Mechanism of inhibition of lung eosinophilia by CpG DNA

哮喘的发病率和死亡率在全球范围内增加，但尚未描述预防既存哮喘患者嗜酸性粒细胞炎症的长期治疗。哮喘是一种气道嗜酸性粒细胞疾病，其由Th 2细胞因子促进，并由Th 1细胞因子如IFN-γ抑制。最近的研究表明，哺乳动物免疫系统识别细菌DNA中存在的未甲基化CpG基序作为“危险信号”。这触发了IFN-γ和Th 1诱导细胞因子的快速产生。这些细胞因子建立了一个肺环境，这是最佳的产生的Th 1细胞和抑制嗜酸性粒细胞募集。在本研究中，我们将在小鼠哮喘模型中评估CpG ODN的快速和长期作用。将通过共聚焦显微镜鉴定内化CpG ODN的细胞。将通过定量RT-PCR和ELISA证明这些细胞产生IL-12、IL-18和IFN-γ的能力。p38、JNK和ERK MAP激酶的作用将通过蛋白质印迹法、免疫复合物激酶测定以及通过使用这些途径的特异性药理学或反义寡核苷酸抑制剂来表征。IFN-γ、IL-12和IL-18的体内作用将通过使用基因敲除动物或通过使用中和抗体来证明。该研究提案对开发哮喘的新疗法具有重要意义，包括那些提供长期保护以对抗嗜酸性粒细胞炎症和哮喘发作的疗法。

There is a global increase in the morbidity and mortality from asthma, but a long-term therapy that prevents eosinophilic inflammation in patients with pre-existing asthma has not been described. Asthma is an eosinophil disease of the airways that is promoted by Th2 cytokines, and inhibited by Th1 cytokines such as IFN-gamma. Recent studies suggest the mammalian immune system recognizes unmethylated CpG motifs present in bacteria DNA as a "danger signal". This triggers rapid production of IFN-gamma and Th1-inducing cytokines. These cytokines set up a lung milieu that is optimal for generation of Th1 cells and inhibition of eosinophil recruitment. In this proposal, the rapid and long-term effects of CpG ODN will be evaluated in a mouse model of asthma. The cells internalizing CpG ODN will be identified by confocal microscopy. The ability of these cells to produce IL-12, IL-18 and IFN-gamma will be demonstrated by quantitative RT-PCR and ELISA. The role of p38, JNK and ERK MAP kinases will be characterized by western blotting, immune complex kinase assays, and by using specific pharmacological or antisense oligonucleotide inhibitors of these pathways. The in vivo role of IFN-gamma, IL-12 and IL-18 will be demonstrated by using gene knockout animals, or by using neutralizing antibodies. The research proposal has important implications in the development of novel therapies for asthma, including those that provide long-term protection against eosinophilic inflammation and asthma attacks.