title: Ex vivo generation of human alloantigen-specific regulatory T cells from CD4(pos)CD25(high) T cells for immunotherapy.
abstract: BACKGROUND
  Regulatory T cell (Treg) based immunotherapy is a potential treatment for several immune disorders. By now, this approach proved successful in preclinical animal transplantation and auto-immunity models. In these models the success of Treg based immunotherapy crucially depends on the antigen-specificity of the infused Treg population. For the human setting, information is lacking on how to generate Treg with direct antigen-specificity ex vivo to be used for immunotherapy.
  
  
  RESULTS
  Here, we demonstrate that in as little as two stimulation cycles with HLA mismatched allogeneic stimulator cells and T cell growth factors a very high degree of alloantigen-specificity was reached in magnetic bead isolated human CD4(pos)CD25(high) Treg. Efficient increases in cell numbers were obtained. Primary allogeneic stimulation appeared a prerequisite in the generation of alloantigen-specific Treg, while secondary allogeneic or polyclonal stimulation with anti-CD3 plus anti-CD28 monoclonal antibodies enriched alloantigen-specificity and cell yield to a similar extent.
  
  
  CONCLUSIONS
  The ex vivo expansion protocol that we describe will very likely increase the success of clinical Treg-based immunotherapy, and will help to induce tolerance to selected antigens, while minimizing general immune suppression. This approach is of particular interest for recipients of HLA mismatched transplants.
authors.affiliation: Department of Bloodtransfusion and Transplantation Immunology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: Jorieke H
authors.initials: JH
authors.lastname: Peters
authors.forename: Luuk B
authors.initials: LB
authors.lastname: Hilbrands
authors.forename: Hans J P M
authors.initials: HJ
authors.lastname: Koenen
authors.forename: Irma
authors.initials: I
authors.lastname: Joosten
mesh_terms: D015704:CD4 Antigens / Q000276:immunology*; D017635:Clonal Anergy; D005434:Flow Cytometry; D006801:Humans; D007167:Immunotherapy; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology*; D007519:Isoantigens / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D015704:CD4 Antigens; D053645:Interleukin-2 Receptor alpha Subunit; D007519:Isoantigens