title: Human T-cell leukemia virus type I tax transactivates the interleukin-6 gene in human rheumatoid synovial cells.
abstract: OBJECTIVE
  To determine the effect of the human T cell leukemia virus type I (HTLV-I) tax gene on interleukin-6 (IL-6) production and gene transcription in synovial cells, we established the synovial cell line, E-11, from a patient with rheumatoid arthritis.
  
  
  METHODS
  E-11 cells were transfected with tax expression vector using the calcium phosphate coprecipitation method. IL-6 production and gene expression were investigated by ELISA and Northern blot analysis, respectively. To clarify how tax induces IL-6 gene expression, we used deletion analysis and chloramphenicol acetyltransferase (CAT) assay, and electrophoretic mobility shift assay (EMSA).
  
  
  RESULTS
  Transfection of the tax gene induced markedly high levels of IL-6 mRNA. Furthermore, the tax gene strongly transactivated IL-6 gene promoter activity assayed by CAT assay. By using deletion and site specific mutations, we have identified a nuclear factor (NF)-kappa B sequence (positions -73 to -63) which is essential for tax transaction. EMSA demonstrated the induction of specific binding of nuclear extracts to the NF-kappa B sequence by HTLV-I tax.
  
  
  CONCLUSIONS
  The HTLV-1 tax gene may transactivate IL-6 gene in the synovial cells through NF-kappa B and may contribute in the pathophysiology of HTLV-I associated arthritis.
authors.affiliation: First Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Mori
authors.forename: F
authors.initials: F
authors.lastname: Shirakawa
authors.forename: M
authors.initials: M
authors.lastname: Abe
authors.forename: Y
authors.initials: Y
authors.lastname: Kamo
authors.forename: Y
authors.initials: Y
authors.lastname: Koyama
authors.forename: S
authors.initials: S
authors.lastname: Murakami
authors.forename: H
authors.initials: H
authors.lastname: Shimizu
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
authors.forename: S
authors.initials: S
authors.lastname: Oda
authors.forename: S
authors.initials: S
authors.lastname: Eto
mesh_terms: D001172:Arthritis, Rheumatoid / Q000235:genetics / Q000473:pathology / Q000821:virology*; D001483:Base Sequence; D002467:Cell Nucleus / Q000737:chemistry; D016355:Genes, pX / Q000502:physiology*; D015368:Human T-lymphotropic virus 1 / Q000235:genetics*; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D015335:Molecular Probes / Q000235:genetics; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism; D011401:Promoter Regions, Genetic; D013583:Synovial Membrane / Q000473:pathology / Q000821:virology*; D014020:Tissue Extracts / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation
chemical_list: D015850:Interleukin-6; D015335:Molecular Probes; D016328:NF-kappa B; D014020:Tissue Extracts