INFLUENZA FUSOGENIC PEPTIDE IN DNA COMPLEX ENHANCES ASIALOGLYCOPROTEIN RECEPTOR-MEDIATED GENE-TRANSFER TO HEPATOMA-CELLS - A STRATEGY FOR LIVER-TARGETING GENE-THERAPY

The asialoglycoprotein receptor-mediated gene transfer system is a use ful method for targeted gene transfer to liver cells. This system is b ased on the finding that hepatocytes have a specific receptor for asia loglycoprotein, The efficiency of this system, however, is very low. T o enhance the efficiency of this system,we examined the effect of a fu sogenic peptide from influenza virus on asialoglycoprotein receptor-me diated gene transfer. It is known that this peptide disrupts the endos omal membrane at acidic pH, and allows DNA to escape from the endosome into the cytosol before attack by lysosomes. A recombinant plasmid DN A carrying a reporter gene was complexed with a poly-L-lysine-conjugat ed 23-residue peptide derived from influenza virus hemagglutinin HA2 N -terminal peptide and galactose-poly-L-lysine conjugate, and added to the culture of HepG2 cells. When the fusogenic peptide was incorporate d into the DNA complex with the galactose-poly-L-lysine conjugate, the luciferase activity in the HepG2 cells was more than 500-fold higher than that of cells transfected with the DNA complex without the peptid e. An antibody against the asialoglycoprotein receptor blocked the tra nsfer of the DNA complex, indicating that the DNA complex was specific ally transferred into the HepG2 cells by asialoglycoprotein receptor-m ediated endocytosis. Our results suggest that the asialoglycoprotein r eceptor-mediated gene delivery system using this fusogenic peptide may be useful for the development of gene therapy targeting the liver.