CD7-negative helper T cells accumulate in inflammatory skin lesions.
Recently, we identified a particular T-cell subset in the peripheral blood of normal individuals that lack CD7 expression. In this study we determined the portion of CD7- T cells in the peripheral blood and skin of patients with various inflammatory skin diseases. We found that skin-infiltrating lymphocytes isolated from different benign and malignant skin lesions (n = 20) contain a high portion of CD7- helper T cells, whereas the number of CD7- T cells in the peripheral blood was not altered compared to healthy controls. Cell activation in vitro did not induce CD7 expression in negative T cells but increased CD7 expression in CD7-positive cells. Thus, lack of CD7 expression seems to be a stable characteristic in a major subset of skin-infiltrating lymphocytes. During long-term culture of CD7- helper T-cell clones derived from a psoriasis skin lesion, no phenotypic change in the CD7 phenotype could be monitored by sequential flow-cytometric analyses. No CD7 mRNA could be detected by Northern blot analysis, indicating transcriptional regulation of CD7 expression. The results show that CD7- T cells accumulate in certain inflammatory skin lesions without alteration of the circulating CD7- population. These cells may be identical to or derived from CD7- T cells of the peripheral blood.
Moll
M
M
Department of Dermatology, University of Bonn, Germany.
Reinhold
U
U
Kukel
S
S
Abken
H
H
Müller
R
R
Oltermann
I
I
Kreysel
H W
HW
D015703:Antigens, CD / Q000032:analysis* / Q000235:genetics; D019011:Antigens, CD7; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis* / Q000235:genetics; D002469:Cell Separation; D002999:Clone Cells; D003872:Dermatitis / Q000097:blood / Q000276:immunology* / Q000473:pathology*; D003876:Dermatitis, Atopic / Q000276:immunology / Q000473:pathology; D005455:Fluorescent Antibody Technique; D006801:Humans; D016130:Immunophenotyping; D008214:Lymphocytes / Q000166:cytology; D016410:Lymphoma, T-Cell, Cutaneous / Q000276:immunology / Q000473:pathology; D010915:Pityriasis / Q000276:immunology / Q000473:pathology; D011565:Psoriasis / Q000276:immunology / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D014158:Transcription, Genetic
D015703:Antigens, CD; D019011:Antigens, CD7; D000945:Antigens, Differentiation, T-Lymphocyte; D012333:RNA, Messenger