GENERATION OF A PROGRAMMABLE SCAFFOLD TO REDIRECT AAV TROPISM

• Published in: Cytotherapy (Oxford, England) England), 2024-06, Vol.26 (6), p.S220-S221
• Main Authors: Sudarshan, B., Cervettini, D., Yerishova, A., Balaskas, N., Rodriques, S.
• Format: Article
• Language: English
• Subjects: AAV; Engineering; Targeting
• ISSN: 1465-3249; 1477-2566
• DOI: 10.1016/j.jcyt.2024.03.447

Achieving cell-type specific targeting remains a crucial challenge in the successful translation of gene therapies. One of the most promising gene delivery tools is the adeno-associated virus (AAV). Despite recent clinical milestones, traditional AAV vectors exhibit broad tissue tropism and typically result in hepatic accumulation upon systemic delivery. To address this, we developed a programmable scaffold to retarget AAV towards desired cell types. We modify the viral capsid with adaptor proteins composed of two separate domains: one that binds covalently to the capsid, and the other to a specific cell-surface receptor (Figure 1). By swapping the latter, the resulting AAVs can be rationally engineered to infect cells expressing desired receptors, creating a modular platform for targeted gene delivery. To engineer a stably bound capsid binding domain, we adapted a fragment of a naturally occurring AAV binding protein. Using a diverse range of synthetic and endogenous receptors, we demonstrate that the attachment of adaptor proteins can successfully alter the tropism of AAVs towards cells of interest. In addition, we show that this method of adaptor protein conjugation is compatible with multiple AAV serotypes. We further identify capsid mutations and ligands that enhance in vitro targeting efficacy. The next phase involves investigating whether similar retargeting can be achieved in mouse models. This research reveals exciting prospects for AAV targeting in both technological and clinical applications, marking a significant step towards the ultimate goal of developing safer and more effective gene delivery tools.