High-efficiency gene transfection of macrophages by lipoplexes

Macrophage transfection studies are crucial for understanding gene regulati on and expression. However, gene transfection in macrophages is difficult. We have shown here that macrophages are more resistant to gene transfection compared with other cell types. To further develop an efficient gene deliv ery system for macrophages, we evaluated various liposomal and non-liposoma l agents including LipofectAMINE(R), Lipofectin(R), DOTAP, DEAE-dextran, an d the DNA condensing agent protamine sulfate for their ability to promote g ene transfection. CMV-luciferase was used as a reporter plasmid. Macrophage transfection was maximal at the DNA:LipofectAMINE:protamine ratio of 1:12: 1 mu g/ml The LipofectAMINE formulation showed a 10-12-fold increase in tra nsfection efficiency over DOTAP and a 4-5-fold increase over Lipofectin. Th is transfection method showed minimal toxicity at the concentrations tested and was at least 20-25-fold superior to the most frequently used DEAE-dext ran method for macrophage transfection. (C) 2000 Elsevier Science B.V. All rights reserved.