[Cyclosporin A inhibits interleukin 5 (IL-5) production from human peripheral lymphocytes]

Inflammation of mucosa and epithelial damage the of bronchi are characteristic pathological features of asthma. Infiltration of T lymphocytes and eosinophils followed by their activation and release of cytokines seems to be a contributing process. We studied the interaction of interleukin 2 (IL-2) and interleukin 5 (IL-5), cytokines which act on eosinophils, using human peripheral lymphocytes. We found that cyclosporin A (CyA) inhibited the IL-5 production from human peripheral lymphocytes induced by IL-2 stimulation. Human peripheral lymphocytes were isolated from healthy volunteers and bronchial asthma patients with mild eosinophilia. Lymphocyte cultures stimulated with IL-2 were cultured at 37 degrees C in a humidified atmosphere of 5% CO2 in air. After 72 hours' incubation, the proliferative response of the lymphocytes was examined by [3H]thymidine uptake, and at the same time IL-5 in the supernatant of the culture medium was assayed by ELISA. The lymphocytes proliferated on IL-2 stimulation in all cases; IL-5 was detected in 3 out of 9 healthy volunteer cases and 7 out of 11 asthma patient cases. CyA added at the beginning of incubation inhibited both of these responses in a dose-dependent manner.