Effects of ultraviolet-irradiated urocanic acid on IL-10 secreted by T lymphocytes.
OBJECTIVE
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Bi
Z
Z
Department of Dermatology, First Affiliated Hospital of Nanjing Medical University, No. 300 Guang Zhou Road, Nanjing 210029, China. zgbi@njmu.edu.cn
Xia
J
J
Ni
L
L
D000328:Adult; D006801:Humans; D016753:Interleukin-10 / Q000235:genetics / Q000378:metabolism*; D010835:Phytohemagglutinins; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D014466:Ultraviolet Rays; D014560:Urocanic Acid / Q000494:pharmacology* / Q000528:radiation effects
D010835:Phytohemagglutinins; D012333:RNA, Messenger; D016753:Interleukin-10; D014560:Urocanic Acid