Bet v 1 and its homologous food allergen Api g 1 stimulate dendritic cells from birch pollen-allergic individuals to induce different Th-cell polarization.
BACKGROUND
Bet v 1 is the most relevant sensitizing protein for birch pollen (BP)-allergic individuals. Its homologues from plant foods are mainly involved in allergic reactions caused by IgE cross reactivity. We aimed to evaluate the polarizing effect of dendritic cells (DCs) pulsed with Bet v 1, Mal d 1, Api g 1 or Dau c 1 on Th-cell responses.


METHODS
Immature DCs were generated from peripheral blood monocytes of BP-allergic and healthy donors by culture with GM-CSF and IL-4 and subsequently pulsed with allergens in combination with maturation factors. Cell surface markers were analysed by FACS. Mature DCs were co-cultured with autologous Th cells and T-cell proliferation and cytokine profiles were determined.


RESULTS
In co-culture, mature allergen-pulsed DCs induced autologous Th cells of BP-allergic donors to proliferate significantly more than those of healthy individuals. Exposure of DCs from BP-allergic donors to Bet v 1 resulted in a robust Th2 skewing with significantly higher quantities of IL-5 and elevated IL-13 compared to maturation factors. In contrast, Api g 1-primed DCs from BP allergics significantly enhanced the production of the Th1 cytokine IFN-γ and significantly down-regulated IL-13 compared to maturation factors. In healthy donors, no significant cytokine production could be detected.


CONCLUSIONS
Bet v 1 in contrast to homologous food allergens seems to possess distinct molecular features that enable it to condition DCs from BP-allergic donors to induce allergen-specific T-cell proliferation and Th2 polarization.
Smole
U
U
Department of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology, and Immunology, Medical University of Vienna Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna, Austria.
Wagner
S
S
Balazs
N
N
Radauer
C
C
Bublin
M
M
Allmaier
G
G
Hoffmann-Sommergruber
K
K
Breiteneder
H
H
D000328:Adult; D000485:Allergens / Q000276:immunology; D052179:Antigens, Plant / Q000276:immunology*; D029662:Betula / Q000276:immunology; D016764:Cell Polarity; D002478:Cells, Cultured; D018920:Coculture Techniques; D003429:Cross Reactions; D016207:Cytokines / Q000096:biosynthesis; D003713:Dendritic Cells / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D010940:Plant Proteins / Q000276:immunology*; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology*; D018417:Th1 Cells / Q000166:cytology / Q000276:immunology; D018418:Th2 Cells / Q000166:cytology / Q000276:immunology
D000485:Allergens; D052179:Antigens, Plant; C096695:Api g 1 protein, Apium graveolens; D016207:Cytokines; C119925:Dau c 1 protein, Daucus carota; C095551:MALD1 protein, Malus domestica; D010940:Plant Proteins; C061312:Bet v 1 allergen, Betula