Dexamethasone suppressed IL-5 gene expression of human T-cell clones stimulated via TCR and IL-2R. (A) T-cell clone (YA5, 2 × 10⁶/well) was cultured in 24-well culture plates for the designated time periods. Some wells were pretreated with OKT3 MoAb (10 μg/mL), as indicated. rIL-2 (100 U/mL) was added to the designated wells. Dexamethasone (100 nmol/L) was included throughout the culture period in some wells, as indicated. Cells were harvested after 0, 4, 8, and 16 hours. Total RNA was then extracted, reverse transcribed, and amplified by PCR. The 279- and 1,128-bp products correspond with the expected size of IL-5 and β-actin amplification products, respectively. (B) T-cell clone (HK2 and HK5) was stimulated for 8 hours.