title: Hepatitis B virus suppresses toll-like receptor-mediated innate immune responses in murine parenchymal and nonparenchymal liver cells.
abstract: We have previously shown that Toll-like receptor (TLR)-activated murine nonparenchymal liver cells [(NPC); Kupffer cells (KC), liver sinusoidal endothelial cells (LSEC)] can suppress hepatitis B virus (HBV) replication. Therefore, the aim of this study was to investigate whether HBV has the ability to counteract the TLR-mediated control of its replication. Freshly purified murine hepatocytes and NPCs obtained from C57BL6 mice were stimulated by TLR 1-9 ligands in the presence or absence of hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), HBV virions, or supernatants from HBV-producing HBV-Met cells, and HBV replication was suppressed by anti- hepatitis B virus X protein (HBx) small interfering RNA (siRNA) in HBV-Met cells. Supernatants were collected and tested for antiviral cytokines by viral protection assay. HBV gene expression and replication was analyzed by southern blot. RNA and proteins were analyzed by quantitative reverse transcription polymerase chain reaction (RT-PCR) or western blot and enzyme-linked immunosorbent assay, respectively. Pretreatment of hepatocytes and NPCs with HBV-Met cells supernatants, HBsAg, HBeAg, or HBV virions almost completely abrogated TLR-induced antiviral activity, which correlated with suppression of interferon beta (IFN-beta) production and subsequent interferon-stimulated gene induction as well as suppressed activation of interferon regulatory factor 3 (IRF-3), nuclear factor kappa B (NF-kappaB), and extracellular signal-regulated kinase (ERK) 1/2. In HBV-infected HBV-Met cells, TLR stimulation did not induce antiviral cytokines in contrast to primary hepatocytes. TLR-stimulated expression of proinflammatory cytokines [tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6)], and activation of IRF-3 was suppressed after up-regulation of HBV replication in HBV-Met cells. Accordingly, suppression of HBV replication by siRNA led to activation or expression of proinflammatory transcription factors and cytokines.
  
  
  CONCLUSIONS
  Our data indicate that HBV can suppress the TLR-induced antiviral activity of liver cells. This has major implications for the interaction between HBV and the immune system.
authors.affiliation: Department of Gastroenterology and Hepatology, University Hospital of Essen, Essen, Germany.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.forename: Zhongji
authors.initials: Z
authors.lastname: Meng
authors.forename: Min
authors.initials: M
authors.lastname: Jiang
authors.forename: Rongjuan
authors.initials: R
authors.lastname: Pei
authors.forename: Martin
authors.initials: M
authors.lastname: Trippler
authors.forename: Ruth
authors.initials: R
authors.lastname: Broering
authors.forename: Agnes
authors.initials: A
authors.lastname: Bucchi
authors.forename: Jan-Peter
authors.initials: JP
authors.lastname: Sowa
authors.forename: Ulf
authors.initials: U
authors.lastname: Dittmer
authors.forename: Dongliang
authors.initials: D
authors.lastname: Yang
authors.forename: Michael
authors.initials: M
authors.lastname: Roggendorf
authors.forename: Guido
authors.initials: G
authors.lastname: Gerken
authors.forename: Mengji
authors.initials: M
authors.lastname: Lu
authors.forename: Joerg F
authors.initials: JF
authors.lastname: Schlaak
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D015536:Down-Regulation; D004686:Encephalomyocarditis virus / Q000276:immunology; D006515:Hepatitis B virus / Q000502:physiology*; D022781:Hepatocytes / Q000276:immunology / Q000378:metabolism; D054884:Host-Pathogen Interactions; D007113:Immunity, Innate; D016899:Interferon-beta / Q000378:metabolism; D008099:Liver / Q000276:immunology / Q000821:virology*; D051379:Mice; D008810:Mice, Inbred C57BL; D011994:Recombinant Proteins / Q000378:metabolism; D051193:Toll-Like Receptors / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D014764:Viral Proteins / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D051193:Toll-Like Receptors; D014157:Transcription Factors; D014764:Viral Proteins; D016899:Interferon-beta