Trefoil factor 3 positively associates with IL-25 in patients with Chronic Rhinosinusitis

BackgroundTrefoil factor family cytokines (TFF1-3) have documented reparative and immunoregulatory effects on mucosal epithelial cells that include: blocking apoptosis, directed cell migration, and regulation of pro-inflammatory cytokine production. TFF1 and TFF3 have been shown to undergo altered expression within sinonasal tissues of patients with various forms of chronic rhinosinusitis including those with or wthout polyp associated disease, but the cellular source(s) of TFF members in CRS remains unclear. To further explore the role of TFF3 in inflammatory sinonasal disease, we sought to determine its expression pattern in immune and non-immune cell types in CRS disease. MethodsPolyp and inferior turbinate tissues were isolated from patients undergoing surgical resection for treatment of CRS. Tissue homogenates and single cell suspensions were subjected to enzyme linked immunosorbent assay (ELISA) and single-cell RNA sequencing. Air liquid interface cultures of sinonasal epithelia were subjected to immunofluorescence (IF) microscopy. Interleukin 25, TFF2 and TFF3 protein levels were compared to sinonasal outcome test scores (SNOT-22) to determine whether levels associated with post-operative outcomes. ResultsTFF3 was broadly expressed in goblet cells, ciliated cells, Tuft cells and T lymphocytes. TFF3 protein levels positively associated with IL-25 in CRSwNP patients. Lastly, TFF3 protein levels positively associated with clinical improvement post-surgery. ConclusionsTFF3 is broadly expressed within multiple epithelial and immune cell lineages in patients with CRSwNP. Protein levels of TFF3 correlate with IL-25 and clinical signs of disease, however TFF3 levels associate with clinical improvement following surgical intervention indicating a potential beneficial role for this reparative cytokine in CRS patients.