Identification of lesional CD4+ CD25+ Foxp3+ regulatory T cells in Psoriasis.
BACKGROUND
Depletion of CD4+ CD25+ Foxp3+ naturally occurring regulatory T cells (T(reg)) induces autoimmune phenomena. These cells have not yet been fully characterized in the skin of psoriatic patients.


OBJECTIVE
To prove that the Zenon immunofluorescent labeling technique is suitable for the demonstration of co-localization of T-cell markers and in particular to show the distribution of T(reg) in psoriatic skin.


METHODS
In biopsies derived from normal and psoriatic skin, CD4+ CD25+, CD4+ CD45RO+, CD8+ CD25+, CD8+ CD45RO+ and CD4+ CD25+ Foxp3+ cells in the dermis and in the epidermis were immunophenotyped, using a quantitative immunofluorescent labeling technique (Zenon), analyzed and compared using image analysis.


RESULTS
The immunofluorescent labeling technique was shown to be an easy and reliable tool to demonstrate co-localization of T-cell markers. In psoriasis, all pathogenic T-cell subsets (CD4+ CD25+, CD4+ CD45RO+, CD8+ CD25+ and CD8+ CD45RO+ cells) were significantly increased in the dermis and in the epidermis, as compared to normal skin (all p < 0.05). Using this labeling technique we were able to reveal CD4+ CD25+ Foxp3+ T(reg) in psoriatic dermis, but not in the dermis of normal skin (p < 0.0001).


CONCLUSIONS
The Zenon immunofluorescence technique in combination with image analysis is suitable for the demonstration of co-localization of T-cell markers in tissue. Increased numbers of pathogenic T cells (CD4+ CD25+, CD4+ CD45RO+, CD8+ CD25+ and CD8+ CD45RO+) were shown in the dermis and epidermis, whereas CD4+ CD25+ Foxp3+ T(reg) were identified in psoriatic skin with a predilection for the upper dermis.
Bovenschen
H J
HJ
Department of Dermatology, Radboud University Nijmegen Medical Center, The Netherlands. j.bovenschen@derma.umcn.nl
van Vlijmen-Willems
I M J J
IM
van de Kerkhof
P C M
PC
van Erp
P E J
PE
D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D015704:CD4 Antigens / Q000378:metabolism*; D004817:Epidermis / Q000378:metabolism / Q000473:pathology; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism*; D008297:Male; D008856:Microscopy, Fluorescence; D011565:Psoriasis / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism
D015415:Biomarkers; D015704:CD4 Antigens; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit