Fig. 4.

(a) Melatonin inhibits the proliferation of 3DO.54·8-Th1-hybridoma. Th1-hybridoma cells were cultured with anti-CD3 antibodies in the presence of melatonin. The proliferation was measured by incorporation of ³H-thymidine. The data are represented as the mean ± s.d. of the cpm. •, αCD3 antibodies + MLT; ○, MLT. (b) Melatonin inhibits the secretion of IL-2 by Th1 hybridoma. The cultures were set as in (a). After 24 h of incubation of Th1-hybridoma, SN were collected and IL-2 levels were checked using HT-2 cells. The results expressed as the percentage inhibition in the IL-2 production were calculated by comparing the secretion of IL-2 by Th1-hybridoma incubated with anti-CD3 antibodies/ConA alone with the secretion from cells cultured with anti-CD3 antibodies/ConA and melatonin. □, 1·0 μg/ml;, 10 μg/ml;, 20 μg/ml;, 40 μg/ml;, 60 μg/ml;, 80 μg/ml; ⊞, 100·00 μg/ml.