title: Redirecting adenoviruses to tumour cells using therapeutic antibodies: Generation of a versatile human bispecific adaptor.
abstract: Effective use of adenovirus-5 (Ad5) in cancer therapy is heavily dependent on the degree to which the virus's natural tropism can be subverted to one that favours tumour cells. This is normally achieved through either engineering of the viral fiber knob or the use of bispecific adaptors that display both adenovirus and tumour antigen receptors. One of the main limitations of these strategies is the need to tailor each engineering event to any given tumour antigen. Here, we explore bispecific adaptors that can utilise established anti-cancer therapeutic antibodies. Conjugates containing bacterially derived antibody binding motifs are efficient at retargeting virus to antibody targets. Here, we develop a humanized strategy whereby we synthesise a re-targeting adaptor based on a chimeric Ad5 ligand/antibody receptor construct. This adaptor acts as a molecular bridge analogous to therapeutic antibody mediated cross-linking of cytotoxic effector and tumour cells during immunotherapy. As a proof or principle, we demonstrate how this adaptor allows efficient viral recognition and entry into carcinoma cells through the therapeutic monoclonal antibodies Herceptin/trastuzumab and bavituximab. We show that targeting can be augmented by use of contemporary antibody enhancement strategies such as the selective elimination of competing serum IgG using "receptor refocusing" enzymes and we envisage that further improvements are achievable by enhancing the affinities between the adaptor and its ligands. Humanized bispecific adaptors offer the promise of a versatile retargeting technology that can exploit both clinically approved adenovirus and therapeutic antibodies.
authors.affiliation: Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom.
authors.forename: Snezana
authors.initials: S
authors.lastname: Vasiljevic
authors.affiliation: Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom.
authors.forename: Emma V
authors.initials: EV
authors.lastname: Beale
authors.affiliation: Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom.
authors.forename: Camille
authors.initials: C
authors.lastname: Bonomelli
authors.affiliation: Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom.
authors.forename: Iona S
authors.initials: IS
authors.lastname: Easthope
authors.affiliation: Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom.
authors.forename: Laura K
authors.initials: LK
authors.lastname: Pritchard
authors.affiliation: Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom.
authors.forename: Gemma E
authors.initials: GE
authors.lastname: Seabright
authors.affiliation: Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom.
authors.forename: Alessandro T
authors.initials: AT
authors.lastname: Caputo
authors.affiliation: Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom.
authors.forename: Christopher N
authors.initials: CN
authors.lastname: Scanlan
authors.affiliation: Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom. Electronic address: martin.dalziel@bioch.ox.ac.uk.
authors.forename: Martin
authors.initials: M
authors.lastname: Dalziel
authors.affiliation: Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom. Electronic address: max.crispin@bioch.ox.ac.uk.
authors.forename: Max
authors.initials: M
authors.lastname: Crispin
mesh_terms: D000256:Adenoviridae / Q000235:genetics* / Q000276:immunology; D000595:Amino Acid Sequence; D018033:Antibodies, Bispecific / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology*; D000951:Antigens, Neoplasm / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D000956:Antigens, Viral / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D000970:Antineoplastic Agents / Q000737:chemistry / Q000276:immunology; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics / Q000276:immunology / Q000473:pathology / Q000628:therapy; D045744:Cell Line, Tumor; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein / Q000235:genetics / Q000276:immunology; D005260:Female; D005822:Genetic Vectors; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D018796:Immunoconjugates / Q000737:chemistry / Q000235:genetics; D007167:Immunotherapy / Q000379:methods; D008969:Molecular Sequence Data; D011485:Protein Binding; D015202:Protein Engineering; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000276:immunology; D017452:Receptors, IgG / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D000068878:Trastuzumab / Q000737:chemistry / Q000276:immunology*
chemical_list: D018033:Antibodies, Bispecific; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D000956:Antigens, Viral; D000970:Antineoplastic Agents; D001426:Bacterial Proteins; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D006026:Glycoside Hydrolases; D018796:Immunoconjugates; D018719:Erb-b2 Receptor Tyrosine Kinases; D017452:Receptors, IgG; D011993:Recombinant Fusion Proteins; D000068878:Trastuzumab; C568771:CLMP protein, human; C496124:FCGR3A protein, human; C508053:ERBB2 protein, human; C431325:NDOS protein, Streptococcus pyogenes; C547825:bavituximab
keywords: Adenovirus; Antibody; Cancer; Endoglycosidase S; Fc Receptor; Glycosylation