title: Immunosuppression by IL-10-transfected human retinal pigment epithelial cells in vitro.
abstract: OBJECTIVE
  Retinal pigment epithelium (RPE) transplantation seems to be a possible therapy for restoring vision in the case of retinal degeneration. As there is a risk of allergic rejection, a gene-transfer of immunosuppressive cytokines into the graft may diminish this reaction. Therefore, we investigated the transfer of interleukin-10 (IL-10) into an immortalised human RPE cell line (hTERT-RPE1) and its effect on the proliferation of allogeneic immune competent cells.
  
  
  METHODS
  The hTERT-RPE1 cells were transiently transfected with the cDNA of human IL-10 using a lipid-based transfection reagent. The expression of IL-10 mRNA was ana-lysed by reverse transcription-polymerase chain reaction and an enzyme-linked immunosorbent assay measured the secretion of the cytokine over 7 days. The effect of the secreted IL-10 on the proliferation of allogeneic T cells with and without homologous macrophages was investigated colorimetrically. To enhance this reaction, RPE cells were pre-activated with interferon-gamma (IFN-gamma). Anti-IL-10 antibodies were used in a neutralising assay.
  
  
  RESULTS
  A transfection efficiency of 23.3 +/- 9.03% was achieved. IL-10 mRNA could only be shown in IL-10-transfected hTERT-RPE1 cells. The same was found for the level of cytokine, with a maximum on day 3 (10.34 +/- 0.09 ng/ml). A significant suppressive effect of the secreted IL-10 on T-cell proliferation was detectable on days 5 and 6. This effect could be significantly abolished with anti-IL-10 antibodies.
  
  
  CONCLUSIONS
  The IL-10-producing hTERT-RPE1 cells had an immunosuppressive action on T-cell proliferation in vitro. A gene-transfer into RPE allografts before transplantation may be able to promote graft survival.
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, University of Leipzig, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Enzmann
authors.forename: M
authors.initials: M
authors.lastname: Hollborn
authors.forename: K
authors.initials: K
authors.lastname: Poschinger
authors.forename: P
authors.initials: P
authors.lastname: Wiedemann
authors.forename: L
authors.initials: L
authors.lastname: Kohen
mesh_terms: D002455:Cell Division; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007165:Immunosuppression Therapy; D007371:Interferon-gamma / Q000494:pharmacology; D016753:Interleukin-10 / Q000235:genetics* / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects / Q000502:physiology; D008264:Macrophages / Q000502:physiology; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000276:immunology*; D014162:Transfection
chemical_list: D012333:RNA, Messenger; D016753:Interleukin-10; D007371:Interferon-gamma