Efficient Nonviral Gene Transfer Mediated by Polyethylenimine in an Insect Cell Line

抄録

An enhanced gene delivery system, monitored by the expression of a luciferase gene, was devised for an insect cell line BmN4, by altering the ratios of several liposome components. First, three kinds of commercially available polyethylenimine (PEI) reagents with different sizes were tested; one (PEI reagent with an average molecular weight of 1,800) gave a much better transfection efficiency than others. Using this particular reagent (PEI-1800), we newly formulated a liposome composed of three polycationic lipids: dioleoylphosphatidylchorine (DOTAP), dioleoylphosphatidylethanolamine (DOPE) and PEI-1800 in a ratio of 1:1:1. The current liposome gave a 2.5-fold efficiency compared to a commercially available liposome (CellFECTIN), a 2:3 mixture of TM-TPS (tetramethyl-tetrapalmitylspermine) and DOPE. The effects of divalent cations on the transfection with the newly devised liposome were investigated in detail. It is concluded that a mixture containing the PEI-1800 reagent provides a low cost and stable transfection procedure for the cultured silkworm cell line.