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: 3748190
• 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/3748190
• 关键词: cytokine; gene expression; genetic regulation; human tissue; immunoregulation; interferon gamma; interleukin 1; interleukin 6; lipopolysaccharides; messenger RNA; monocyte; neutralizing antibody; tissue /cell culture; tumor necrosis factor alpha

The bacterial endotoxin, lipopolysaccharide (LPS), induces expression of multiple early response genes in human monocytes, including the proinflammatory cytokines TNF-a, IL-1b and IL-6. IL-10 expression, which is also LPS-inducible in monocytes, is delayed relative to that of TNF-a, IL-1b and IL-6. IL-10 feedback inhibits expression of these cytokines, as well as IL-10 itself, thereby providing an efficient mechanism for controlling cytokine production in monocytes. The Th1-type lymphokine, interferon-g (IFN-g), markedly upregulates TNF-a production in human monocytes. In this project, we are investigating the effects of IFN-g on IL-10 expression in LPS-stimulated monocytes. We are also examining the relationship between between IL-10 and TNF-a levels in IFN-g-primed cells. LPS stimulation induces rapid and ordered expression of cytokine mRNA. Steady-state mRNA levels for TNF-a increase rapidly, reach maximum levels by 2-3 hr post stimulation, and then decline sharply. IL-1b and IL-6 mRNA levels also increase markedly following stimulation with LPS, but decrease more slowly than TNF-a. Downregulation of mRNA for TNF-a, IL-1b and IL-6 coincides with a delayed amd more gradual increase in IL- 10 mRNA levels. Furthermore, neutralization of endogenous IL-10 with anti-IL-10 antibody prolongs TNF-a mRNA expression, and significantly increases TNF production. IFN-g inhibited expression of IL-10 mRNA in LPS-stimulated monocytes, and decreased net IL-10 production in a dose- dependent manner. The reduction in IL-10 mRNA levels was associated with a marked increase in both the magnitude and duration of TNF-a mRNA expression. Thus, potentiation of TNF-a production in IFN-g-primed monocytes is coupled to inhibition of endogenous IL-10 expression. In future experiments, we will attempt to define the molecular mechanism by which IL-10 downregulates cytokine production, particularly TNF-a, in LPS-stimulated monocytes.

细菌内毒素，脂多糖（LPS），诱导表达 人单核细胞中的多种早期反应基因，包括 促炎细胞因子TNF-α、IL-1b和IL-6。 IL-10表达， 在单核细胞中也是LPS诱导的，相对于TNF-α延迟， IL-1b和IL-6。 IL-10反馈抑制这些细胞因子的表达， 以及IL-10本身，从而提供了一种有效的机制， 控制单核细胞中细胞因子的产生。 Th 1型淋巴因子， 干扰素-g（IFN-g）显著上调人TNF-α的产生 单核细胞 在这个项目中，我们正在研究IFN-g的影响 对LPS刺激的单核细胞中IL-10表达的影响。 我们亦正研究 IFN-γ致敏小鼠IL-10与TNF-α水平关系 细胞 LPS刺激诱导细胞因子快速有序表达 mRNA。 TNF-α的稳态mRNA水平迅速增加，达到最大值 刺激后2-3小时水平，然后急剧下降。 IL-1b和 IL-6 mRNA水平在LPS刺激后也显著增加， 但比TNF-α下降更慢。 TNF-α mRNA的下调， IL-1b和IL-6与IL-1b和IL-6的延迟和逐渐增加相一致。 10个mRNA水平。 此外，内源性IL-10与 抗IL-10抗体抑制TNF-α mRNA表达， 增加TNF的产生。 IFN-γ抑制IL-10 mRNA的表达， LPS刺激的单核细胞，并减少净IL-10的生产，在剂量- 依赖的方式。 IL-10 mRNA水平的降低与 TNF-α mRNA表达的幅度和持续时间均显著增加， 表情 因此，在IFN-γ-致敏的小鼠中增强TNF-α的产生是可能的。 单核细胞与内源性IL-10表达的抑制偶联。 在 在未来的实验中，我们将尝试通过以下方式来定义分子机制： 其中IL-10下调细胞因子的产生，特别是TNF-α， LPS刺激的单核细胞。