Assessment of a novel, capsid-modified adenovirus with an improved vascular gene transfer profile

Abstract

BackgroundCardiovascular disorders, including coronary artery bypass graft failure and in-stent restenosis remain significant opportunities for the advancement of novel therapeutics that target neointimal hyperplasia, a characteristic of both pathologies. Gene therapy may provide a successful approach to improve the clinical outcome of these conditions, but would benefit from the development of more efficient vectors for vascular gene delivery. The aim of this study was to assess whether a novel genetically engineered Adenovirus could be utilised to produce enhanced levels of vascular gene expression.MethodsVascular transduction capacity was assessed in primary human saphenous vein smooth muscle and endothelial cells using vectors expressing the LacZ reporter gene. The therapeutic capacity of the vectors was compared by measuring smooth muscle cell metabolic activity and migration following infection with vectors that over-express the candidate therapeutic gene tissue inhibitor of matrix metalloproteinase-3 (TIMP-3).ResultsCompared to Adenovirus serotype 5 (Ad5), the novel vector Ad5T*F35++ demonstrated improved binding and transduction of human vascular cells. Ad5T*F35++ mediated expression of TIMP-3 reduced smooth muscle cell metabolic activity and migration in vitro. We also demonstrated that in human serum samples pre-existing neutralising antibodies to Ad5T*F35++ were less prevalent than Ad5 neutralising antibodies.ConclusionsWe have developed a novel vector with improved vascular transduction and improved resistance to human serum neutralisation. This may provide a novel vector platform for human vascular gene transfer.

Incorporation of Peptides Targeting EGFR and FGFR1 into the Adenoviral Fiber Knob Domain and Their Evaluation as Targeted Cancer Therapies

“…Viruses were preincubated in serum − medium or medium supplemented either with hFX or with 2.5% cell-free ascitic fluid obtained from patients OAS000 and OAS001 consistent with previous studies evaluating the nAb responses to Ad-based vectors from patient isolates. 11 , 35 …”

The myeloid-binding peptide adenoviral vector enables multi-organ vascular endothelial gene targeting

“…One approach to EC transductional targeting has been vector pseudotyping. Ad5 vectors pseudotyped with fibers or fiber knobs from different human, or from non-human, serotypes exhibited improved transduction efficiency of cultured human or rodent (rat) ECs 28–30 . Another approach has been addition of “angio-adenobodies” onto the Ad vector capsid.…”

“…However, the transcriptional strategy, when applied alone, does not alter the Kupffer cell sequestration or hepatocyte transduction. Recent efforts have focused on the combination of transductional and transcriptional strategies to achieve enhanced organ or disease specific EC vector transgene expression 10, 30 . Despite progress, systemically administered Ad vectors are still ineffective in gene transfer to some clinically important organs.…”

Efficient Transduction of Primary Vascular Cells by the Rare Adenovirus Serotype 49 Vector

“…Samples were considered neutralizing if transduction was reduced by 90% compared with virus alone, previously shown to be ideal for studying neutralization patterns of Ads. 22 , 34 Ad5 was neutralized by 31% (32/103) of serum samples, while none of the 103 serum samples reduced Ad49 cell transduction by 90% ( Fig. 4B ).…”

“…To increase transgene expression in the vasculature, pseudotyping of Ad5 has been shown to be effective. 22 Several subgroup B adenoviruses, including Ad35, use CD46 as a receptor, 23 which is relatively highly expressed on VSMCs, and chimeric Ad5/Ad35 viruses show more efficient gene transfer to the vasculature than Ad5. 17 An alternative strategy is exploitation of the natural tropism of novel Ad serotypes.…”