Innate and adaptive AAV-mediated immune responses in a mouse model of Duchenne muscular dystrophy

Michael R Emami; Alejandro Espinoza; Courtney S Young; Feiyang Ma; Philip K Farahat; Philip L Felgner; Jeffrey S Chamberlain; Xiangmin Xu; April D Pyle; Matteo Pellegrini; S Armando Villalta; Melissa J Spencer

doi:10.1016/j.omtm.2023.06.002

Innate and adaptive AAV-mediated immune responses in a mouse model of Duchenne muscular dystrophy

Mol Ther Methods Clin Dev. 2023 Jun 12:30:90-102. doi: 10.1016/j.omtm.2023.06.002. eCollection 2023 Sep 14.

Authors

Michael R Emami¹, Alejandro Espinoza^{2

3

4}, Courtney S Young⁵, Feiyang Ma⁶, Philip K Farahat⁷, Philip L Felgner⁷, Jeffrey S Chamberlain^{8

9

10

11}, Xiangmin Xu¹², April D Pyle^{13

14}, Matteo Pellegrini^{3

15}, S Armando Villalta^{7

16

17}, Melissa J Spencer^{1

14}

Affiliations

¹ Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
² Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA, USA.
³ Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, USA.
⁴ Institute for Quantitative and Computational Biosciences - The Collaboratory, University of California, Los Angeles, Los Angeles, CA, USA.
⁵ MyoGene Bio, San Diego, CA, USA.
⁶ Division of Rheumatology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA.
⁷ Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA.
⁸ Department of Neurology, University of Washington School of Medicine, Seattle, WA, USA.
⁹ Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, University of Washington School of Medicine, Seattle, WA, USA.
¹⁰ Department of Biochemistry, University of Washington School of Medicine, Seattle, WA, USA.
¹¹ Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.
¹² Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA.
¹³ Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, USA.
¹⁴ Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA, USA.
¹⁵ Institute for Genomics and Proteomics, University of California, Los Angeles, Los Angeles, CA, USA.
¹⁶ Institute of Immunology, University of California, Irvine, Irvine, CA, USA.
¹⁷ Department of Neurology, University of California, Irvine, Irvine, CA, USA.

Abstract

High systemic doses of adeno-associated viruses (AAVs) have been associated with immune-related serious adverse events (SAEs). Although AAV was well tolerated in preclinical models, SAEs were observed in clinical trials, indicating the need for improved preclinical models to understand AAV-induced immune responses. Here, we show that mice dual-dosed with AAV9 at 4-week intervals better recapitulate aspects of human immunity to AAV. In the model, anti-AAV9 immunoglobulin G (IgGs) increased in a linear fashion between the first and second AAV administrations. Complement activation was only observed in the presence of high levels of both AAV and anti-AAV IgG. Myeloid-derived pro-inflammatory cytokines were significantly induced in the same pattern as complement activation, suggesting that myeloid cell activation to AAV may rely on the presence of both AAV and anti-AAV IgG complexes. Single-cell RNA sequencing of peripheral blood mononuclear cells confirmed that activated monocytes were a primary source of pro-inflammatory cytokines and chemokines, which were significantly increased after a second AAV9 exposure. The same activated monocyte clusters expressed both Fcγ and complement receptors, suggesting that anti-AAV-mediated activation of myeloid cells through Fcγ receptors and/or complement receptors is one mechanism by which anti-AAV antigen complexes may prime antigen-presenting cells and amplify downstream immunity.

Keywords: Luminex; adaptive immunity; adeno-associated virus; innate immunity; muscular dystrophy; single-cell RNA sequencing.

Abstract

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