Department of Pediatrics & Human Development, Michigan State University, Grand Rapids, MI 49503, USA.
Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA.
Cells. 2021 Apr 25;10(5):1014. doi: 10.3390/cells10051014.
Cystic fibrosis (CF) is caused by genetic mutations of the CF transmembrane conductance regulator (CFTR), leading to disrupted transport of Cl and bicarbonate and CF lung disease featuring bacterial colonization and chronic infection in conducting airways. CF pigs engineered by mutating CFTR develop lung disease that mimics human CF, and are well-suited for investigating CF lung disease therapeutics. Clinical data suggest small airways play a key role in the early pathogenesis of CF lung disease, but few preclinical studies have focused on small airways. Efficient targeted delivery of CFTR cDNA to small airway epithelium may correct the CFTR defect and prevent lung infections. Adeno-associated virus 4 (AAV4) is a natural AAV serotype and a safe vector with lower immunogenicity than other gene therapy vectors such as adenovirus. Our analysis of AAV natural serotypes using cultured primary pig airway epithelia showed that AAV4 has high tropism for airway epithelia and higher transduction efficiency for small airways compared with large airways. AAV4 mediated the delivery of CFTR, and corrected Cl transport in cultured primary small airway epithelia from CF pigs. Moreover, AAV4 was superior to all other natural AAV serotypes in transducing ITGα6β4 pig distal lung progenitor cells. In addition, AAV4 encoding eGFP can infect pig distal lung epithelia in vivo. This study demonstrates AAV4 tropism in small airway progenitor cells, which it efficiently transduces. AAV4 offers a novel tool for mechanistical study of the role of small airway in CF lung pathogenesis in a preclinical large animal model.
囊性纤维化（CF）是由 CF 跨膜电导调节因子（CFTR）的基因突变引起的，导致 Cl 和碳酸氢根的转运中断，CF 肺部疾病的特征是在传导气道中细菌定植和慢性感染。通过突变 CFTR 工程化的 CF 猪会发展出类似于人类 CF 的肺部疾病，非常适合研究 CF 肺部疾病的治疗方法。临床数据表明，小气道在 CF 肺部疾病的早期发病机制中起着关键作用，但很少有临床前研究集中在小气道上。CFTR cDNA 向小气道上皮的有效靶向递送可能纠正 CFTR 缺陷并预防肺部感染。腺相关病毒 4（AAV4）是一种天然的 AAV 血清型，是一种比其他基因治疗载体（如腺病毒）免疫原性更低的安全载体。我们使用培养的原代猪气道上皮细胞对 AAV 天然血清型进行的分析表明，与大气道相比，AAV4 对气道上皮具有高亲嗜性，并且对小气道的转导效率更高。AAV4 介导 CFTR 的递送，并纠正 CF 猪原代小气道上皮中的 Cl 转运。此外，AAV4 在转导 ITGα6β4 猪远端肺祖细胞方面优于所有其他天然 AAV 血清型。此外，编码 eGFP 的 AAV4 可以在体内感染猪远端肺上皮。这项研究证明了 AAV4 在小气道祖细胞中的亲嗜性，它可以有效地转导这些细胞。AAV4 为在临床前大型动物模型中研究小气道在 CF 肺部发病机制中的作用提供了一种新的工具。
