Mutations in the CFTR gene that lead to premature stop codons or splicing defects cause cystic fibrosis (CF) and are not amenable to treatment by small-molecule modulators. Here, we investigate the use of adenine base editor (ABE) ribonucleoproteins (RNPs) that convert A•T to G•C base pairs as a therapeutic strategy for three CF-causing mutations. Using ABE RNPs, we corrected in human airway epithelial cells premature stop codon mutations (R553X and W1282X) and a splice-site mutation (3849 + 10 kb C > T). Following ABE delivery, DNA sequencing revealed correction of these pathogenic mutations at efficiencies that reached 38–82% with minimal bystander edits or indels. This range of editing was sufficient to attain functional correction of CFTR-dependent anion channel activity in primary epithelial cells from CF patients and in a CF patient-derived cell line. These results demonstrate the utility of base editor RNPs to repair CFTR mutations that are not currently treatable with approved therapeutics.

中文翻译：

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使用腺嘌呤碱基编辑器对人气道上皮细胞 CFTR 突变进行功能校正

导致过早终止密码子或剪接缺陷的 CFTR 基因突变会导致囊性纤维化 (CF)，并且不适合小分子调节剂的治疗。在这里，我们研究了使用腺嘌呤碱基编辑器 (ABE) 核糖核蛋白 (RNP) 将 A•T 转换为 G•C 碱基对作为三个引起 CF 突变的治疗策略。使用 ABE RNP，我们在人气道上皮细胞中纠正了过早终止密码子突变（R553X 和 W1282X）和剪接位点突变（3849 + 10 kb C > T）。在 ABE 交付后，DNA 测序显示这些致病突变的校正效率达到 38-82%，且旁观者编辑或插入缺失最少。这一编辑范围足以实现对 CF 患者原代上皮细胞和 CF 患者衍生细胞系中 CFTR 依赖性阴离子通道活性的功能校正。这些结果证明了碱基编辑器 RNP 可用于修复目前无法用已批准的疗法治疗的 CFTR 突变。