Detection of CFTR function and modulation in primary human nasal cell spheroids

Abstract

Background Expansion of CFTR modulators to patients with rare/undescribed mutations will be facilitated by patient-derived models quantifying CFTR function and restoration. We aimed to generate a personalized model system of CFTR function and modulation using non-surgically obtained nasal epithelial cells (NECs). Methods NECs obtained by curettage from healthy volunteers and CF patients were expanded and grown in 3-dimensional culture as spheroids, characterized, and stimulated with cAMP-inducing agents to activate CFTR. Spheroid swelling was quantified as a proxy for CFTR function. Results NEC spheroids recapitulated characteristics of pseudostratified respiratory epithelia. When stimulated with forskolin/IBMX, spheroids swelled in the presence of functional CFTR, and shrank in its absence. Spheroid swelling quantified mutant CFTR restoration in F508del homozygous cells using clinically available CFTR modulators. Conclusions NEC spheroids hold promise for understanding rare CFTR mutations and personalized modulator testing to drive evaluation for CF patients with common, rare or undescribed mutations.

Brushed nasal epithelial cells are a surrogate for bronchial epithelial CFTR studies

“…Cell expansion was performed as previously described, with minor modifications (28,34,35). bHNEs and bHBEs were kept separate, with mirrored steps performed for each sample.…”

“…ALI culture. Passaged bHNEs and bHBEs were grown at ALI as previously described (11,28). In brief, passaged cell pellets were suspended in differentiation media (see Table 2) and counted with a hemocytometer.…”

“…Once mature, select inserts were pretreated with VX-809 (3 μM; Selleck Chemicals) for 48 hours prior to study. Inserts were removed from media and rinsed of any pretreatment drugs, then mounted in Ussing chambers (Physiologic Instruments) and studied as previously described (28). All studies were performed in an asymmetric chloride Ringer buffer (see Table 3 for buffer solutions), producing a basolateral-to-apical Clsecretory gradient.…”

“…In search of an easily obtained, noninvasive source of respiratory tissue, investigators have begun to examine brushed human nasal epithelial cells (bHNEs) (27)(28)(29)(30). The nasopharynx harbors a ciliated, pseudostratified respiratory epithelium with many similarities to the bronchial epithelium, making this a feasible model representative of the lower airway.…”

Intestinal organoids for Cystic Fibrosis research

“…In addition, ASC-derived airway organoids are of special interest as CF mortality is mainly a result of pulmonary failure and enable the assessment of airway-specific fluid transport, mucus viscosity and patient-specific drug responses [41] in the context of airway cell environment. Culturing of airway-derived cells in matrigel results in the formation of spheroids that allow for CFTR function measurement in a comparable fashion to intestinal organoids, via FIS [42] . Also the presence of non-CFTR ion channels, like Na + channels and TMEM16a in nasal spheroids [43] and bronchial-derived organoids [44] respectively, shows the potential of using airway organoids for the development of alternative non-CFTR targeting therapies.…”