Development of novel gene delivery system

阳离子脂泡介导的基因转移已成为体外基因传递的一种常见方法。然而，血清往往会影响转染率。我们以前报道的DDAB(二甲基二十八烷基溴化铵)脂泡介导的基因转移也有同样的问题。为了克服这一障碍，我们开发了一种新型的利用鱼精蛋白修饰的DDAB脂泡的转基因载体。在以前的研究中，鱼精蛋白只是简单地添加到DNA/脂质复合体中，而在本方法中，鱼精蛋白被化学连接到硬脂酸上，并被结合到DDAB脂泡中。用该方法在含10%血清的培养液中对培养细胞的基因转移无明显抑制作用。蛋白质修饰的DDAB脂泡也提高了利用复制缺陷逆转录病毒载体在血清存在下的病毒转导效率。此外，这些囊泡还可以在体内有效地进行禽类胚胎的基因转移。这些结果表明，该方法可用于转基因动物的生产和基因治疗。

Cationic lipid vesicle-mediated gene transfer has become common for in vitro gene delivery. However, the transfection efficiency is often impaired by serum. DDAB (dimethyldioctadecyl ammonium bromide) lipid vesicle-mediated gene transfer, which we previously reported, has the same problem. To overcome this obstacle, we develop a novel transfection vehicle using protamine-modified DDAB lipid vesicles. While free protamine was simply added to the DNA/lipid complex in the previous study, in the present method the protamine is chemically conjugated to stearic acid and incorporated into DDAB lipid vesicles. Gene transfer was not significantly inhibited in 10% serumcontaining medium by this method for the transfection of cultured cells. Protaminemodified DDAB lipid vesicles also enhanced virus transduction efficiency in the presence of serum using a replication'defective retroviral vector. Furthermore, the vesicles allowed efficient gene transfer for avian embryos in vivo. These results indicate that the method is useful for the production oftransgenic animals and gene therapy.