Effects of ultraviolet-irradiated urocanic acid on IL-10 secreted by T lymphocytes
Bi, Z.; Xia, J.; Ni, L.
Chinese Medical Journal 112(6): 509-511
1999
ISSN/ISBN: 0366-6999 PMID: 11601328 Document Number: 500025
To further investigate the effects of ultraviolet (UV)-irradiated urocanic acid (UCA) on T lymphocytes, the effects of cis-UCA on T lymphocyte IL-10 secretion was studied. Four groups of normal lymphocytes were cultured in RPMI-1640 containing 15% fetal calf serum. Besides negative and phytohemagglutinin (PHA) positive control, the cis-UCA and trans-UCA groups were set. The number of lymphocytes was 1.5 x 10(6). PHA was 0.05 mg/ml in each group. Both cis-UCA and trans-UCA were detected by 1.00, 0.75, 0.50 and 0.20 mmol/L respective concentrations. IL-10 was detected by ELISA method after 48 hours' culture. IL-10 mRNA expression level was assayed by RT-PCR. The results indicated cis-UCA could reduce IL-10 secreted by T lymphocytes much more than trans-UCA (t = 2.91, P < 0.05) could. It was also found that the concentrations of cis-UCA were negatively correlated with IL-10 levels (r = -0.99, tr = 9.23, P < 0.01). The IL-10 mRNA expression of T lymphoctytes was inhibited by cis-UCA. Our investigations revealed that cis-UCA, a major UV receptor in the stratum comeum of epidermis, could inhibit T lymphoctes secreting IL-10 by suppressing IL-10 mRNA expression, finally affects the humoral immune response.