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Perez-Osorio, A. C.

Publications and source records attributed to Perez-Osorio, A. C..

2 recordsLinked to original sources

Clinical performance evaluation of a tiling amplicon panel for whole genome sequencing of respiratory syncytial virus

Accurate genomic characterization of respiratory syncytial virus (RSV) is crucial for studies of epidemiology and viral evolution, and monitoring potential escape from newly authorized vaccines and antivirals. We adapted a viral whole genome tiling amplicon panel (UW-ARTIC) and developed a custom bioinformatic pipeline for high-throughput, cost-effective sequencing of RSV-A and RSV-B. We established genome acceptability criteria and determined the performance characteristics of the panel including assay sensitivity, specificity, breadth of genome recovery, accuracy, and precision using contrived and remnant clinical specimens. High-quality genomes (>95% genome completeness; >500X and >1000X average depth for whole genome and fusion gene respectively) were recovered from samples with Ct [≤] 30 ([~]594 and 2,004 copies per reaction for RSV-A and RSV-B respectively). Minor variants were accurately identified in sample mixtures of 5:95 and higher. The assay showed high accuracy when compared against Sanger, shotgun metagenomic, and hybridization capture-based sequencing; and high repeatability and reproducibility. The UW-ARTIC RSV panel has utility in genomic surveillance, clinical and research applications. It has been used to generate FDA-reportable data for clinical trials of RSV antiviral products, with robust performance characteristics in samples from around the globe from as recently as the 2023/24 season. Continued genomic surveillance and future updates to primer sets will be essential for continued recovery of genomes as RSV continues to evolve.

genomics↗

Minimization of gene editing off-target effects by tissue restriction of expression

Therapeutic in vivo gene editing with highly specific nucleases has the potential to revolutionize treatment for a wide range of human diseases, including genetic disorders and latent viral infections like herpes simplex virus (HSV). However, challenges regarding specificity, efficiency, delivery, and safety must be addressed before its clinical application. A key concern is the risk of off-target effects, which can cause unintended and potentially harmful genetic changes. We previously developed a curative in vivo gene editing approach to eliminate latent HSV using HSV-specific meganuclease delivered by an AAV vector. In this study, we investigate off-target effects of meganuclease by identifying potential off-target sites through GUIDE-tag analysis and assessing genetic alterations using amplicon deep sequencing in tissues from meganuclease treated mice. Our results show that meganuclease expression driven by a ubiquitous promoter leads to high off-target gene editing in the mouse liver, a non-relevant target tissue. However, restricting the meganuclease expression with a neuron-specific promoter and/or a liver-specific miRNA target sequence efficiently reduces off-target effects in both liver and trigeminal ganglia. These findings suggest that incorporation of regulatory DNA elements for tissue-specific expression in viral vectors can reduce off-target effects and improve the safety of therapeutic in vivo gene editing.

molecular biology↗