Nasal epithelial cell membranes and associated mucosal immune cells

The nasal epithelial cell membranes and associated mucosal immune cells represent a complex biological system rather than a single molecular target. This system serves as the primary physical and immunological barrier of the upper respiratory tract, utilizing a combination of tight junctions, mucociliary clearance, and specialized immune structures like nasopharyngeal-associated lymphoid tissue (NALT) to defend against inhaled pathogens and allergens (StatPearls, Anatomy, Nasal Mucosa). The nasal epithelium is a major site for viral entry, particularly for respiratory viruses such as SARS-CoV-2 and influenza, which exploit receptors like ACE2 expressed on these cell membranes (Nature Medicine, 2020). Pharmacologically, this system is targeted for the localized delivery of corticosteroids, antihistamines, and decongestants to treat allergic rhinitis and sinusitis. Furthermore, it is an active area of research for mucosal vaccines, which aim to induce a robust secretory IgA response directly at the site of pathogen entry. Because this 'target' encompasses various cell types—including ciliated cells, goblet cells, and dendritic cells—it is considered a tissue-level therapeutic site rather than a specific protein or enzyme. Understanding its cellular composition and receptor density is critical for optimizing intranasal drug delivery and systemic bioavailability of nasally administered therapeutics.

Other names

Nasal mucosaNasopharyngeal-associated lymphoid tissue (NALT)Schneiderian membraneNasal epitheliumNasal airway surface

Drugs targeting this system typically act by modulating local inflammatory cytokine production, stabilizing mast cells, inducing vasoconstriction of mucosal blood vessels, or stimulating local production of secretory IgA to provide mucosal immunity.