title: Photopheresis with UV-A light and 8-methoxypsoralen leads to cell death and to release of blebs with anti-inflammatory phenotype in activated and non-activated lymphocytes.
abstract: BACKGROUND
  Extracorporeal photopheresis is a therapy for treatment of autoimmune diseases, cutaneous T-cell lymphoma, organ graft rejection as well as graft-versus-host diseases. The exact mechanism how the combination of 8-methoxypsoralen plus UV-A irradiation (PUVA) acts is still unclear. We investigated the cell death of activated and non-activated lymphocytes after PUVA treatment as well as the rate of released blebs and their antigen composition.
  
  
  RESULTS
  In presence of 8-MOP, UV-A light highly significantly increased the cell death of activated lymphocytes. The same was observed to a lesser extent in non-activated cells. Blebs derived from activated lymphocytes after PUVA treatment showed the highest surface exposition of phosphatidylserine. These blebs also displayed a high exposure of the antigens CD5 and CD8 as well as a low exposure of CD28 and CD86.
  
  
  CONCLUSIONS
  PUVA treatment exerts anti-inflammatory effects by inducing apoptosis and apoptotic cell-derived blebs with immune suppressive surface composition.
authors.affiliation: Department for Internal Medicine 3, University Hospital Erlangen, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Stadler
authors.forename: B
authors.initials: B
authors.lastname: Frey
authors.forename: L E
authors.initials: LE
authors.lastname: Munoz
authors.forename: S
authors.initials: S
authors.lastname: Finzel
authors.forename: J
authors.initials: J
authors.lastname: Rech
authors.forename: R
authors.initials: R
authors.lastname: Fietkau
authors.forename: M
authors.initials: M
authors.lastname: Herrmann
authors.forename: A
authors.initials: A
authors.lastname: Hueber
authors.forename: U S
authors.initials: US
authors.lastname: Gaipl
mesh_terms: D000954:Antigens, Surface / Q000276:immunology; D017209:Apoptosis; D001768:Blister / Q000276:immunology; D002478:Cells, Cultured; D006801:Humans; D007249:Inflammation / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects / Q000528:radiation effects; D008214:Lymphocytes / Q000187:drug effects* / Q000528:radiation effects*; D008730:Methoxsalen / Q000494:pharmacology*; D010718:Phosphatidylserines / Q000276:immunology; D017893:Photopheresis; D014466:Ultraviolet Rays
chemical_list: D000954:Antigens, Surface; D010718:Phosphatidylserines; D008730:Methoxsalen