Dendritic cells in atopic dermatitis: expression of FcepsilonRI on two distinct inflammation-associated subsets.
BACKGROUND
Dendritic cells (DCs) represent a major portion within the infiltrate of atopic dermatitis (AD) lesions. As antigen-presenting cells they have the ability to regulate both the quantity and quality of T-cell responses and, thus, are likely to play a key role in the pathogenesis of T-cell-dominated skin diseases such as AD. Thus we sought to identify the DC repertoire occurring in AD patients.


METHODS
For this purpose, we phenotypically analyzed various defined DC subsets of AD patients and healthy controls in skin biopsies and peripheral blood by immunofluorescence staining.


RESULTS
In AD lesions, two inflammation-associated DC subsets with varying expression of costimulatory molecules occurred besides epidermal Langerhans cells (LCs) and dermal myeloid DCs (dmDCs) indigenously residing in normal skin: (1) CD1a+/CD1c+/FcepsilonRI+/IgE+/CD207- myeloid DCs (mDCs) in the epidermis and dermis and (2) CD123+/BDCA-2+/CD45RA+/CD68+ plasmacytoid DCs (pDCs) in the dermis. In the peripheral blood of the patients, these cells exhibited an immature phenotype. Interestingly, we found FcepsilonRI and cell-bound IgE to be expressed not only on myeloid, but also on plasmacytoid DCs from both the skin and peripheral blood of AD patients.


CONCLUSIONS
It is tempting to speculate that the disease-regulating role of inflammatory DCs in AD is influenced by both FcepsilonRI occupancy and their degree of maturity.
Stary
Georg
G
Department of Dermatology, Division of Immunology, Allergy and Infectious Diseases, Medical University of Vienna, Vienna, Austria.
Bangert
Christine
C
Stingl
Georg
G
Kopp
Tamara
T
D000328:Adult; D001707:Biopsy, Needle; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D003876:Dermatitis, Atopic / Q000097:blood / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D016130:Immunophenotyping; D008297:Male; D008856:Microscopy, Fluorescence; D017455:Receptors, IgE / Q000096:biosynthesis* / Q000276:immunology
D017455:Receptors, IgE; D007073:Immunoglobulin E