title: Immunosuppressive drugs affect induction of IFNy+ Treg in vitro.
abstract: BACKGROUND
  We reported previously that patients with poor long-term graft function are able to form IFNy+ Treg in vitro pretransplant, but late posttransplant have more frequently undetectable or lower levels of IFNy+ Treg in the peripheral blood than patients with good long-term graft outcome. In the present study, we investigated the induction of IFNy+ and Tbet+ Treg subsets in the presence of immunosuppressants in vitro.
  
  
  METHODS
  PBL of 10 healthy individuals were stimulated with PMA/Ionomycin in the presence of different immunosuppressive drugs at 2 different concentrations that were chosen to approximately mirror the blood levels in renal transplant recipients. IFNy+, Tbet+, CD119+, and Helios+ CD4+CD25+CD127-Foxp3+ Treg subsets were analyzed using 8-color-fluorescence-flow-cytometry.
  
  
  RESULTS
  Cyclosporine (p<0.01) and 6α-methylprednisolone (p<0.05) at both concentrations as well as high doses of azathioprine (p<0.05) and mycophenolate mofetil (p<0.05) inhibited the induction of IFNy+ and Tbet+ Treg, whereas lower concentrations of azathioprine and mycophenolate mofetil tended to increase IFNy+, Tbet+ and CD119+ Treg (p⩽0.05).
  
  
  CONCLUSIONS
  Drug-induced inhibition of Treg induction might result in low IFNy+ Treg levels with the consequence of T effector activation and impaired graft function. Further studies will show whether monitoring of IFNy+ Treg might help to prevent clinical complications provoked by an inappropriate immunosuppressive protocol.
authors.affiliation: Department of Transplantation-Immunology, Institute of Immunology, University Hospital Heidelberg, Im Neuenheimer Feld 305, 69120 Heidelberg, Germany. Electronic address: Volker.Daniel@med.uni-heidelberg.de.
authors.forename: Volker
authors.initials: V
authors.lastname: Daniel
authors.affiliation: Department of Transplantation-Immunology, Institute of Immunology, University Hospital Heidelberg, Im Neuenheimer Feld 305, 69120 Heidelberg, Germany.
authors.forename: Karina
authors.initials: K
authors.lastname: Trojan
authors.affiliation: Department of Transplantation-Immunology, Institute of Immunology, University Hospital Heidelberg, Im Neuenheimer Feld 305, 69120 Heidelberg, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Opelz
mesh_terms: D015703:Antigens, CD / Q000378:metabolism; D001379:Azathioprine / Q000494:pharmacology; D002478:Cells, Cultured; D016572:Cyclosporine / Q000494:pharmacology; D006084:Graft Rejection / Q000188:drug therapy* / Q000276:immunology; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D007371:Interferon-gamma / Q000378:metabolism; D016030:Kidney Transplantation; D008213:Lymphocyte Activation / Q000187:drug effects; D008775:Methylprednisolone / Q000494:pharmacology; D009173:Mycophenolic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D020825:T-Box Domain Proteins / Q000235:genetics / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects* / Q000276:immunology; D000098815:T-bet Transcription Factor
chemical_list: D015703:Antigens, CD; D007166:Immunosuppressive Agents; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor; D007371:Interferon-gamma; D016572:Cyclosporine; D009173:Mycophenolic Acid; D001379:Azathioprine; D008775:Methylprednisolone
keywords: IFNy+ Treg; Immunosuppression; Immunosuppressive drugs; Induced Treg; Natural Treg; Tbet+ Treg; Th1-like Treg