Phenotypes of CF rabbits generated by CRISPR/Cas9-mediated disruption of the CFTR gene

Abstract

Existing animal models of cystic fibrosis (CF) have provided key insights into CF pathogenesis but have been limited by short life spans, absence of key phenotypes, and/or high maintenance costs. Here, we report the CRISPR/Cas9-mediated generation of CF rabbits, a model with a relatively long lifespan and affordable maintenance and care costs. CF rabbits supplemented solely with oral osmotic laxative had a median survival of ~ 40 days and died of gastrointestinal disease, but therapeutic regimens directed toward restoring gastrointestinal transit extended median survival to ~ 80 days. Surrogate markers of exocrine pancreas disorders were found in CF rabbits with declining health. CFTR expression patterns in WT rabbit airways mimicked humans, with widespread distribution in nasal respiratory and olfactory epithelia, as well as proximal and distal lower airways. CF rabbits exhibited human CF-like abnormalities in the bioelectric properties of the nasal and tracheal epithelia. No spontaneous respiratory disease was detected in young CF rabbits. However, abnormal phenotypes were observed in surviving 1 year-old CF rabbits as compared to WT littermates, which were especially evident in the nasal respiratory and olfactory epithelium. The CF rabbit model may serve as a useful tool for understanding gut and lung CF pathogenesis and for the practical development of CF therapeutics.

Intestinal Dysbiosis in Young Cystic Fibrosis Rabbits

“…Intestinal obstruction is the primary cause of mortality in CF rabbits [ 12 ], as exampled in Figure 2 . The proximal colon of CF rabbits is often dilated, and the distal colon presents a paucity of stool pellets ( Figure 2 A), which are not observed in WT animals ( Figure 2 B).…”

“…On the other hand, compared to the mouse model, CF rabbits are large, making many experimental procedures more practical. Importantly, rabbit airway epithelial cells responded to CFTR modulator drug VX770 in a similar manner as human airway epithelial cells do, supporting the use of these animals in preclinical studies for CF [ 12 ].…”

“…Heterozygous CFTR∆9/WT (HT CF) rabbits were produced as described previously [ 12 ]. Male and female HT CF rabbits were bred to produce homozygous CFTR∆9/∆9, and WT rabbits were used in the present study.…”

“…We recently produced CF rabbits by knocking out the CFTR gene using CRISPR/Cas9 [ 12 ]. These CF rabbits manifest many typical CF pathologies, including growth retardation, airway inflammation, and metabolic disorders, among others.…”

Gene Editing in Rabbits: Unique Opportunities for Translational Biomedical Research

“…In 2020, Xu et al (2020) reported the production of CF rabbit models by CRISPR/Cas9. CF rabbits manifest many typical disease phenotypes, including and beyond those observed in CF mice.…”