Suppression of Natural Killer Cell Activity in Humans by Radiation from Solarium Lamps Depleted of UVB

• Published in: Journal of investigative dermatology Vol. 90; no. 3; pp. 305 - 310
• Main Authors: Hersey, Peter, MacDonald, Malcolm, Henderson, Christine, Schibeci, Stephen, D'Alessandro, Gennaro, Pryor, Maureen, Wilkinson, Frank J.
• Format: Journal Article
• Language: English
• Published: Danvers, MA Elsevier Inc 01.03.1988; Nature Publishing
• Subjects: Adult; Animal models; Biological and medical sciences; Biopsy; Blood; Bone marrow; Dermatology; Epithelium - immunology; Female; Filtration; Humans; Hypersensitivity (delayed); Immune system; Injuries of the skin. Diseases of the skin due to physical agents; Interleukin-2 - biosynthesis; Killer Cells, Natural - immunology; Killer Cells, Natural - radiation effects; Langerhans cells; Lotions; Lymphocytes; Lymphocytes - classification; Lymphocytes - radiation effects; Male; Medical sciences; Natural killer cells; Neoplasia; Skin; Skin Tests; Sunscreens; Suppressor cells; Traumas. Diseases due to physical agents; U.V. radiation; Ultraviolet Rays; Natural killer cell; Skin disease; Ultraviolet radiation; Physical agent; Experimental study
• ISSN: 0022-202X; 1523-1747
• DOI: 10.1111/1523-1747.ep12456090

Previous studies have shown that ultraviolet radiation (UVR) from solarium lamps suppressed natural killer (NK) cell activity in the blood and that sunscreen lotions offered no protection against this effect. In the present study we tried to determine whether the effects on NK cell activity were caused by the UVB or the UVA components of radiation from solarium lamps by filtering out UVB with Mylar sheeting. Groups of 10 normal subjects were either left untreated or exposed for 30mm on 12 consecutive days to radiation that was filtered or not filtered through a 0.1mm thick Mylar sheeting. NK cell activity was depressed in the group exposed to solarium radiation and this was not prevented by filtration through Mylar. The latter procedure, however, appeared to prevent changes in blood lymphocyte subsets that are induced by solarium radiation as well as the reduction in Langerhans cell numbers in skin biopsies taken after exposure to solarium radiation. Suppression of NK cell activity was evident up to 14 days after cessation of UVR exposure. This would be consistent with the replacement of NK cells from bone marrow that had been damaged as a result of direct effects of UVA on NK cells in the microcirculation of the skin or else indicate functional suppression of NK cells by suppressor cells induced by UVR as postulated for UVR-induced suppression of delayed hypersensitivity responses in murine models. These studies suggest that UVA may be important in the induction of certain effects on the immune system in human subjects. Further studies are required to assess the implications of these findings with respect to induction of neoplasia and the design of sunscreens effective against UVA.