title: [Interleukin-32 expression is induced by hepatitis B virus].
abstract: OBJECTIVE
  To investigate whether hepatitis B virus (HBV) can induce the expression of the host-encoded cytokine interleukin-32 (IL-32) and its effects on host signaling mechanisms related to HBV pathogenesis.
  
  
  METHODS
  A eukaryotic expression vector harboring an enhanced green fluorescent protein was constructed with HBV genomic sequences (pIRES2-HBV-EGFP) and transfected into HepG2 cells. In addition, the nuclear factor-kappa B (NF-kB) subunits, p50 and p65, were transfected respectively into HepG2 cells. In both cases, 48 hrs after transfection, IL-32 expression was determined at the mRNA and protein levels using real-time PCR and ELISA and western blot, respectively. The HepG2 cells transfected with pIRES2-HBV-EGFP were also treated with the NF-kB inhibitor SN50 at various concentrations, and the effects on IL-32 protein expression 48 hrs later were evaluated by western blot. Significance of between-group differences was assessed by the Student's t-test.
  
  
  RESULTS
  Transfection with pIRES2-HBV-EGFP led to significantly higher IL-23 expression than transfection with empty vector (mRNA: 2.8-fold higher and protein: 4.5-fold higher; both P less than 0.05). Transfection of p50 and p65 proteins led to significantly higher IL-32 expression (both P less than 0.05), and NF-kB activation was found to be required for HBV-induced IL-32 expression.
  
  
  CONCLUSIONS
  IL-32 expression is induced by HBV in HepG2 cells. This host-encoded cytokine, and its downstream activation of NF-kB, may be involved in the pathogenesis of HBV, especially in the subsequent liver inflammation that accompanies HBV infection.
authors.affiliation: Department of Infectious Diseases, the Third Affiliated Hospital, Sun Yat-sen University, Guangzhou 510630, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Cao
authors.forename: Xing-fei
authors.initials: XF
authors.lastname: Pan
authors.forename: Ka
authors.initials: K
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Shu
authors.forename: Gang
authors.initials: G
authors.lastname: Li
mesh_terms: D005822:Genetic Vectors; D056945:Hep G2 Cells / Q000378:metabolism; D006515:Hepatitis B virus; D054884:Host-Pathogen Interactions; D006801:Humans; D007378:Interleukins / Q000378:metabolism*; D052002:NF-kappa B p50 Subunit / Q000378:metabolism; D051996:Transcription Factor RelA / Q000378:metabolism; D014162:Transfection
chemical_list: C496971:IL32 protein, human; D007378:Interleukins; D052002:NF-kappa B p50 Subunit; C489548:NFKB1 protein, human; C498143:RELA protein, human; D051996:Transcription Factor RelA