AAVLINK platform has enabled accurate delivery of therapeutic genes to the nervous system

Researchers in China have reported a novel adeno-associated virus strategy that enables efficient in vivo reassembly and expression of large therapeutic genes, addressing a long-standing limitation of AAV-based gene therapy for neurological disorders

The delivery of the therapeutic genes is essential to the success of gene therapy, particularly for inherited neurological disorders. Adeno-associated viruses (AAV) are widely used as gene delivery vectors because they offer favourable safety profiles, flexible gene segmentation and efficient gene reconstitution. However, their limited packaging capacity has posed a major obstacle to the delivery of large genes constraining the range of diseases that AAV-based therapies can address.

In a recent study a team led by Professor Lu Zhonghua at the Shenzhen Institutes of Advanced Technology – part of the Chinese Academy of Sciences – working with colleagues from the Peking University First Hospital, reported the development of a novel platform termed AAV with translocation LINKage – abbreviated to AAVLINK. The approach harnessed Cre–lox mediated intermolecular DNA recombination to enable the reassembly of large genes directly within living tissue.

The researchers reported that AAVLINK permitted flexible design of gene segmentation while achieving high-efficiency reconstitution of full-length genes. Importantly, the strategy markedly reduced the formation of aberrant truncated proteins, a recognised limitation of several conventional multi-vector AAV approaches. This improvement was reported to enhance both the fidelity and functional relevance of gene expression following delivery.

In animal models, the team demonstrated that AAVLINK enabled robust expression of the full-length Shank3 gene in the nervous system. Restoration of Shank3 expression significantly ameliorated autism-like behavioural phenotypes in mice that are deficient in this gene. In parallel experiments, delivery of the large epilepsy-associated gene SCN1A using the AAVLINK process was shown to restore gene expression and alleviated seizure phenotypes in mutant mice. These findings were reported to provide strong evidence that AAVLINK can support functional delivery of large therapeutic genes within neural tissue.

To address potential safety concerns linked to prolonged recombination activity, the researchers also introduced a destabilised form of Cre recombinase and developed an updated platform termed AAVLINK 2.0. This iteration allowed tighter temporal control of recombination while preserving high gene reconstitution efficiency, thereby reducing the theoretical risk of off-target genomic effects.

Using the AAVLINK strategy, the team constructed a vector bank covering 193 large genes associated with inherited disorders, including autism and epilepsy. The researchers reported validation of gene reconstitution capacity across all constructs. The vector bank also included five CRISPR-based genetic tools, which the authors suggested illustrated the broader applicability of the platform beyond conventional gene replacement.

The study proposed that AAVLINK represents a practical strategy to overcome the size constraints that have historically limited AAV-based gene therapy. By enabling efficient delivery and expression of large gene cargoes, the approach has expanded the therapeutic possibilities for a range of genetic diseases that have previously been considered inaccessible using AAV vectors.

For further reading please visit: 10.1016/j.cell.2025.12.039