UMMS Affiliation

Horae Gene Therapy Center; Department of Pediatrics

Publication Date


Document Type



Analytical, Diagnostic and Therapeutic Techniques and Equipment | Genetics and Genomics | Molecular Biology | Viruses


With the US Food and Drug Administration (FDA) and European Medicines Agency (EMA) approvals for Zolgensma, Luxturna, and Glybera, recombinant adeno-associated viruses (rAAVs) are considered efficient tools for gene transfer. However, studies in animals and humans demonstrate that intramuscular (IM) AAV delivery can trigger immune responses to AAV capsids and/or transgenes. IM delivery of rAAV1 in humans has also been described to induce tolerance to rAAV characterized by the presence of capsid-specific regulatory T cells (Tregs) in periphery. To understand mechanisms responsible for tolerance and parameters involved, we tested 3 muscle-directed administration routes in rhesus monkeys: IM delivery, venous limb perfusion, and the intra-arterial push and dwell method. These 3 methods were well tolerated and led to transgene expression. Interestingly, gene transfer in muscle led to Tregs and exhausted T cell infiltrates in situ at both day 21 and day 60 post-injection. In human samples, an in-depth analysis of the functionality of these cells demonstrates that capsid-specific exhausted T cells are detected after at least 5 years post-vector delivery and that the exhaustion can be reversed by blocking the checkpoint pathway. Overall, our study shows that persisting transgene expression after gene transfer in muscle is mediated by Tregs and exhausted T cells.


AAV, Tregs, adeno-associated virus, exhausted T cells, exhaustion, gene therapy, gene transfer, immunity, regulatory T cells, tolerance

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Copyright 2020 The Author(s). This is an open access article under the CC BY-NC-ND license (

DOI of Published Version



Gernoux G, Gruntman AM, Blackwood M, Zieger M, Flotte TR, Mueller C. Muscle-Directed Delivery of an AAV1 Vector Leads to Capsid-Specific T Cell Exhaustion in Nonhuman Primates and Humans. Mol Ther. 2020 Jan 13:S1525-0016(20)30010-1. doi: 10.1016/j.ymthe.2020.01.004. Epub ahead of print. PMID: 31982038. Link to article on publisher's site

Journal/Book/Conference Title

Molecular therapy : the journal of the American Society of Gene Therapy

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Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.