Abstract: AIM: To investigate the effects of low-dose theophylline on differentiation of the naive T lympho-cyte.METHODS: Naive T lymphocytes and monocytes were isolated from cord blood in neonate. Theophylline (10 mg·L^-1) was added in naive T lymphocytes and monocytes which stimulated by PHA (200 mg·L^-1) for 3 days, and the differentiation of T cells was analyzed by flow cytometry. Cytokines were measured by enzyme linked immuno-sorbent assay (ELISA). RESULTS: Theophylline significantly promoted differentiation from Thl cells to naive T cells (P < 0.05), but it had no sig-nificant effect on differentiation to Th2. The ratio of Thl/Th2 was increased (P < 0.05). The production of IL-4 and IL-5 were lower and IFN-y was higher than that in the control group (P < 0.05). CONCLUSION: Low-dose theophylline can modulate the differentiation of naive T cells and exert its anti-inflammatory effect.

Key words: phaimacodynainics, asthma, theophylline, Thl cells, Th2 cells, cytokine