CpG ODN佐剂促进HBsAg疫苗诱导小鼠细胞免疫应答的探讨

CpG ODN adjuvant enhances the cellular immune response in mice vaccinated with recombinant hepatitis B surface antigen

目的 探讨cpG ODN对重组乙型肝炎表面抗原（HBsAg）诱导小鼠细胞免疫应答的影响。方法HBsAg和HBsAg＋CpG ODN分别肌肉注射免疫Balb／c小鼠后，从淋巴组织（脾和淋巴结）和非淋巴组织（肺）分离淋巴细胞，体外经HBsAg抗原刺激后，利用ELISA检测细胞培养液中IFN-γ的水平，再利用流式细胞仪在单个细胞水平上检测IFN-γ^＋细胞的频率，分析IFN-7^＋细胞亚群。结果对照组和HBsAg免疫组IFN-γ产生的水平很低，当HBsAg加强免疫1～2次后，IFN-γ表达仍然没有明显升高；而CpG ODN＋HBsAg免疫1次或加强免疫后，CpG显著促进HBsAg诱导的IFN-γ产生。进一研究结果表明CpG促进HBsAg诱导淋巴器官和非淋巴器官内CD4^＋和CD8^＋T细胞IFN-γ的表达。结论CpG免疫佐剂不仅能诱导细胞免疫应答同时也诱导体液免疫应答，提示CpG ODN可以用于HBsAg预防和治疗性佐剂。

Objective To investigate the effects of synthetic oligodeoxynucleotide containing CpG motifs （CpG ODN） on the cellular immune response in mice immunized with hepatitis B surface antigen （rHBsAg）. Methods Balb/c mice were immunized i.m. with HBsAg or HBsAg ＋ CpG ODN. Single cell suspensions were prepared from lymphoid （ spleens and lymph nodes） and non-lymphoid tissues （lung）. The cells were then stimulated with HBsAg. IFN-γ in culture supernatants was assessed by ELISA. The IFN-γ-producing cell subsets were determined and analyzed by FACS. Results HBsAg immunization was not able to induce detectable levels of IFN-γ production. CpG could significantlyelevate the HBsAg-induced IFN-γ production by lymphoid and non-lymphoid tissues after prime and boost vaccination. Moreover, CpG promoted IFN-γ expression by both CD4^＋ and CD8^＋ T cells. Conclusion CpG ODN can enhance both cellular and humoral immune responses induced by HBsAg in lymphoid and non-lymphoid organs.