A - Viral Vector Development -> AAV Vectors – Virology and Vectorology, Vectorology, and Engineering
1409: A Multi-Dimensional Survey of AAV Tropism in Mice
Type: Poster Session
Poster Board Number: 1409
Presentation Details
Session Title: Friday Poster Session
Location:
Start Time: 5/19/2023 12:00
End Time: 5/19/2023 14:00
Adeno-associated viruses (AAVs) have emerged as the leading vector for in vivo gene therapy. To expand their utility, it is important to understand the biodistribution and transduction efficiency of different AAV serotypes following delivery. To this end, we undertook a large-scale survey of AAV tropism in mice following systemic administration. AAVs from ten different naturally occurring serotypes of relevance to human gene therapy were examined, including AAV 3b, 4, 5, 6, 7, 8, 9, rh8, rh10, and rh74. Recombinant AAV were packaged to contain a bidirectional transgene cassette for ubiquitous expression of both a ZsGreen fluorescent protein and Cre recombinase. The AAV vectors were tested in“Ai9” reporter mice, which express the tdTomato fluorescent protein upon Cre-induced recombination. In doing so, we hoped to acquire information about the level of transgene expression (ZsGreen), as well as a highly sensitive means of fate-mapping transduced cells (tdTomato). Multiple mice of both sexes were injected intravenously with 1E12 genome copies of each of the ten serotypes and followed for 4 weeks. A comprehensive panel of 20 tissues (including reproductive organs) from each mouse was prepared for both molecular and histological analysis. To evaluate biodistribution, we quantified vector genome copy number in each organ from every mouse by qPCR. As expected, the majority of AAV serotypes had a strong tropism for the liver. In addition, our data identified several sex differences in transduction efficiency, as well as high tropism of some serotypes in several organs not often considered as targets for AAV transduction. For example, we found that AAV4 strongly transduced lung. Functional tropism analysis by fluorescent imaging has confirmed and extended these results, providing additional information about efficiency of delivery and cell type specific resolution. In addition, a complementary experiment using AAV9 to deliver CRISPR/Cas9 editing reagents demonstrated the adaptability of our approach to genome editing. This work will be publicly available as part of NIH’s Somatic Cell Genome Editing (SCGE) initiative, and we anticipate that it will prove to be a valuable resource for researchers aiming to use AAVs to target specific organs and cell types, especially for appropriate selection of capsids in preclinical gene therapy.
Christopher J. Walkey1, Kathy Snow2, Alexa Martinez1, Jote T. Bulcha3, Aaron Cox4, Cecilia Ljungberg5, Sean Hartig6, John R. Seavitt7, Dan Wang8, Stephen A. Murray9, Jason E. Heaney7, Guangping Gao10, William R. Lagor1
1Department of Integrative Physiology, Baylor College of Medicine, Houston, TX,2The Jackson Laboratory, Bar Harbor, ME,3University of Massachusetts Medical School, Worcester, MA,4Department Medicine, Baylor College of Medicine, Houston, TX,5Department of Pediatrics, Baylor College of Medicine, Houston, TX,6Department of Medicine, Baylor College of Medicine, Houston, TX,7Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX,8Horae Gene Therapy Center and Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA,9The Jackson Laboratory, Bar Harbor, ME,10UMass Chan Medical School, Worcester, MA
C.J. Walkey: None.
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