Dual-locus CRISPR strategy improves CFTR gene replacement efficiency in pig genome
A preprint from Cold Spring Harbor Laboratory describes a helper-dependent adenoviral vector approach targeting two genomic loci to overcome low homology-directed repair rates in CFTR replacement.
Researchers at Cold Spring Harbor Laboratory have posted a preprint to bioRxiv describing a dual-locus targeting strategy intended to improve the efficiency of CRISPR/Cas9-mediated replacement of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in the porcine genome.
Cystic fibrosis (CF) arises from loss-of-function variants in the CFTR gene and affects epithelial tissues throughout the body, with lung disease driving most clinical burden. Gene replacement — inserting a functional copy of CFTR after CRISPR-generated double-strand breaks — has been explored as a potential universal strategy, but progress has been constrained by the low frequency of homology-directed repair (HDR) relative to competing, error-prone repair pathways. The preprint reports that targeting two distinct genomic loci simultaneously, delivered via a helper-dependent adenoviral (HDAd) vector, raised integration efficiency compared with single-locus approaches in porcine cells.
The authors use the pig as a model because swine airways share physiological features with human lungs that make them a more relevant pre-clinical system than rodent models for CF research. The work remains at a pre-clinical, proof-of-concept stage; no data in human cells or animals with CF-causing variants are presented in the lede. As a preprint, the findings have not yet undergone peer review.
The study adds to a body of research exploring how delivery vehicle design and locus selection interact to determine HDR yield in large-genome organisms — a key variable for any future somatic gene-replacement programme.
Plain-language version
For patients, families, and general readers. Educational only — not medical advice.
Cystic fibrosis (CF) is a hereditary condition caused by faults in a gene called CFTR. Scientists have long hoped that gene replacement — putting a working copy of the CFTR gene into cells — could one day be a treatment. However, this has proved technically very difficult because the molecular machinery cells use to insert new DNA accurately does not work very often.
Researchers have now posted a study — not yet checked by independent scientific reviewers — describing a way of targeting two places in the genome at once, using a specially designed delivery vehicle, to improve how often the correct gene gets inserted. The experiments were carried out in pig cells, which are used in research because pig airways are similar in some ways to human airways.
This is early laboratory research, and it does not directly change what is available for people with CF today. Researchers say it may help refine the tools needed for future gene replacement approaches.
This is an educational summary, not medical advice. If anything here raises questions for you, please speak with your GP or a clinical professional.
Sources
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Primary sourcePreprint bioRxiv (Cold Spring Harbor Laboratory) · 2026-06-11A Dual-Locus-Targeting Strategy to Enhance CRISPR/Cas9-mediated CFTR Replacement via Helper-Dependent Adenoviral vector in porcine genome