title: Ablating adenovirus type 5 fiber-CAR binding and HI loop insertion of the SIGYPLP peptide generate an endothelial cell-selective adenovirus.
abstract: Adenovirus type 5 (Ad) based vectors transduce vascular endothelial cells (EC) and have been widely used for vascular gene transfer. However, many cell types express the Ad receptor (cox-sackievirus adenovirus receptor; CAR), preventing selective EC infection and precluding clinical use. We previously isolated the human EC-binding peptides SIGYPLP and LSNFHSS by phage display and demonstrated by means of a bispecific antibody that SIGYPLP directs efficient, high-level, EC-selective Ad-mediated gene transfer. We now generate genetically modified Ad fiber proteins with selective EC tropism by engineering these peptides into the HI loop of the Ad fiber. SIGYPLP, but not LSNFHSS, enhanced EC selectivity, demonstrating maintenance of peptide-cell binding fidelity upon incorporation into virions. Combining fiber mutations that block CAR binding (detargeting) with SIGYPLP insertion (retargeting) generated a novel Ad vector, AdKO1SIG, in a single component system. AdKO1SIG demonstrated efficient and selective tropism for EC compared with control Ad vectors. This is the first demonstration of genetic incorporation of a novel, mammalian, cell-selective ligand that retains its targeting fidelity in the Ad fiber HI loop, in combination with point mutations that abolish fiber-CAR interaction. This study demonstrates the potential for improving the cell-selectivity and safety of adenoviral vectors.
authors.affiliation: Department of Medicine and Therapeutics, University of Glasgow, Glasgow G11 6NT, UK.
authors.forename: S A
authors.initials: SA
authors.lastname: Nicklin
authors.forename: D J
authors.initials: DJ
authors.lastname: Von Seggern
authors.forename: L M
authors.initials: LM
authors.lastname: Work
authors.forename: D C
authors.initials: DC
authors.lastname: Pek
authors.forename: A F
authors.initials: AF
authors.lastname: Dominiczak
authors.forename: G R
authors.initials: GR
authors.lastname: Nemerow
authors.forename: A H
authors.initials: AH
authors.lastname: Baker
mesh_terms: D000256:Adenoviridae / Q000502:physiology*; D001665:Binding Sites; D001667:Binding, Competitive; D002478:Cells, Cultured; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D017931:DNA Primers / Q000737:chemistry; D004730:Endothelium, Vascular / Q000821:virology*; D005434:Flow Cytometry; D018390:Gene Targeting / Q000379:methods; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins; D006801:Humans; D015151:Immunoblotting; D008164:Luminescent Proteins / Q000378:metabolism; D010446:Peptide Fragments / Q000235:genetics*; D010957:Plasmids / Q000235:genetics; D011991:Receptors, Virus / Q000235:genetics / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism; D014161:Transduction, Genetic; D014162:Transfection
chemical_list: C568771:CLMP protein, human; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D017931:DNA Primers; D008164:Luminescent Proteins; D010446:Peptide Fragments; D011991:Receptors, Virus; D049452:Green Fluorescent Proteins