Inherent hepatocytic heterogeneity determines expression and retention of edited F9 alleles post-AAV/CRISPR infusion

Significance Application scope, underlying mechanisms, and potential limitation of AAV/CRISPR-mediated hepatic gene editing remain unexplored. Here we report that a synthetic enhancer/promoter (P2) incorporation empowered AAV/CRISPR to restore FIX-encoding capacity of a severe F9 defect involving the regulatory region. Systemic analyses revealed a critical role of host cell heterogenicity in determining the therapeutic benefit of this regimen, wherein a subclinical inflammation posttreatment regulated the P2 activity and the retention of the edited F9 alleles in a hepatocytic subset–dependent manner. Moreover, preeminent hepatic presence of hematopoietic cells implicated their involvement in fueling and restricting this hepatic inflammation. Collectively, these results characterize the critical factors determining the efficacy and durability of AAV/CRIPSR-mediated gene editing in dealing with complicated hepatic monogenic disorders.