GENE REGULATION IN THE IMMUNE SYSTEM

免疫系统中的基因调控

• 批准号: 6108064
• 负责人: Keiko Ozato
• 金额: --
• 依托单位: EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH & HUMAN DEVELOPMENT
• 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/6108064
• 关键词: DNA footprinting; cell growth regulation; developmental genetics; genetic regulation; genetic regulatory element; genetic transcription; hormone receptor; immune system; immunogenetics; interferons; laboratory mouse; polymerase chain reaction; retinoids; tissue /cell culture; transcription factor; transfection

This group works on gene regulation in the immune system. During this period we have worked on the function of ICSBP, a transcription factor that belongs to the interferon regulatory factor (IRF). Previous work showed that ICSBP acts as a repressor for a number of interferon (IFN) inducible genes that carry the ISRE DNA element in their promoter. In more recent efforts using ICSBP-/- mice, we found that ICSBP has a critical role in host defense. By studying parasite infection model, the defect in ICSBP-/- mice was traced to the impairment of macrophage function, particularly their inability to induce a cytokine IL-12. This cytokine is very important for host defense, as it stimulates the production of IFN( and IL-2, which exert anti-viral/batericidal activities and stimulate T cell proliferation, leading to the activation of specific immune responses. The IL-12 P40 gene is induced in macrophages upon stimulation by many pathogens in immunocompetent hosts Based on the results from -/- mice, we have further investigated the role for ICSBP in IL-12p40 regulation The IL-12 promoter is well conserved in mouse and humans, and contains several cis regulatory elements, which appear to be involved in IL-12 p40 transcription. In transfection analysis IL-12 p40-luciferase reporters are activated by bacterial lipopolysaccharides, LPS and IFN( in macrophages. However, we found that ectopic expression of ICSBP results in marked enhancement of IL-12p40 reporter activity in a ICSBP does dependent manner and even in the absence of LPS and IFN( stimulation. These stimuli further enhanced reporter activity in ICSBP+/+ cells. The ability to stimulate IL-12 reporter activity was unique to ICSBP, since no other members of the IRF family tested stimulated reporter activity. Detailed deletion analysis of the 5= flanking region of the Il-12 promoter led us to conclude that ICSBP acts primarily through the ets site. By DNA affinity binding assays we show that the endogenous ICSBP expressed in macrophages bound to the ets site, presumably as a complex with other proteins. These results show that ICSBP is a transcriptional activator for IL-12p40, that acts by binding to a unique site in cooperation with other nuclear proteins.

该组从免疫中的基因调节工作 系统。在此期间，我们从事 ICSBP，属于干扰素的转录因子 监管因素（IRF）。以前的工作表明，ICSBP是 许多干扰素（IFN）诱导基因的阻遏物 在其启动子中携带ISRE DNA元素。在最近的 使用ICSBP - / - 小鼠的努力，我们发现ICSBP具有关键 在宿主防御中的作用。通过研究寄生虫感染模型， ICSBP - / - 小鼠的缺陷被追溯到损害 巨噬细胞功能，尤其是他们无法诱导 细胞因子IL-12。这种细胞因子对于宿主防御非常重要，因为 它刺激IFN的产生（和IL-2）的产生 抗病毒/生物杀菌活性并刺激T细胞增殖， 导致特定免疫反应的激活。 IL-12 许多人刺激巨噬细胞诱导p40基因 免疫能力宿主中的病原体基于 - / - 的结果 小鼠，我们进一步研究了ICSBP在IL-12P40中的作用 调节IL-12启动子在小鼠和 人类，并包含几种顺式调节元素，这些元素出现 参与IL-12 p40转录。在转染分析中 IL-12 p40-葡萄氧化酶报道器被细菌激活 脂多糖，LP和IFN（在巨噬细胞中。但是，我们 发现ICSBP的异位表达会导致标记 ICSBP中IL-12P40报告基因活性的增强 依赖方式，甚至在没有LP和IFN的情况下（ 刺激。这些刺激进一步增强了报告基因的活性 ICSBP+/+细胞。刺激IL-12报告基因活性的能力是 ICSBP独有的，因为IRF家族的其他成员都没有测试 刺激的记者活动。 5 =的详细缺失分析 IL-12启动子的侧面区域使我们得出结论，ICSBP 主要通过ETS网站起作用。通过DNA亲和力结合测定 我们表明内源性ICSBP在巨噬细胞中表达 绑定到ETS位点，大概是与其他蛋白质的复合物。 这些结果表明，ICSBP是一种转录激活器 IL-12P40，通过与独特的站点合作而起作用 其他核蛋白。