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Coote, K.

Publications and source records attributed to Coote, K..

3 recordsLinked to original sources

Lipid Nanoparticles for the Delivery of CRISPR/Cas9 Machinery to Enable Site-Specific Integration of CFTR and Mutation-Agnostic Disease Rescue

We report the engineering of lipid nanoparticles (LNPs) to transport CRISPR/Cas9 payloads, including double-stranded DNA (dsDNA) donor templates, designed for homology directed repair (HDR)-mediated site-specific insertion of the cystic fibrosis transmembrane conductance regulator (CFTR) gene to correct cystic fibrosis (CF) in diseased airway epithelium. We screened various nanoparticle formulations, adjusting ratios of Cas9-encoding mRNA, single guide RNAs (sgRNAs), and dsDNA donor templates to optimize gene editing using human bronchial epithelial cells (16HBE14o-) harboring a CF-causing mutation (G542X). Populations of G542X cells edited via LNP delivery of CFTR donors achieved 3 - 3.5% gene integration and yielded comparable CFTR protein expression compared to normal 16HBE14o- controls. These edited populations exhibit restoration of CFTR-dependent Cl- current to ca. 80% of values measured in normal 16HBE14o- cell monolayers. This LNP platform adds capabilities for transporting large gene editing machinery to airway epithelial cells for genomic integration of entire genes, enabling therapeutic solutions that achieve correction of any CF-causing mutation.

bioengineering↗

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↗

A multimodal iPSC platform for cystic fibrosis drug testing

Cystic fibrosis (CF) is a monogenic lung disease caused by dysfunction of the cystic fibrosis transmembrane regulator (CFTR) anion channel, resulting in significant morbidity and mortality. The progress in elucidating the role of the CFTR channel using established animal and cell-based models led to the recent discovery of effective CFTR modulators for most individuals with CF. However, a subset of individuals with CF do not respond to these modulators and there is an urgent need to develop novel therapeutic strategies. In this study, we assembled a panel of iPSCs derived from individuals with common or rare variants representative of three distinct classes of CFTR dysfunction. To measure CFTR function in patient-specific iPSCs we adapted two established in vitro assays of CFTR function to iPSC-derived airway cells. In both a 3-D spheroid assay using forskolin-induced swelling as well as planar cultures composed of polarized mucociliary airway epithelial cells, we quantified CFTR baseline function and response to CFTR modulators and detected genotype-specific differences. Our results demonstrate the potential of the human iPSC platform as a research tool to study cystic fibrosis and in particular accelerate therapeutic development for CF caused by rare mutations.

developmental biology↗