title: Tropism modification of adenovirus vectors by peptide ligand insertion into various positions of the adenovirus serotype 41 short-fiber knob domain.
abstract: Recombinant adenoviruses have emerged as promising agents in therapeutic gene transfer, genetic vaccination, and viral oncolysis. Therapeutic applications of adenoviruses, however, would benefit substantially from targeted virus cell entry, for example, into cancer or immune cells, as opposed to the broad tropism that adenoviruses naturally possess. Such tropism modification of adenoviruses requires the deletion of their natural cell binding properties and the incorporation of cell binding ligands. The short fibers of subgroup F adenoviruses have recently been suggested as a tool for genetic adenovirus detargeting based on the reduced infectivity of corresponding adenovectors with chimeric fibers in vitro and in vivo. The goal of our study was to determine functional insertion sites for peptide ligands in the adenovirus serotype 41 (Ad41) short fiber knob. With a model peptide, CDCRGDCFC, we could demonstrate that ligand incorporation into three of five analyzed loops of the knob, namely, EG, HI, and IJ, is feasible without a loss of fiber trimerization. The resulting adenovectors showed enhanced infectivity for various cell types, which was superior to that of viruses with the same peptide fused to the fiber C terminus. Strategies to further augment gene transfer efficacy by extension of the fiber shaft, insertion of tandem copies of the ligand peptide, or extension of the ligand-flanking linkers failed, indicating that precise ligand positioning is pivotal. Our study establishes that internal ligand incorporation into a short-shafted adenovirus fiber is feasible and suggests the Ad41 short fiber with ligand insertion into the top (IJ loop) or side (EG and HI loops) of the knob domain as a novel platform for genetic targeting of therapeutic adenoviruses.
authors.affiliation: Virotherapy Lab, Department of Dermatology, University Hospital Erlasngen, Hartmannstrasse 14, Erlangen, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Hesse
authors.forename: Daniela
authors.initials: D
authors.lastname: Kosmides
authors.forename: Roland E
authors.initials: RE
authors.lastname: Kontermann
authors.forename: Dirk M
authors.initials: DM
authors.lastname: Nettelbeck
mesh_terms: D000260:Adenoviruses, Human / Q000145:classification / Q000235:genetics / Q000502:physiology*; D000595:Amino Acid Sequence; D002213:Capsid / Q000737:chemistry* / Q000502:physiology*; D002460:Cell Line; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D002472:Cell Transformation, Viral; D004730:Endothelium, Vascular / Q000166:cytology; D005240:Feasibility Studies; D005347:Fibroblasts / Q000166:cytology; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006801:Humans; D015603:Keratinocytes / Q000166:cytology; D008024:Ligands; D008545:Melanoma / Q000473:pathology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D012867:Skin / Q000166:cytology; D014161:Transduction, Genetic; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D008024:Ligands; D009842:Oligopeptides; D011993:Recombinant Fusion Proteins; C047981:arginyl-glycyl-aspartic acid