title: Downregulation of IL-13 gene transcription by T-bet in human T cells.
abstract: BACKGROUND
  Downregulation of a Th2 cytokine, IL-4, by a Th1-specific transcription factor, T-bet, has been demonstrated. However, the regulatory role of T-bet in another Th2 cytokine, IL-13, is not fully delineated.
  
  
  METHODS
  IL-13 mRNA expression in Jurkat cells was examined by quantitative RT-PCR, while the transcriptional activity of 5'-flanking region in the IL-13 gene encompassing -1077 to +49 was investigated by fluorescence-based promoter reporter assay. The effect of T-bet was investigated by transfection of the cells with the T-bet expression vector.
  
  
  RESULTS
  Stimulation with phorbol ester plus Ca2+ ionophore clearly induced IL-13 gene transcription in Jurkat cells. Ectopically expressed T-bet significantly suppressed the inducible mRNA expression and promoter activity of IL-13.
  
  
  CONCLUSIONS
  IL-13 expression was downregulated by T-bet at the level of gene transcription, independently of the modulation of Th1/Th2 balance. T-bet is the potential key factor in the development of Th1/Th2-related diseases.
authors.affiliation: Department of Allergy and Immunology, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Suzuki
authors.forename: Osamu
authors.initials: O
authors.lastname: Kaminuma
authors.forename: Takachika
authors.initials: T
authors.lastname: Hiroi
authors.forename: Fujiko
authors.initials: F
authors.lastname: Kitamura
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Miyatake
authors.forename: Fumio
authors.initials: F
authors.lastname: Takaiwa
authors.forename: Hideki
authors.initials: H
authors.lastname: Tatsumi
authors.forename: Soichi
authors.initials: S
authors.lastname: Nemoto
authors.forename: Noriko
authors.initials: N
authors.lastname: Kitamura
authors.forename: Akio
authors.initials: A
authors.lastname: Mori
mesh_terms: D002118:Calcium / Q000378:metabolism; D015536:Down-Regulation / Q000235:genetics; D006801:Humans; D018793:Interleukin-13 / Q000235:genetics / Q000378:metabolism*; D007476:Ionophores / Q000494:pharmacology; D019169:Jurkat Cells; D010703:Phorbol Esters / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020825:T-Box Domain Proteins / Q000235:genetics / Q000378:metabolism*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D014158:Transcription, Genetic; D000098815:T-bet Transcription Factor
chemical_list: D018793:Interleukin-13; D007476:Ionophores; D010703:Phorbol Esters; D012333:RNA, Messenger; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor; D002118:Calcium