title: In vivo reprogramming of UV radiation-induced regulatory T-cell migration to inhibit the elicitation of contact hypersensitivity.
abstract: BACKGROUND
  Regulatory T (Treg) cells induced by UV radiation (UVR) inhibit only the induction and not the elicitation of contact hypersensitivity (CHS) because they migrate into the lymph nodes but not the skin. The tissue-homing receptor expression and migratory behavior of Treg cells can be altered by means of in vitro coincubation with skin-derived antigen-presenting cells. On this in vitro treatment, Treg cells migrate into the skin and thus inhibit the elicitation of CHS.
  
  
  OBJECTIVE
  We attempted to determine whether Treg cells can be induced by UVR in sensitized mice and manipulated entirely in vivo in such a way that they suppress the elicitation of immune responses.
  
  
  METHODS
  Treg cells were induced by applying contact allergens onto UV-exposed skin in wild-type, langerin diphtheria toxin receptor knock-in, or depletion of Treg cell transgenic mice.
  
  
  RESULTS
  UVR-induced Treg cells inhibit the elicitation of CHS in sensitized mice when stimulated by means of an antigen-specific boost through the skin. This requires cutaneous antigen-presenting cells that alter the migratory behavior of Treg cells and drive them out of the lymph nodes into the skin.
  
  
  CONCLUSIONS
  The indication is that antigen-specific Treg cells can be induced in sensitized hosts and manipulated in such a way that they suppress the elicitation of specific immune reactions. Because this is achieved entirely in vivo without invasive interventions, our findings might have important implications for strategies aiming to induce and use Treg cells in a therapeutic setting.
authors.affiliation: Department of Dermatology and Allergology, University Kiel, Kiel, Germany.
authors.forename: Agatha
authors.initials: A
authors.lastname: Schwarz
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Navid
authors.forename: Tim
authors.initials: T
authors.lastname: Sparwasser
authors.forename: Björn E
authors.initials: BE
authors.lastname: Clausen
authors.forename: Thomas
authors.initials: T
authors.lastname: Schwarz
mesh_terms: D000485:Allergens / Q000009:adverse effects / Q000494:pharmacology; D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D000954:Antigens, Surface / Q000235:genetics / Q000276:immunology; D002465:Cell Movement / Q000235:genetics / Q000276:immunology / Q000528:radiation effects*; D002478:Cells, Cultured; D018920:Coculture Techniques; D003877:Dermatitis, Contact / Q000235:genetics / Q000276:immunology*; D055879:Gene Knock-In Techniques; D006801:Humans; D037181:Lectins, C-Type / Q000235:genetics / Q000276:immunology; D008198:Lymph Nodes / Q000276:immunology; D037241:Mannose-Binding Lectins / Q000235:genetics / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D014466:Ultraviolet Rays
chemical_list: D000485:Allergens; D000954:Antigens, Surface; C498497:Cd207 protein, mouse; D037181:Lectins, C-Type; D037241:Mannose-Binding Lectins