title: Expression of Stat3 and indoleamine 2, 3-dioxygenase in cornea keratocytes as factor of ocular immune privilege.
abstract: OBJECTIVE
  Ocular immune privilege is a multifactorial phenomenon evolutionally selected to prevent immunogenic inflammation from disrupting the visual axis and causing blindness. Here, we investigated the role of signal transducers and activators of transcription (Stat3) and indoleamine 2,3-dioxygenase (IDO) in ocular immune privilege in corneal stromal cells.
  
  
  METHODS
  Human keratocytes were isolated and cultured in vitro, and Stat3 and IDO expression on keratocytes was investigated by reverse transcription polymerase chain reaction (RT-PCR). The active form of Stat3 was detected by flow-cytometry, and IDO enzyme activity following IFN-γ stimulation of keratocytes was measured by tryptophan to kynurenine conversion with photometric determination of kynurenine concentration in the supernatant.
  
  
  RESULTS
  Stat3 was constitutively expressed in cultured keratocytes and up-regulated following IFN-γ stimulation. The active form of Stat3 was also up-regulated following IFN-γ stimulation. IDO expression and enzyme activity was markedly induced following IFN-γ stimulation, but this induction was prevented by the IDO specific inhibitor, 1-methyl tryptophan (1-MT).
  
  
  CONCLUSIONS
  On the basis of this study, Stat3 and IDO may act as a factor of ocular immune privilege in corneal keratocytes. Thus, focus on these inhibitory molecules should be considered in studies aimed at developing therapeutic agents for controlling ocular inflammatory or immune diseases.
authors.affiliation: Department of Ophthalmology, Busan Paik Hospital, Inje University Medical College, Gaegum-dong, Busanjin-gu, Busan 633-165, Korea. eyeyang@inje.ac.kr
authors.forename: Jae Wook
authors.initials: JW
authors.lastname: Yang
authors.forename: Dong Sik
authors.initials: DS
authors.lastname: Ham
authors.forename: Hyun Woong
authors.initials: HW
authors.lastname: Kim
authors.forename: Sul Gee
authors.initials: SG
authors.lastname: Lee
authors.forename: Sae Kwang
authors.initials: SK
authors.lastname: Park
authors.forename: Su Kil
authors.initials: SK
authors.lastname: Seo
mesh_terms: D000328:Adult; D002478:Cells, Cultured; D060527:Corneal Keratocytes / Q000276:immunology*; D003319:Corneal Stroma / Q000166:cytology; D005434:Flow Cytometry; D015870:Gene Expression; D006801:Humans; D007108:Immune Tolerance / Q000502:physiology*; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000235:genetics* / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050796:STAT3 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D012333:RNA, Messenger; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D007371:Interferon-gamma
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