Comparison of strain specific pathogenicity of Herpes Simplex Virus Type 1 by high-throughput sequencing.

Herpes Simplex Virus Type 1 (HSV-1) is a widespread human pathogen known for causing a spectrum of clinical manifestations, ranging from mild cold sores to severe complications like encephalitis. Understanding the strain-specific variations of HSV-1 is crucial for elucidating its pathogenesis and developing targeted therapeutic interventions. In this multifaceted study, we investigated the strain-specific characteristics of HSV-1 using an in vivo rat model. Firstly, a pilot study was conducted to assess the capacity of three HSV-1 strains (Fisher (F), KOS (K), and MacIntyre (M)) to induce cold sores in rats. Remarkably, the F strain exhibited pronounced pathogenicity, inducing erythema, swelling, and disrupted epidermis with ulceration, distinguishing it from the K and M strains. Subsequently, the treatment capability of intravenous acyclovir injection in HSV-1 F strain-infected rats was evaluated. Acyclovir treatment resulted in a significant reduction in HSV-1 viral copy numbers in serum and dissected neuronal tissues, particularly in the spinal cord, brain, and lower lip. Lastly, whole genome sequencing data revealed that high-impact mutations occurred in the K and M strains within the UL49, US2, and US3 genes. These mutations may play a pivotal role in influencing viral replication, dissemination, pathogenesis, and infectivity. In contrast, the moderate missense variant mutations detected in the US12, US8, UL3, UL30, UL31, and UL36 genes appeared to have no effect on viral pathogenesis and infectivity, based on RT-PCR data for spinal cord, trigeminal nerve, brain, and the lower lip. These strain-specific mutations underscore the dynamic nature of HSV-1 evolution. Collectively, our findings contribute to a deeper understanding of HSV-1 strain diversity and pave the way for the development of targeted therapeutic strategies against this medically significant virus.

Unveiling Off-Target Mutations in CRISPR Guide RNAs: Implications for Gene Region Specificity.

The revolutionary CRISPR-Cas9 technology has revolutionized genetic engineering, and it holds immense potential for therapeutic interventions. However, the presence of off-target mutations and mismatch capacity poses significant challenges to its safe and precise implementation. In this study, we explore the implications of off-target effects on critical gene regions, including exons, introns, and intergenic regions. Leveraging a benchmark dataset and using innovative data preprocessing techniques, we have put forth the advantages of categorical encoding over one-hot encoding in training machine learning classifiers. Crucially, we use latent class analysis (LCA) to uncover subclasses within the off-target range, revealing distinct patterns of gene region disruption. Our comprehensive approach not only highlights the critical role of model complexity in CRISPR applications but also offers a transformative off-target scoring procedure based on ML classifiers and LCA. By bridging the gap between traditional target-off scoring and comprehensive model analysis, our study advances the understanding of off-target effects and opens new avenues for precision genome editing in diverse biological contexts. This work represents a crucial step toward ensuring the safety and efficacy of CRISPR-based therapies, underscoring the importance of responsible genetic manipulation for future therapeutic applications.