Project: Evolving High Potency AAV Vectors for Neuromuscular Genome Editing
Recombinant adeno-associated viruses (AAV) have emerged as safe and effective vectors for clinical gene therapy applications including systemic treatment of neuromuscular diseases such as Spinal Muscular Atrophy (SMA), Duchenne Muscular Dystrophy (DMD), and Giant Axonal Neuropathy (GAN) amongst others. However, genome editing in neuromuscular tissue, in particular, is challenging. The current proposal is on a comprehensive and innovative approach to evolve high potency AAV variants for systemic neuromuscular genome editing.
Summary of data submissions:
- Data for 2 experiments were submitted on 2020-11-19 SCGE ID:1015
- Data for 5 experiments were submitted on 2021-09-16 SCGE ID:1056
- 1 of 7 experiments have been validated
Submissions Details
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Testing virus region 8 (VR8) mutant cross-species compatible Adeno Associated Viruses (ccAAVs) in mice.
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In Vivo | C57BL/6 mice (N=3) were injected intravenously at a dose of 5e13 vg/kg per mouse with a self-complementary AAV9 or ccAAV vector encoding a GFP reporter. The biodistribution of of virus transduction was chacterized in various tissues and cell types by fluorescence imaging quantification. | |||||
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Testing virus region 4 (VR4) mutant cross-species compatible Adeno Associated Viruses (ccAAVs) in mice.
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In Vivo | C57BL/6 mice (N=3) were injected intravenously at a dose of 5e13 vg/kg per mouse with a self-complementary AAV9 or ccAAV vector encoding an mCherry reporter. The biodistribution of of virus transduction was chacterized in various tissues and cell types by fluorescence imaging quantification. | |||||
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| Experiment Name | Type | Description |
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Cre Recombinase dose escalation study in Ai9 mice
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In Vivo | A single stranded cmv cre cassette was packaged into AAV9 or AAVcc47 and injected intravenously in Ai9 mice. We injected n=3 at three different doses (1e10, 1e11, 1e12 vg) and harvested organs 4 weeks post injection. Fluorescence intensity in liver, heart, and skeletal muscle was quantified with tiff based images in Image J and neuronal transduction from each vector was quantified at the 1e12vg dose by counting the number of tdTomato+ neurons and number of NeuN+ cells from multiple sections and images. |
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Comparing CRISPR/Cas9 gene editing efficencies between AAV9 and AAVcc47 in Ai9 mice with a 1:1 Cas9 to sgRNA ratio (CB promoter)
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In Vivo | A dual vector strategy was employed: one delivering a single guide RNA and CB driven SaCas9, and another delivering the second guide RNA and CB driven SaCas9. This strategy was evaluted with both AAV9 (n=4) and AAVcc47 (n=5) by intravenous injection in Ai9 mice. A total dose of 2e12vg was injected into each mouse (1e12vg each vector mixed 1:1) and organs were harvested 4 weeks post injection. Editing efficency was determined by calculating percent TdTomato+ cells normalized to Dapi+ cells in liver and heart. |
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Comparing CRISPR/Cas9 gene editing efficencies between AAV9 and AAVcc47 in Ai9 mice with a 1:1 cas9 to sgRNA ratio (CMV promoter)
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In Vivo | A dual vector strategy was employed: one delivering two single guide RNAs targeting the Rosa26 locus and one delivering CMV driven SaCas9 (both single stranded AAV cassettes). This strategy was evaluted with both AAV9 (n=3) and AAVcc47 (n=3) by intravenous injection in Ai9 mice. A total dose of 3e12vg was injected into each mouse (1.5e12vg each vector mixed 1:1) and organs were harvested 4 weeks post injection. Editing efficency was determined by calculating percent TdTomato+ cells normalized to Dapi+ cells in liver and heart. |
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Comparing CRISPR/Cas9 gene editing efficencies between AAV9 and AAVcc47 in Ai9 mice with a 1:1 Cas9 to sgRNA ratio (CMV promoter) and self complementary sgRNA vector.
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In Vivo | A dual vector strategy was employed: one self complementary vector delivering two single guide RNAs targeting the Rosa26 locus and one delivering CMV driven SaCas9 (single stranded vector). This strategy was evaluted with both AAV9 (n=4) and AAVcc47 (n=4) by intravenous injection in Ai9 mice. A total dose of 4e12vg was injected into each mouse and vectors mixed in a 1:1 ratio of cas9 to guide RNA (2e12vg of CMV Sacas9 vector and 2e12vg of the self complementary sgRNA vector) and organs were harvested 4 weeks post injection. Editing efficency was determined by calculating percent TdTomato+ cells normalized to Dapi+ cells in liver and heart. |
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Comparing CRISPR/Cas9 gene editing efficiencies between AAV9 and AAVcc47 in Ai9 mice with a 1:3 Cas9 to sgRNA ratio (CMV promoter)
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In Vivo | A dual vector strategy was employed: one delivering two single guide RNAs targeting the Rosa26 locus and one delivering CMV driven SaCas9 (both single stranded AAV cassettes). This strategy was evaluted with both AAV9 (n=4) and AAVcc47 (n=5) by intravenous injection in Ai9 mice. A total dose of 4e12vg was injected into each mouse and vectors mixed in a 1:4 ratio of cas9 to guide RNA (1e12vg of CMV Sacas9 vector and 3e12vg of the sgRNA vector) and organs were harvested 4 weeks post injection. Editing efficency was determined by calculating percent TdTomato+ cells normalized to Dapi+ cells in liver and heart. |