Exposure to multiple doses of UVB radiation reduces the numbers of epidermal Langerhans cells and lymph node dendritic cells in mice.
Immune suppression following UVB irradiation is partly attributed to the effects of the exposure on antigen-presenting cells. Following a single UVB irradiation, there is a decrease in epidermal Langerhans cell numbers; this is accompanied by an increase in the number of dendritic cells (DC) in lymph nodes draining the irradiated site. We investigated whether a similar effect occurred following multiple UVB exposures. Mice were irradiated on their ears and shaved dorsal skin twice a week for 3 weeks. After the final exposure, the number of ATPase(+) Langerhans cells in epidermal sheets prepared from the ears was found to be decreased by 33% compared to unirradiated controls. The number of DC in the draining lymph nodes (DLN) did not increase as might have been expected; rather, a significant decrease of approximately 30% in DC numbers in the DLN of UVB-irradiated mice compared with unirradiated controls occurred. This decrease in antigen-presenting cells in both the epidermis and the DLN may be an important contributing factor to the immune suppression that follows multiple UVB exposures.
Macve
Joanna C
JC
Medical Microbiology, University of Edinburgh Medical School, Teviot Place, Edinburgh, UKEH8 9AG.
McKenzie
Roddie C
RC
Norval
Mary
M
D000818:Animals; D002462:Cell Membrane / Q000528:radiation effects; D003713:Dendritic Cells / Q000166:cytology / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D007801:Langerhans Cells / Q000166:cytology / Q000528:radiation effects*; D008198:Lymph Nodes / Q000166:cytology / Q000528:radiation effects*; D051379:Mice; D008809:Mice, Inbred C3H; D014466:Ultraviolet Rays