title: Genetic characterization of bovine viral diarrhea virus strains in Beijing, China and innate immune responses of peripheral blood mononuclear cells in persistently infected dairy cattle.
abstract: To acquire epidemiological data on the bovine viral diarrhea virus (BVDV) and identify cattle persistently infected (PI) with this virus, 4,327 samples from Holstein dairy cows were screened over a four-year period in Beijing, China. Eighteen BVD viruses were isolated, 12 from PI cattle. Based on genetic analysis of their 5'-untranslated region (5'-UTR), the 18 isolates were assigned to subgenotype BVDV-1m, 1a, 1d, 1q, and 1b. To investigate the innate immune responses in the peripheral-blood mononuclear cells of PI cattle, the expression of Toll-like receptors (TLRs), RIG-I-like receptors, interferon-α (IFN-α), IFN-β, myxovirus (influenza virus) resistance 1 (MX1), and interferon stimulatory gene 15 (ISG15) was assessed by qPCR. When compared with healthy cattle, the expression of TLR-7, IFN-α, and IFN-β mRNA was downregulated, but the expression of MX1 and ISG-15 mRNA was upregulated in PI cattle. Immunoblotting analysis revealed that the expression of interferon regulatory factor 3 (IRF-3) and IRF-7 was lower in PI cattle than in healthy cattle. Thus, BVDV-1m and 1a are the predominant subgenotypes in the Beijing region, and the strains are highly divergent. Our findings also suggest that the TLR-7/IRF-7 signaling pathway plays a role in evasion of host restriction by BVDV.
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Xiao Gang
authors.initials: XG
authors.lastname: Weng
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Quan Jiang
authors.initials: QJ
authors.lastname: Song
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wu
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Ming Chao
authors.initials: MC
authors.lastname: Liu
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Meng Ling
authors.initials: ML
authors.lastname: Wang
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Jiu Feng
authors.initials: JF
authors.lastname: Wang
mesh_terms: D020121:5' Untranslated Regions; D000818:Animals; D000068476:Beijing; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000235:genetics* / Q000276:immunology* / Q000821:virology; D002417:Cattle; D003612:Dairying; D030241:Diarrhea Virus 1, Bovine Viral / Q000235:genetics / Q000502:physiology*; D005786:Gene Expression Regulation; D007113:Immunity, Innate; D016898:Interferon-alpha / Q000378:metabolism; D016899:Interferon-beta / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008969:Molecular Sequence Data; D019590:Nucleocapsid Proteins / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism
chemical_list: D020121:5' Untranslated Regions; D016898:Interferon-alpha; D019590:Nucleocapsid Proteins; D012367:RNA, Viral; D016899:Interferon-beta
keywords: Toll-like receptor; bovine viral diarrhea virus; interferon regulatory factor; persistent infection; phylogenetic analysis