title: Lack of FasL expression in cultured human retinal pigment epithelial cells.
abstract: Retinal pigment epithelial (RPE) cells have been proposed to play a part in maintaining the eye as an immune privileged organ. However, our knowledge of the implicated mechanism is still sparse. Fas ligand (FasL) expression of RPE cells is generally recognized to be essential for the immune privilege of the eye, but due to contradictory published results, it is unclear whether RPE cells express this molecule. The purpose of this study was to investigate the expression of FasL in RPE cells in vitro and in vivo. Cultured human fetal and adult RPE cells were examined by flow cytometry, Western blotting, RT-PCR and RNase Protection assay for FasL expression. Additionally, sections of ocular tissue were stained for FasL by immunohistochemistry. None of the used methods indicated FasL expression in cultured fetal or adult RPE cells of various passages. However, RPE cells in vivo, as judged from tissue sections, were positive for FasL, indicating a discrepancy between RPE cells in vitro and in vivo with regard to this molecule.
authors.affiliation: Institute of Medical Anatomy, Section A, The Panum Institute, University of Copenhagen, Copenhagen, Denmark.
authors.forename: C G
authors.initials: CG
authors.lastname: Kaestel
authors.forename: H O
authors.initials: HO
authors.lastname: Madsen
authors.forename: J U
authors.initials: JU
authors.lastname: Prause
authors.forename: A
authors.initials: A
authors.lastname: Jørgensen
authors.forename: Y
authors.initials: Y
authors.lastname: Liang
authors.forename: M
authors.initials: M
authors.lastname: la Cour
authors.forename: G M
authors.initials: GM
authors.lastname: Lui
authors.forename: N
authors.initials: N
authors.lastname: Odum
authors.forename: M H
authors.initials: MH
authors.lastname: Nissen
authors.forename: C
authors.initials: C
authors.lastname: Röpke
mesh_terms: D000328:Adult; D015153:Blotting, Western; D002460:Cell Line; D053222:Fas Ligand Protein; D005333:Fetus; D005434:Flow Cytometry; D006801:Humans; D007106:Immune Sera / Q000378:metabolism; D007150:Immunohistochemistry; D008024:Ligands; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012260:Ribonucleases / Q000378:metabolism; D019014:fas Receptor / Q000378:metabolism*
chemical_list: C505661:FASLG protein, human; D053222:Fas Ligand Protein; D007106:Immune Sera; D008024:Ligands; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D019014:fas Receptor; D012260:Ribonucleases