title: Rise in gamma interferon expression during resolution of duck hepatitis B virus infection.
abstract: Gamma interferon (IFN-gamma) expression plays a crucial role in the control of mammalian hepatitis B virus (HBV) infection. However, the role of duck INF-gamma (DuIFN-gamma) in the outcome of duck HBV (DHBV) infection, a reference model for hepadnavirus replication studies, has not yet been investigated. This work explored the dynamics of DuIFN-gamma expression in liver and peripheral blood mononuclear cells (PBMCs) during resolution of DHBV infection in adolescent ducks in relation to serum and liver markers of virus replication, histological changes and humoral response induction. DHBV infection of 3-week-old ducks resulted in transient expression of intrahepatic preS protein (days 3-14) and mild histological changes. Low-level viraemia was detected only during the first 10 days of infection and was accompanied by early anti-preS antibody response induction. Importantly, a strong increase in intrahepatic DuIFN-gamma RNA was detected by real-time RT-PCR at days 6-14, which coincided with a sharp decrease in both viral DNA and preS protein in the liver. Interestingly, liver DuIFN-gamma expression remained augmented to the end of the follow-up period (day 66) and correlated with portal lymphocyte infiltration and persistence of trace quantities of intrahepatic DHBV DNA in animals that had apparently completely resolved the infection. Moreover, in infected ducks, a moderate increase was detected in the levels of DuIFN-gamma in PBMCs (days 12-14), which coincided with the peak in liver DuIFN-gamma RNA levels. These data reveal that increased DuIFN-gamma expression in liver and PBMCs is concomitant with viral clearance, characterizing the resolution of infection, and provide new insights into the host-virus interactions that control DHBV infection.
authors.affiliation: INSERM Unit 271, 151 Cours Albert Thomas, 69003 Lyon, France.
authors.forename: Ramamurthy
authors.initials: R
authors.lastname: Narayan
authors.affiliation: Ecole Nationale Vétérinaire, Marcy l'Etoile, France.|INSERM Unit 271, 151 Cours Albert Thomas, 69003 Lyon, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Buronfosse
authors.affiliation: Department of Internal Medicine II/Molecular Biology, University Hospital, Freiburg, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Schultz
authors.affiliation: CHU Lyon, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Chevallier-Gueyron
authors.affiliation: Novotec, Lyon, France.
authors.forename: Sylviane
authors.initials: S
authors.lastname: Guerret
authors.affiliation: Laboratoires Marcel Mérieux, Lyon, France.
authors.forename: Michelle
authors.initials: M
authors.lastname: Chevallier
authors.affiliation: INSERM Unit 271, 151 Cours Albert Thomas, 69003 Lyon, France.
authors.forename: Fadi
authors.initials: F
authors.lastname: Saade
authors.affiliation: INSERM Unit 271, 151 Cours Albert Thomas, 69003 Lyon, France.
authors.forename: Benedicte
authors.initials: B
authors.lastname: Ndeboko
authors.affiliation: INSERM Unit 271, 151 Cours Albert Thomas, 69003 Lyon, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Trepo
authors.affiliation: INSERM Unit 271, 151 Cours Albert Thomas, 69003 Lyon, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Zoulim
authors.affiliation: INSERM Unit 271, 151 Cours Albert Thomas, 69003 Lyon, France.
authors.forename: Lucyna
authors.initials: L
authors.lastname: Cova
mesh_terms: D000818:Animals; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D004372:Ducks; D018347:Hepadnaviridae Infections / Q000097:blood / Q000378:metabolism / Q000662:veterinary* / Q000821:virology; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000276:immunology / Q000378:metabolism; D015611:Hepatitis B Virus, Duck / Q000302:isolation & purification; D006524:Hepatitis, Viral, Animal / Q000097:blood / Q000378:metabolism* / Q000821:virology; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008099:Liver / Q000378:metabolism* / Q000821:virology; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000032:analysis / Q000235:genetics; D013997:Time Factors; D014766:Viremia
chemical_list: D004279:DNA, Viral; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D012367:RNA, Viral; D007371:Interferon-gamma