Description
Urocanic acid (UCA) is a major epidermal chromophore that undergoes trans to cis photoisomerisation following exposure to solar ultraviolet radiation (UVR). Although there is considerable evidence that cis-UCA suppresses cell-mediated immune response in mouse skin, the molecular events are not fully understood. In this study, we examined involvement of gene transcription in the immunomodulatory effects of cis-UCA on primary human keratinocytes.