title: Regulatory T cells induced by 1 alpha,25-dihydroxyvitamin D3 and mycophenolate mofetil treatment mediate transplantation tolerance.
abstract: 1alpha,25-dihydroxyvitamin D3, the active form of vitamin D3, and mycophenolate mofetil, a selective inhibitor of T and B cell proliferation, modulate APC function and induce dendritic cells (DCs) with a tolerogenic phenotype. Here we show that a short treatment with these agents induces tolerance to fully mismatched mouse islet allografts that is stable to challenge with donor-type spleen cells and allows acceptance of donor-type vascularized heart grafts. Peritransplant macrophages and DCs from tolerant mice express down-regulated CD40, CD80, and CD86 costimulatory molecules. In addition, DCs from the graft area of tolerant mice secrete, upon stimulation with CD4+ cells, 10-fold lower levels of IL-12 compared with DCs from acutely rejecting mice, and induce a CD4+ T cell response characterized by selective abrogation of IFN-gamma production. CD4+ but not CD8+ or class II+ cells from tolerant mice, transferred into naive syngeneic recipients, prevent rejection of donor-type islet grafts. Graft acceptance is associated with impaired development of IFN-gamma-producing type 1 CD4+ and CD8+ cells and an increased percentage of CD4+CD25+ regulatory cells expressing CD152 in the spleen and in the transplant-draining lymph node. Transfer of CD4+CD25+ cells from tolerant but not naive mice protects 100% of the syngeneic recipients from islet allograft rejection. These results demonstrate that a short treatment with immunosuppressive agents, such as 1alpha,25-dihydroxyvitamin D3/mycophenolate mofetil, induces tolerance to islet allografts associated with an increased frequency of CD4+CD25+ regulatory cells that can adoptively transfer transplantation tolerance.
authors.affiliation: Roche Milano Ricerche, Milan, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Gregori
authors.forename: M
authors.initials: M
authors.lastname: Casorati
authors.forename: S
authors.initials: S
authors.lastname: Amuchastegui
authors.forename: S
authors.initials: S
authors.lastname: Smiroldo
authors.forename: A M
authors.initials: AM
authors.lastname: Davalli
authors.forename: L
authors.initials: L
authors.lastname: Adorini
mesh_terms: D000284:Administration, Oral; D019264:Adoptive Transfer; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis; D018122:B7-1 Antigen / Q000096:biosynthesis; D051940:B7-2 Antigen; D015704:CD4 Antigens / Q000096:biosynthesis; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000637:transplantation; D019013:CD40 Antigens / Q000096:biosynthesis; D002117:Calcitriol / Q000008:administration & dosage*; D002465:Cell Movement / Q000276:immunology; D002478:Cells, Cultured; D015536:Down-Regulation / Q000276:immunology; D004359:Drug Therapy, Combination; D005260:Female; D006084:Graft Rejection / Q000276:immunology / Q000517:prevention & control; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D016381:Islets of Langerhans Transplantation / Q000276:immunology* / Q000473:pathology; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D009173:Mycophenolic Acid / Q000008:administration & dosage* / Q000031:analogs & derivatives*; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis; D016176:T-Lymphocyte Subsets / Q000187:drug effects* / Q000637:transplantation*; D023001:Transplantation Tolerance / Q000187:drug effects / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D015704:CD4 Antigens; D019013:CD40 Antigens; C497965:Cd86 protein, mouse; D007166:Immunosuppressive Agents; D008562:Membrane Glycoproteins; D015375:Receptors, Interleukin-2; D002117:Calcitriol; D009173:Mycophenolic Acid