Improved transfection using epithelial cell line-selected ligands and fusogenic peptides

Synthetic gene transfer vectors can be optimised by combining DNA-binding p eptides, cell surface receptor ligands, and fusogenic and nuclear localisat ion peptides. We have used the phage display technique to identify ligands of the tracheal epithelial cell line CFT-2. The peptides harboured by two p hages were selected for transfection studies: peptide 7 (GRGDGDV) that cont ained the integrin-binding motif RGD, and peptide 9 (RFDSLKV) that was foun d in six out of 24 phages analysed. Both peptides, fused with the DNA-bindi ng peptide P2 (SPKRSPKRSPKR), enhanced transfection efficiency in cell line s CFT-2, NT-1, NIH-3T3 and ECV-304. In particular, peptide P2-7 increased t ransfection efficiency from 36.5% to 44.8% in NIH-3T3 cells and from 10.9% to 14.4% in CFT-2 cells, when compared to transfections performed with pept ide P2. Two fusogenic peptides. HA (GLFEAIAEFIEGGWEGLIEGC) and JTS-1 (GLFEA LLELLESLWELLLEA), were then added to the complexes and shown to improve tra nsfection efficiency to the same extent. For instance, when combined to pep tide P2-7, transfection levels of 54.1% and 55.2% were attained in NIH-3T3 cells with HA and JTS-1, respectively. The addition of the ligands and fuso genic peptides thus allowed us to construct greatly improved transfection r eagents. (C) 2000 Elsevier Science B.V, All rights reserved.