Figure 1: IL-21 induces Il1b mRNA expression via STAT3.

(a) cDCs were rested 1 h, treated with 100 ng ml⁻¹ IL-21 at the indicated time points, and Il1b mRNA assessed relative to Rpl7 by reverse transcription–PCR (RT–PCR). Shown is one of two similar experiments. (b) Il21r^+/+ and Il21r^−/− cDCs were treated with IL-21 for 5 h and Il1b mRNA assessed. (c) cDCs were rested 1 h, treated with 100 ng ml⁻¹ IL-21 or LPS at the indicated time points and Il1b mRNA assessed relative to Rpl7 by RT–PCR. Shown are the combined results of two independent experiments. (d) cDCs were incubated with 10 μM MLN120B for 1 h, treated with IL-21 or LPS for 4 h and Il1b mRNA assessed. (e) cDCs were rested 1 h, stimulated with 100 ng ml⁻¹ IL-21 or LPS for 30 min, and the expression of phosphorylated and total IκBα was determined. Shown is one of two similar experiments. (f,g) cDCs from Stat3^+/+ and Stat3^−/− mice were treated with IL-21 (f) or LPS (g) as in b, and Il1b mRNA assessed. In g, NS, P=0.3. Data in b and d–g are representative of three experiments; error bars are technical duplicates of the representative experiment; shown is expression relative to Rpl7 assessed by RT–PCR. (h) Human peripheral blood DCs were rested 16 h and stimulated with IL-21 for 15 min. pSTAT3 in CD1c⁺ cells was measured by flow cytometry. Shown are data representative of five samples in three experiments. (i) Human CD1c⁺ cDCs were rested 16 h, stimulated with IL-21 for 4 h, and IL1B mRNA relative to ACTB was assessed by RT–PCR. Data are from three experiments (six total samples); error bars are means±s.e.m. Statistical analysis was performed by Student’s t-test.