Effect of suppressive sequences to inflammatory response induced by bacterial DNA CpG motif - a basic research on SIRS therapy.

抑制序列对细菌DNA CpG基序诱导的炎症反应的影响——SIRS治疗的基础研究。

• 批准号: 13671602
• 负责人: ABE Yoichiro
• 金额: $ 2.05万
• 依托单位: YOKOHAMA CITY UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13671602/
• 关键词: Bacterial DNA; CpG motif; Inflammatory response; SIRS; Suppressive sequences; TNF-α; IL-12; MIP-2; RAW 246.7 cell; 肺; ARDS; IL-6; interferon-gamma

CpG motifs that frequently appear in bacterial DNA are recognized by mammalian immune system as danger signal to the host and induce immune responses. Mammalian DNA suppresses CpG-induced immune responses. Based on the observation, Yamada et al. and Klieg et al. independently designed suppressive sequences. They extensively studied the nature of this suppression, taking therapeutic application of the novel suppressive sequences into scope. Oligodeoxynucleotides (ODN) with suppressive sequences inhibited IL-6 and IL-12 production by CpG motifs in a dose dependent manner in mouse RAW cells. IgM production, proliferation and the production of IL-6 and IL-12 were also inhibited by suppressive ODN in RPMI 8227 human B cell line in vitro. In vivo study showed that suppressive ODN significantly inhibited CpG-induced pulmonary inflammation, including the production of pro-inflammatory cytokines TNF-, IL-6 chemokines MIP-2 and KC, and mobilization of neutrophils into alveolar spaces as was reported by Yamada, et al. NO is important gaseous mediator of pulmonary inflammation. Immuno-fluorescence assay and RT-PCR showed ODN sup decreased iNOS expression induced by CpG motifs. IL-12 is a key cytokine that switches Th2 immune response to Th1 response. Inhibition of IL-12 production by suppressive ODN was thus studied. Both RT-PCR and luciferase assay for IL-12 p40 showed that suppressive ODN blocked IL-12 mRNA induction. Their findings were confirmed by our observations. CpG motifs cause several diseases such as arthritis, meningitis SLF, and systemic inflammatory response syndrome; SIRS. Suppressive ODN we tested in this study may have therapeutic potency.

细菌DNA中常见的CpG基序被哺乳动物的免疫系统识别为危险信号，并诱导免疫应答。哺乳动物DNA抑制CpG诱导的免疫应答。基于这一观察，Yamada et al.和Klieg et al.独立设计了抑制序列。他们广泛研究了这种抑制的性质，将新型抑制序列的治疗应用纳入范围。在小鼠RAW细胞中，具有抑制序列的寡脱氧核苷酸（ODN）以剂量依赖性方式抑制CpG基序产生IL-6和IL-12。抑制性ODN对RPMI 8227人B细胞IgM的产生、增殖及IL-6、IL-12的产生也有抑制作用。体内研究表明，抑制性ODN显著抑制CpG诱导的肺部炎症，包括促炎细胞因子TNF-α、IL-6趋化因子MIP-2和KC的产生，以及如Yamada等报道的中性粒细胞向肺泡腔的动员。免疫荧光和RT-PCR结果显示，ODN抑制CpG基序诱导的iNOS表达。IL-12是将Th2免疫应答转换为Th1应答的关键细胞因子。因此研究了抑制性ODN对IL-12产生的抑制。RT-PCR和荧光素酶法检测IL-12 p40表达均显示抑制性ODN阻断了IL-12 mRNA的诱导。我们的观察证实了他们的发现。CpG基序引起几种疾病，如关节炎、脑膜炎SLF和全身炎症反应综合征; SIRS。我们在本研究中测试的抑制性ODN可能具有治疗效力。