title: Inhibition of T-cell activation by retinal pigment epithelial cells derived from induced pluripotent stem cells.
abstract: OBJECTIVE
  The purpose of this study was to determine whether human retinal pigment epithelial (RPE) cells from induced pluripotent stem (iPS) cells could inhibit T-cell activation in vitro.
  
  
  METHODS
  Cultured iPS-derived RPE (iPS-RPE) cells were established from fresh skin tissues or dental pulp cells obtained from healthy donors or a retinal patient after informed consent was obtained. To confirm expression of the specific markers on iPS and iPS-RPE cells, immunohistochemistry, quantitative RT-PCR (qRT-PCR), and flow cytometry were performed. Target T cells were obtained from peripheral blood mononuclear cells of healthy donors. Target T cells were assessed for proliferation by incorporation of bromodeoxyuridine or carboxyfluorescein succinimidyl ester for production of cytokines such as IFN-γ. Expression of TGFβ and other candidate molecules by iPS-RPE cells was evaluated with flow cytometry, ELISA, multiplex cytokine array, immunohistochemistry, and qRT-PCR.
  
  
  RESULTS
  The RPE cells we established from iPS cells had many characteristics of mature RPE cells but no characteristics of pluripotent stem cells. Cultured iPS-RPE cells inhibited cell proliferation and production of IFN-γ by activated CD4(+) T cells. In some bystander T cells, iPS-derived RPE cells induced CD25(+)Foxp3(+) regulatory T cells in vitro. Induced pluripotent stem-RPE cells constitutively expressed TGFβ and suppressed activation of T cells via soluble TGFβ, because TGFβ-downregulated iPS-RPE cells did not inhibit this T-cell activation.
  
  
  CONCLUSIONS
  Cultured iPS-derived retinal cells fully suppress T-cell activation. Transplantation of iPS-RPE cells into the eye might be a therapy for retinal disorders.
authors.affiliation: Laboratory for Retinal Regeneration, Center for Developmental Biology, RIKEN, Kobe, Japan.
authors.forename: Sunao
authors.initials: S
authors.lastname: Sugita
authors.affiliation: Laboratory for Retinal Regeneration, Center for Developmental Biology, RIKEN, Kobe, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kamao
authors.affiliation: Laboratory for Retinal Regeneration, Center for Developmental Biology, RIKEN, Kobe, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Iwasaki
authors.affiliation: Laboratory for Retinal Regeneration, Center for Developmental Biology, RIKEN, Kobe, Japan Department of Physiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Okamoto
authors.affiliation: Laboratory for Retinal Regeneration, Center for Developmental Biology, RIKEN, Kobe, Japan.
authors.forename: Tomoyo
authors.initials: T
authors.lastname: Hashiguchi
authors.affiliation: Laboratory for Retinal Regeneration, Center for Developmental Biology, RIKEN, Kobe, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Iseki
authors.affiliation: Laboratory for Retinal Regeneration, Center for Developmental Biology, RIKEN, Kobe, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Hayashi
authors.affiliation: Laboratory for Retinal Regeneration, Center for Developmental Biology, RIKEN, Kobe, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Mandai
authors.affiliation: Laboratory for Retinal Regeneration, Center for Developmental Biology, RIKEN, Kobe, Japan.
authors.forename: Masayo
authors.initials: M
authors.lastname: Takahashi
mesh_terms: D049109:Cell Proliferation; D002478:Cells, Cultured; D004247:DNA / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D006801:Humans; D007111:Immunity, Cellular; D007150:Immunohistochemistry; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology*; D060888:Real-Time Polymerase Chain Reaction; D055213:Retinal Pigment Epithelium / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000096:biosynthesis / Q000235:genetics
chemical_list: D016212:Transforming Growth Factor beta; D004247:DNA
keywords: PS cells; TGFβ; cytokine