Biology subjects

Spelier, S.

Publications and source records attributed to Spelier, S..

6 recordsLinked to original sources

bioRxiv2026

A functional comparison of readthrough agent ELX-02 across a wide range of nonsense CFTR variants

BackgroundNonsense variants in CFTR account for ~10% of cystic fibrosis (CF) variants and cannot be treated with approved CFTR modulators. Translational readthrough agents such as ELX-02 offer a potential therapeutic strategy, but clinical trials evaluated mainly in G542X CFTR nonsense variant and underlined limited efficacy. This study aimed to evaluate ELX-02-mediated CFTR rescue across a broad range of nonsense variants using patient-derived intestinal organoids (PDIOs) to define variant-specific determinants of readthrough efficacy and assess its potential across a genetically diverse CF population. MethodThe ex vivo response to ELX-02 was assessed in 206 PDIOs carrying heterogeneous nonsense variants. CFTR function was quantified using forskolin-induced swelling (FIS) assay after 48-hour exposure to ELX-02. Responses were analysed by genotype and stop codon identity, with secondary validation performed in a selected subset of PDIOs (n = 60). ResultsELX-02-mediated CFTR rescue varied markedly, ranging from responses approaching those observed with approved CFTR modulators (LUM/IVA) to responses at or below detection limit. Overall, maximal responses were modest and at the lower end of the functional range for CFTR modulators. Rescue was dose-dependent and higher in PDIOs carrying two nonsense variants when compared with PDIOs carrying a single nonsense variant combined with a residual or minimal function variant. Nonsense variants in nucleotide-binding domain 1, including G542X, S466X, G550X and R553X, showed relatively higher responsiveness. ConclusionELX-02 induces limited and highly heterogeneous CFTR rescue across nonsense variants. PDIO-based functional screening provides a framework to guide patient selection and stratification for future readthrough therapy trials.

molecular biology↗

bioRxiv2024

Small molecule-directed differentiation of submerged-cultured human nasal airway epithelia for respiratory disease modelling

Submerged cultures of undifferentiated or transformed epithelial cells are widely used in respiratory research due to their ease of use and scalability. However, these systems fail to capture the cellular diversity of the human airway epithelium. In this study, we developed an in vitro model where cryopreserved human nasal epithelial cells, collected by brushings, are differentiated under submerged conditions on standard plastic cultureware. By applying small-molecule inhibitors targeting Notch and BMP signaling, we achieved efficient differentiation of cultures containing basal, secretory, and ciliated cells. This approach supports scalable culturing of both 2D epithelial monolayers and 3D organoids, validated as (personalized) disease models for primary ciliary dyskinesia, cystic fibrosis, and respiratory syncytial virus infection. This model offers a cost-effective, scalable platform that combines the simplicity of traditional cultures with the cellular complexity of the human airway epithelium, providing a valuable tool for respiratory disease research.

cell biology↗

bioRxiv2024

Anticodon Engineered Transfer RNAs (ACE-tRNAs) are a Platform Technology for Suppressing Nonsense Mutations

Nonsense mutations arise from single nucleotide substitutions that result in premature termination codons (PTCs). PTCs result in little to no full-length protein production and loss of mRNA expression through the nonsense-mediated mRNA decay (NMD) pathway. We demonstrate that anticodon engineered (ACE-) tRNAs efficiently suppress the most prevalent cystic fibrosis (CF) causing PTCs, promoting significant rescue of endogenous cystic fibrosis transmembrane conductance regulator (CFTR) transcript abundance and channel function in different model systems. We demonstrate that our best-performing ACE-tRNA, that decodes all UGA PTCs to a leucine amino acid, markedly rescues CFTR channel function from the most prevalent CF causing PTCs that arise from non-leucine encoding codons. Using this single ACE-tRNA variant, we demonstrate significant rescue of CFTR channel function in an immortalized airway cell line and two different primary CF patient-derived intestinal cell models with CFTR nonsense mutations. Thus, ACE-tRNAs have promise as a platform therapeutic for CF and other nonsense-associated diseases.

molecular biology↗

bioRxiv2022

FDA-Approved Drug Screening in Patient-Derived Organoids Demonstrates Potential of Drug Repurposing for Rare Cystic Fibrosis Genotypes

BackgroundPreclinical cell-based assays that recapitulate human disease play an important role in drug repurposing. We previously developed a functional forskolin induced swelling (FIS) assay using patient-derived intestinal organoids (PDIOs), allowing functional characterization of CFTR, the gene mutated in people with cystic fibrosis (pwCF). CFTR function-increasing pharmacotherapies have revolutionized treatment for approximately 85% of people with CF, but a large unmet need remains to identify new treatments for all pwCF. MethodsWe used 76 non-homozygous F508del-CFTR PDIOs to test the efficacy of 1400 FDA-approved drugs on improving CFTR function, as measured in FIS assays. ResultsBased on the results of a secondary validation screen, we investigated CFTR elevating function of PDE4 inhibitors and currently existing CFTR modulators in further detail. We show that PDE4 inhibitors are potent CFTR function inducers in PDIOs and that CFTR modulator treatment rescues of CF genotypes that are currently not eligible for this therapy. ConclusionsThis study exemplifies the feasibility of high-throughput compound screening using PDIOs and we show the potential of repurposing drugs for pwCF that are currently not eligible for therapies. One-sentence SummaryWe screened 1400 FDA-approved drugs in CF patient-derived intestinal organoids using the previously established functional FIS assay, and show the potential of repurposing PDE4 inhibitors and CFTR modulators for rare CF genotypes.

molecular biology↗

bioRxiv2022

High-Throughput Functional Assay in Cystic Fibrosis Patient-Derived Organoids Allows Drug Repurposing

Cystic fibrosis (CF) is a rare hereditary disease caused by mutations in the CFTR gene. Recent therapies enable effective restoration of CFTR function of the most common F508del CFTR mutation. This shifts the unmet clinical need towards people with rare CFTR mutations such as nonsense mutations, of which G542X and W1282X are most prevalent. CFTR function measurements in patient-derived cell-based assays played a critical role in preclinical drug development for CF and may play an important role to identify new drugs for people with rare CFTR mutations. Here, we miniaturized the previously described forskolin induced swelling (FIS) assay in intestinal organoids from a 96-wells to a 384-wells plate screening format. Using this novel assay, we tested CFTR increasing potential of a 1400-compound FDA-approved drug library in organoids from donors with W1282X/W1282X CFTR nonsense mutations. The 384-wells FIS-assay demonstrated uniformity and robustness based on CV and Z-factor calculations. In the primary screen, the top 5 compound combinations that increased CFTR function all contained at least one statin. In the secondary screen, we indeed verified that four out of the five statins, Mevastatin; Lovastatin; Simvastatin and Fluvastatin increased CFTR function when combined with CFTR modulators. Statin-induced CFTR rescue was W1282X specific, as increased CFTR function was not shown for patient-derived organoids harbouring R334W/R334W and F508del/F508del mutations. Future studies should focus on elucidating genotype specificity and mode-of-action of statins into more detail. This study exemplifies proof-of-principle of large-scale compound screening in a functional assay using patient derived organoids. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=169 SRC="FIGDIR/small/500147v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@fccbfdorg.highwire.dtl.DTLVardef@b459ceorg.highwire.dtl.DTLVardef@7414fborg.highwire.dtl.DTLVardef@10d9c35_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2021

Optical nanoscopy reveals SARS-CoV-2-induced remodeling of human airway cells

A better understanding of host cell remodeling by the coronavirus SARS-CoV-2 is urgently needed to understand viral pathogenesis and guide drug development. Expression profiling and electron microscopy have frequently been used to study virus-host interactions, but these techniques do not readily enable spatial, sub-cellular and molecular analysis of specific cellular compartments. Here, we use diffraction-unlimited fluorescence microscopy to analyze how SARS-CoV-2 infection exploits and repurposes the subcellular architecture of primary human airway cells. Using STED nanoscopy, we detect viral entry factors along the motile cilia of ciliated cells and visualize key aspects of the viral life cycle. Using Tenfold Robust Expansion (TREx) microscopy, we analyze the extensively remodeled three-dimensional ultrastructure of SARS-CoV-2-infected ciliated cells and uncover Golgi fragmentation, emergence of large and atypical multivesicular bodies enclosing viral proteins, ciliary clustering, and remodeling of the apical surface. These results demonstrate a broadly applicable strategy to study how viruses reorganize host cells with spatial and molecular specificity and provide new insights into SARS-CoV-2 infection in primary human cell models.

cell biology↗