title: Adenovirus 5 fibers mutated at the putative HSPG-binding site show restricted retargeting with targeting peptides in the HI loop.
abstract: Adenoviral vectors are commonly used for liver-directed gene therapy following systemic administration owing to their strong propensity for hepatocyte transduction. However, many disease applications would benefit from the delivery of adenoviruses to alternate tissues via this route. Research has thus focused on stripping the virus of native hepatic tropism in conjunction with modifying virus capsid proteins to incorporate novel tropism. Recently, the KO1S* adenovirus serotype 5 fiber mutant, devoid of both coxsackie and adenovirus receptor binding in the fiber knob domain and mutated at the putative heparan sulphate proteoglycan binding site in the fiber shaft, was shown to possess strikingly poor hepatic tropism in mice, rats, and non-human primates. Thus, it is an ideal candidate for retargeting strategies. We therefore assessed the ability of peptide-modified KO1S* fibers to retarget adenovirus. Peptide insertions were well tolerated and virions produced to high titers. However, expected retargeting at the level of transduction was not observed, despite cell-binding studies showing enhanced vector targeting at the cell surface. Cy3 labeling studies showed retarded trafficking of S*-containing fibers. Taken together, our data demonstrates that KO1S* mutant fibers are ineffective for cell retargeting strategies.
authors.affiliation: BHF Glasgow Cardiovascular Research Centre, Division of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK.
authors.forename: Angelika B
authors.initials: AB
authors.lastname: Kritz
authors.forename: Campbell G
authors.initials: CG
authors.lastname: Nicol
authors.forename: Kate L
authors.initials: KL
authors.lastname: Dishart
authors.forename: Ruth
authors.initials: R
authors.lastname: Nelson
authors.forename: Susan
authors.initials: S
authors.lastname: Holbeck
authors.forename: Dan J
authors.initials: DJ
authors.lastname: Von Seggern
authors.forename: Lorraine M
authors.initials: LM
authors.lastname: Work
authors.forename: John H
authors.initials: JH
authors.lastname: McVey
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Nicklin
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Baker
mesh_terms: D000260:Adenoviruses, Human / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D036022:Capsid Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D017931:DNA Primers / Q000235:genetics; D005164:Factor IX / Q000378:metabolism; D005170:Factor X / Q000378:metabolism; D005818:Genetic Engineering; D005822:Genetic Vectors; D019812:Heparan Sulfate Proteoglycans / Q000378:metabolism*; D006801:Humans; D009154:Mutation; D011991:Receptors, Virus / Q000378:metabolism; D020349:Surface Plasmon Resonance; D014161:Transduction, Genetic
chemical_list: C568771:CLMP protein, human; C568772:CLMP protein, mouse; D036022:Capsid Proteins; C568773:Clmp protein, rat; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D017931:DNA Primers; D019812:Heparan Sulfate Proteoglycans; D011991:Receptors, Virus; C018315:hexon capsid protein, Adenovirus; D005164:Factor IX; D005170:Factor X