Immunosuppression by ultraviolet B radiation: initiation by urocanic acid.
Irradiation with UV-B, a component of natural sunlight, initiates systemic immunosuppression of delayed-type hypersensitivity responses. This may be a fundamental regulatory mechanism, controlling the interaction between mammals and potentially deleterious environmental UV radiation. Here, Frances Noonan and Edward De Fabo assess the evidence that suppression is initiated by the photoisomerization of trans-urocanic acid (UCA) in the stratum corneum, discuss the significance of this mechanism for skin cancer outgrowth and propose applications for UCA in transplantation.
Noonan
F P
FP
Dept of Dermatology, George Washington University, Washington, DC 20037.
De Fabo
E C
EC
D000818:Animals; D006085:Graft Survival / Q000528:radiation effects; D006638:Histidine Ammonia-Lyase / Q000172:deficiency / Q000235:genetics / Q000502:physiology; D007108:Immune Tolerance / Q000528:radiation effects*; D007536:Isomerism; D051379:Mice; D008817:Mice, Mutant Strains / Q000378:metabolism; D010777:Photochemistry; D012867:Skin / Q000737:chemistry / Q000528:radiation effects*; D016038:Skin Transplantation / Q000276:immunology; D014466:Ultraviolet Rays; D014560:Urocanic Acid / Q000528:radiation effects*
D006638:Histidine Ammonia-Lyase; D014560:Urocanic Acid