title: Vitamin D3 affects differentiation, maturation, and function of human monocyte-derived dendritic cells.
abstract: We studied the effects of 1alpha,25-dihydroxyvitamin D3 (1alpha, 25-(OH)2D3) on differentiation, maturation, and functions of dendritic cells (DC) differentiated from human monocytes in vitro in the presence of GM-CSF and IL-4 for 7 days. Recovery and morphology were not affected by 1alpha,25-(OH)2D3 up to 100 nM. DC differentiated in the presence of 10 nM 1alpha,25-(OH)2D3 (D3-DC) showed a marked decrease in the expression of CD1a, while CD14 remained elevated. Mannose receptor and CD32 were significantly increased, and this correlated with an enhancement of endocytic activity. Costimulatory molecules such as CD40 and CD86 were slightly decreased or nonsignificantly affected (CD80 and MHC II). However, after induction of DC maturation with LPS or incubation with CD40 ligand-transfected cells, D3-DC showed marginal increases in MHC I, MHC II, CD80, CD86, CD40, and CD83. The accessory cell function of D3-DC in classical MLR was also inhibited. Moreover, allogeneic T cells stimulated with D3-DC were poor responders in a second MLR to untreated DC from the same or an unrelated donor, thus indicating the onset of a nonspecific hyporesponsivity. In conclusion, our data suggest that 1alpha,25-(OH)2D3 may modulate the immune system, acting at the very first step of the immune response through the inhibition of DC differentiation and maturation into potent APC.
authors.affiliation: Laboratory of Experimental Surgery, Surgical Department, San Raffaele Scientific Institute, Milan, Italy. piermonti.lorenzo@hsr.it
authors.forename: L
authors.initials: L
authors.lastname: Piemonti
authors.forename: P
authors.initials: P
authors.lastname: Monti
authors.forename: M
authors.initials: M
authors.lastname: Sironi
authors.forename: P
authors.initials: P
authors.lastname: Fraticelli
authors.forename: B E
authors.initials: BE
authors.lastname: Leone
authors.forename: E
authors.initials: E
authors.lastname: Dal Cin
authors.forename: P
authors.initials: P
authors.lastname: Allavena
authors.forename: V
authors.initials: V
authors.lastname: Di Carlo
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000941:Antigens / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology / Q000187:drug effects* / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007108:Immune Tolerance / Q000187:drug effects; D007166:Immunosuppressive Agents / Q000494:pharmacology; D018664:Interleukin-12 / Q000096:biosynthesis; D009000:Monocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology* / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D000276:Adjuvants, Immunologic; D000941:Antigens; D007166:Immunosuppressive Agents; C118756:dihydroxy-vitamin D3; D014807:Vitamin D; D018664:Interleukin-12