Innate immunity in the mucosal immune system.
The mucosal immune system is equipped with unique innate and acquired defense mechanisms which provide a first line of protection against ingested and inhaled infectious agents. Peyer's patches (PPs) and nasopharynx-associated lymphoid tissue (NALT) have been shown to be important inductive sites for the initiation of the acquired phase of antigen-specific immune responses. In addition, the mucosal innate immune system acts as both a physical and an immunological boundary, playing a key role in the sensing and eliminating of pathogens and in the creating of symbiosis. The mucus layer covering the mucosal epithelium acts as a first physical and biochemical barrier. An additional layer of physical protection against microorganisms is provided by a tightly interlaced cell-to-cell network of epithelial cells and intraepithelial lymphocytes. Various antimicrobial peptides produced by the epithelium and secreted into the mucosal lumen can directly kill the invading pathogenic bacteria. Finally, Toll-like receptors (TLRs) associated with the mucosal compartment have been shown to recognize the pathogen-associated molecular patterns (PAMPs) of a variety of pathogenic and commensal microorganisms. Therefore, a greater understanding of the immunological progression from mucosal innate to acquired immune systems should facilitate the development of new generation of mucosal vaccines to prevent and control infectious diseases.
Nochi
Tomonori
T
Division of Mucosal Immunology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, 108-8639, Japan.
Kiyono
Hiroshi
H
D000818:Animals; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology*; D018928:Immunity, Mucosal / Q000276:immunology*; D009092:Mucous Membrane / Q000276:immunology