title: Analogs of 1alpha,25-dihydroxyvitamin D3 as pluripotent immunomodulators.
abstract: The active form of vitamin D(3), 1,25(OH)(2)D(3), is known, besides its classical effects on calcium and bone, for its pronounced immunomodulatory effects that are exerted both on the antigen-presenting cell level as well as directly on the T lymphocyte level. In animal models, these immune effects of 1,25(OH)(2)D(3) are reflected by a strong potency to prevent onset and even recurrence of autoimmune diseases. A major limitation in using 1,25(OH)(2)D(3) in clinical immune therapy are the adverse side effects on calcium and on bone. TX527 (19-nor-14,20-bisepi-23-yne-1,25(OH)(2)D(3)) is a structural 1,25(OH)(2)D(3) analog showing reduced calcemic activity associated with enhanced in vitro and in vivo immunomodulating capacity compared to the mother-molecule. Indeed, in vitro TX527 is more potent that 1,25(OH)(2)D(3) in redirecting differentiation and maturation of dendritic cells and in inhibiting phytohemagglutinin-stimulated T lymphocyte proliferation. In vivo, this enhanced potency of TX527 is confirmed by a stronger potential to prevent type 1 diabetes in nonobese diabetic (NOD) mice and to prolong the survival of syngeneic islets grafts, both alone and in combination with cyclosporine A, in overtly diabetic NOD mice. Moreover, these in vivo effects of TX527 are obtained without the adverse side effects observed for 1,25(OH)(2)D(3) itself. We believe therefore that TX527 is a potentially interesting candidate to be considered for clinical intervention trails in autoimmune diseases.
authors.affiliation: Laboratory for Experimental Medicine and Endocrinology, Catholic University of Leuven, Leuven, Belgium.
authors.forename: Evelyne
authors.initials: E
authors.lastname: Van Etten
authors.forename: Brigitte
authors.initials: B
authors.lastname: Decallonne
authors.forename: Lieve
authors.initials: L
authors.lastname: Verlinden
authors.forename: Annemieke
authors.initials: A
authors.lastname: Verstuyf
authors.forename: Roger
authors.initials: R
authors.lastname: Bouillon
authors.forename: Chantal
authors.initials: C
authors.lastname: Mathieu
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000480:Alkynes; D000818:Animals; D002117:Calcitriol / Q000276:immunology / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002762:Cholecalciferol / Q000276:immunology / Q000494:pharmacology*; D003713:Dendritic Cells / Q000187:drug effects; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy / Q000276:immunology / Q000517:prevention & control; D005260:Female; D006801:Humans; D051379:Mice; D016688:Mice, Inbred NOD; D013601:T-Lymphocytes / Q000187:drug effects
chemical_list: D000276:Adjuvants, Immunologic; D000480:Alkynes; C409043:inecalcitol; D002762:Cholecalciferol; D002117:Calcitriol