Glycofection: The ubiquitous roles of sugar bound on glycoplexes

Glycofection (transfection by using sugar-substituted polylysine) was assessed in order to provide an alternative to viral vectors for the transfer of genes into vascular smooth muscle cells, A rabbit vascular smooth muscle cell line (Rb-l cells) was selectively transfected by using glycoplexes (glycosylated polylysine/pSV2LUC complexes) in the presence of 10 mu M of the fusogenic peptide GALA, A sugar-specific transfection was obtained when the glycofection was conducted for 1 h with glycoplexes containing either alpha-Gal, alpha-Glc, alpha-GalNAc, beta-GlcNAc, or beta-GalNAc residues. The gene expression was high after transfection, with glycoplexes bearing alpha-Gal, alpha-GalNAc, or beta-GalNAc residues that were weakly internalized, and low with glycoplexes carrying Lact or Rha residues that were well taken up by cells, These results suggest that 1) glycofection can be a good approach for a selective transfer of genes into vascular smooth muscle cells, 2) an efficient uptake of the glycoplexes is not the unique limiting step for an efficient transfection, and 3) the sugar-dependent trafficking of the glycoplexes inside the cells may account for the transfection efficiency.