Molecular Therapy最新文献

KRAS mutations are instrumental in the development and progression of pancreatic ductal adenocarcinoma (PDAC). Nevertheless, the efficacy of direct targeting of KRAS mutations to inhibit tumor development remains doubtful. It is therefore necessary to gain a deeper insight into the mechanism in which KRAS mutations influence the effectiveness of clinical treatments. In this study, KRAS^G12D protein was detected in cancer-associated fibroblasts (CAFs) from clinical samples of pancreatic ductal adenocarcinoma (PDAC). In vitro experiments demonstrated that KRAS^G12D protein in CAFs was not expressed from its own mutant gene but was derived from the ingestion of tumor cell-derived extracellular vesicles (EVs). The presence of KRAS^G12D protein in CAFs resulted in enhanced proliferation and migration. Furthermore, KRAS^G12D-containing CAFs were observed to promote tumor chemoresistance to gemcitabine treatment both in vitro and in vivo. Application of a KRAS mutation-specific inhibitor, MRTX1133, has been demonstrated to reverse chemoresistance in PDAC. Moreover, clinical data suggest that patients with KRAS mutations have poorer prognosis following adjuvant chemotherapy. These findings elucidate the mechanism by which oncogenic KRAS mutations promote cancer chemoresistance and remodel tumor environment in a non-autonomous manner, suggesting a novel strategy for targeting KRAS mutations to enhance chemosensitivity in PDAC.

Antibody-mediated rejection (AMR) remains a major complication after solid organ transplantation (SOT). Current treatment options are inefficient and result in drastic impairment of the general immunity. To selectively eliminate responsible alloreactive B cells characterized by anti-donor-HLA B-cell receptors (BCRs), we generated T cells overcoming rejection by antibodies (CORA-Ts) engineered with a novel chimeric receptor comprising a truncated donor-HLA molecule as antigen recognition domain. As proof-of-concept, CORA receptors based on HLA-A*02 were developed. In co-cultures with anti-HLA-A*02 B-cell lines, CORA-Ts were specifically activated, released pro-inflammatory mediators, and exhibited strong cytotoxicity resulting in an effective reduction of anti-HLA-A*02 antibody release. Significant reduction of growth of an anti-HLA-A*02 B-cell line could be confirmed using an in vivo mouse model. Modification of the CORA receptor effectively abrogated T-cell binding, thereby avoiding T-cell sensitization. Additionally, using CRISPR/Cas9-mediated knockout of the FKBP12 gene, CORA-Ts were able to resist immunosuppressive treatment with tacrolimus, thereby allowing high efficiency in transplant patients. Our results demonstrate that CORA-Ts are able to specifically eliminate alloreactive, anti-HLA B cells, thus selectively preventing anti-HLA antibody release even under immunosuppressive conditions. This suggests CORA-Ts as potent approach to combat AMR and improve long-term graft survival in SOT patients while preserving their overall B-cell immunity.

The development of efficient and targeted methods for delivering DNA in vivo has long been a major focus of research. In this study, we introduce a gene Delivery approach Admitted by small Metabolites, named gDAM, for the efficient and targeted delivery of naked DNA into astrocytes in the adult brains of mice. gDAM utilizes a straightforward combination of DNA and small metabolites, including glycine, L-proline, L-serine, L-histidine, D-alanine, Gly-Gly, and Gly-Gly-Gly, to achieve astrocyte-specific delivery of naked DNA, resulting in transient and robust gene expression in these cells. Using gDAM, we successfully co-deliver the PiggyBac (PB) transposon and the CRISPR/Cas9 system to induce long-term overexpression of the oncogene EGFRvIII and knockout of tumor suppressor genes Nf1, Pten, and Trp53 in astrocytes, leading to the development of astrocyte-derived gliomas in immunocompetent mice. Furthermore, gDAM facilitates the delivery of naked DNA to peripheral glioma astrocytes. The overexpression of interferon-β (IFN-β) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in these peripheral glioma astrocytes significantly prolongs the overall survival of mice bearing 73C glioma cells. This approach offers a new perspective on developing gene delivery systems that specifically target astrocytes to meet the varied needs of both research and gene therapy. The innovative strategy behind gDAM is expected to provide fresh inspiration in the quest for DNA delivery to other tissues, such as skeletal muscle and skin.

Ornithine transcarbamylase deficiency (OTCD) is the most common urea cycle disorder, characterized by hyperammonemia and accompanied by a high unmet patient need. mRNA therapies have been shown to be efficacious in hypomorphic Sparse-fur abnormal skin and hair (Spf-ash) mice, a model of late-onset disease. However, studying the efficacy of ornithine transcarbamylase (OTC) mRNA therapy in traditional knockout mice, a model for severe early-onset OTCD, is hampered by the rapid lethality of the model, and poor lipid nanoparticle (LNP) uptake into neonatal mouse liver. We developed a novel tamoxifen-inducible mouse to study the effect of mRNA therapy in the context of complete or near-complete OTC loss in adult animals. Characterization of the model showed that it is highly reproducible, 100% penetrant, and phenocopies hallmarks of human disease, with animals exhibiting decreased body weight, hyperammonemia, and brain edema. Delivery of OTC mRNA increased survival, maintained body weight, delayed the onset of hyperammonemia, and reduced brain edema. Therefore, this model provides a platform to study LNP-mediated mRNA therapies for the treatment of late-onset OTCD.

Amyotrophic lateral sclerosis (ALS) and fronto-temporal dementia (FTD) are part of a spectrum of diseases that share several causative genes, resulting in a combinatory of motor and cognitive symptoms and abnormal protein aggregation. Multiple unbiased studies have revealed that proteostasis impairment at the level of the endoplasmic reticulum (ER) is a transversal pathogenic feature of ALS/FTD. The transcription factor XBP1s is a master regulator of the unfolded protein response (UPR), the main adaptive pathway to cope with ER stress. Here we provide evidence of suboptimal activation of the UPR in ALS/FTD models under experimental ER stress. To artificially engage the UPR, we intracerebroventricularly administrated adeno-associated viruses (AAV) to express the active form of XBP1 (XBP1s) in the nervous system of ALS/FTD models. XBP1s expression improved motor performance and extended life span of mutant SOD1 mice, associated with reduced protein aggregation. AAV-XBP1s administration also attenuated disease progression in models of TDP-43 and C9orf72 pathogenesis. Proteomic profiling of spinal cord tissue revealed that XBP1s overexpression improved proteostasis and modulated the expression of a cluster of synaptic and cell morphology proteins. Our results suggest that strategies to improve ER proteostasis may serve as a pan-therapeutic strategy to treat ALS/FTD.

Autoreactive antibodies (AAB) are currently being investigated as causative or aggravating factors during post-COVID. In this study we analyze the effect of immunoadsorption therapy on symptom improvement and the relationship with immunological parameters in post-COVID patients exhibiting symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) induced or aggravated by an SARS-CoV-2 infection. This observational study includes 12 post-COVID patients exhibiting a predominance of ME/CFS symptoms alongside increased concentrations of autonomic nervous system receptors (ANSR) autoantibodies and neurological impairments. We found that following immunoadsorption therapy, the ANSR autoantibodies were nearly eliminated from the patients' blood. The removal of IgG antibodies was accompanied by a decrease of pro-inflammatory cytokines including IL4, IL2, IL1β, TNF and IL17A serum levels, and a significant reduction of soluble spike protein. Notably, a strong positive correlation between pro-inflammatory cytokines and ASNR-AABs β1, β2, M3, and M4 was observed in spike protein-positive patients, whereas no such correlation was evident in spike protein-negative patients. 30 days post-immunoadsorption therapy, patients exhibited notable improvement in neuropsychological function and a modest but statistically significant amelioration of hand grip strength was observed. However, neither self-reported symptoms nor scores on ME/CFS questionnaires showed a significant improvement and a rebound of the removed proteins occurring within a month.

mRNA delivered using lipid nanoparticles (LNPs) has become an important subunit vaccine modality, but mechanisms of action for mRNA vaccines remain incompletely understood. Here, we synthesized a metal chelator-lipid conjugate enabling positron emission tomography (PET) tracer labeling of LNP/mRNA vaccines for quantitative visualization of vaccine trafficking in live mice and non-human primates (NHPs). Following i.m. injection, we observed LNPs distributing through injected muscle tissue, simultaneous with rapid trafficking to draining lymph nodes (dLNs). Deltoid injection of LNPs mimicking human vaccine administration led to stochastic LNP delivery to 3 different sets of dLNs. LNP uptake in dLNs was confirmed by histology, and cellular analysis of tissues via flow cytometry identified antigen-presenting cells as the primary cell type responsible for early LNP uptake and mRNA translation. These results provide insights into the biodistribution of mRNA vaccines administered at clinically relevant doses, injection volumes, and injection sites in an important large animal model for vaccine development.

CRISPR-Cas9 ribonucleoproteins (RNPs) have been heavily considered for gene therapy due to their high on-target efficiency, rapid activity and lack of insertional mutagenesis relative to other CRISPR-Cas9 delivery formats. Genetic diseases such as hypertrophic cardiomyopathy currently lack effective treatment strategies and are prime targets for CRISPR-Cas9 gene editing technology. However, current in-vivo delivery strategies for Cas9 pose risks of unwanted immunogenic responses. This proof-of-concept study aimed to demonstrate that focused ultrasound (FUS) in combination with microbubbles can be used to deliver Cas9-sgRNA (single guide RNA) RNPs and functionally edit human induced pluripotent stem cells (hiPSCs) in-vitro, a model system that can be expanded to cardiovascular research via hiPSC-derived cardiomyocytes. Here, we first determine acoustic conditions suitable for the viable delivery of large proteins to hiPSC with clinical Definity® microbubble agents using our customized experimental platform. From here, we delivered Cas9-sgRNA RNP complexes targeting the EGFP (enhanced green fluorescent protein) gene to EGFP-expressing hiPSCs for EGFP knockout. Simultaneous acoustic cavitation detection during treatment confirmed a strong correlation between microbubble disruption and viable FUS-mediated protein delivery in hiPSCs. This study shows, for the first time, the potential for an FUS-mediated technique for targeted and precise CRISPR-Cas9 gene editing in human stem cells.

Cystic Fibrosis (CF) is a life-shortening autosomal recessive disease caused by mutations in the CFTR gene, resulting in functional impairment of the encoded ion channel. F508del mutation, a trinucleotide deletion, is the most frequent cause of CF affecting approximately 80% of persons with cystic fibrosis (pwCFs). Even though current pharmacological treatments alleviate the F508del-CF disease symptoms there is no definitive cure. Here we leveraged revertant mutations (RMs) in cis with F508del to rescue CFTR protein folding and restore its function. We developed CRISPR base editing strategies to efficiently and precisely introduce the desired mutations in the F508del locus. Both editing and CFTR function recovery were verified in CF cellular models including primary epithelial cells derived from pwCFs. The efficacy of the CFTR recovery strategy was validated in cultures of pseudostratified epithelia from pwCF cells showing full recovery of ion transport. Additionally, we observed an additive effect by combining our strategy with small molecules that enhance F508del activity, thus paving the way to combinatorial therapies.