Autocrine IL-10 is required for TTP-mediated control of STAT3 activation. A, Ttp+/+ and Ttp−/− BMDMs were incubated with medium alone (−) or with (+) LPS (100 ng/ml) in the absence or presence of IgG control antibody (10 ug/ml), Enbrel (10 ug/ml), or anti-IL-10 antibody (1.0 ug/ml), as indicated for 4 hours. Lysates were prepared and examined for STAT3 phosphorylation by immunoblotting. B, Relative amounts of phosphorylated STAT3 were determined relative to total STAT3. Each measurement represents the mean and SD (n = 3).