质粒DNA促进HBsAg-抗HBs复合型疫苗诱生的免疫应答的研究  

Plasmid DNA switches on Th1 response in mice immunized with antigen-antibody complex

作　　者：瞿涤[1] 应哲康[1] 王文逸 张悦庆 袁正宏 闻玉梅 

机构地区：[1]上海医科大学卫生部医学分子病毒学重点实验室

出　　处：《中华微生物学和免疫学杂志》2000年第4期365-369,共5页Chinese Journal of Microbiology and Immunology

基　　金：国家863高科技计划项目(Z18);国家教委留学回国人员科研启动基金

摘　　要：目的　研究HBsAg 抗HBs 质粒DNA复合型疫苗的免疫原性及其诱生细胞免疫应答的类型。方法　分别以HBsAg、HBsAg 抗 HBs(IC)、pI/AmpHBs、IC pI/AmpHBs及IC pI/Amp免疫小鼠 ,检测抗 HBs的效价 ,分析抗 HBsIgG亚类 (ELISA) ;取免疫小鼠脾细胞 ,体外抗原刺激 ,用竞争性RT PCR方法检测IFN γ及IL 4mRNA转录水平。结果　IC pI/AmpHBs诱生的抗 HBs效价明显高于IC或pI/AmpHBs单独免疫组 ,其IgG2a/IgG1比值高于IC免疫组 ,而低于pI/AmpHBs免疫组。IC pI/AmpHBs免疫小鼠脾细胞在HBsAg刺激下 ,IFN γmRNA转录水平明显高于其他免疫组 ,其IFN γmRNA的T/C(目的片段Target/竞争片段Competitor)比值为IC免疫小鼠脾细胞的 10倍 ;IC pI/AmpHBs免疫小鼠脾细胞IL 4mRNA转录水平亦高于其他免疫组 ,其IL 4mRNA的T/C比值为IC免疫小鼠脾细胞的 2倍。结论　HBsAg 抗HBs 质粒DNA复合型疫苗在增强体液免疫应答的同时可诱导脾细胞IFN γ的表达水平增高。Objective Our previous study showed that plasmid DNA could substitute alum as an adjuvant to enhance anti-HBs response to hepatitis B surface antigen (HBsAg)-anti-HBs immunogenic complex (IC) in mice (Viral Immunology, 1998, 11:65). In the present study, we further investigated the mechanisms of plasmid DNA on the immunogenicity of IC. Methods BALB/c mice were immunized separately with (a) HBsAg, (b) IC, (c) pI/AmpHBs DNA, a plasmid encoding HBsAg, (d) IC combined with pI/AmpHBs, and (e) IC combined with the vector pI/Amp by i.m injection. Anti-HBs IgG subclasses in mouse serum were analyzed. The expression of IFN-γ mRNA and IL-4 mRNA in spleen cells from mice immunized with HBsAg in vitro were assayed by semi-quantification RT-PCR. Results It was showed that serum anti-HBs titer from group d was the highest among immunized groups, and its ratio of IgG2a/IgG1 reaching 0.91 was higher than that from group a (0.73) and group b (0.82), but was lower than that from group c (1.12). Higher level of IFN-γ mRNA was found in spleen cells of group d and its ratio T/C (target/competitor) was 6.25 and 9.09, at 24 and 48 hours after HBsAg-stimulation. IFN-γ mRNA level detected in group d was tenfold higher than that in group b (T/C ratio 0.83/0.13). T/C ratio of IFN-γ in group a was 0.57/0.02, group c 1.05/0.24 and group e 3.68/0.06. IL-4 mRNA level detected in group d was also higher than that in other groups. T/C ratio of IL-4 in group d was 0.96 and 1.68 at 24 and 48 hours after HBsAg-stimulation meaning twofold higher than that in group b (T/C ratio 0.43 and 0.79). Conclusion Results indicated that plasmid DNA combined with IC switches on Th1 response with no adverse effects on inducing high titer of anti-HBs.

关 键 词：免疫原性复合物疫苗 DNA疫苗 免疫应答 HBSAG 

分 类 号：R392[医药卫生—免疫学]