Single-Dose Lentiviral Mediated Gene Therapy Recovers CFTR Function in Cystic Fibrosis Knockout Rats.

Nicole Reyne,Alexandra Mccarron,Juliette Delhove,Patricia Cmielewski,Martin Donnelley,David Parsons

doi:10.3389/fphar.2021.682299

Abstract

Cystic fibrosis (CF) is a genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, resulting in defective ion transport in the airways. Addition of a functioning CFTR gene into affected airway cells has the potential to be an effective treatment for lung disease. The therapeutic efficacy of airway gene transfer can be quantified in animal models by assessing ion transport in the treated nasal epithelium using the nasal potential difference (PD) measurement technique. The nasal PD technique is routinely used in CF mice, however when applied to a recently developed CF rat model those animals did not tolerate the initial nasal PD assessment, therefore the procedure was firstly optimised in rats. This study evaluated the effect of lentiviral (LV)-mediated CFTR airway gene delivery on nasal PD in a CFTR knockout rat model. LV gene vector containing the CFTR gene tagged with a V5 epitope tag (LV-V5-CFTR) was delivered to the nasal epithelium of CF rats, and one week later nasal PD was analysed. This study demonstrated for the first time that LV-V5-CFTR treatment produced a mean correction of 46% towards wild-type chloride response in treated CF rats. Transduced cells were subsequently identifiable using V5 immunohistochemical staining. These findings in the nose validate the use of airway gene therapy for future lung based experiments.

Highlights

Cystic fibrosis (CF) is a common, life-shortening, recessive genetic disorder, resulting from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene (Davis, 2006)
Nasal potential difference (PD) Assessment Was Optimized in Rats
To improve nasal PD assessments in rats we developed an optimised testing method

Summary

Introduction

Cystic fibrosis (CF) is a common, life-shortening, recessive genetic disorder, resulting from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene (Davis, 2006). CF affects multiple organs and despite symptomatic treatments and CFTR modulator therapies that improve quality of life it remains incurable, with lung disease the major cause of mortality (Carlon et al, 2017). The pathophysiology of CF results from a loss of CFTR chloride channel function and via its interaction with other ion channels such as the epithelial sodium channel (ENaC). Together these channels regulate chloride and sodium ion movement across the epithelial surface of many organs, maintaining osmolarity. CF airways experience a continuous cycle of infection and inflammation, leading to permanent lung damage and respiratory failure (Chmiel et al, 2002)

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Conclusion