title: Differential T-helper cell polarization after allergen-specific stimulation of autologous dendritic cells in polysensitized allergic patients.
abstract: BACKGROUND
  Dendritic cells (DCs) play an important role in the induction and regulation of adaptive immune responses by polarizing T-helper (Th) cells. In allergic disease this response is dominated by Th2 cells. It is still unclear whether the activation of Th cells by DCs in atopic individuals is allergen specific.
  
  
  METHODS
  Monocyte-derived DCs (MoDCs) obtained from polysensitized patients were stimulated with purified Bet v 1, Phl p 5 and Act d 10, and the surface marker expression was analysed. Proliferation and cytokine profiles of autologous naïve CD4+ T cells co-cultured with allergen-pulsed MoDCs were assessed.
  
  
  RESULTS
  The addition of either Bet v 1 or Phl p 5 did not further increase the expression of surface markers from matured MoDCs in all study groups. In co-cultures, autologous naïve CD4+ T cells proliferated when DCs obtained from individuals allergic to birch and grass pollen were stimulated with Bet v 1 and Phl p 5, respectively. In the co-culture supernatants, significantly increased levels of IL-5 and IL-13 were detected. This effect correlated with the sensitization background and was absent when applying an unspecific allergen, Act d 10. The levels of IL-10 in supernatants of MoDCs and the levels of IL-10 and IFN-γ in supernatants of T cells remained unchanged upon stimulation with allergens.
  
  
  CONCLUSIONS
  In this study we observed that allergen-specific stimulation of MoDCs induces T-cell proliferation and upregulation of Th2-type cytokines. Interestingly, this Th2 polarization was only observed in cells stimulated with the allergen to which the patients were sensitized.
authors: Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria.
authors: Kazem
authors: K
authors: Ashjaei
authors: Merima
authors: M
authors: Bublin
authors: Ursula
authors: U
authors: Smole
authors: Nina
authors: N
authors: Lengger
authors: Christine
authors: C
authors: Hafner
authors: Heimo
authors: H
authors: Breiteneder
authors: Stefan
authors: S
authors: Wagner
authors: Karin
authors: K
authors: Hoffmann-Sommergruber
mesh_terms: D000328:Adult; D000485:Allergens / Q000276:immunology*; D052179:Antigens, Plant / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation / Q000187:drug effects; D018920:Coculture Techniques; D016207:Cytokines / Q000032:analysis / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010940:Plant Proteins / Q000276:immunology*; D012260:Ribonucleases / Q000276:immunology*; D018709:Statistics, Nonparametric; D055815:Young Adult
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D016207:Cytokines; D010940:Plant Proteins; C061312:Bet v 1 allergen, Betula; C102306:Phl p Vb protein, Phleum pratense; D012260:Ribonucleases