title: Hepatocyte targeting of nucleic acid complexes and liposomes by a T7 phage p17 peptide.
abstract: A critical step for liver-directed gene therapy is the selective targeting of nucleic acids to hepatocytes. We have previously discovered that the proximal half of the T7 phage tail fiber protein (p17) targeted intact T7 phage and recombinant proteins to hepatocytes in vivo. In the present study, we have localized the targeting activities to a 33 amino acid sequence within the p17 coiled-coil rod domain. Given that the tail fiber domain from which the peptide was derived may form alpha and triple helical structures, biophysical studies (CD spectra and analytical ultracentrifugation) were conducted to determine the secondary and tertiary structures of the peptide. This peptide is able to target proteins, polymers, and siRNA and also particles such as DNA polyplexes and liposomes to hepatocytes. A variety of coupling strategies and chemistries were employed, thus demonstrating that this peptide is a versatile system for delivering cargo. The ability of this hepatocyte-targeting peptide to target DNA-containing particles suggests that it should be useful in the development of both nonviral and viral vectors. However, biological function of delivered cargo has not been demonstrated. This was primarily due to failure of delivered cargo to escape the endosomes. Further studies are in progress to provide functional activity of delivered nucleic acids by enabling their endosomal escape.
authors.affiliation: Mirus Bio Corporation, 505 South Rosa Road, Madison, Wisconsin 53719, USA.
authors.forename: So C
authors.initials: SC
authors.lastname: Wong
authors.forename: Darren
authors.initials: D
authors.lastname: Wakefield
authors.forename: Jason
authors.initials: J
authors.lastname: Klein
authors.forename: Sean D
authors.initials: SD
authors.lastname: Monahan
authors.forename: David B
authors.initials: DB
authors.lastname: Rozema
authors.forename: David L
authors.initials: DL
authors.lastname: Lewis
authors.forename: Lori
authors.initials: L
authors.lastname: Higgs
authors.forename: James
authors.initials: J
authors.lastname: Ludtke
authors.forename: Alex V
authors.initials: AV
authors.lastname: Sokoloff
authors.forename: Jon A
authors.initials: JA
authors.lastname: Wolff
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017123:Bacteriophage T7 / Q000235:genetics*; D001483:Base Sequence; D002232:Carbocyanines; D005456:Fluorescent Dyes; D018390:Gene Targeting; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism*; D008081:Liposomes; D051379:Mice; D008813:Mice, Inbred ICR; D008969:Molecular Sequence Data; D009696:Nucleic Acids / Q000008:administration & dosage* / Q000235:genetics*; D010446:Peptide Fragments / Q000008:administration & dosage / Q000737:chemistry / Q000235:genetics; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000235:genetics; D014764:Viral Proteins / Q000008:administration & dosage* / Q000737:chemistry / Q000235:genetics*
chemical_list: D002232:Carbocyanines; D005456:Fluorescent Dyes; D008081:Liposomes; D009696:Nucleic Acids; D010446:Peptide Fragments; D034741:RNA, Small Interfering; D014764:Viral Proteins; C069680:bacteriophage T7 leg protein gp17; C089187:cyanine dye 3