REGULATION OF CYTOKINE PRODUCTION BY IL-10 IN ENDOTOXIN-STIMULATED MONOCYTES

内毒素刺激的单核细胞中IL-10对细胞因子产生的调节

• 批准号: 6101222
• 负责人: R. P DONNELLY
• 金额: --
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6101222
• 关键词: T lymphocyte; autocrine; cell type; cytokine; cytokine receptors; endotoxins; human tissue; immunoregulation; interferon gamma; interleukin 1; interleukin 10; interleukin 6; lipopolysaccharides; messenger RNA; monocyte; protein biosynthesis; tissue /cell culture; tumor necrosis factor alpha

Stimulation of human monocytes with bacterial endotoxin, lipopolysaccharide (LPS), induces expression of multiple cytokines, including tumor necrosis factor-alpha (TNF-a), interleukin-1 (IL-1), IL-6 and IL-10. IL-10 expression is delayed relative to that of TNF, IL-1 and IL-6. Furthermore, IL-10 feedback inhibits expression of TNF, IL-1 and IL-6, thus providing an efficient autocrine mechanism for controlling proinflammatory cytokine production in monocytes. We are examining the mechanism by which IL-10 down-regulates production of cytokines such as TNF and IL-1 in endotoxin-stimulated monocytes. We are also evaluating the effects of IL-10 on cell signaling events that are activated by specific cytokines in monocytes. We have found that IL-10 can antagonize activation and gene expression by a variety of cytokines, including IL-4 and IFN-gamma (Dickensheets and Donnelly. 1997. J. Immunol. 159:6226). We have also determined that the ability of IL-10 to inhibit IL-4-induced gene expression is a consequence of decreased tyrosine phosphorylation and nuclear translocation of the IL-4-inducible transcription factor, STAT6. In future studies, we will examine the cell type specificity of these IL-10-induced effects by evaluating the effects of IL-10 on gene expression in a variety of hematopoietic and non-hematopoietic cell types. To further define the actions of IL-10 on monocyte functional activities, we are evaluating the effects of this cytokine on synthesis and release of soluble cytokine receptors, including the type-I and type-II IL-1 receptors (IL-1RI and IL-1RII) and the type-1 and type-2 TNF receptors by monocytes. TNF-R are shed from monocytes after stimulation by LPS, and can function as TNF antagonists by competing with membrane-associated TNF-R for available TNF. We have found that IFN-gamma (IFN-g) down-regulates expression of both membrane TNF-R2 and solubleTNF-R2 (sTNF-R2) by LPS-stimulated monocytes (Dickensheets et al. 1997. Blood 90:4162). The decreased production of sTNF-R2 in cultures of IFN-g-treated monocytes correlates directly with decreased levels of TNF-R2 mRNA and inversely with the levels of TNF-a mRNA. In contrast, IL-10 up-regulates production of sTNF-R2 and markedly inhibits production of TNF-a. IL-10 also reverses the ability of IFN-g to suppress production of sTNF-R2 and to potentiate production of TNF-a. These findings demonstrate that IL-10 coordinately down-regulates production of TNF-a (a TNF-R agonist), and up-regulates production of sTNF-R2 (a TNF-R antagonist) in monocytes. They also provide another example of how IL-10 can antagonize cytokine-induced responses in monocytes. IL-10 is currently being tested as a potential therapeutic agent for the treatment of a number of inflammatory diseases, including rheumatoid arthritis and Crohn~s disease. The results of our studies will increase our knowledge of the biological actions of IL-10, and thereby improve our ability to regulate the clinical use of this biologic agent.

用细菌内毒素刺激人类单核细胞， 脂多糖（LPS），诱导多种细胞因子的表达， 包括肿瘤坏死因子-α (TNF-a)、白介素-1 (IL-1)、IL-6 和IL-10。 IL-10 的表达相对于 TNF、IL-1 和 IL-6。 此外，IL-10 反馈抑制 TNF、IL-1 和 IL-6，从而提供有效的自分泌机制来控制 单核细胞中促炎细胞因子的产生。 我们正在审查 IL-10 下调细胞因子产生的机制，例如 内毒素刺激的单核细胞中的 TNF 和 IL-1。 我们也在评估 IL-10 对细胞信号转导事件的影响 单核细胞中的特异性细胞因子。 我们发现IL-10可以拮抗 多种细胞因子（包括 IL-4）的激活和基因表达 和 IFN-γ（Dickensheets 和 Donnelly.1997.J.Immunol.159：6226）。 我们还确定了 IL-10 抑制 IL-4 诱导的能力 基因表达是酪氨酸磷酸化减少的结果 和 IL-4 诱导转录因子的核转位， 统计6。 在未来的研究中，我们将检查细胞类型特异性 通过评估 IL-10 对基因的影响来评估这些 IL-10 诱导的作用 在多种造血和非造血细胞中表达 类型。 进一步明确IL-10对单核细胞功能的作用 活性，我们正在评估这种细胞因子对合成的影响 和可溶性细胞因子受体的释放，包括 I 型和 II 型 IL-1 受体（IL-1RI 和 IL-1RII）以及 1 型和 2 型 TNF 单核细胞的受体。 刺激后 TNF-R 从单核细胞中脱落 通过 LPS 作用，并可通过与 TNF 竞争而发挥 TNF 拮抗剂的作用 膜相关的 TNF-R 可获取可用的 TNF。 我们发现 IFN-gamma (IFN-g) 下调膜 TNF-R2 和 TNF-R2 的表达 LPS 刺激的单核细胞可溶性 TNF-R2 (sTNF-R2)（Dickensheets 等人，2017） 1997。血90：4162）。 培养物中 sTNF-R2 的产生减少 IFN-g 处理的单核细胞的数量与 IFN-g 处理的单核细胞水平的降低直接相关 TNF-R2 mRNA 水平与 TNF-α mRNA 水平成反比。 相比之下， IL-10 上调 sTNF-R2 的产生并显着抑制其产生 TNF-a。 IL-10 还可逆转 IFN-g 抑制的能力 sTNF-R2 的产生并增强 TNF-a 的产生。 这些 研究结果表明 IL-10 协同下调生产 TNF-a（一种 TNF-R 激动剂），并上调 sTNF-R2（一种 单核细胞中的 TNF-R 拮抗剂）。 他们还提供了另一个例子来说明如何 IL-10 可以拮抗单核细胞中细胞因子诱导的反应。 IL-10 是 目前正在测试作为治疗的潜在治疗剂 多种炎症性疾病，包括类风湿性关节炎和 克罗恩病。 我们的研究结果将增加我们的知识 IL-10 的生物作用，从而提高我们的能力 规范该生物制剂的临床使用。