Comparative Phylogeny of the Nasopharynx-Associated Lymphoid Tissue
Mucosal surfaces are the main points of contact between animal bodies and the external environment. The olfactory system of vertebrates is one of the most ancient and conserved sensory systems and is responsible for the rapid detection of chemical stimuli. Apart from chemosensory functions, olfactory systems have evolved to defend animal hosts from invading pathogens. Although we know very little about the biological principles that govern nasal immune responses in nonmammalian vertebrates, our knowledge has increased over the past few years. This chapter reviews the phylogeny of olfactory systems and their associated lymphoid tissue, the nasopharynx-associated lymphoid tissue, and highlights how nasal vaccination studies have illuminated some of the immunological aspects of nasal immune systems from teleost fish to mammals.