Chitosan-DNA疫苗诱导Th1型特异性免疫应答  

Th1 Polarized Immune Responses Specific Against CVB3 Induced by Chitosan-DNA Vaccine

作　　者：徐薇[1] 吴蓉[1] 沈燕[1] 储以微[1] 熊思东[1] 

机构地区：[1]复旦大学上海医学院免疫学系-教育部分子医学重点实验室-上海基因免疫与疫苗研究中心,上海200032

出　　处：《复旦学报（医学版）》2003年第5期451-454,共4页Fudan University Journal of Medical Sciences

基　　金：国家重点基础研究发展计划 ( 2 0 0 1CB5 10 0 0 6);国家杰出青年科学基金 ( 3 992 5 0 3 1)资助项目

摘　　要：目的　在我们前期研究发现脱乙酰壳多糖 (chitosan)包裹质粒DNA形成的chitosan pcDNA3 VP1疫苗基因免疫诱生较高水平特异性免疫应答的基础上 ,探讨该疫苗诱导T辅助细胞 (Th)应答的类型 ,为chitosan DNA新型疫苗的分子设计奠定基础。方法　以chitosan pcDNA3 VP1、pcDNA3 VP1和 pcDNA3分别滴鼻免疫BALB/c小鼠 ,以ELISA法检测VP1体外表达和IgG亚型 ;以3 H TdR掺入法检测淋巴细胞增殖反应 ;并通过RT PCR检测了小鼠心肌内细胞因子表达情况。结果　chitosan pcDNA3 VP1体外转染后VP1的表达水平与 pcDNA3 VP1转染组无显著差异 (P >0 .0 5 ) ,表明chitosan的加入不改变 pcDNA3 VP1质粒在体外细胞内的表达 ;chitosan pcDNA3 VP1组脾淋巴细胞和肠系膜淋巴细胞增殖指数分别达 3.0和 2 .74 ,均显著高于 pcDNA3 VP1组和 pcDNA3组 (P <0 .0 1) ;chitosan pcDNA3 VP1免疫可显著增强IgG2a的生成 ,第 6周和第 12周IgG2a/IgG1比值分别为 2 .2 6和4 4 .2 ,而 pcDNA3 VP1组IgG2a表达稍高于IgG1、IgG2b和IgG3表达 ,IgG2a/IgG1比值为 1.6 3(P <0 .0 5 ) ;细胞因子检测表明chitosan pcDNA3 VP1组IFN γ表达显著高于IL 4 ,相对定量后IFN γ/IL 4比值为 2 .1;而 pcDNA3 VP1、pcDNA3组分别为 1.2 5和 0 .78。结论　chitosanPurpose To elucidate the type of Th immune responses induced by chitosan-DNA vaccine. Methods BALB/c mice were immunized with chitosan-pcDNA3?VP1 vaccine intranasally.Conventional DNA vaccine containing VP1 encoding sequences(pcDNA?VP1) and mock DNA(pcDNA3) were used as controls.Lymphoproliferation to VP1 peptide was detected by 3H?TdR incorporation assay;mRNA transcription of cytokines IFN?γ,IL?4,TNF?α and IL?6 were analyzed by RT?PCR.IgG subtypes specific to CVB3 were detected by ELISA. Results In vitro expression revealed that chitosan-DNA complex did not influence VP1 expression in vitro compared with pcDNA3?VP1-lipofectamine complex(P>0.05).The specific lymphoproliferation of both splenocytes and mesenteric lymphocytes derived from chitosan-pcDNA3?VP1 immunized mice was stronger than that in pcDNA3?VP1 and pcDNA3 group(P<0.01).The major IgG subtype of chitosan-pcDNA3?VP1 immunized mice was IgG2a and IgG2a/IgG1 value reached 2.26 at wk6 and even up to 44.2 following CVB3 challenge(wk12).Whereas the IgG2a/IgG1 value in pcDNA3?VP1 immunized mice was 1.63 at wk6(P< 0.05).Detection of the cytokines expression revealed that IFN?γ/IL?4 value in chitosan-pcDNA3?VP1 immunized group went up to 2.1 versus 1.25 and 0.78 in pcDNA3?VP1 and pcDNA3 group. Conclusions Chitosan-DNA vaccine tended to induce Th1 polaried immune responses.

关 键 词：Chitosan-DNA 疫苗 脱乙酰壳多糖 Thl型特异性免疫应答 

分 类 号：R392.12[医药卫生—免疫学]