IL-10 inhibits proinflammatory gene transcription. (A) Cells were treated with LPS with or without IL-10 for 30 or 120 min. RNA was isolated and used in quantitative RT-PCR with probes specific for the indicated mRNA. (B) Position of PCR primers for detecting downstream Pol II at the TNF, IL6, NFKBIA, and NFKBIZ genes. (C) Cells were stimulated for the indicated times with LPS, followed by ChIP using Pol II antibodies (filled bars) or a rabbit isotype control (open bars) at downstream regions of the TNF and IL6 genes. (D) Cells were treated with LPS with or without IL-10 for 30 or 120 min and Pol II was measured by ChIP at the downstream regions of TNF, IL6, NFKBIZ, and NFKBIA. Data in A and C are expressed as mean ± SD of triplicate measurements for a single donor, representative of three independent experiments using different donors. Data in D are pooled data from three donors and are expressed as mean ± SEM. Statistical significance was assessed using the paired Student’s t test. *, P < 0.05; NS (not significant).