Mucosal Remodeling in Chronic Rhinosinusitis with Nasal Polyps: The Role of Innate Lymphoid Cells and Reprogramming Under IL-4Rα Blockade

The nasal mucosa functions as a highly specialized barrier that integrates epithelial, stromal, neuronal, and immune signals to maintain homeostasis and mount rapid responses to environmental challenges. Among its resident immune populations, innate lymphoid cells-particularly type 2 ILCs (ILC2s)-play a pivotal role in orchestrating type 2 inflammation driven by epithelial-derived alarmins such as IL-25, IL-33, and TSLP. Upon activation, ILC2s release IL-5 and IL-13, promoting eosinophilic inflammation, goblet cell hyperplasia, mucus hypersecretion, and tissue remodeling, all central features of chronic rhinosinusitis with nasal polyps (CRSwNP) and severe allergic rhinitis. Recent advances have revealed substantial ILC plasticity, the presence of nasal-resident ILC progenitors, and the influence of metabolic and neuroimmune cues in shaping ILC activation and persistence. Dupilumab, a monoclonal antibody targeting IL-4Rα, has emerged as a highly effective therapy, providing unique mechanistic insight into the epithelial-ILC axis. By blocking IL-4/IL-13 signaling, dupilumab dampens ILC2 effector functions, reduces IL-5/IL-13 output, restores epithelial barrier integrity, interrupts alarmin-driven amplification loops, and rebalances innate and adaptive immune networks. Clinical and translational studies indicate that baseline ILC2 phenotypes-particularly inflammatory ILC2 subsets-may predict treatment responsiveness, positioning ILC profiling as a promising biomarker strategy. This review synthesizes current knowledge of ILC classification, plasticity, progenitor biology, and epithelial-ILC communication in the nasal mucosa, while integrating emerging evidence on dupilumab-mediated immunomodulation. Collectively, these insights highlight ILCs as central drivers of type 2 inflammation and key targets for precision immunomodulation, offering a framework for personalized treatment approaches in CRSwNP and allergic rhinitis.