Role of phosphatidylinositol-3 kinase in transcriptional regulation of TLR-induced IL-12 and IL-10 by Fcγ receptor ligation in murine macrophages
Role of phosphatidylinositol-3 kinase in transcriptional regulation of TLR-induced IL-12 and IL-10 by Fcγ receptor ligation in murine macrophages
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DOI：
10.4049/jimmunol.179.1.236
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发表时间：
2007-07-01
影响因子：
4.4
通讯作者：
Vogel, Stefanie N.
中科院分区：
文献类型：
--
作者：
Polumuri, Swamy Kumar;Toshchakov, Vladimir Y.;Vogel, Stefanie N.
Fc gamma R 连接与 LPS 刺激小鼠巨噬细胞同时导致 IL-12 产量减少和 IL-10 产量增加。由于 PI3K 缺乏与 IL-12 增加相关，因此我们假设 PI3K 对于 Fc gamma R 连接对 TLR 诱导的 IL-12 的抗炎作用至关重要。巨噬细胞的 Fc gamma R 连接增加了 pAKT（与 PI3K 活性相关），高于 TLR4 或 TLR2 激动剂诱导的水平。这种增加被 PI3K 抑制剂、渥曼青霉素或 LY294002 阻断，Fc gamma R 连接对 TLR 诱导的 IL-12 和 IL-10 的影响也是如此。 LPS 诱导的 NF-κ B 与 IL-12 p40 启动子的结合 NF-κ B 结合位点在 1 小时时不受 Fc gamma R 连接的影响；然而，4 小时后，NF-κ B 结合明显受到抑制，这通过染色质免疫沉淀分析原位证实。该效应对渥曼青霉素敏感。虽然 TLR 诱导的 I kappa B α 降解不受 Fc gamma R 连接的影响，但 I kappa B α 在用 LPS 和 Fc gamma R 连接处理 4 小时处理的细胞核中积累，并被 PI3K 抑制剂阻断。 LPS 诱导的 IFN 调节因子 8/IFN 共有序列结合蛋白 mRNA 和 IFN 调节因子 8 依赖性基因 Nos2 被同时的 Fc gamma R 连接所抑制，并且渥曼青霉素也能逆转这种情况。因此，Fc gamma R 连接通过多种 PI3K 敏感途径调节 LPS 诱导的 IL-12，这些途径影响 IL-12 诱导所需的关键 DNA 结合蛋白的产生、积累和结合。
Ligation of Fc gamma R concurrent with LPS stimulation of murine macrophages results in decreased IL-12 and increased IL-10 production. Because PI3K deficiency has been associated with increased IL-12, we hypothesized that PI3K was central to the anti-inflammatory effect of Fc gamma R ligation on TLR-induced IL-12. Fc gamma R ligation of macrophages increased pAKT, a correlate of PI3K activity, above levels induced by TLR4 or TLR2 agonists. This increase was blocked by PI3K inhibitors, wortmannin or LY294002, as was the effect of Fc gamma R ligation on TLR-induced IL-12 and IL-10. LPS-induced binding of NF-kappa B to the IL-12 p40 promoter NF-kappa B-binding site was not affected by Fc gamma R ligation at 1 h; however, by 4 h, NF-kappa B binding was markedly inhibited, confirmed in situ by chromatin inimunoprecipitation analysis. This effect was wortmannin sensitive. Although TLR-induced I kappa B alpha degradation was not affected by Fc gamma R ligation, I kappa B alpha accumulated in the nuclei of cells treated with LPS and Fc gamma R ligation for 4 h, and was blocked by PI3K inhibitors. LPS-induced IFN regulatoryfactor-8/IFN consensus sequence-binding protein mRNA, and an IFN regulatory factor-8-dependent gene, Nos2, were inhibited by concurrent Fc gamma R ligation, and this was also reversed by wortmannin. Thus, Fc gamma R ligation modulates LPS-induced IL-12 via multiple PI3K-sensitive pathways that affect production, accumulation, and binding of key DNA-binding proteins required for IL-12 induction.