Macrophage

Abstract

There are various immunocompetent cells including the so-called macrophages in human nasal mucosa. Those cells are essential for a defense system against various invading pathogens such as bacteria and virus. On the other hand, those cells are also key players in the pathogenesis of rhinosinusitis and allergic rhinitis at the epithelial linings of nasal cavity and paranasal sinuses. Among them, macrophages are well known to have immunologically an important role as a scavenger cell and antigen-presenting cells (APCs), in order to mount innate and acquired immunity in the upper and lower respiratory tract (Kaneda et al., Auris Nasus Larynx 18:331-342, 1991;Yamada et al., Rhinology 43:190-198, 2005). In this chapter, general concept of macrophage lineage cells and its function are introduced, and the exact role of those cells in the pathogenesis of rhinosinusitis and allergic rhinitis can be discussed in accordance with previously published data and our unpublished data as well.