Gene Delivery into T cells using Ternary Complexes of DNA, Lipofectamine, and Carboxy-terminal Phenylalanine-modified Dendrimers.

T-cells play critical roles in various immune reactions, and genetically engineered T-cells have attracted attention for the treatment of cancer and autoimmune diseases. Previously, we showed that a polyamidoamine dendrimer of generation 4 (G4), modified with 1,2-cyclohexanedicarboxylic anhydride (CHex) and phenylalanine (Phe) (G4-CHex-Phe), was useful for delivery into T cells and their subsets. In this study, we constructed an efficient non-viral gene delivery system using this dendrimer. Ternary complexes were prepared using different ratios of plasmid DNA, Lipofectamine, and G4-CHex-Phe. A carboxyl-terminal dendrimer lacking Phe (G3.5) was used for comparison. These complexes were characterized using agarose gel electrophoresis, dynamic light scattering, and ζpotential measurements. In Jurkat cells, the ternary complex with G4-CHex-Phe at a P/COOH ratio of 1/5 showed higher transfection activity than other complexes such as binary and ternary complexes with G3.5 and without any significant cytotoxicity. The transfection efficiency of the G4-CHex-Phe ternary complexes decreased considerably in the presence of free G4-CHex-Phe and on altering the complex preparation method. These results suggest that G4-CHex-Phe promotes the cellular internalization of the complexes, which is useful for gene delivery into T cells. This article is protected by copyright. All rights reserved.