VikAD, a Vika site-specific recombinase-based system for efficient and scalable helper-dependent adenovirus production

• Published in: Molecular therapy. Methods & clinical development 2022-03, Vol.24, p.117-126
• Main Authors: Phillips, Stacia, Ramos, Paula Valino, Veeraraghavan, Priyadharishini, Young, Samuel M.
• Format: Article
• Language: English
• Subjects: adenovirus; cell-type-specific expression; genetic intersectional strategies; helper-dependent adenovirus; Original; production; site-specific recombinases; viral vectors
• ISSN: 2329-0501; 2329-0501
• DOI: 10.1016/j.omtm.2021.12.001

Recombinant viral vectors have become integral tools for basic in vivo research applications. Helper-dependent adenoviral (HdAd) vectors have a large packaging capacity of ∼36 kb of DNA that mediate long-term transgene expression in vitro and in vivo. The large carrying capacity of HdAd enables basic research or clinical applications requiring the delivery of large genes or multiple transgenes, which cannot be packaged into other widely used viral vectors. Currently, common HdAd production systems use an Ad helper virus (HV) with a packaging signal (Ψ) that is flanked by either loxP or FRT sites, which is excised in producer cells expressing Cre or Flp recombinases to prevent HV packaging. However, these production systems prevent the use of HdAd vectors for genetic strategies that rely on Cre or Flp recombination for cell-type-specific expression. To overcome these limitations, we developed the VikAD production system, which is based on producer cells expressing the Vika recombinase and an HV that contains a Ψ flanked by vox sites. The availability of this production system will greatly expand the utility and flexibility of HdAd vectors for use in research applications to monitor and manipulate cellular activity with increased specificity. [Display omitted] VikAD is a helper-dependent adenovirus (HdAd) production platform that utilizes a cell line expressing the Vika site-specific recombinase and an Ad HV that contains the packaging sequence flanked by vox sites. VikAD enables use of HdAd with genetic intersectional strategies using Cre and Flp or other site-specific recombinases.