NASAL-MUCOSA - IMMUNOLOGICAL MECHANISMS O F DEFENSE

The repiratory tract is a complex anatomical entity including the nasa l cavities and the oropharyngeal junction. This area is protected by n on-specific biochemical, epithelial and cellular mechanisms as well as by specific immunoglobulins and immunocompetent cells. The nasal muco sa belongs to the common mucosal immune system, because of its morphol ogical and functional characteristics, by the predominance of secretor y IgA production and through the homing mechanisms used by cells colon izing this anatomical area. The Waldeyer ring is equivalent to the NAL T (Nasal Associated Lymphoid tissue) recently described in rats. It ap pears more and more likely that the nasal mucosa contributes to the in formation of the mucosal immune system, by its histological structure and cellular interactions.