PTPεC inhibits IL-10–induced activation of STAT3.

(A) Binding of biotinylated IL-10 to M1 stable clones was analyzed by flow cytometry as described in “Materials and methods.” (B) M1 stable clones were treated with IL-10 at 20 ng/mL for 20 minutes and lysed. STAT3 tyrosine phosphorylation was analyzed as in Figure 2. (C) Total RNA was prepared from M1 stable clones cultured for 20 hours in the presence of 20 ng/mL IL-10 and analyzed for expression of FcγRI and β-actin mRNA by Northern blotting (upper panel). Data represent 1 of 3 independent experiments.