Gene Therapy最新文献

Retinitis pigmentosa (RP) associated with mutations in the rhodopsin gene (RHO) is a significant cause of blindness. Here we report on the application of adenine base editing of the c.1030C>T (p.Q344X) RHO mutation linked to RP. Using a fluorescence reporter cell system, we optimized editing by exploring base editors, sgRNA, and delivery methods. Flow cytometry, western blotting, and immunofluorescence microscopy confirmed the restoration of full-length rhodopsin after editing. DNA sequencing verified editing at the target nucleotide and the absence of bystander edits within the editing window. Polyethylenimine cationic polymer transfection of cells with a plasmid containing the NG-ABE8e adenine base editor and A6 guide RNA that placed the targeted adenine in position 6 of the editing window resulted in 31.0% gDNA sequence correction and 26.3% rhodopsin protein correction as determined by flow cytometry. Purified NG-ABE8e protein complexed with A6-sgRNA showed 32.2% gDNA editing and 44.5% rhodopsin correction. Plasmid NG-ABE8e and A6-sgRNA co-encapsulated into lipid nanoparticles (LNPs) and transfected into the reporter cell system resulted in the highest editing (42.6% gDNA editing and 65.9% rhodopsin correction). These results demonstrate the successful correction of the c.1030C>T RHO mutation and provide the foundation for base editing as a treatment for RP.

Adeno-associated viruses (AAVs) hold significant promise for gene therapy targeting the central nervous system (CNS). However, current delivery methods are either invasive or cause significant systemic exposure. Intranasal (IN) delivery presents a promising noninvasive alternative for direct CNS targeting, though its efficacy in delivering AAVs to the brain has seldom been explored. Here, we quantitatively assessed AAV transduction in the brain and peripheral organs of Swiss, BALB/c, and C57BL/6 J mice following IN administration, using intravenous (IV) injection as a benchmark for comparison. Our findings revealed that IN administration of the AAV9 vector achieved approximately 15% of the transduction efficiency and 9% of the gene expression levels observed with IV delivery. Importantly, IN delivery significantly reduced systemic exposure to most major peripheral organs by up to 1.34 × 10⁴-fold compared to IV injection. The ratios of gene transduction between the brain and various peripheral tissues were calculated, revealing that for key organs such as the liver, stomach, kidney, and spleen, IN delivery achieved higher brain-to-peripheral transduction ratios than IV delivery. These findings underscore the potential of IN delivery for noninvasive brain-targeted gene delivery with significant reductions in peripheral exposure.

Base Editing (BE) and Prime Editing (PE), novel precision tools of the CRISPR/Cas toolbox, have emerged as transformative technologies that enable highly specific genetic modifications. Their compatibility with post-mitotic cell types makes them invaluable for treating genetic skeletal muscle disorders. Despite their severity and progressive nature, monogenic muscle diseases remain without definitive treatments. They are caused by diverse mutations in critical muscle proteins, for which gene editing offers a promising therapeutic avenue. However, traditional CRISPR/Cas9 applications face challenges such as genotoxicity and inefficiency in post-mitotic tissues. BE and PE technologies overcome these limitations by enabling safe and efficient modifications without causing double-strand breaks or requiring homology-directed repair. Their therapeutic potential comes from two key features: their ability to work in non-dividing cells such as myotubes and cardiomyocytes, and their capacity to target a broad range of mutations found in genetic muscle diseases. In this review, we explore mechanisms of BE and PE and summarize their current applications in monogenic skeletal muscle disorders. We discuss the challenges of in vivo application in skeletal muscle and highlight innovations to bypass them. Collectively, both systems offer flexible precision solutions with immense potential for mutation-specific and personalized gene therapy approaches for monogenic skeletal muscle disorders.

Beyond its well-known role in orofacial recurrent infections, HSV-1 has garnered significant attention in neuroscience for contrasting reasons. On one hand, it has been found to be involved in neurodegenerative processes; on the other, it may represent a versatile platform for gene therapy of brain diseases, due to its large genome that enables the delivery of sizable or multiple genes. These opposite features underscore the importance of understanding HSV-1 interactions with neural tissues in view of its employment as a gene therapy platform. We recently developed a new generation of highly defective backbones that proved very efficient and safe after direct injection in the brain parenchyma. Here we aimed at probing in depth the safety of viral batches that lack obvious unwanted (specifically, fusogenic) activities during production and, therefore, may escape negative selection. We employed whole-genome sequencing, electrophysiology, and viral engineering to compare different viral batches. We identified mutations (in particular A to I at position 549 in the UL27 gene) that confer fusogenic capacity to the envelop glycoprotein gB, inducing a hyperexcitable phenotype in transduced neurons. Such syncytial variants should be identified and avoided for any application of HSV-1 vectors implicating their direct injection in the nervous system.

Recombinant adeno-associated viruses (AAVs) have become increasingly popular as gene therapy vectors in recent years. Like all viruses, AAVs undergo dynamic structural changes in response to varying temperature and pH conditions. However, the specific capsid regions involved in these processes remain unknown. In this study, we employed Hydrogen-Deuterium Exchange Mass Spectrometry (HDX-MS) to investigate the impact of pH and temperature on the structure and conformational dynamics of AAV capsids. Our analysis identified specific regions of the capsid that are sensitive to these environmental changes. Additionally, our data elucidated the structural basis for DNA uncoating or leakage triggered by low pH or high temperature. Detailed structural characterization of AAVs by HDX-MS in this study deepens our understanding of viral capsid conformational dynamics and stability in AAV transduction and manufacturing and storage conditions, paving the way for formulation development and next-generation capsid engineering.

Adeno-associated virus (AAV)-based gene replacement therapies in Duchenne muscular dystrophy (DMD) aim to restore dystrophin function via the introduction of micro- or mini-dystrophins. We report dystrophin and mini-dystrophin concentrations generated by immunoaffinity liquid chromatography-tandem mass spectrometry (IA-LC-MS/MS) in skeletal muscle biopsies from ambulatory participants with DMD in a phase 1b study of fordadistrogene movaparvovec, an AAV9-based gene replacement construct. The assay performed robustly for 26 months, as demonstrated by limited variability in calibration standards for peptides LLQV (dystrophin and mini-dystrophin) and LEMP (mini-dystrophin only), quality control samples consisting of spiked mini-dystrophin in DMD skeletal muscle lysate, as well as unspiked, pooled, non-dystrophic skeletal muscle lysate (normal pool). Average values for LLQV in the normal pool tested as part of clinical sample and long-term stability runs were similar to validated values. Biopsy samples showed minor or absent LLQV and absent LEMP signals pre-treatment with fordadistrogene movaparvovec infusion, but signals substantially increased at Days 60 and 360, on average. There was strong concordance in LEMP and LLQV expression change between Days 60 and 360 (R² = 0.91; p < 0.001). IA-LC-MS/MS enables reproducible, stable, and reliable quantification of dystrophin/mini-dystrophin following fordadistrogene movaparvovec infusion. ClinicalTrials.gov identifier: NCT03362502.

Collagen disorders encompass a wide range of genetic conditions caused by pathogenic variants in collagen genes for which there is an unmet need for treatments. They present various clinical features, ranging from localised tissue abnormalities to severe systemic complications. Symptoms differ significantly and depend on the pathogenic variant, which can affect various systems, including the musculoskeletal, cardiovascular, and respiratory systems, highlighting the complex implications of collagen gene pathogenic variants and the wide range of expression patterns among different collagen types. Gene-editing technologies, particularly Clustered Regularly Interspaced Palindromic Repeats (CRISPR)-Cas systems, have emerged as promising therapeutic options for these disorders, representing a putative one-for-all treatment strategy. This review provides an overview of current gene-editing strategies aimed at collagen-related diseases, including osteogenesis imperfecta, Alport syndrome, and dystrophic epidermolysis bullosa. We explore the application of CRISPR-Cas9, which facilitates targeted DNA modifications, base editing (BE), and prime editing (PE), enabling precise single-nucleotide alterations without double-strand breaks (DSB). Preclinical and clinical studies have shown the potential of gene therapy to enhance collagen production, restore tissue integrity, and alleviate symptoms. However, challenges persist, including the lack of recurring mutations, the need for improved delivery methods, the reduction of off-target effects, and the development of novel therapies. Despite these challenges, advancements in gene editing techniques appear promising in enhancing editing efficiency while minimising unintended mutations, paving the way for more precise and safer genetic interventions for collagen disorders. Gene editing is fundamentally transforming medicine and biotechnology. Its applications encompass advanced diagnostics, tailored therapeutic strategies, and solutions for rare genetic disorders. By enabling precise genetic modifications, gene editing is paving the way for treatments of previously untreatable diseases, including those linked to collagen pathogenic variants. This review discusses the latest advancements in gene therapy techniques targeting collagen-related disorders. It explores innovative approaches like CRISPR-Cas9-mediated gene editing and highlights emerging strategies, such as allele-specific inactivation and base editing (BE). By examining these cutting-edge therapies and their potential clinical applications, this review highlights the transformative impact of gene editing in treating collagen-related conditions, while also identifying critical challenges and future directions for research.

Genetic/genomic manipulation techniques (gene transfer/delivery, gene editing, etc.) have become more and more mature, and the illegal use as gene doping in sports has drawn attentions. World Anti-Doping Agency (WADA) strictly prohibits gene doping, and has issued guideline on quantitative real-time PCR (qPCR) detections. However, the technical feature of qPCR makes it difficult to detect new doping targets, and codon changes on targets may also affect detection efficiency. Here, we prepare standard materials for genomic and transgenic versions of human EPO (hEPO) gene, and design qPCR primers to check the consequences of codon changes on gene doping detection. We confirm that carefully designed qPCR assays could indeed capture transgene signal, but codon changes on the transgene could severely undermine detection efficiency. We have also mimicked real world gene doping scenario by mixing genomic and transgenic versions of hEPO, and qPCR could detect wild-type but not codon-changed transgenes. As a method validation for such a challenge, we also use Sanger sequencing to confirm that sequencing could easily capture gene doping even for codon-changed transgenes. Our study confirms that codon changes will challenge qPCR-based gene doping detection, and calls for un-biased detection tools based on high-throughput sequencing in the future.

Lentivirus vectors are effective for treatment of genetic disease. However, safety associated with vector related genotoxicity is of concern and currently available models are not reliably predictive of safety in humans. We have developed ^hInGeTox as the first human in vitro platform that uses induced pluripotent stem cells and their hepatocyte like cell derivatives to better understand vector-host interactions that relate vectors to their potential genotoxicity. Using lentiviral vectors carrying the eGFP expression cassette under SFFV promoter activity, that only differ by their LTR and SIN configuration, we characterised vector host interactions potentially implicated in genotoxicity. To do this, lentiviral infected cells were subjected to an array of assays and data from these was used for multi-omics analyses of vector effects on cells at early and late harvest time points. Data on the integration sites of lentiviral vectors in cancer genes and differential expression levels of these genes, showed that both vector configurations are capable of activating cancer genes. Through IS tracking in bulk infected cell populations, we also saw an increase in the viral sequence count in cancer genes present over time which were differentially regulated. RNASeq also showed each vector had potential to generate fusion transcripts with the human genome suggestive of gene splicing or vector mediated readthrough from the internal SFFV promoter. Initially, after infection, both vector configurations were associated with differential expression of genes associated cytokine production, however, after culturing over time there were differences in differential expression in cells infected by each LV. This was marked in particular by the expression of genes involved in the response to DNA damage in cells transduced by the SIN vector, suggesting effects likely to prevent tumour development, in contrast to the expression of genes involved in methylation, characteristic of tumour development, in cells transduced by the LTR vector. Both sets of lentiviral infected cells were also found associated with differential expression of MECOM and LMO2 genes known to be associated with clonal dominance, supporting their potential genotoxicity. Alignment of transcriptomic signatures from iPSC and HLC infected cultures with known cancer gene signatures showed the LTR vector with a higher cancer score than the SIN vector over time in iPSC and also in HLC, which further suggests higher genotoxic potential by the LTR configuration lentivirus. By application of ^hInGeTox to cells infected with LV at the pre-clinical stage of development, we hope that ^hInGeTox can act as a useful pre-clinical tool to identify lentivirus-host interactions that may be considered contributory to genotoxicity to improve safer lentiviral vector design for gene therapy.