Gene Therapy最新文献

Previously, we confirmed that BaEV-LVs outperformed VSV-G-LVs for gene delivery or correction of human T cells, B cells, NK cells and HSPCs correlating with high expression of its receptors, ASCT-1 and ASCT-2 on these cells. Since HERV-W gp uses the same entry receptors, we compared transduction efficiencies for BaEV-LVs and HERV-W-LVs in hematopoietic cells. HERV-W LV transduction was efficient but inferior to BaEV-LV in TCR-stimulated T cells (40% versus 80%) and this low efficiency was even more pronounced in IL-7/IL-15 pre-stimulated T cells. BaEV-LVs were significantly superior over HERV-W-LVs for the transduction of B cells and NK cells. High HERV-W-LV mediated transduction levels were achieved for pre-stimulated hCD34+ cells, which remained though lower than for the BaEV-LVs. Additionally, BaEV-LVs reached over 80% of transduction in severe combined immunodeficiency (SCID) repopulating cells (SRC) in 6/6 engrafted NBSGW mice. HERV-W-LVs reached this transduction level in 1/5 mice, while 3/5 engrafted NBSGW mice reached significantly lower transduction levels (20-50%). For both vectors the transduction levels were equivalent in the lymphoid and myeloid lineages in all hematopoietic tissues, suggesting transduction of immature HSPCs. Summarizing, BaEV-LVs outperformed HERV-W-LVs for transduction of important gene therapy target cells such as NK, B, T cells and CD34+ HSPCs.

Efficient delivery of CRISPR ribonucleoproteins into primary hematopoietic stem and progenitor cells (HSPCs) is essential for durable gene editing therapies but remains challenging. Here, we advance a modular, benchtop-assembled gold-polymer hybrid nanoparticle (CRISPR-AuNP) platform that enables non-viral delivery of multiple CRISPR systems into HSPCs. Guided by a mechanistic understanding of Cas9's interaction with gold surfaces, we engineered the formulation by conjugating pre-formed RNP-polymer complexes, assembled using thiolated polyethyleneimine-polyethylene glycol, to gold nanoparticles. This system achieved efficient editing in primary CD34+ HSPCs for Cas9, Cas12a, and Cas12a-M29-1 without compromising cell viability. Notably, the nanoformulation can be assembled in under 2 h in a PCR tube for less than $70/million HSPCs treated. This work establishes a scalable, cost-effective, and accessible gene editing system with the potential to democratize CRISPR applications in HSPC research and therapy.

Immune responses against recombinant adeno-associated virus (rAAV) are one of the major obstacles in gene therapy. We investigated the potential of Programmed Death 1 ligands 1 and 2 (PD-L1/2) to protect AAV-transduced cells from immunological clearance. Ligand compatibility for co-delivery was first evaluated using two transgenes, VEGF-B186 and muSEAP, separated from PD-L1/2 by a self-cleaving P2A peptide. After proper cleavage and biological activity of the co-produced proteins were demonstrated in vitro, the effect of PD-L1/2 co-expression on muSEAP production and persistence was studied in naïve and vector pre-immunized mice. Vectors (rAAV6-muSEAP, rAAV6-muSEAP-PD-L1, or rAAV6-muSEAP-PD-L2) were injected into two sites of the gastrocnemius muscle at a total dose of 1×10¹⁰ vg. Co-delivery of PD-L1, particularly, significantly enhanced muSEAP secretion into the bloodstream up to 12 weeks despite elevated anti-AAV6 responses in pre-immunized mice. muSEAP secretion increased 33.3- and 31.4-fold with the co-delivery of PD-L1, while the increase was only 5.6- and 9.3-fold in the muSEAP control group at 5 and 12 weeks, respectively. Ligand-treated pre-immunized animals also had less T-cell infiltration into the treated muscle compared to naïve animals. In summary, co-delivery of PD-L1/2 alongside a transgene represents a promising strategy for achieving sustained gene expression in individuals pre-exposed to AAV.

Adoptive Cell Therapies based on cytokine-induced killer cells (CIKs) can address the heterogeneity of solid tumors due to their multiple mechanisms of cancer cell recognition. However, tumor trafficking is one of the main limitations. In this work, we describe that a high proportion of CIKs obtained from pancreatic ductal adenocarcinoma patients express the CXCR3 and CCR5 receptors, and they migrate towards their corresponding chemokines CXCL10 and CCL5 in vitro. Using an immune competent orthotopic PDAC mouse model, we have investigated the ability of different clinically compatible interventions to increase the expression of these chemokines. No significant elevation was obtained with chemotherapy (5-fluorouracil, irinotecan, oxaliplatin, paclitaxel, gemcitabine or temozolomide), tyrosine kinase inhibitors sorafenib and sunitinib, or the immunostimulatory agents polyinosinic:polycytidylic acid, Mycobacterium tuberculosis antigens and diphtheria/pertussis/tetanus vaccine. In contrast, CXCL10 and CCL5 expression was stimulated by local administration of an adenoviral vector equipped with a drug-inducible expression system for interleukin-12 (IL-12). Combination of the vector and CIKs obtained a strong antitumor effect in the PDAC model, although it was mainly due to vector-mediated recruitment of endogenous immune cells. We conclude that additional barriers beyond chemokine expression should be overcome in order to unleash the full potential of CIKs on solid tumors.

Adeno-associated virus (AAV)-based gene therapies have garnered significant attention and investment due to their clinical success and potential to address underlying causes of many diseases. AAV vectors provide effective delivery of therapeutic genetic material to disease-relevant tissues. When evaluating safety and efficacy of recombinant AAV vectors, biodistribution profiles play a critical role in novel therapy development. Herein, a biodistribution metadata analysis was performed on ten studies involving 51 cynomolgus macaques (Macaca fascicularis). The macaques received a self-complementary or single-stranded AAV9 vector containing chicken ß-actin (CBA) or cytomegalovirus (CMV173) promoters expressing fluorescent reporters or a human SMN1 gene. These studies covered various routes of administration (ROA) including intravenous (IV), intracisternal magna (ICM), and lumbar puncture intrathecal (IT) injection. Metadata analysis of AAV9 biodistribution showed relatively uniform vector genome delivery throughout spinal cord tissues over multiple timepoints and ROAs. Moreover, decreased expression efficiency of viral DNA in liver was observed regardless of the ROA, macaque age, or viral construct used. To understand this trend, epigenetic profiling of tissue-localized AAV9 vector genome DNA was performed. Experimental evidence supports partial silencing and repression of transgene expression in macaque liver. These findings point to plausible strategies to consider in preclinical development of AAV9 mediated gene therapies.

This article provides a regulatory perspective on secondary malignancy of T-cell origin as a rare adverse reaction to the currently marketed CD19- or BCMA-directed chimeric antigen receptor (CAR) T-cell therapies. To assess the risk, causality between reported suspected adverse reactions and CAR T-cell therapy was assessed applying the principles of the World Health Organization-Uppsala Monitoring Centre causality categories, alongside a review of scientific publications and data from registries/ databases. By 11 April 2024, 38 cases of T-cell malignancy after CAR T-cell therapy were reported in patients aged 29-80 years. In 19 patients, tumour samples were tested for the presence of CAR transgene, which was detected in seven cases. Most of the T-cell malignancies were diagnosed within 12 months of treatment (22/33; 67%). The reporting rate is approximately one case per 1000 patients treated. An overall causal relationship was established with at least a reasonable possibility. Regulatory measures included updates to the product information, risk management plan, and educational materials. An additional pharmacovigilance activity was requested from the marketing authorisation holders (MAHs) to strengthen the process of genetic testing of residual tumour samples. To further characterise this risk and understand underlying mechanisms, continued efforts from healthcare professionals, MAHs and regulators are essential. Well-documented case reports, including information on genetic testing of tumour samples, are considered crucial elements.

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.