细菌DNA及其来源的具有免疫刺激效应的寡聚核苷酸(ISS-ODN)(含有非甲基化CpG基序)是TLF9的配体。ISS-ODN能够刺激Th1型细胞因子的产生,上调抗原提呈细胞表达共刺激分子,增强宿主对入侵病原微生物的防御功能。ISS-ODN能够防止或明显减轻CD4+T细胞依赖和CD4+T细胞非依赖实验性大肠炎的发生或炎症程度,但这种保护作用是短暂的,不具有免疫记忆效应,表明ISS-ODN介导的抗实验性大肠炎效应是天然免疫应答。通过T细胞和B细胞缺陷的SCID和RAG-/-小鼠,发现ISS-ODN对RAG-/-小鼠发生实验性大肠炎具有保护机制,而这种效应主要是通过ISS-ODN活化TLR9信号通路产生的Ⅰ型IFN来发挥作用。 Bacterial DNA and its source of immunostimulatory oligonucleotides (ISS-ODNs), containing unmethylated CpG motifs, are ligands for TLF9. ISS-ODN stimulates the production of Th1-type cytokines, up-regulates the expression of costimulatory molecules by antigen-presenting cells, and enhances the host defense against invading pathogenic microorganisms. ISS-ODN can prevent or significantly reduce the incidence of CD4 + T cell-dependent and CD4 + T-independent experimental colitis or inflammation, but this protective effect is transient and does not have immune memory effect, indicating that ISS-ODN mediated The anti-experimental colitis effect is a natural immune response. ISS-ODN was found to have a protective mechanism against experimental colitis in RAG - / - mice by SCID and RAG - / - mice deficient in T cells and B cells, and this effect is mainly due to activation of TLR9 signaling by ISS-ODN Pathways produce type I IFN to play a role.