ABSTRACT
DNA transfection and gene expression are very complex processes. To date not many studies have dealt with the mechanisms involved. Only some particular steps were studied. Early models, based on rhodamine lipid fluorescence studies which quickly spread to the cell surface, envisioned complex fusion with cell membranes, while recently most researchers believe that the complex enters cells by an endocytotic pathway. In some experiments endosome-disrupting agents could increase gene expression indicating an endocytotic pathway. Endosomal acidification can be reduced by using chloroquine, monesin, or ammonium chloride while colchicine interferes with endosomal uptake. Brefeldin B interferes with endosomal trafficking. In vitro transfection consists of incubating a cell culture with a genosome dispersion. Interactions between genosomes and cells occur via free diffusion of complexes above the plated cells. Practically all experiments show that positively charged complexes are much more effective for gene expression.
