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.
10.4142/jvs.2015.16.4.491
- Author:
Xiao Gang WENG
1
;
Quan Jiang SONG
;
Qiong WU
;
Ming Chao LIU
;
Meng Ling WANG
;
Jiu Feng WANG
Author Information
1. College of Veterinary Medicine, China Agricultural University, Beijing 100193, China. jiufeng_wang@hotmail.com
- Publication Type:Original Article
- Keywords:
bovine viral diarrhea virus;
interferon regulatory factor;
persistent infection;
phylogenetic analysis;
Toll-like receptor
- MeSH:
Animals;
Cattle*;
China*;
Diarrhea*;
Immunity, Innate*;
Immunoblotting;
Interferon Regulatory Factor-3;
Interferon-alpha;
Interferons;
Orthomyxoviridae;
RNA, Messenger;
Toll-Like Receptors
- From:Journal of Veterinary Science
2015;16(4):491-500
- CountryRepublic of Korea
- Language:English
-
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-alpha (IFN-alpha), IFN-beta, 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-alpha, and IFN-beta 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.
