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Immunosuppression reduces rAAV2.5T neutralizing antibodies that limit efficacy following repeat dosing to ferret lungs
Journal article   Open access   Peer reviewed

Immunosuppression reduces rAAV2.5T neutralizing antibodies that limit efficacy following repeat dosing to ferret lungs

Yinghua Tang, Shahab Fakhari, Eric D. Huntemann, Zehua Feng, Peipei Wu, William Y. Feng, Junying Lei, Feng Yuan, Katherine J. Excoffon, Kai Wang, …
Molecular therapy. Methods & clinical development, Vol.29, pp.70-80
06/08/2023
DOI: 10.1016/j.omtm.2023.02.015
PMCID: PMC10025970
PMID: 36950451
url
https://doi.org/10.1016/j.omtm.2023.02.015View
Published (Version of record) Open Access

Abstract

The efficacy of redosing the recombinant adeno-associated virus (rAAV) vector rAAV2.5T to ferret lung is limited by AAV neutralizing antibody (NAb) responses. While immunosuppression strategies have allowed for systemic rAAV repeat dosing, their utility for rAAV lung-directed gene therapy is largely unexplored. To this end, we evaluated two immunosuppression (IS) strategies to improve repeat dosing of rAAV2.5T to ferret lungs: (1) a combination of three IS drugs (Tri-IS) with broad coverage against cellular and humoral responses (methylprednisolone [MP], azathioprine, and cyclosporine) and (2) MP alone, which is typically used in systemic rAAV applications. Repeat dosing utilized AAV2.5T-SP183-fCFTRΔR (recombinant ferret CFTR transgene), followed 28 days later by AAV2.5T-SP183-gLuc (for quantification of transgene expression). Both the Tri-IS and MP strategies significantly improved transgene expression following repeat dosing and reduced AAV2.5T NAb responses in the bronchioalveolar lavage fluid (BALF) and plasma, while AAV2.5T binding antibody subtypes and cellular immune responses by ELISpot were largely unchanged by IS. One exception was the reduction in plasma AAV2.5T binding immunoglobulin G (IgG) in both IS groups. Only the Tri-IS strategy significantly suppressed splenocyte expression of IFNA (interferon α [IFN-α]) and IL4. Our studies suggest that IS strategies may be useful in clinical application of rAAV targeting lung genetic diseases such as cystic fibrosis. [Display omitted] John Engelhardt and colleagues developed an immunosuppressive strategy to mitigate neutralizing antibody responses to an AAV2.5T (adeno-associated viral vector) and improve transgene expression following repeat administration to the ferret lung for gene therapy of cystic fibrosis.
Gene Therapy Immunosuppression AAV readministration CFTR cystic fibrosis transmembrane conductance regulator cytotoxic T lymphocytes ferret immune response neutralizing antibody rAAV recombinant adeno-associated virus

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