title: Lipid-mediated enhancement of transfection by a nonviral integrin-targeting vector.
abstract: Nonviral vectors consisting of integrin-targeting peptide/DNA (ID) complexes have the potential for widespread application in gene therapy. The transfection efficiency of this vector, however, has been limited by endosomal degradation. We now report that lipofectin (L) incorporated into the ID complexes enhances integrin-mediated transfection, increasing luciferase expression by more than 100-fold. The transfection efficiency of Lipofectin/Integrin-binding peptide/DNA (LID) complexes, assessed by beta-galactosidase reporter gene expression and X-gal staining, was improved from 1% to 10% to over 50% for three different cell lines, and from 0% to approximately 25% in corneal endothelium in vitro. Transfection complexes have been optimized with respect to their transfection efficiency and we have investigated their structure, function, and mode of transfection. Both ID and LID complexes formed particles, unlike the fibrous network formed by lipofectin/DNA complexes (LD). Integrin-mediated transfection by LID complexes was demonstrated by the substantially lower transfection efficiency of LKD complexes in which the integrin-biding peptide was substituted for K16 (K). Furthermore, the transfection efficiency of complexes was shown to be dependent on the amount of integrin-targeting ligand in the complex. Finally, a 34% reduction in integrin-mediated transfection efficiency by LID complexes was achieved with a competing monoclonal antibody. The role of lipofectin in LID complexes appears, therefore, to be that of a co-factor, enhancing the efficiency of integrin-mediated transfection. The mechanism of enhancement is likely to involve a reduction in the extent of endosomal degradation of DNA.
authors.affiliation: Molecular Immunology Unit, Institute of Child Health, University College London Medical School, UK.
authors.forename: S L
authors.initials: SL
authors.lastname: Hart
authors.forename: C V
authors.initials: CV
authors.lastname: Arancibia-Cárcamo
authors.forename: M A
authors.initials: MA
authors.lastname: Wolfert
authors.forename: C
authors.initials: C
authors.lastname: Mailhos
authors.forename: N J
authors.initials: NJ
authors.lastname: O'Reilly
authors.forename: R R
authors.initials: RR
authors.lastname: Ali
authors.forename: C
authors.initials: C
authors.lastname: Coutelle
authors.forename: A J
authors.initials: AJ
authors.lastname: George
authors.forename: R P
authors.initials: RP
authors.lastname: Harbottle
authors.forename: A M
authors.initials: AM
authors.lastname: Knight
authors.forename: D F
authors.initials: DF
authors.lastname: Larkin
authors.forename: R J
authors.initials: RJ
authors.lastname: Levinsky
authors.forename: L W
authors.initials: LW
authors.lastname: Seymour
authors.forename: A J
authors.initials: AJ
authors.lastname: Thrasher
authors.forename: C
authors.initials: C
authors.lastname: Kinnon
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D002460:Cell Line; D003315:Cornea; D004337:Drug Carriers; D005822:Genetic Vectors; D006801:Humans; D008024:Ligands; D008081:Liposomes; D018625:Microscopy, Atomic Force; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism; D010455:Peptides / Q000138:chemical synthesis / Q000378:metabolism; D010714:Phosphatidylethanolamines; D000644:Quaternary Ammonium Compounds; D011817:Rabbits; D017469:Receptors, Fibronectin / Q000378:metabolism*; D011993:Recombinant Fusion Proteins; D014162:Transfection / Q000379:methods*
chemical_list: D004337:Drug Carriers; D008024:Ligands; D008081:Liposomes; D009842:Oligopeptides; D010455:Peptides; D010714:Phosphatidylethanolamines; D000644:Quaternary Ammonium Compounds; D017469:Receptors, Fibronectin; D011993:Recombinant Fusion Proteins; C054005:N-(1-(2,3-dioleyloxy)propyl)-N,N,N-trimethylammonium; C094877:dioleoyl phosphatidylethanolamine; C020888:1,2-dielaidoylphosphatidylethanolamine; C047981:arginyl-glycyl-aspartic acid