2.1 Liver tissue structure
Sinusoidal endothelium and hyperperfusion make the liver susceptible to intravenous administration of AAV, but hepatocytes, stellate cells, and endothelial cells cannot be confused with the same target.
2.2 AAV serotype selection
AAV8 is often used as a starting point in mice; AAV5 has clinical experience; AAV3B is often evaluated in human hepatocyte models.
2.3 Liver-specific promoter
Hepatocytes are commonly used with TBG, hAAT or LP1; non-hepatocyte targeting must include cell type verification.
2.4 Administration method and dosage reference
Systemic vein (IV): first choice for liver targeting. 1×10^11-1×10^12 vg/mouse (approximately 5×10^12-5×10^13 vg/kg), 100-300 μL, 27-30 G needle, slow infusion for 30-60 s; AAV8/9 reaches 90%+ hepatocyte transduction with dose, and detected in 2-6 weeks [2-1,2-5].
Portal vein (PV): direct liver targeting. 1×10^10-1×10^12 vg/mouse, ≤100 μL, open abdominal puncture with 33 G needle, and inject slowly for 1-2 min. AAV8 can transduce 90-95% of hepatocytes through PV; the minimally invasive alternative is to inject 50 μL through the spleen parenchyma. Whole body off-target is significantly lower than IV, but laparotomy is costly and unrepeatable [2-4,2-6].
Intraperitoneal (IP): Less bioavailable than IV but with enhanced diaphragm/adipose/pancreatic transduction. 1×10^11-1×10^12 vg/mouse, 100-200 μL injected into the left lower abdomen; liver transduction is lower than IV. Note that there are species differences in the distribution of liver lobule zones (mouse perihilar vs NHP pericentral) [2-4,2-5].
2.5 Key research evidence
Barcode amplicon sequencing systematically compares the administration route-dependent transduction profiles of commonly used AAV variants in mice, providing a quantitative basis for IV/PV/IP route selection [2-5]; retrograde zone distribution studies reveal that the transduction zones in mice and NHP liver lobes are opposite, and care must be taken when extrapolating hepatocyte expression across species [2-4]; The JoVE protocol details the operation of injecting AAV8-shRNA through the spleen to achieve efficient gene knockdown in the liver [2-6]. The species and previous neutralizing antibodies have obvious effects, and the expression of blood factors does not equal the complete recovery of liver cell function.
2.6 References for this chapter
[2-1] Wang D, et al. AAV vector as a platform for gene therapy delivery. Nat Rev Drug Discov. 2019. [H]
[2-2] Pipe SW, et al. Etranacogene dezaparvovec for hemophilia B. N Engl J Med. 2023;388:706-718. DOI:10.1056/NEJMoa2211644. PMID:36812434. [N/H]
[2-3] Ben-Moshe S, Itzkovitz S. Spatial heterogeneity in the mammalian liver. Nat Rev Gastroenterol Hepatol. 2019;16:395-410. [H]
[2-4] Inverse zonation of hepatocyte transduction with AAV vectors between mice and non-human primates. Mol Ther. 2014. PMC3269907. [H]
[2-5] Mapping administration route-dependent transduction profiles of commonly used AAV variants in mice by barcode amplicon sequencing. 2025. PMID:40337478. [N]
[2-6] Efficient gene knockdown in liver via intrasplenic injection of shRNA delivered by AAV8. JoVE. 2024;(163):e67376. DOI:10.3791/67376. [F]