Kinetics and durability of transgene expression after intrastriatal injection of AAV9 vectors.

Autor:	Hollidge BS; Research and Early Development, REGENXBIO Inc., Rockville, MD, United States., Carroll HB; Research and Early Development, REGENXBIO Inc., Rockville, MD, United States., Qian R; Research and Early Development, REGENXBIO Inc., Rockville, MD, United States., Fuller ML; Research and Early Development, REGENXBIO Inc., Rockville, MD, United States., Giles AR; Research and Early Development, REGENXBIO Inc., Rockville, MD, United States., Mercer AC; Research and Early Development, REGENXBIO Inc., Rockville, MD, United States., Danos O; Research and Early Development, REGENXBIO Inc., Rockville, MD, United States., Liu Y; Research and Early Development, REGENXBIO Inc., Rockville, MD, United States., Bruder JT; Research and Early Development, REGENXBIO Inc., Rockville, MD, United States., Smith JB; Research and Early Development, REGENXBIO Inc., Rockville, MD, United States.
Jazyk:	angličtina
Zdroj:	Frontiers in neurology [Front Neurol] 2022 Nov 14; Vol. 13, pp. 1051559. Date of Electronic Publication: 2022 Nov 14 (Print Publication: 2022).
DOI:	10.3389/fneur.2022.1051559
Abstrakt:	Understanding the kinetics and durability of AAV-mediated transgene expression in the brain is essential for conducting basic neuroscience studies as well as for developing gene therapy approaches for CNS diseases. Here, we characterize and compare the temporal profile of transgene expression after bilateral injections into the mouse striatum of rAAV9 encoding GFP under the control of either a ubiquitous promoter (CAG), or the neuron-specific human synapsin (hSyn) and CamKII promoters. GFP protein expression with the CAG promoter was highest at 3 weeks, and then decreased to stable levels at 3 and 6 months. Surprisingly, GFP mRNA levels continued to increase from 3 weeks to 3 months, despite GFP protein expression decreasing during this time. GFP protein expression with hSyn increased more slowly, reaching a maximum at 3 months, which was equivalent to protein expression levels from CAG at that time point. Importantly, transgene expression driven by the hSyn promoter at 6 months was not silenced as previously reported, and GFP mRNA was continuing to rise even at the final 6-month time point. Thus, hSyn as a promoter for transgene expression demonstrates long-term durability but may require more time after vector administration to achieve steady-state levels. Because CAG had the highest GFP protein expression in our comparison, which was at 3 weeks post administration, the early kinetics of transgene expression from CAG was examined (1, 2, 5, and 10 days after injection). This analysis showed that GFP protein expression and GFP mRNA increased during the first 3 weeks after administration. Interestingly, vector DNA rapidly decreased 10-fold over the first 3 weeks following injection as it assembled into stable circular episomes and concatemers. Surprisingly, the processing of vector genomes into circular episomes and concatemers was continually dynamic up to 3 months after injection. These results provide novel insight into the dynamic processing of vector genomes and promoter-specific temporal patterns of transgene expression in the brain. Competing Interests: This study received funding from REGENXBIO Inc. The funder had the following involvement in the study. All authors are employees of REGENXBIO Inc. and thus designed the studies, performed the experiments, analyzed the data, generated the figures, and wrote the manuscript. (Copyright © 2022 Hollidge, Carroll, Qian, Fuller, Giles, Mercer, Danos, Liu, Bruder and Smith.)
Databáze:	MEDLINE
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