FIG. 3.

PI3K plays a role in cmvIL-10-mediated cytokine suppression. (A) LPS-stimulated monocytes (1 ng/ml) were incubated with a panel of different commercially available signal transduction inhibitors [JAK3 inhibitor 4-(4′-hydroxyphenyl)amino-6,7-dimethoxyquinazoline (Calbiochem), MEK1 inhibitor U0126 and PI3K inhibitor LY249002 (Cell Signaling), or wortmannin and p38 mitogen-activated protein kinase inhibitor SB203580 (Sigma)] in the presence or absence of 10 ng/ml cmvIL-10. Trypan blue analysis confirmed cells from each treatment were viable and then supernatants were analyzed for TNF-α levels by ELISA after 18 h. Gray bars, LPS treatment only; black bars, LPS plus cmvIL-10. Statistical analysis showed that TNF-α levels increased significantly in the presence of cmvIL-10 only with treatment with PI3K inhibitors LY249002 and wortmannin. *, P < 0.01, Student's t test. Results are representative of experiments performed on cells from five different donors. (B) Monocytes were incubated in the presence of the JAK1 inhibitor (circle), the PI3K inhibitor (LY249002; square), or both inhibitors (triangle) for 1 hour prior to LPS stimulation in the presence of 10 ng/ml cmvIL-10 and then TNF-α levels were measured by ELISA. A single black diamond indicates the level of TNF-α in the presence of LPS only. Results are representative of experiments performed on cells from three different donors. Error bars represent standard deviations.