Retargeting FX-binding-ablated HAdV-5 to vascular cells by inclusion of the RGD-4C peptide in hexon hypervariable region 7 and the HI loop.

Stacy Robertson,Carolyn Clarke,Alan L Parker,Margaret R Duffy,Andrew H Baker,Raul Alba,Stuart A Nicklin

doi:10.1099/jgv.0.000505

Stacy Robertson, Carolyn Clarke + Show 5 more

Open Access

https://doi.org/10.1099/jgv.0.000505

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Abstract

Recent studies have generated interest in the function of human adenovirus serotype 5 (HAdV-5) hexon: factor X (FX) binding and subsequent hepatocyte transduction and interaction with the immune system. Here, we retargeted adenovirus serotype 5 vectors, ablated for FX interaction, by replacing amino acids in hexon HVR7 with RGD-4C or inserting the peptide into the fibre HI loop. These genetic modifications in the capsid were compatible with virus assembly, and could efficiently retarget transduction of the vector via the αvβ3/5 integrin-mediated pathway, but did not alter immune recognition by pre-existing human neutralizing anti-HAdV-5 antibodies or by natural antibodies in mouse serum. Thus, FX-binding-ablated HAdV-5 can be retargeted but remain sensitive to immune-mediated attack. These findings further refine HAdV-5-based vectors for human gene therapy and inform future vector development.

Highlights

Retargeting factor X (FX)-binding-ablated human adenovirus serotype 5 (HAdV-5) to vascular cells by inclusion of the RGD-4C peptide in hexon hypervariable region 7 and the HI loop
Our research has focussed on the use of adenoviral vectors as a tool for ex vivo manipulation of coronary artery bypass material to overexpress antiproliferative genes (e.g. TIMP-3, p53) in coronary artery vascular smooth muscle cells (VSMCs), to prevent their migration, proliferation and formation of a neointimal lesion, and graft reocclusion and failure following grafting (George et al, 2011)
Applications, HAdV-5 efficiently and selectively transduces hepatocytes (Huard et al, 1995) in a process mediated through the engagement of the blood coagulation factor X (FX) with the hypervariable regions (HVRs) of the HAdV-5 hexon protein (Hofherr et al, 2008; Kalyuzhniy et al, 2008; Waddington et al, 2008)

Summary

Short Communication

Recent studies have generated interest in the function of human adenovirus serotype 5 (HAdV5) hexon: factor X (FX) binding and subsequent hepatocyte transduction and interaction with the immune system. We retargeted adenovirus serotype 5 vectors, ablated for FX interaction, by replacing amino acids in hexon HVR7 with RGD-4C or inserting the peptide into the fibre HI loop. These genetic modifications in the capsid were compatible with virus assembly, and could efficiently retarget transduction of the vector via the avb3/5 integrin-mediated pathway, but did not alter immune recognition by pre-existing human neutralizing anti-HAdV-5 antibodies or by natural antibodies in mouse serum. Vectors were linearized and electroporated into BJ5183 bacteria cells with digested pAd5CMVlacZ for homologous recombination

HI loop

Vector genomes