Suppressing microtubule detyrosination augments adeno-associated virus 2 endosomal escape and gene delivery.

Adeno-associated virus (AAV) is a widely used vector for gene delivery, yet the host intracellular trafficking barriers often limit its therapeutic efficacy. Here, we identify microtubule detyrosination - a microtubule post-translational modification - as a key regulator of AAV2 endo-lysosomal processing. Using super-resolution microscopy (SIM/STORM), we show that upon AAV2 endocytosis, the host upregulates microtubule detyrosination via the GSK3β-CLASP2 signaling axis. Single-particle tracking of recombinant virus reveals that detyrosinated microtubules form a physical and functional barrier, restricting AAV2 motility and promoting lysosomal trapping. Restoring microtubule tyrosination via tubulin-tyrosine ligase overexpression or pharmacological inhibition of detyrosination with parthenolide, enhances endosomal escape and perinuclear accumulation of AAV2, translating to improved gene delivery in host cells. Notably, a clinically relevant pro-drug of parthenolide (DMAPT) also displayed a similar trend of enhancing AAV2-driven coagulation factor IX expression in hemophilia B mouse models. Our findings uncover a host mechanism that reshapes the microtubule landscape to restrict AAV2 trafficking and identify microtubule detyrosination as a novel druggable target to improve AAV-based gene therapy.