Modulating gene expression using DNA vaccines with different 3'-UTRs influences antibody titer, seroconversion and cytokine profiles.
Modulating gene expression using DNA vaccines with different 3'-UTRs influences antibody titer, seroconversion and cytokine profiles.
复制标题
DOI：
10.1016/s0264-410x(02)00740-5
复制
发表时间：
2003-04
期刊：
影响因子：
5.5
通讯作者：
J. Zinckgraf;L. Silbart
中科院分区：
文献类型：
--
作者：
J. Zinckgraf;L. Silbart
为了确定调节DNA疫苗产生的外源抗原的量是否可以影响随后的免疫应答的总体强度和细胞因子极化，构建了三种不同的质粒，每种质粒编码B（HB）表面抗原。在每种构建体中，HBs基因表达由巨细胞病毒立即早期启动子驱动，但在含有多聚腺苷酸化序列的3′-非翻译区（3′-UTR）中存在差异。这些3′-UTR序列来源于B型肝炎病毒（HBVpA）、牛生长激素（BGHpA）或兔β-珠蛋白（βpA）。用等摩尔量的每种质粒肌内免疫BALB/c小鼠，每两周收集一次血液。免疫后，总IgG滴度与体外抗原产生水平（来自转染的CHO细胞）相关，如以下应答模式所证明：HBVpA>BGHpA βpA。所有组均表现出对Th 1免疫应答的严重偏向，如高血清IgG 2a/IgG 1比率和培养的脾细胞分泌的IFN-γ相对于IL-4的优势所证明。此外，HBVpA构建体导致100%的血清转化率，而BGHpA组为40-50%，βpA组为0%。令人惊讶的是，从用βpA构建体免疫的小鼠中分离的脾细胞分泌最高水平的IFN-γ。总之，这些发现表明，改变基因表达水平不仅影响接种动物的总体滴度和血清转化率，而且可能在调节细胞因子谱中发挥作用。
To determine if modulating the amount of foreign antigen produced by a DNA vaccine can influence the overall intensity and cytokine polarization of the ensuing immune response, three different plasmids, each encoding the hepatitis B (HB) surface antigen, were constructed. In each construct, HBs gene expression was driven by the cytomegalovirus immediate early promoter, but differed in the 3′-untranslated regions (3′-UTR) containing the polyadenylation sequence. These 3′-UTR sequences were derived from either the hepatitis B virus (HBVpA), bovine growth hormone (BGHpA), or rabbit β-globin (βpA). BALB/c mice were immunized intramuscularly with equimolar amounts of each plasmid and blood was collected bi-weekly. Following immunization, total IgG titers correlated with in vitro antigen production levels (from transfected CHO cells), as evidenced by the following response pattern: HBVpA>BGHpA⪢βpA. All groups demonstrated a heavy bias toward a Th1 immune response, as evidenced by high serum IgG2a/IgG1 ratios and the predominance of IFN-γ over IL-4 secretion from cultured splenocytes. In addition, the HBVpA construct resulted in a seroconversion rate of 100%, in comparison to 40–50% in the BGHpA, and 0% in the βpA group. Surprisingly, splenocytes isolated from mice immunized with the βpA construct secreted the highest levels of IFN-γ. Taken together, these findings suggest that altering the level of gene expression not only affects the overall titer and seroconversion rates of vaccinated animals, but also may play a role in modulating cytokine profiles.