Sugar-mediated uptake of glycosylated polylysines and gene transfer into normal and cystic fibrosis airway epithelial cells

We have examined the membrane lectin expressed by immortalized normal and c ystic fibrosis (CF) airway epithelial cells, using fluorescein-labeled neog lycoproteins; the uptake of plasmid DNA using fluoresceinylated glycoplexes (plasmid/glycosylated polylysine complexes); and the efficiency of gene tr ansfer when glycosylated polylysines and glycosylated, partially gluconoyla ted polylysines were used as vectors, The most efficient up-take of neoglyc oproteins by normal and CF cells was obtained with mannosylated BSA (bovine serum albumin). Similarly, the most efficient uptake of plasmid DNA was ob tained with glycoplexes bearing alpha-D-Man residues, Surprisingly, glycopl exes bearing alpha-D-Man residues were poorly efficient for gene transfer i nto normal and CF cells. The highest luciferase activity was achieved with lactosylated polylysine- and beta-D-GlcNAc-substituted gluconoylated polyly sine as vectors. Gene transfer efficiency obtained with gluconoylated polyl ysine bearing beta-D-GlcNAc residues was similar to that observed with poly ethylenimine (PEI; 25 and 800 kDa) and 10-fold higher than that observed wi th lipofectin and LipofectAMINE. These results suggest that the transfectio n efficiency with glycoplexes is not determined only by the specificity of the lectin expressed at the cell surface membrane but also by intracellular trafficking of the glycoplexes, which could be mediated by lectins present inside the cells.