Transcriptional activation of the HTLV-I gene in monocytes and macrophages.

单核细胞和巨噬细胞中 HTLV-I 基因的转录激活。

基本信息

批准号：
13671089
负责人：
TSUKADA Junichi
金额：
$ 2.3万
依托单位：
University of Occupational and Environmental Health, Japan
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13671089/
关键词：
HTLV-I adult T-cell leukemia Tax HTLV-I リポポリサッカライド成人T細胞性白血病

项目摘要

The human T-cell leukemia virus type I (HTLV-I) is the etiologic agent of an aggressive form of human malignancy, adult T-cell leukemia/lymphoma (ATLL) and is also associated with many inflammatory diseases including myelopathy/tropical spastic paraparesis (HAM/TSP), arthropathy (HAAP), bronchopneumonopathy (HAB), uveitis and Sjogren syndrome. HTLV-I infection is widely distributed among mammalian cells including B lymphocytes, monocyte/macrophage cells and fibroblasts. Monocyte/macrophage cells are versatile secretory cells able to release various kinds of cytokines which contribute substantially to host defence and inflammation. Recently, HTLV-I-infected monocyte/macrophage cells from patients with ATLL or HAM/TSP have been demonstrated to participate in various pathological events in ATLL and HTLV-I-associated inflammatory diseases. In addition, a recent paper has shown that IL-2 production by primary ATLL cells is macrophage-dependent.In the present study, we clarified cell-type sp … More ecific transcriptional activation of the HTLV-I LTR in monocytes. CAT reporters containing the HTLV-I LTR were transfected into THP-1 monocytes. As a result, LPS as well as p40Tax dose-dependently activated the HTLV-I LTR in monocytes. The LTR possesses 3 GGAA motifs, PuB1, PET and PuB2. Mutation studies further showed that 2 GGAA motifs, PET and PuB2 are essential to the LPS induction of the LTR in monocytes. In contrast, Tax-induction of the LTR in T-cells did not require either PuB2 or PET. These results demonstrate that GGAAs within the LTR are monocyte-specific LPS-responsive elements. Our EMSA data using a PuB2 probe and LPS-stimulated THP-1 nuclear extracts revealed binding of PU.1 (Spi-1), an Ets family transcription factor to PuB2, showing the importance of PU.1 binding in LPS-induction of the LTR in monocytes. In vitro translated recombinant PU.1 also bound to PET. Moreover, any Ets proteins including PU.1 did not bind to the PuB2 sequence. Interestingly, the THP-1 nuclear extract/PuB2 complex migrated significantly slower than recombinant PU.1/PuB2 complex did. Anti-IRF-8 Ab supershifted the slow complex, showing IRF-8, a co-factor for PU.1 is involved in the slow complex. Based upon the results obtained in the present study, the LTR of the HTLV-I gene is a LPS-responsive element recognized by PU.1 in monocytes. We propose cell-type specific transcriptional regulation of the HTLV-I gene in monocytes and T-cells. Less

人类 T 细胞白血病病毒 I 型 (HTLV-I) 是一种侵袭性人类恶性肿瘤、成人 T 细胞白血病/淋巴瘤 (ATLL) 的病原体，也与许多炎症性疾病相关，包括脊髓病/热带痉挛性截瘫(HAM/TSP)、关节病(HAAP)、支气管肺炎(HAB)、葡萄膜炎和干燥综合征广泛分布于其中。哺乳动物细胞，包括B淋巴细胞、单核细胞/巨噬细胞和成纤维细胞，是多功能的分泌细胞，能够释放多种细胞因子，这些细胞因子对宿主防御和炎症有很大贡献。最近，来自患者的HTLV-I感染的单核细胞/巨噬细胞。 ATLL 或 HAM/TSP 已被证明参与 ATLL 和 HTLV-I 相关炎症性疾病的各种病理事件。结果表明，原代 ATLL 细胞产生的 IL-2 是巨噬细胞依赖性的。在本研究中，我们阐明了转染含有 HTLV-I LTR 的单核细胞中 HTLV-I LTR 的有效转录激活。结果，LPS 和 p40Tax 剂量依赖性地激活单核细胞中的 HTLV-1 LTR。 GGAA 基序、PuB1、PET 和 PuB2 突变研究进一步表明，2 个 GGAA 基序、PET 和 PuB2 对于单核细胞中 LTR 的 LPS 诱导至关重要，相反，T 细胞中 LTR 的 Tax 诱导不需要其中任何一个。 PuB2 或 PET。这些结果表明 LTR 内的 GGAA 是单核细胞特异性 LPS 响应元件。我们使用 PuB2 探针获得的 EMSA 数据。 LPS 刺激的 THP-1 核提取物揭示了 PU.1 (Spi-1)（一种 Ets 家族转录因子）与 PuB2 的结合，表明 PU.1 结合在单核细胞 LTR 体外翻译的 LPS 诱导中的重要性。重组 PU.1 也与 PET 结合，而且，包括 PU.1 在内的任何 Ets 蛋白均不与 PuB2 序列结合，即 THP-1 核提取物/PuB2 复合物。抗 IRF-8 Ab 的迁移速度明显慢于重组 PU.1/PuB2 复合物，表明 PU.1 的辅助因子 IRF-8 参与了慢复合物。在本研究中，HTLV-I 基因的 LTR 是单核细胞中 PU.1 识别的 LPS 响应元件，我们提出了 HTLV-I 基因的细胞类型特异性转录调控。单核细胞和 T 细胞较少。