Lentiviral vector cargo gene silencing during manufacturing

Lentiviral vectors (LVV) are commonly used for cargo gene delivery in cell and gene therapy. Although constitutive cargo gene expression in the target cells is desirable, production can be problematic.

An ideal production system would silence cargo gene expression and retain high titres. Thus, the viral RNA must not be damaged or inhibited. However, since the viral RNA contains the entire sequence of the cargo gene mRNA, typical silencing approaches would disrupt vector production. To address this challenge, we have engineered a distinction between the viral RNA and the cargo mRNA, enabling selective silencing of the cargo gene while leaving titres and cargo gene expression in target cells unaffected.

Our system will enable the use of consistent upstream and downstream processes with different cargo genes, thus expediting, derisking, and reducing the cost of therapeutic development. Using our system, cargo gene expression has been reduced by 95% during lentiviral vector production.

By engineering a distinction between the cargo mRNA and the viral RNA, we have overcome the challenges associated with silencing the cargo without disruption of vector production.

We anticipate that with therapeutically relevant cargo genes, e.g. CARs, this technology will improve titres and particle quality, while derisking therapeutic development by reducing the number of unknowns associated with novel cargo genes.