Efficient gene transfer into human epithelial cell lines using glycosylated cationic carriers and neutral...

To date, no clear and constant relationship has been established between the chemical structure and the efficiency of non-viral transfection reagents. Despite the improvement of synthetic transfection systems, the capacity to transfect a target cell in a specific way is still a major challenge that gene therapy needs to overcome to be successful. Consequently, we developed a strategy aimed specifically at improving transfection of targeted human epithelial cells and to examine the possible effects of electrostatic interactions. Our attention therefore focused on the development of novel glycosylated formulations, based upon the introduction of one or two different carbohydrate ligands into (i) cationic lipid structures and (ii) synthetic neutral lipids incorporated into DNA and lipoplexes. Then, these formulations were tested in vitro on two human cell lines [HeLa and 16HBE14o(-)]. We report here that one of those formulations (CG 1/DOPE) is more efficient than DOTAP/DOPE. We determined that this non-viral transfection process is partially due to an endocytotic phenomenon mediated by targeting specific receptors directed toward specific carbohydrate elements. This was shown on 16HBE14o(-) cells where we observed a 43% and a 69% decrease in transfection when we blocked these receptors by the addition of free lactose and mannose, respectively. These results highlight the large adaptability of such monocationic glycolipids in the context of targeting and gene delivery.