q000472:pathogenicity*; D007371:Interferon-gamma / Q000097:blood
chemical_list: D017304:Annexin A5; D007371:Interferon-gamma
keywords: Apoptosis; Bovine viral diarrhea virus; Flow cytometric analysis; IFN-γ; Non-cytopathic; TNF-α