Neuraminidase-mediated desialylation augments AAV9-mediated gene expression in skeletal muscle

Hongling Zhu, Tao Wang, Robert John Lye, Brent A. French, Brian H. Annex

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


Background: Following systemic delivery, AAV9-mediated gene expression is significantly increased in ischemic versus non-ischemic muscle, suggesting that AAV9 is an attractive vector for treating peripheral arterial disease. Potential mechanisms underlying ischemia-augmented expression include: (i) increased vascular permeability and (ii) “unmasking” of endogenous AAV9 receptors. In the present study, we aimed to reconstitute the ischemic induction of AAV9 in vivo, using local injection of histamine (to increase vascular permeability) and neuraminidase (to desialylate cell surface glycans). Methods: Bioassays were performed to optimize the effects of histamine and neuraminidase after intramuscular injection. Histamine and/or neuraminidase were then injected intramuscularly shortly before intravenous injection of an AAV9 vector expressing luciferase. Luciferase expression was serially assessed with bioluminescence imaging. At the end of the study, tissues were harvested for assays of luciferase activity and AAV9 genome copy number aiming to assess AAV-mediated gene expression and transduction, respectively. Results: Intramuscular injection of either neuraminidase or neuraminidase plus histamine significantly increased both transduction and gene expression, whereas histamine alone had little effect. Pre-injection with neuraminidase increased AAV9-mediated gene delivery by four- to nine-fold and luciferase activity by 60–100-fold. Luciferase activity in neuraminidase-injected muscle was > 100-fold higher than in any off-target tissue (including heart, liver and brain). Conclusions: The ischemic induction of AAV9-mediated gene expression in muscle can largely be reconstituted by pre-injecting neuraminidase intranmuscularly. This strategy may prove useful in future human gene therapy protocols as a quick and efficient means to selectively target systemically injected AAV9 to localized regions of muscle, thus decreasing the potential for adverse effects in off-target tissues.

Original languageEnglish (US)
Article numbere3049
JournalJournal of Gene Medicine
Issue number9
StatePublished - Sep 2018
Externally publishedYes


  • Adeno-associated virus
  • gene therapy
  • muscle-specific promoter
  • neuraminidase
  • receptor

ASJC Scopus subject areas

  • Molecular Medicine
  • Molecular Biology
  • Genetics
  • Drug Discovery
  • Genetics(clinical)


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