Intravenous injection of AAV-PHP.eB across the blood-brain barrier in the adult mouse for central nervous system gene therapy

Objective: To verify the neurotypicality of AAV-PHP.eB after tail vein injection in adult mice and its efficiency in crossing the blood-brain barrier (BBB). Methods: The rAAV-SYN-GFP plasmid was constructed, and adult C57BL mice were injected with AAVPHP.eB: SYN-GFP in the tail vein (300 nL, virus titer 3 × 109 vg) and in the prefrontal lobe (50 L, virus titer 5 × 1011 vg). The green fluorescent protein (GFP) signal in the brain was observed at two weeks, while the GFP signal in the peripheral organs was observed at four weeks. Results: Two weeks after tail vein injection, GFP expression was observed throughout the brain, especially in the cortex, hippocampus, and geniculate nucleus. No GFP signal was observed or detected by western blotting in the peripheral organs after four weeks. GFP signal was observed mainly at the local site after prefrontal lobe injection. Conclusion: AAV-PHP.eB: SYN-GFP can effectively cross the BBB in adult mice. Using a neuron-specific promoter allows exogenous gene expression in neurons; therefore, AAV-PHP.eB can be used as an effective carrier for studying diseases in the central nervous system (CNS).