title: Hexon-specific PEGylated adenovirus vectors utilizing avidin-biotin interaction.
abstract: PEGylation of recombinant adenovirus (Ad) vectors is a promising approach for not only evasion from neutralizing anti-Ad antibodies and uptake by phagocytic cells, but also prolongation of the blood retention time of Ad vectors after systemic administration. However, the conventional PEGylation leads to significant reduction in the transduction activity of Ad vectors, probably because PEG is nonspecifically conjugated to the Ad capsid protein and inhibits the binding of Ad vectors to the primary receptor, coxsackievirus-adenovirus receptor (CAR). In order to PEGylate an Ad vector without significant reduction in the transduction activity, the biotin-binding peptide (BAP) was inserted into the hypervariable region (HVR) 5 of the hexon, which is not involved in the binding to CAR, and PEG was then specifically conjugated to the hexon HVR5 via avidin-biotin interaction. In vitro transduction experiments demonstrated that the hexon-specific PEGylation did not cause an apparent reduction in the transduction efficiency of the Ad vector, although the insertion of the BAP into the HVR5 itself reduced the transduction efficiency by 50-fold, compared with the conventional Ad vector, in the absence of anti-Ad serum. In the presence of anti-Ad serum, the transduction with the Ad vector with the BAP in the hexon HVR5 was significantly blocked; however, anti-Ad serum only slightly inhibited the transduction with the hexon-specifically PEGylated Ad vector (Ad-BAP/Bio/Avi/Bio-PEG-L2). Intravenous administration of Ad-BAP/Bio/Avi/Bio-PEG-L2 resulted in prolonged blood retention, significant reduction in the transduction in the liver, and accumulation in the tumor; however, unexpectedly, the transduction efficiency of Ad-BAP/Bio/Avi/Bio-PEG-L2 in the tumor was almost at the background level.
authors.affiliation: Laboratory of Gene Transfer and Regulation, National Institute of Biomedical Innovation, Osaka, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Suzuki-Kouyama
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Katayama
authors.forename: Fuminori
authors.initials: F
authors.lastname: Sakurai
authors.forename: Tomoko
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Shinnosuke
authors.initials: S
authors.lastname: Kurachi
authors.forename: Kenji
authors.initials: K
authors.lastname: Kawabata
authors.forename: Shinsaku
authors.initials: S
authors.lastname: Nakagawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mizuguchi
mesh_terms: D000256:Adenoviridae / Q000737:chemistry* / Q000235:genetics*; D000818:Animals; D001360:Avidin / Q000737:chemistry*; D001710:Biotin / Q000737:chemistry*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D005260:Female; D005822:Genetic Vectors / Q000008:administration & dosage / Q000737:chemistry*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D020959:Polyethylene / Q000737:chemistry*; D014161:Transduction, Genetic / Q000379:methods
chemical_list: D001360:Avidin; D001710:Biotin; D020959:Polyethylene