IL-13-programmed airway tuft cells produce PGE2, which promotes CFTR-dependent mucociliary function

Abstract

Chronic type 2 (T2) inflammatory diseases of the respiratory tract are characterized by mucus overproduction and disordered mucociliary function, which are largely attributed to the effects of IL-13 on common epithelial cell types (mucus secretory and ciliated cells). The role of rare cells in airway T2 inflammation is less clear, though tuft cells have been shown to be critical in the initiation of T2 immunity in the intestine. Using bulk and single cell RNA sequencing of airway epithelium and mouse modeling, we find that IL-13 expands and programs airway tuft cells towards eicosanoid metabolism, and that tuft cell deficiency leads to a reduction in airway prostaglandin E2 (PGE2) concentration. Allergic airway epithelia bear a signature of prostaglandin E2 activation, and PGE2 activation leads to CFTR-dependent ion and fluid secretion and accelerated mucociliary transport. Together these data reveal a role for tuft cells in regulating epithelial mucociliary function in the allergic airway.

IL-13 associated epithelial remodeling correlates with clinical severity in nasal polyposis

“…We discovered that polyp brushings had increased numbers of tuft cells newly expressing eicosanoid synthetic enzymes, and an associated PGE2-induced transcriptional signature across the polyp epithelium. By applying these novel transcriptional signatures to a larger cohort of banked bulk RNA from sinus epithelial brushings from 24 patients with CRSwNP, 7 patients with CRSsNP and 8 healthy control subjects, we determined that these scSeq-derived transcriptional signatures could be effectively applied to bulk RNA samples to confirm and extend our findings in a distinct patient cohort (3). Here we examine additional cell type and stimulation-state transcriptional signatures in those specimens in order to more broadly examine epithelial remodeling in CRS.…”

“…The copyright holder for this preprint this version posted October 7, 2022. ; https://doi.org/10.1101/2022.10.06.22280802 doi: medRxiv preprint and ILC2 cells (30; 31). Its tissue effects include the ability to elicit potent interstitial edema (32; 33) and activate epithelial fluid secretion via CFTR (3), which together may act to impair normal sinus drainage. PGE2 may also stimulate goblet cell development and mucin secretion, further enhancing the effects of IL-13 on goblet cell differentiation (34)(35)(36).…”

“…Subjects between the ages of 18 and 75 years (previously described in (3)) were recruited from the University of California, San Francisco Hospital (San Francisco, California) Otolaryngology clinic between 2013 and 2019 to participate in a UCSF Sinus Tissue Bank. The UCSF Committee on Human Research approved the study, and all subjects provided written informed consent.…”

“…As described in (3), cytologic brushes were placed in RNAlater (Qiagen) until RNA extraction. These were defrosted on ice, diluted with sterile PBS, centrifuged, and brushes were removed and placed into lyse E tube.…”

“…Additionally, existing data on cell type composition changes that might be driven by inflammation are inconsistent. For instance, basal cells have been reported in some publications to be increased in polyps (2), but this finding has not been consistent (3). Moreover, the airway epithelial landscape includes rare and less-understood populations of epithelial cells such as ionocytes, neuroendocrine cells, and tuft cells, which likely modify mucociliary and immune behaviors but have not been well characterized in the setting of airway inflammation.…”