title: Dendritic cells as key targets for immunomodulation by Vitamin D receptor ligands.
abstract: Vitamin D receptor (VDR) ligands, in addition to controlling calcium metabolism, exert important effects on the growth and differentiation of many cell types and possess pronounced pro-tolerogenic immunoregulatory activities. VDR ligands can act directly on T cells, but antigen-presenting cells (APCs), and in particular dendritic cells (DCs), appear to be primary targets for their tolerogenic properties. The capacity of VDR ligands to target APCs and T cells is mediated by VDR expression in both cell types and by the presence of common targets in their signal transduction pathways, such as the nuclear factor NF-kB that is down-regulated in APCs and in T cells. VDR ligands can induce in vitro and in vivo tolerogenic DCs able to enhance CD4(+)CD25(+) suppressor T cells that, in turn, inhibit Th1 cell responses. These mechanisms of action can explain some of the immunoregulatory properties of VDR ligands, and are potentially relevant for the treatment of Th1-mediated autoimmune diseases and allograft rejection.
authors.affiliation: BioXell, Via Olgettina 58, I-20132 Milano, Italy. luciano.adorini@bioxell.com
authors.forename: Luciano
authors.initials: L
authors.lastname: Adorini
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Penna
authors.forename: Nadia
authors.initials: N
authors.lastname: Giarratana
authors.forename: Andrea
authors.initials: A
authors.lastname: Roncari
authors.forename: Susana
authors.initials: S
authors.lastname: Amuchastegui
authors.forename: Kenn C
authors.initials: KC
authors.lastname: Daniel
authors.forename: Milan
authors.initials: M
authors.lastname: Uskokovic
mesh_terms: D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism*; D018167:Receptors, Calcitriol / Q000378:metabolism*
chemical_list: D018167:Receptors, Calcitriol