Towards the Engineering of High-Capacity Viral Vectors for Neuromuscular Diseases

Projektbeschreibung

Effiziente, vielseitige virale Vektoren zum Umgang mit komplexen genetischen Erkrankungen

Gentherapien sind vielversprechend für die Behandlung genetischer Störungen, doch die derzeitigen Methoden stehen vor Herausforderungen. Adeno-assoziierte virale Vektoren (AAV) sind wirksam, haben jedoch Schwierigkeiten, auf bestimmte Zelltypen (Muskelzellen) zu zielen, und können keine großen Gene tragen, die für neuromuskuläre Störungen oft erforderlich sind. Das im Rahmen der Marie-Skłodowska-Curie-Maßnahmen geförderte Projekt TEHC wird sich diesen Herausforderungen mit zwei innovativen Ansätzen stellen. Erstens werden die Forschenden versuchen, das AAV-Targeting zu verbessern, indem sie Nanokörper in das virale Kapsid integrieren und durch gezielte Evolution verfeinern. Dies sollte dazu beitragen, Immunreaktionen zu vermeiden. Zweitens werden die Forschenden Pionierarbeit bei der Verwendung eines auf Bakteriophagen basierenden Vektors leisten, der große Gene mit bis zu 171 Kilobasenpaaren übertragen kann. Ist dies erfolgreich, wird TEHC dazu beitragen, die Genübertragung bei komplexen genetischen Erkrankungen zu verbessern.

Ziel

Gene therapies are a fast becoming a realistic treatment for patients suffering from genetic disorders. To date, systemically applied in
vivo gene therapies exclusively rely on adeno-associated viral (AAV) vectors for gene delivery to affected cells. AAV vectors have many
features that make them successful gene delivery tools and through biomining and bioengineering efforts over the years, AAV
variants are able to transduce a number of clinically relevant targets. However, many cell types, including human muscle cells, are not
sufficiently transduced by existing viral vectors. Another challenge is the small genome size of AAV vectors, which is frequently a
problem for neuromuscular disorders where affected genes are larger than in other types of disorders. In the light of these challenges,
we are proposing to tackle new avenues for viral vector engineering in two separate, but related, objectives. Objective one is a new
way of viral vector re-targeting through incorporation of single domain antibodies (nanobodies) followed by a directed evolution
affinity maturation step. This approach of adds value to an already published method and should create a capsid-nanobody fusion
that is fit for purpose and potentially also has benefits regarding the evasion of pre-existing antibodies and improved packaging. The
second and more ambitious objective of our proposal consists of the adoption of a novel bacteriophage-based viral vector capable of
transducing mammalian cells and delivering up to 171 kilo base pairs of DNA. We are proposing to couple this new vector system
with our experience in capsid bioengineering and gene therapy, which has not been done before. For this objective, we propose to
incorporate antibody-derived targeting molecules such as nanobodies and single-chain variable fragments to highly protruding fibre
proteins on the bacteriophage surface and create cell type-specific viral vectors capable of delivering large genes, i.e. human
dystrophin.