Hepatitis B virus e antigen downregulates cytokine production in human hepatoma cell lines.
Disease activities of hepatitis B are affected by the status of hepatitis B e antigen (HBeAg). The function of the hepatitis B virus (HBV) precore or HBeAg is unknown. We assumed that HBeAg blocks aberrant immune responses, although HBeAg is not required for viral assembly, infection, or replication. We examined the interaction of HBeAg and the immune system, including cytokine production. The inflammatory cytokine TNF, IL-6, IL-8, IL-12A, IFN-α1, and IFN-ß mRNA were downregulated in HBeAg-positive HepG2, which stably expresses HBeAg, compared to HBeAg-negative HepG2 cells. The results of real-time RT-PCR-based cytokine-related gene arrays showed the downregulation of cytokine and IFN production. We also observed inhibition of the activation of NF-κB- and IFN-ß-promoter in HBeAg-positive HepG2, as well as inhibition of IFN and IL-6 production in HBeAg-positive HepG2 cell culture fluids. HBeAg might modify disease progression by inhibiting inflammatory cytokine and IFN gene expression, while simultaneously suppressing NF-κB-signaling- and IFNß-promoter activation.
Wu
Shuang
S
Department of Medicine and Clinical Oncology, Chiba University, Graduate School of Medicine, Chiba, Japan.
Kanda
Tatsuo
T
Imazeki
Fumio
F
Arai
Makoto
M
Yonemitsu
Yutaka
Y
Nakamoto
Shingo
S
Fujiwara
Keiichi
K
Fukai
Kenichi
K
Nomura
Fumio
F
Yokosuka
Osamu
O
D002460:Cell Line; D016207:Cytokines / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000276:immunology*; D020869:Gene Expression Profiling; D006513:Hepatitis B e Antigens / Q000276:immunology*; D006515:Hepatitis B virus / Q000276:immunology* / Q000472:pathogenicity*; D022781:Hepatocytes / Q000276:immunology / Q000821:virology; D006801:Humans; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D037521:Virulence Factors / Q000276:immunology*
D016207:Cytokines; D006513:Hepatitis B e Antigens; D012333:RNA, Messenger; D037521:Virulence Factors