Posted on the website on 1 February 2003.
Immunotoxic Effects of cis-Urocanic Acid Exposure in C57BL/6N and C3H/HeN Mice ¶
Article first published online: 1 MAY 2007
Photochemistry and Photobiology
Volume 77, Issue 4, pages 383–389, April 2003
How to Cite
Prater, M. R., Gogal, R. M., De Fabo, E. C., Longstreth, J. and Holladay, S. D. (2003), Immunotoxic Effects of cis-Urocanic Acid Exposure in C57BL/6N and C3H/HeN Mice . Photochemistry and Photobiology, 77: 383–389. doi: 10.1562/0031-8655(2003)0770383IEOCAE2.0.CO2
- Issue published online: 1 MAY 2007
- Article first published online: 1 MAY 2007
- Received 23 July 2002; accepted 13 December 2002
Exposure to ultraviolet radiation results in increased levels of intradermal cis-urocanic acid (cUCA) and alters cutaneous immunity by interfering with processing and presentation of antigen by Langerhans cells. Reports on effects of systemic immunotoxicity with 30 day cUCA exposure in laboratory rodents include thymic atrophy, thymic hypocellularity and decreased T-cell–mediated immunity; however, immune effects of single exposure or 5 day cUCA administration, which may better mimic human exposures, are poorly defined. The present study initially evaluated immune effects of single, 5 day, and 4 week cUCA exposure in C57BL/6N mice. Single administration of intradermal cUCA resulted in decreased splenocyte phagocytosis that persisted for 30 days after cUCA exposure. Five day consecutive cUCA exposure decreased numbers of phenotypically mature CD4+CD8− and CD4−CD8+ (single positive) thymocytes, increased CD4+CD8+ (double positive) immature thymocytes and increased splenocyte proliferation. Prolonged cUCA exposure (4 weeks) caused profound thymic hypocellularity and splenic hypercellularity and increased splenic macrophage chemiluminescence. Because of this apparent sensitivity of C57BL/6N mice to cUCA, thymic hypocellularity was compared between C57BL/6N and C3H/HeN mice dosed with cUCA, and was found to be more pronounced in the C57BL/6N strain. These results are an extension of previous conclusions on immune modulation caused by cUCA in the spleen and thymus. Further, the observed variation in sensitivity between the mouse strains is consistent with known genetic susceptibility of these strains to the immunomodulatory effects of exposure to sunlight.