title: Induction of immunosuppressive functions of dendritic cells in vivo by CD4+CD25+ regulatory T cells: role of B7-H3 expression and antigen presentation.
abstract: Suppressive functions of CD4+CD25+ regulatory T cells (Treg) are mainly studied by their interaction with conventional T cells. However, there is evidence that Treg also interact with antigen-presenting cells (APC), leading to suppression of APC function in in vitro coculture systems. Studying the in vivo distribution of Treg after injection, we found that Treg are located in direct proximity to dendritic cells (DC) and affect their functional maturation status. After contact to Treg, DC up-regulate the inhibitory B7-H3 molecule and display reduced numbers of MHC-peptide complexes, leading to impaired T cell stimulatory function. When Treg-exposed DC were used to immunize animals against antigens, the DC failed to produce a robust immune response as compared to control DC. Thus, these data indicate that Treg are able to inhibit DC activation and produce an inhibitory phenotype of DC. Accordingly, Treg may recruit DC for the amplification of immunosuppression by restraining their maturation in vivo and inducing an immunosuppressive phenotype of DC.
authors.affiliation: Department of Dermatology, University Hospital Heidelberg, Heidelberg, Germany. karsten.mahnke@med.uni-heidelberg.de
authors.forename: Karsten
authors.initials: K
authors.lastname: Mahnke
authors.forename: Sabine
authors.initials: S
authors.lastname: Ring
authors.forename: Theron S
authors.initials: TS
authors.lastname: Johnson
authors.forename: Sonja
authors.initials: S
authors.lastname: Schallenberg
authors.forename: Kurt
authors.initials: K
authors.lastname: Schönfeld
authors.forename: Volker
authors.initials: V
authors.lastname: Storn
authors.forename: Tanja
authors.initials: T
authors.lastname: Bedke
authors.forename: Alexander H
authors.initials: AH
authors.lastname: Enk
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D060887:B7 Antigens; D018122:B7-1 Antigen / Q000276:immunology; D015704:CD4 Antigens / Q000276:immunology; D002450:Cell Communication / Q000276:immunology; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000276:immunology*; D005434:Flow Cytometry; D016753:Interleukin-10 / Q000276:immunology; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D060887:B7 Antigens; D018122:B7-1 Antigen; D015704:CD4 Antigens; C486038:Cd276 protein, mouse; D053645:Interleukin-2 Receptor alpha Subunit; D016753:Interleukin-10