title: Delivery of alloantigens via apoptotic cells generates dendritic cells with an immature tolerogenic phenotype.
abstract: BACKGROUND
  Dendritic cells (DCs) are professional antigen-presenting cells able to induce immunity or tolerance. The interactions of immature DCs with naive T lymphocytes induce peripheral tolerance through mechanisms that include anergy or deletion of lymphocytes or the generation of regulatory T cells. Because of the central role of DCs in the immune response, they are potential targets for the induction of experimental tolerance. Thus, the generation of immature (tolerogenic) DCs able to capture and present alloantigens to T cells represents an important aim in our efforts to achieve better transplant acceptance.
  
  
  METHODS
  In this work, we generated immature DCs by using vitamin D(3) (VD3) during the process of DC differentiation.
  
  
  RESULTS
  The VD3-DCs showed an immature phenotype characterized by a low expression of major histocompatibility complex antigens of class II, CD86, and CD80 molecules and the secretion of a tolerogenic cytokine pattern. Furthermore, we showed that VD3-DCs phagocytose apoptotic allogeneic cells efficiently without inducing DC maturation or activation. Most important, our experiments demonstrated that mice treated with VD3 produce immature DCs in vivo, and that DCs from VD3-treated mice immunized with allogeneic apoptotic cells maintained their tolerogenic phenotype.
  
  
  CONCLUSIONS
  Our results show that allogeneic apoptotic cells in combination with VD3 generate DCs with tolerogenic characteristics that could be used to induce tolerance towards alloantigens.
authors.affiliation: Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile.
authors.forename: M A
authors.initials: MA
authors.lastname: Gleisner
authors.forename: M
authors.initials: M
authors.lastname: Rosemblatt
authors.forename: J A
authors.initials: JA
authors.lastname: Fierro
authors.forename: M R
authors.initials: MR
authors.lastname: Bono
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000276:immunology; D015214:Antigens, Differentiation, Myelomonocytic / Q000276:immunology; D017209:Apoptosis; D018122:B7-1 Antigen / Q000276:immunology; D002454:Cell Differentiation; D002478:Cells, Cultured; D002762:Cholecalciferol / Q000494:pharmacology; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D007108:Immune Tolerance; D016130:Immunophenotyping; D007519:Isoantigens / Q000276:immunology*; D008297:Male; D008546:Melanoma, Experimental / Q000235:genetics / Q000276:immunology; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009336:Necrosis; D010587:Phagocytosis; D010641:Phenotype; D060168:Thymocytes / Q000276:immunology* / Q000473:pathology / Q000637:transplantation; D013997:Time Factors; D014162:Transfection; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D018122:B7-1 Antigen; D002762:Cholecalciferol; D016207:Cytokines; D000949:Histocompatibility Antigens Class II; D007519:Isoantigens; D008565:Membrane Proteins; C081026:CD68 protein, mouse; D000097382:CD68 Molecule; C084881:flt3 ligand protein