Solar-simulated ultraviolet irradiation induces selective influx of CD4+ T lymphocytes in normal human skin.
The proportion and composition of the human cutaneous CD3+ T lymphocyte population was determined in situ following a single exposure to physiological, erythema-inducing doses of simulated solar radiation, mainly consisting of UV radiation. Biopsies were taken 1, 2 and 7 days after local irradiation of normal volunteers with 1, 2 and 4 MED by a xenonarc lamp and immunohistochemistry was performed on cryostat sections. Ultraviolet radiation caused an initial decrease of intraepidermal CD3+ T-cell numbers or even could lead to T-cell depletion 24 and 48 h postirradiation, and this was followed by an infiltration of T cells in the epidermis as determined 1 week after UV exposure. The number of dermal CD3+ T cells was increased 24 h after irradiation, reached a maximum at 48 h and subsequently declined at day 7, though remained significantly higher than the unirradiated control. Double staining demonstrated that the CD3+ T cells, which immigrated into the (epi)dermis upon UV exposure, coexpressed CD4 but not CD8. Therefore the CD4/CD8 ratio in skin was markedly increased during the first week upon UV exposure. Our time course study shows that UV radiation affects the T-cell population within human skin by depleting the majority of epidermal T cells and initiating a selective influx of CD4+ T cells.
Di Nuzzo
S
S
Department of Dermatology, University of Amsterdam, The Netherlands.
de Rie
M A
MA
van der Loos
C M
CM
Bos
J D
JD
Teunissen
M B
MB
D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000528:radiation effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012867:Skin / Q000166:cytology / Q000528:radiation effects*; D013472:Sunlight; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000528:radiation effects
D015703:Antigens, CD