CpG-DNA的功能及应用前景

The Function of CpG-DNA and its Future Use

在细菌及病毒的 DNA中普遍存在的以及人工合成的非甲基化的 Cp G基序能通过 Toll样受体 9能直接活化 B细胞 ,诱导其增殖并抑制其凋亡 ;能促进免疫球蛋白和 IL -6、IL -1 0以及 IL -1 2等细胞因子分泌 ;增加 MHCII类分子和 B7共刺激分子的表达 ;激活单核巨噬细胞及树突状细胞分泌各种 Th1型细胞因子和趋化因子 ;促进淋巴细胞增殖 ,诱发体液和细胞介导的免疫反应。Cp G-DNA还可以间接活化细胞毒性T细胞 ,促进 Ig G2 a及 Ig M的优势表达 ,从而转换免疫反应的类型 (Th 到 Th ) ,因此 Cp G-DNA作为一类有希望的免疫增强剂在增强疫苗免疫效果和抗感染免疫中都有潜在的应用前景。

Bacterial DNA contains immunostimulatory motifs that stimulate the immune system and trigger an innate immune response characterized by the production of predominantly Th1-type cytokines such as IL-6?IL-10 and IFN,and so on these motifs consist of an unmethylated CpG dinucleotede flanked on two 5′purines and two 3′pyrimidines.CpG-DNA provides a broad adjuvant effect including: stimulation of B cells to proliferate, secrete immunoglobulin (Ig),cytokines and to be protected from apoptosis, enhancement expression of class II MHC and B7 costimulatory molecules,and direct activation of monocytes,macrophages and dendritic cells to secrete various cytokines and chemokines.they also play an active part in anticoncomitant immunity.