Incorporation of adenovirus into a ligand-based DNA carrier system results in retention of original receptor specificity and enhances targeted gene expression.
Adenovirus type 5 was modified by coupling an asialoglycoprotein-polylysine conjugate to the virus by reactions that activate carbohydrate residues. Wild-type virus modified in this manner had greatly decreased infectivity toward normally susceptible HeLa S3 (asialoglycoprotein receptor (-)) and SK Hep1 (asialoglycoprotein receptor (-)) cells leaving 91 and 86% viable, respectively, after 48 h. However, with Huh 7 (asialoglycoprotein receptor (+)) cells, modified virus retained its infectivity leaving only 19% of cells viable under identical conditions. Modified virus was complexed to DNA in the form of a plasmid, pSVHBV surf, containing the gene for hepatitis B surface antigen as a marker of gene expression. Huh 7, receptor (+), cells treated with modified wild type, and modified replication-defective d1312 virus complexed to DNA raised antigen levels by approximately 13- and 30-fold, respectively, compared with asialoglycoprotein-polylysine DNA complex alone. Competition with a large excess of an asialoglycoprotein blocked the enhancement by more than 95%. Using a beta-galactosidase marker gene, the number of cells transfected by modified virus was found to be 200-fold higher than complex alone. Yet, specificity was retained exclusively for asialoglycoprotein receptor-bearing cells. These data indicate that adenovirus can be chemically modified by coupling ligands resulting in targeted gene expression dictated specifically by receptor recognition of the attached ligand.
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Department of Medicine, University of Connecticut School of Medicine, Farmington 06030.
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Rosenberg
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D000260:Adenoviruses, Human / Q000235:genetics*; D037263:Asialoglycoprotein Receptor; D001212:Asialoglycoproteins; D002467:Cell Nucleus / Q000378:metabolism; D004337:Drug Carriers; D005819:Genetic Markers; D005822:Genetic Vectors; D006367:HeLa Cells; D006514:Hepatitis B Surface Antigens / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D010957:Plasmids; D011107:Polylysine / Q000031:analogs & derivatives; D011956:Receptors, Cell Surface / Q000378:metabolism*; D014162:Transfection / Q000379:methods*; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000235:genetics
D037263:Asialoglycoprotein Receptor; D001212:Asialoglycoproteins; D004337:Drug Carriers; D005819:Genetic Markers; D006514:Hepatitis B Surface Antigens; D011956:Receptors, Cell Surface; C086457:asialoglycoprotein-polylysine conjugate; D011107:Polylysine; D001616:beta-Galactosidase