Peripheral blood dendritic cells express Fc epsilon RI as a complex composed of Fc epsilon RI alpha- and Fc epsilon RI gamma-chains and can use this receptor for IgE-mediated allergen presentation.

摘要: Originally limited to basophils and mast cells, the spectrum of high affinity IgE receptor (Fc epsilon RI-bearing cells has expanded recently include Langerhans dermal dendritic (DC), monocytes, eosinophils. As a result studies on distribution, structure, function Fc RI APCs, we discovered minor nonbasophil, nonmonocyte PBMC population that can bind via RI. This occurs surface these as multimeric structure containing alpha- gamma-chains but, unlike its counterpart basophils, lacking beta. Further experiments revealed alpha gamma-expressing closely resemble peripheral blood DC by immunophenotype (HLA-DRhigh, HLA-DQhhigh; CD4+, CD11a+, CD32+, CD33+, B7/2 (CD86)+; CD11blow, CD14low, CD40low, CD54low, CD64low) cell morphology. These features allowed us isolate RI-expressing from investigate their immunostimulatory properties. We found RI-positive be efficient stimulators both primary (allogeneic MLR) RI/IgE-dependent, secondary T responses at low numbers. Thus, may not only amplify established type I allergic immune reactions semiprofessional able prime naive common and/or cryptic epitopes IgE-reactive Ags.