Self-targeting sites within the Adeno-associated virus-Cas12a vector genome (AAV-Cas12a self-targeting sites)

Self-targeting sites within the AAV-Cas12a vector genome are specific DNA sequences engineered into or naturally occurring within an Adeno-associated virus (AAV) delivery vehicle that are complementary to the guide RNA (crRNA) loaded into the Cas12a nuclease. This configuration is primarily utilized in 'self-inactivating' CRISPR systems designed to limit the duration of Cas12a expression within host cells. By targeting its own delivery blueprint, the Cas12a enzyme effectively shuts down its own production once a threshold level of protein is reached, which helps minimize off-target editing risks and reduces potential long-term immunogenicity associated with bacterial protein expression. While not a therapeutic target in the traditional sense of a disease-causing protein, these sites are critical regulatory elements in the design of safe and controllable gene therapy vectors. The interaction between the Cas12a-crRNA complex and these intra-vector sites results in double-strand breaks that lead to the degradation of the episomal AAV genome (PMID: 31019253, PMID: 35105764).

Other names

AAV-Cas12a self-cleavage sitesSelf-inactivating AAV-CRISPR vectorsVector-targeting guide RNA sitesIntra-vector CRISPR targets

The Cas12a enzyme, guided by a specific crRNA, recognizes and cleaves complementary DNA sequences located within its own AAV delivery vector, leading to the degradation of the vector genome and cessation of Cas12a production.