Abstract
The nasopharyngeal mucosa is the first line of defense of the upper respiratory tract (URT), protecting it from invading foreign antigens. It is well known that the mucosal lining of the URT is equipped with non-specific and specific defense mechanisms. Thanks to new advanced molecular biology techniques, the nasopharyngeal mucosa has become to the focus of investigations on local immune response, in order to use it clinically in vaccination therapy against microbial infections or in hyposensitization therapy for nasal allergies. Therefore, it is very important for otolaryngologists to have a better understanding of the mechanism of mucosal immunity in the nasopharynx, because so many kinds of upper respiratory infections and also allergic inflammation, have to be treated by ideal therapeutic strategies.