Wagner E, Cotten M, Foisner R, Birnstiel M L
Research Institute of Molecular Pathology, Vienna, Austria.
Proc Natl Acad Sci U S A. 1991 May 15;88(10):4255-9. doi: 10.1073/pnas.88.10.4255.
We have previously described a gene delivery system based upon the receptor-mediated endocytosis of DNA complexed with transferrin-polycation conjugates. This delivery system has been found to be very effective for both the internalization and the expression of genetic material in cells that have many transferrin receptors. Upon scrutinization of the parameters involved in this method, which we have termed transferrinfection, we note two important features of the process: the polycation in polycation-transferrin conjugates, as expected, serves to attach the transferrin moiety to the DNA and, in addition, the polycation functions to condense the DNA into a doughnut structure. Electron microscopic analysis of a range of poorly active to highly active transferrinfection samples reveals a strong correlation between DNA condensation and cellular DNA uptake. Furthermore, we demonstrate that the transfection activity of the DNA complex can be increased by addition of free polycation as long as a sufficient quantity of polycation-transferrin conjugates remains in the complex to ensure its binding to the cellular receptor.
我们之前描述了一种基于与转铁蛋白 - 聚阳离子共轭物复合的DNA的受体介导内吞作用的基因递送系统。已发现该递送系统对于在具有许多转铁蛋白受体的细胞中遗传物质的内化和表达非常有效。在仔细研究我们称为转铁蛋白感染的该方法所涉及的参数时，我们注意到该过程的两个重要特征：如预期的那样，聚阳离子 - 转铁蛋白共轭物中的聚阳离子用于将转铁蛋白部分附着到DNA上，此外，聚阳离子还起到将DNA浓缩成甜甜圈结构的作用。对一系列活性低至高活性的转铁蛋白感染样品的电子显微镜分析揭示了DNA浓缩与细胞DNA摄取之间的强相关性。此外，我们证明只要复合物中保留足够量的聚阳离子 - 转铁蛋白共轭物以确保其与细胞受体结合，通过添加游离聚阳离子就可以提高DNA复合物的转染活性。
