# A universal genome editing strategy to develop an airway stem cell therapy for cystic fibrosis

> **NIH NIH R00** · RESEARCH INST NATIONWIDE CHILDREN'S HOSP · 2024 · $249,000

## Abstract

Project Summary
Cystic fibrosis (CF) is caused by mutations in a single gene called the cystic fibrosis transmembrane conductance
regulator (CFTR), which codes for an ion channel that transports Cl- ions. CF affects many organs but lung failure
caused by repeated respiratory infections is the leading cause of death. When CF was first described, most
patients died as children. Therapeutic interventions that do not restore CFTR function still enabled patients to
survive into adulthood. Recently developed small molecule modulators restore CFTR function modestly and
have been shown to reduce pulmonary exacerbations. However, these therapies are expensive, have side-
effects and cannot treat all CF patients. As a monogenic disease, CF has been the target of several in vivo gene
therapy studies that aimed to restore CFTR function. However, these studies were unsuccessful due to
challenges in delivery and immunity mediated against viral vectors. Ex-vivo gene therapy in which corrected
airway stem cells are transplanted into patients have been proposed. However, these are limited by our failure
to efficiently correct CFTR mutations in a readily accessible airway stem cell type. W e have identified the sinuses
as a readily accessible source of sinus basal stem cells and optimized the use of Cas9 and adeno-associated
virus (AAV) to gene edit these basal stem cells. We have corrected the most common CFTR mutation (F508del
mutation) in >40% alleles. However, several other mutations which cannot be treated using current therapies
remain. Moreover, the safety of gene editing using Cas9 and the long-term differentiation potential of edited
sinus basal stem cells to regenerate the sinus and bronchial epithelia need to be characterized. Here, we propose
to use Cas9/AAV to insert the CFTR cDNA with a truncated CD19 (tCD19) enrichment marker at exon 1 of the
endogenous CFTR locus to achieve universal correction of CFTR mutations. We will characterize the safety of
genome editing using next-generation sequencing and the differentiation potential of edited sinus basal stem
cells using single-cell RNA seq and immunohistochemistry. Preliminary results show that we can obtain an
enriched population of tCD19+ sinus basal stem cells after gene editing. These corrected sinus basal stem cells
retain their differentiation potential to produce epithelial sheets that show >90% CFTR function (response to
CFTR inhibitor or activator) relative to wild-type samples in an Ussing chamber electrophysiological assay.
However, further work is needed to determine if the corrected sinus basal stem cells generate all the other airway
cell types. Over the period of this grant, we will further validate the safety and efficacy of this platform and
evaluate the long-term differentiation potential of these cells to generate all the cell types present in both the
sinus and bronchial epithelia. These experiments are an important first step to optimize the autologous
transplantation of edited air...

## Key facts

- **NIH application ID:** 10909248
- **Project number:** 5R00HL151900-05
- **Recipient organization:** RESEARCH INST NATIONWIDE CHILDREN'S HOSP
- **Principal Investigator:** Sriram Vaidyanathan
- **Activity code:** R00 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $249,000
- **Award type:** 5
- **Project period:** 2022-09-01 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10909248

## Citation

> US National Institutes of Health, RePORTER application 10909248, A universal genome editing strategy to develop an airway stem cell therapy for cystic fibrosis (5R00HL151900-05). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10909248. Licensed CC0.

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