IL-21 does not accelerate the decay of IL-4–induced germ line Cε transcripts in B cells.

Purified splenic B cells were stimulated with LPS (10 μg/mL) and IL-4 (20 ng/mL) for 15 hours and then incubated with or without IL-21 (10 ng/mL) in the presence of actinomycin D (10 μg/mL) for 1, 3, or 5 hours. Cells were harvested and RT-PCR analysis for germ line Cε transcripts and β-actin (as a control) was performed. Shown are representative data from 3 independent experiments.