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: 5200749
• 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/5200749
• 关键词: T lymphocyte; autocrine; cytokine; gene induction /repression; human tissue; interferon gamma; interleukin 1; 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 TNF-a, IL-1b, IL-6 and IL-10. IL-10 expression is delayed relative to that of TNF-a, IL-1b and IL-6. Furthermore, IL-10 feedback inhibits expression of TNF-a, IL-1b and IL-6, thus providing an efficient autocrine mechanism for controlling proinflammatory cytokine production in monocytes. The Th1-type lymphokine, IFN-g, markedly upregulates TNF-a production in monocytes. However, the precise mechanism by which IFN-g mediates this effect is unknown. We examined the effects of IFN-g on IL-10 expression in LPS-stimulated monocytes, and the relationship between IL-10 and TNF-a production in these cells. LPS stimulation induced rapid, ordered expression of multiple cytokines. Steady-state mRNA levels for TNF-a increased rapidly, reached maximal levels by 2-3 hr post stimulation, and then declined sharply. IL-1b and IL-6 mRNA levels also increased markedly following stimulation with LPS, but decreased more slowly than TNF-a. Downregulation of mRNA for TNF-a, IL-1b and IL-6 coincided with a delayed and more gradual increase in IL-10 mRNA levels. Furthermore, neutralization of IL-10 with anti-IL-10 antibodies prolonged TNF-a mRNA expression, and significantly increased net TNF-a production. IFN-g suppressed expression of IL-10 mRNA and protein in a dose-dependent manner. Moreover, inhibition of IL-10 production correlated with a marked increase in both the magnitude and duration of TNF-a expression. Thus, potentiation of TNF-a production by IFN-g in monocytes is coupled to inhibition of endogenous IL-10 expression. These findings were recently documented in a paper in the Journal of Immunology (Donnelly et al. 1995. J. Immunol. 155:1420-1427). In future experiments, we will attempt to define the mechanism by which IL-10 downregulates cytokine production, particularly TNF-a, in activated monocytes. In this context, we will also examine the tissue specificity of this IL-10-induced effect. In preliminary experiments, we have found that although IL-10 markedly inhibits production of TNF-a in monocytes, it does not inhibit expression of TNF-a in activated CD3+ T cells. Thus, the inhibitory action of IL-10 may be inducible in monocytic but not lymphocytic cells. The results of these and related studies will enhance our knowledge of the biological actions of IL-10, and thereby improve our ability to regulate this cytokine as a potential therapeutic agent for the treatment of certain inflammatory diseases.

用细菌内毒素刺激人单核细胞， 脂多糖（LPS），诱导多种细胞因子的表达， 包括TNF-α、IL-1b、IL-6和IL-10。 IL-10表达延迟 相对于TNF-α、IL-1b和IL-6。 此外，IL-10反馈 抑制TNF-α、IL-1b和IL-6的表达，从而提供有效的 控制促炎细胞因子产生的自分泌机制 在单核细胞中。 Th 1型淋巴因子IFN-g显著上调TNF-α 单核细胞中的生产。 然而，IFN-g 介导这种效应是未知的。 我们研究了IFN-γ对 脂多糖刺激单核细胞中IL-10的表达及其关系 IL-10和TNF-α之间的关系。 LPS刺激 诱导多种细胞因子的快速有序表达。 稳态 TNF-α的mRNA水平迅速升高，在2-3小时达到最大水平， hr刺激后，然后急剧下降。 IL-1b和IL-6 mRNA 在LPS刺激后水平也显著增加，但 比TNF-α下降更慢。 TNF-α mRNA的下调， IL-1b和IL-6与延迟和更渐进的增加相一致， IL-10 mRNA水平。 此外，用抗IL-10中和IL-10 抗体延长TNF-α mRNA表达，并显著增加 净TNF-α产量。 IFN-γ抑制IL-10 mRNA的表达， 蛋白质以剂量依赖的方式。 此外，抑制IL-10 生产与幅度和 TNF-α表达的持续时间。 因此，TNF-α产生的增强通过 单核细胞中的IFN-g与内源性IL-10的抑制偶联 表情 这些研究结果最近被记录在一篇论文中， Journal of Immunology（Donnelly等人，1995. J. Immunol. 155：1420-1427）。在未来的实验中，我们将尝试定义 IL-10下调细胞因子产生的机制，特别是 TNF-α，在活化的单核细胞中。 在这方面，我们还将审查 这种IL-10诱导效应的组织特异性。 初步 实验中，我们发现，虽然IL-10显著抑制 在单核细胞中TNF-α的产生，它不抑制TNF-α的表达 活化的CD 3 + T细胞。 因此，IL-10的抑制作用可能是 在单核细胞而不是淋巴细胞中可诱导。 的结果予以 相关研究将增强我们对生物学作用的认识， IL-10，从而提高我们调节这种细胞因子的能力， 用于治疗某些炎症的潜在治疗剂， 疾病