title: Effect of age on the pathogenesis of DHV-1 in Pekin ducks and on the innate immune responses of ducks to infection.
abstract: Duck hepatitis virus (DHV) affects 1-week-old but not 3-week-old ducks, and it causes a more severe disease in the younger ducks. These differences may be partially due to the host response to DHV infection. In order to understand this difference, we characterized the pathobiology of and innate immune response to DHV infection in 1-day-old (1D) and 3-week-old (3 W) ducks. Viral RNA was detected in duck livers at 24, 36 and 72 h after inoculation with DHV at a dose of 10(3) LD50. Virus-induced pathology ranged from no clinical signs to severe disease and death, and it was more severe in the 1D ducks. Infection with DHV induced up-regulation of gene expression of Toll-like receptor (TLR)-7, TLR3, retinoic-acid-inducible gene I (RIG-I), melanoma differentiation-associated gene 5 (MDA-5), interleukin (IL)-6, interferon (IFN)-α, interferon-induced transmembrane protein 1 (IFITM1), interferon-stimulated gene 12 (ISG12), and 2'-5' oligoadenylate synthetase-like gene (OASL) in the livers of 3 W ducks. Of these, IL-6, OASL and ISG12 mRNA levels were more than 100-fold higher in infected 3 W ducks than in mock-infected ducks of the same age. These genes were induced much less in infected 1D ducklings. We present evidence that a lower level of viral replication in the hepatocytes of 3 W ducks, whose basal level of cytokines is higher than that in 1D ducklings, may be related to the strong innate immunity induced. From our data, we conclude that duck age plays an important role in the pathogenicity of and innate immune responses to DHV.
authors.affiliation: Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, 46 Xinkang Road, Ya'an, 625014, China.
authors.forename: Cuiping
authors.initials: C
authors.lastname: Song
authors.forename: Shengqing
authors.initials: S
authors.lastname: Yu
authors.forename: Yunbing
authors.initials: Y
authors.lastname: Duan
authors.forename: Yue
authors.initials: Y
authors.lastname: Hu
authors.forename: Xvsheng
authors.initials: X
authors.lastname: Qiu
authors.forename: Lei
authors.initials: L
authors.lastname: Tan
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Sun
authors.forename: Mingshu
authors.initials: M
authors.lastname: Wang
authors.forename: Anchun
authors.initials: A
authors.lastname: Cheng
authors.forename: Chan
authors.initials: C
authors.lastname: Ding
mesh_terms: D000375:Aging; D000818:Animals; D004372:Ducks; D005786:Gene Expression Regulation / Q000276:immunology; D004371:Hepatitis Virus, Duck / Q000276:immunology / Q000472:pathogenicity*; D006524:Hepatitis, Viral, Animal / Q000276:immunology / Q000473:pathology / Q000821:virology*; D007113:Immunity, Innate; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000821:virology; D010850:Picornaviridae Infections / Q000276:immunology / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D011201:Poultry Diseases / Q000276:immunology / Q000821:virology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D060888:Real-Time Polymerase Chain Reaction; D051193:Toll-Like Receptors / Q000235:genetics / Q000378:metabolism
chemical_list: D015850:Interleukin-6; D012333:RNA, Messenger; D012367:RNA, Viral; D051193:Toll-Like Receptors