title: Role of the putative heparan sulfate glycosaminoglycan-binding site of the adenovirus type 5 fiber shaft on liver detargeting and knob-mediated retargeting.
abstract: Liver tropism hampers systemic administration of adenovirus in gene therapy and virotherapy. In consequence, tumour targeting requires the combination of capsid modifications that abrogate liver transduction and redirect adenoviral vectors to tumour cells. Coxsackievirus and adenovirus receptor (CAR), integrins and heparan sulfate glycosaminoglycans (HSG) are receptors involved in adenovirus type 5 (Ad5) entry into cells. The in vitro and in vivo properties of Ad5 vectors unable to bind CAR, integrins and HSG with and without Arg-Gly-Asp (RGD) inserted at the HI loop of the fiber were studied. As was previously observed with CAR-ablated vectors, CAR and integrin double binding-ablated vectors transduced hepatocytes less efficiently in vitro but not in vivo. On the contrary, the role of HSG on Ad5 infectivity was evident in vitro only when CAR binding was abrogated, but the shaft mutation that ablated HSG binding on the background of a normal capsid was sufficient to abrogate liver transduction in vivo. The insertion of amino acids RGD at the HI loop in a shaft-mutated fiber only partially rescued integrin-mediated infectivity. These results indicate that the shaft mutation precluded HSG binding and affected the structure of the fiber. The insertion of ligands at the hexon or protein IX may be required to benefit from the fiber shaft mutation-detargeting properties.
authors.affiliation: Translational Research Laboratory, IDIBELL-Institut Catala d'Oncologia, Av. Gran Via s/n Km 2.7, L'Hospitalet de Llobregat, 08907 Barcelona, Spain.
authors.forename: Neus
authors.initials: N
authors.lastname: Bayo-Puxan
authors.affiliation: Translational Research Laboratory, IDIBELL-Institut Catala d'Oncologia, Av. Gran Via s/n Km 2.7, L'Hospitalet de Llobregat, 08907 Barcelona, Spain.
authors.forename: Manel
authors.initials: M
authors.lastname: Cascallo
authors.affiliation: Translational Research Laboratory, IDIBELL-Institut Catala d'Oncologia, Av. Gran Via s/n Km 2.7, L'Hospitalet de Llobregat, 08907 Barcelona, Spain.
authors.forename: Alena
authors.initials: A
authors.lastname: Gros
authors.affiliation: Center for Genomic Regulation, UPF, Barcelona, Spain.
authors.forename: Meritxell
authors.initials: M
authors.lastname: Huch
authors.affiliation: Center for Genomic Regulation, UPF, Barcelona, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Fillat
authors.affiliation: Translational Research Laboratory, IDIBELL-Institut Catala d'Oncologia, Av. Gran Via s/n Km 2.7, L'Hospitalet de Llobregat, 08907 Barcelona, Spain.
authors.forename: Ramon
authors.initials: R
authors.lastname: Alemany
mesh_terms: D000260:Adenoviruses, Human / Q000235:genetics* / Q000502:physiology*; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D045744:Cell Line, Tumor; D004279:DNA, Viral / Q000235:genetics; D015316:Genetic Therapy; D005822:Genetic Vectors; D006497:Heparan Sulfate / Q000378:metabolism*; D022781:Hepatocytes / Q000378:metabolism / Q000821:virology; D006801:Humans; D066298:In Vitro Techniques; D016023:Integrins / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D016254:Mutagenesis, Insertional; D011991:Receptors, Virus / Q000235:genetics / Q000502:physiology; D014161:Transduction, Genetic
chemical_list: D004279:DNA, Viral; D006497:Heparan Sulfate; D016023:Integrins; D011991:Receptors, Virus