title: Increased production of soluble HLA-G molecules in stimulated peripheral blood mononuclear cells following extracorporeal photopheresis: is it a mechanism involved in the therapeutic effect of the procedure?
abstract: We hypothesized that the effects of extracorporeal photopheresis (ECP) are mediated by induction of immunosuppressive cytokines like IL-10, which enhances synthesis of HLA-G molecules. HLA-G products are expressed by CD14+ peripheral blood mononuclear cells (PBMC) and play an important role in inhibition of cell mediated immunity. ECP induces apoptosis in lymphocytes but not in CD14+ cells. We, therefore, investigated the concentrations both of IL-10 and of soluble HLA-G5/sHLA-G1 molecules in supernatants from cultures of lipopolysaccharide-stimulated PBMC obtained from leukocyte collection bags of 10 patients receiving ECP for graft versus host disease both before (pre-irradiation) and after (post-irradiation) exposure to 8-methoxypsoralen and UVA irradiation. Levels of both IL-10 and HLA-G5/sHLA-G1 molecules were increased in the post-irradiation cultures. This suggests that therapeutic effects of ECP could be mediated by increased production of IL-10 and tolerogenic HLA-G molecules.
authors.affiliation: Department of Experimental and Diagnostic Medicine, Section of Medical Genetics, University of Ferrara, Ferrara, Italy. rbr@unife.it
authors.forename: Roberta
authors.initials: R
authors.lastname: Rizzo
authors.forename: Loredana
authors.initials: L
authors.lastname: Melchiorri
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Tazzari
authors.forename: Cristina
authors.initials: C
authors.lastname: Tassi
authors.forename: Maurizio
authors.initials: M
authors.lastname: Soli
authors.forename: Monica
authors.initials: M
authors.lastname: Lunghi
authors.forename: Maurizio
authors.initials: M
authors.lastname: Belloni
authors.forename: Roberto
authors.initials: R
authors.lastname: Conte
authors.forename: Olavio R
authors.initials: OR
authors.lastname: Baricordi
mesh_terms: D002478:Cells, Cultured; D006086:Graft vs Host Disease / Q000378:metabolism / Q000628:therapy*; D006680:HLA Antigens / Q000096:biosynthesis*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis*; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis*; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D017893:Photopheresis
chemical_list: D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I; D008070:Lipopolysaccharides; D016753:Interleukin-10