Title:	Structure and quality determination of novel AAV
DNr:	Berzelius-2025-305
Project Type:	LiU Berzelius
Principal Investigator:	Johan Rockberg <farsan@kth.se>
Affiliation:	Kungliga Tekniska högskolan
Duration:	2025-09-26 – 2026-04-01
Classification:	30401
Keywords:

Abstract

Adeno-associated viruses (AAVs) are increasingly used in gene therapy to treat patients with monogenic diseases. Despite their recent success (6 approved AAV-gene therapies since 2017), issues remain with AAV target selectivity. The viruses have a lot of off-target infectivity as well as rather poor on-target selectivity. We have developed a modular platform for selecting targeting of AAVs towards cell surface receptors through the grafting of Affibody molecules. These small molecules have been genetically fused to the AAV capsid, making the Affibody molecules re-direct AAVs towards a target cell receptor. We have demonstrated this effect both in vitro and in vivo. Considering the smörgåsbord of Affibody molecules available, our platform can be used to improve safety and efficacy of gene therapies. We graft Affibody molecules to the AAVs in a novel way. Hence, there is yet no structure determined of our viral vector. Additionally, despite the same sites that we use for Affibody integration, have been used previously to fuse other affinity proteins, there is no solved structure for those modified AAVs either. If we were to solve a structure for Affibody-AAVs, we would be the first in the world to solve an AAV with an affinity protein grafted to its surface. A clear structure would also show us how the Affibody folds on the AAV surface, giving us clues into how we could optimise the fusion and the Affibody sequence to create better gene therapies. An AAV is also highly symmetrical, consisting of the same 60 proteins on its surface, with several symmetry axises. This makes them especially suitable for Cryo-EM structure reconstruction.