Interleukin-4 induction of the CC chemokine TARC (CCL17) in murine macrophages is mediated by multiple STAT6 sites in the TARC gene promoter.
Interleukin-4 induction of the CC chemokine TARC (CCL17) in murine macrophages is mediated by multiple STAT6 sites in the TARC gene promoter.
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DOI：
10.1186/1471-2199-7-45
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发表时间：
2006-11-29
影响因子：
--
通讯作者：
Greaves DR
中科院分区：
文献类型：
--
作者：
Liddiard K;Welch JS;Lozach J;Heinz S;Glass CK;Greaves DR
巨噬细胞（Mθ）在天然免疫应答和慢性炎症性疾病的病理学中起着重要作用。用Th 2型细胞因子如白细胞介素-4（IL-4）和白细胞介素-13（IL-13）处理的巨噬细胞表现出改变的表型，并且这种交替活化的巨噬细胞在以过敏性炎症为特征的疾病（包括哮喘和特应性皮炎）的病理学中是重要的。CC趋化因子Thr 4和活化调节趋化因子（TARC/CCL 17）及其鼠同系物（mTARC/ABCD-2）与趋化因子受体CCR 4结合，并指导T细胞和巨噬细胞募集到过敏性炎症区域。阐明IL-4诱导TARC表达的分子机制对于更好地理解Th 2细胞因子在变应性疾病中的作用至关重要。我们证明，在原代巨噬细胞（Mθ）中，mTARC mRNA和蛋白质被Th 2细胞因子白细胞介素-4（IL-4）有效诱导，并被干扰素-γ（IFN-γ）抑制。IL-4诱导mTARC发生在PI 3激酶途径和翻译抑制剂的存在下，但不是在没有STAT 6转录因子的情况下，这表明直接作用的STAT 6介导的mTARC转录激活途径。我们已经在mTARC近端启动子中鉴定了11个推定的STAT 6位点的功能特征，并确定其中5个有助于IL-4诱导mTARC。通过体外结合试验和将分离的位点瞬时转染到RAW 264.7 Mθ细胞系中，我们证明这些位点对STAT 6的结合和激活具有广泛不同的能力。在mTARC近端启动子的背景下，这些位点的定点诱变揭示了人和小鼠基因之间保守的两个最近端位点是IL-4应答的重要介质。IL-4对mTARC的诱导是mTARC基因启动子内STAT 6位点之间协同相互作用的结果。值得注意的是，我们已经表明，9个最近的mTARC STAT 6位点在其内源性构象的转移赋予有效的（高达130倍）IL-4诱导异源启动子。这些启动子元件构成重要且敏感的IL-4应答转录单位，其可用于驱动体内Th 2炎症位点中的转基因表达。
Macrophages (Mθ) play a central role in the innate immune response and in the pathology of chronic inflammatory diseases. Macrophages treated with Th2-type cytokines such as Interleukin-4 (IL-4) and Interleukin-13 (IL-13) exhibit an altered phenotype and such alternatively activated macrophages are important in the pathology of diseases characterised by allergic inflammation including asthma and atopic dermatitis. The CC chemokine Thymus and Activation-Regulated Chemokine (TARC/CCL17) and its murine homologue (mTARC/ABCD-2) bind to the chemokine receptor CCR4, and direct T-cell and macrophage recruitment into areas of allergic inflammation. Delineating the molecular mechanisms responsible for the IL-4 induction of TARC expression will be important for a better understanding of the role of Th2 cytokines in allergic disease. We demonstrate that mTARC mRNA and protein are potently induced by the Th2 cytokine, Interleukin-4 (IL-4), and inhibited by Interferon-γ (IFN-γ) in primary macrophages (Mθ). IL-4 induction of mTARC occurs in the presence of PI3 kinase pathway and translation inhibitors, but not in the absence of STAT6 transcription factor, suggesting a direct-acting STAT6-mediated pathway of mTARC transcriptional activation. We have functionally characterised eleven putative STAT6 sites identified in the mTARC proximal promoter and determined that five of these contribute to the IL-4 induction of mTARC. By in vitro binding assays and transient transfection of isolated sites into the RAW 264.7 Mθ cell-line, we demonstrate that these sites have widely different capacities for binding and activation by STAT6. Site-directed mutagenesis of these sites within the context of the mTARC proximal promoter revealed that the two most proximal sites, conserved between the human and mouse genes, are important mediators of the IL-4 response. The induction of mTARC by IL-4 results from cooperative interactions between STAT6 sites within the mTARC gene promoter. Significantly, we have shown that transfer of the nine most proximal mTARC STAT6 sites in their endogenous conformation confers potent (up to 130-fold) IL-4 inducibility on heterologous promoters. These promoter elements constitute important and sensitive IL-4-responsive transcriptional units that could be used to drive transgene expression in sites of Th2 inflammation in vivo.
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影响因子：
32.4
作者：
GREENLUND, AC;MORALES, MO;SCHREIBER, RD
通讯作者：
SCHREIBER, RD
影响因子：
8.7
作者：
Greaves, DR;Häkkinen, T;Ylä-Hertualla, S
通讯作者：
Ylä-Hertualla, S
影响因子：
6.5
作者：
Fujita, H;Asahina, A;Tamaki, K
通讯作者：
Tamaki, K
影响因子：
15.3
作者：
Bonecchi, R;Bianchi, G;Bordignon, P P;D'Ambrosio, D;Lang, R;Borsatti, A;Sozzani, S;Allavena, P;Gray, P A;Mantovani, A;Sinigaglia, F
通讯作者：
Sinigaglia, F
影响因子：
4.8
作者：
Baden, HA;Sarma, SP;Waugh, DS
通讯作者：
Waugh, DS