未甲基化CpG寡聚脱氧核苷酸对小鼠脾细胞产生免疫球蛋白E的抑制作用

Inhibitory Effect of Non-methylation CpG Oligodeoxynucleotide on Production of Immunoglobulin E by Murine Splenocytes

【目的】探讨未甲基化CpG的寡聚脱氧核苷酸(CpG ODN)在体外对小鼠脾细胞和纯化B细胞产生免疫球蛋白E(IgE)的作用及其机制。【方法】在体外,小鼠脾淋巴细胞和纯化B细胞与白细胞介素4(IL-4)+抗CD40单克隆抗体(anti-CD40)在CpG ODN存在或不存在的条件下刺激3d或7d后,用酶联免疫吸附试验法检测IgE的水平,用流式细胞仪检测CD19阳性B细胞的分裂及活化情况。【结果】CpG ODN呈剂量及时间依赖性地抑制由IL-4+anti-CD40诱导的小鼠脾细胞IgE的产生,anti-IFN-γmAb及anti-IL-12mAb不能完全拮抗CpG ODN对IgE产生的抑制作用。同样地,CpG ODN抑制小鼠纯化B细胞IgE的产生。进一步分析结果表明,CpG ODN促进B细胞活化及共刺激分子CD80的表达,但抑制B细胞分裂。【结论】CpGODN直接作用于B细胞而发挥对IgE的抑制作用,该研究为基础和临床研究提供科学理论依据。

[Objective] To evaluate the effect and mechanism of non-methylation CpGoligodeoxynucle otide （CpG ODN） on production of immunoglobulin E （IgE） by murine splenocytes and purified splenic B ceils in vitro. [Methods] Splenocytes and purified splenic B cell from BALB/c mice were prepared and stimulated at time points with IL-4 ＋ anti-CD40 in the presence or absence of CpG ODN at different concentration. After stimulation for 3 or 7 days, the level of IgE in the culture supernatant was assayed by ELISA, and B cell activation and division was evaluated in vitro by flow cytometry. [Results] CpG ODN inhibited the production of IgE production by IL-4 ＋ anti-CD40 stimulated murine splencytes or purified splenic B cells in a dose-dependent manner and in a time course way in vitro. Anti-IFN-γ mAb or anti-IL-12 mAb completely failed to abolish CpG ODN mediated inhibition of IgE production by murine splencytes. Cellular analysis demonstrated that CpG ODN elicited the activation but inhibited division of B cells. [Conclusion ] CpG ODN may exert its inhibition on IgE production via the direct effect on B cell, our results provide an important applicatin of CpG ODN in the clinical studies.