Development of plasmid DNA delivery methods to antigen presenting cells for optimized DNA vaccination

为了构建一种优化DNA疫苗载体DNA传递的策略，进行了一系列的体外和体内研究。用培养的巨噬细胞和树突状细胞进行的体外研究表明，这些细胞中涉及聚阴离子的特定机制。体外细胞活化实验表明，裸质粒DNA及其阳离子脂质体复合体以CpG基序依赖的方式激活树突状细胞。另一方面，裸露DNA对巨噬细胞的激活依赖于CpG基序，而DNA与阳离子脂质体复合后可以不依赖CpG基序的方式激活巨噬细胞。在小鼠体内的局部免疫研究表明，DNA与阳离子载体甲基化牛血清白蛋白复合后可增强DNA疫苗的抗体诱导作用，提示可通过控制DNA与载体的络合作用来调节免疫反应，从而为DNA疫苗的体外和体内研究提供了有用的信息。

To construct a strategy for optimizing plasmid DNA delivery for DNA vaccination, a series of in vitro and in vivo studies were carried out. In vitro studies using cultured macrophages and dendritic cells demonstrated that a specific mechanism for polyanions would be involved in these cells. In vitro cellular activation experiments revealed that dendritic cells were activated by naked plasmid DNA and its cationic liposome complexes in CpG motif-dependent manner. On the other hand, macrophage activation by naked DNA was dependent on CpG motif while DNA can stimulate macrophages in a CpG motif-independent manner when it is complexed with the cationic liposomes. In vivo local immunization studies using mice demonstrated that plasmid DNA complexed with a cationic carrier, methylated bovine serum albumin can enhance antibody induction with DNA vaccination, suggesting that immune reactions can be modulated by the control of local disposition of plasmid DNA with complexation with the carrier, Thus, the present study provides useful in vitro and in vivo information about the DNA vaccination approach.