REGULATION OF GENE EXPRESSION IN HUMAN T CELL BY INTERLEUKIN 12, 1, 18 AND TNF

白细胞介素12、1、18和TNF对人T细胞基因表达的调节

• 批准号: 6101213
• 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/6101213
• 关键词: CD3 molecule; T lymphocyte; gene expression; human tissue; immunoregulation; interferon gamma; interleukin 1; interleukin 10; interleukin 12; interleukin 2; leukocyte activation /transformation; protein biosynthesis; tumor necrosis factor alpha

IL-12 is known to up-regulate synthesis of interferon-gamma (IFN-g) in activated T cells; however, the effects of IL-12 on expression of other cytokines are less well defined. In this project, we are examining the effects of IL-12 on production of multiple cytokines, including IFN-g, IL-2, IL-4, IL-10 and IL-13, by purified, normal, human CD3+ T cells. Although resting T cells are largely IL-12-nonresponsive, anti-CD3-activated T cell blasts are highly IL-12-responsive as demonstrated by the ability of IL-12 to induce STAT4-mediated DNA-binding activity. We have found that activation of purified human T lymphocytes on immobilized anti-CD3 mAb induces rapid expression of TNF-a and IL-2 mRNA, and more gradual increases in mRNA levels for IFN-g, IL-10 and IL-13. Changes in mRNA expression levels were measured by RNase protection assay using primer template sets that facilitate analysis of multiple cytokine genes simultaneously. We have found that IL-12 markedly up-regulates expression of IFN-g and IL-10, and down-regulates production of IL-2. Inhibition of IL-2 production by IL-12 correlates directly with increased production of IL-10. Moreover, neutralization of IL-10 activity with anti-IL-10 antibodies normalizes IL-2 production in IL-12-treated T cells demonstrating that the inhibitory effects of IL-12 are IL-10-mediated. Thus, we have found that IL-12 simultaneously up-regulates production of IFN-g and IL-10, and, by a direct IL-10-dependent pathway, feedback inhibits production of IL-2. The fact that IL-12 differentially regulates synthesis of IFN-g and IL-2 in T cells demonstrates that IL-12 does not globally enhance expression of all Th1-type lymphokines. Furthermore, the ability of IL-12 to up-regulate production of IL-10 provides a mechanism for limiting the IL-2-dependent clonal expansion of activated T cells, and defines a novel cytokine regulatory pathway that is inducible by IL-12. In future studies, we plan to further define the effects of IL-12 on production of other cytokines, particularly the Th2-type cytokines IL-4 and IL-13 by activated T cells, and to compare the effects of IL-12 with that of other macrophage-derived immunoregulatory cytokines, most notably IL-1 beta and TNF-alpha. We will also further explore the functional consequences of increased IL-10 production in IL-12-treated T cells. The results of these studies will broaden our current understanding of the actions of IL-12 on immune effector cells. This information may be useful in interpreting any therapeutic activity induced by IL-12 in clinical trials that are now underway. It may also provide insight to the physiological basis for certain toxicities associated with high dose IL-12 therapy. Furthermore, analysis of the effects of IL-12 on cytokine expression in vitro may facilitate identification of surrogate markers of IL-12 bioactivity that could be useful in monitoring the potency of recombinant IL-12 in human recipients.

已知IL-12可上调人γ干扰素（IFN-g）的合成 激活的T细胞;然而，IL-12对其他T细胞表达的影响， 细胞因子的定义不太明确。 在这个项目中，我们正在研究 IL-12对多种细胞因子，包括IFN-γ， IL-2、IL-4、IL-10和IL-13，通过纯化的正常人CD 3 + T细胞。 虽然静息T细胞在很大程度上是IL-12非应答性的， 抗CD 3活化的T细胞母细胞是高度IL-12应答性的， 通过IL-12诱导STAT 4介导的DNA结合的能力证明 活动 我们已经发现纯化的人T淋巴细胞的活化 固定化抗CD 3 mAb诱导TNF-α和IL-2的快速表达 mRNA水平的逐渐增加，IFN-γ、IL-10和 IL-13。 RNA酶测定mRNA表达水平的变化 使用引物模板组的保护测定， 多个细胞因子基因。 我们发现IL-12 显著上调IFN-γ和IL-10的表达，下调IFN-γ和IL-10的表达。 生产IL-2。 IL-12对IL-2产生的抑制相关 与IL-10的产生直接相关。 此外， 用抗IL-10抗体降低IL-10活性使IL-2产生正常化 在IL-12处理的T细胞中，证实了 IL-12是IL-10介导的。 因此，我们发现IL-12同时 上调IFN-g和IL-10的产生，并通过直接 IL-10依赖性途径，反馈抑制IL-2的产生。 的事实 IL-12差异调节T细胞IFN-γ和IL-2的合成， 细胞表明IL-12并不全面增强所有细胞的表达。 Th 1型淋巴因子。 此外，IL-12的上调能力， IL-10的产生提供了一种限制IL-2依赖性免疫应答的机制。 活化T细胞的克隆扩增，并定义了一种新的细胞因子 IL-12可诱导的调节途径。 在未来的研究中，我们 计划进一步确定IL-12对其他 细胞因子，特别是Th 2型细胞因子IL-4和IL-13， 活化的T细胞，并比较IL-12与其他 巨噬细胞源性免疫调节细胞因子，最显著的是IL-1 β 和TNF-α 我们还将进一步探讨功能性后果 在IL-12处理的T细胞中增加IL-10的产生。 的结果 这些研究将拓宽我们目前对人类行为的理解， IL-12对免疫效应细胞的作用。 这些信息可能有助于 解释临床试验中IL-12诱导的任何治疗活性 现在正在进行中。 它还可以提供对生理的洞察力， 与高剂量IL-12治疗相关的某些毒性的基础。 此外，分析IL-12对细胞因子表达的影响， 体外可能有助于识别IL-12的替代标志物 生物活性，可用于监测重组的效力 人受体中的IL-12。