ABSTRACT
Mucosal inductive sites include the nasopharyngeal-associated lymphoid tissues and Peyer's patches in the gut-associated lymphoreticular tissues (GALTs) for the initiation of mucosal secretory Immunoglobulin A (SIgA) antibody (Ab) responses. This chapter focuses on the nasal-oral immune system in the induction of antigen (Ag)-specific SIgA Ab responses in the nasal and oral cavities, the portals of Ag entry into the aerodigestive tract. Mammals have evolved a complex immune system consisting of an integrated network of tissues, lymphoid and mucous membrane-associated cells, and effector Ab molecules that serve to maintain homeostasis in exposed mucosal surfaces. In the mouse, isolated lymphoid follicles in the small intestine are thought to be part of the GALT for the induction of mucosal immune responses. Nasal immunization with a trivalent influenza vaccine given with B subunit of CT containing a trace amount of native cholera toxin results in the induction of cross-protective SIgA antibodies against a broad range of viruses.
