title: Innate immunity in allergic disease.
abstract: The innate immune system consists of multiple cell types that express germline-encoded pattern recognition receptors that recognize pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs). Allergens are frequently found in forms and mixtures that contain PAMPs and DAMPs. The innate immune system is interposed between the external environment and the internal acquired immune system. It is also an integral part of the airways, gut, and skin. These tissues face continuous exposure to allergens, PAMPs, and DAMPs. Interaction of allergens with the innate immune system normally results in immune tolerance but, in the case of allergic disease, this interaction induces recurring and/or chronic inflammation as well as the loss of immunologic tolerance. Upon activation by allergens, the innate immune response commits the acquired immune response to a variety of outcomes mediated by distinct T-cell subsets, such as T-helper 2, regulatory T, or T-helper 17 cells. New studies highlighted in this review underscore the close relationship between allergens, the innate immune system, and the acquired immune system that promotes homeostasis versus allergic disease.
authors.affiliation: Asthma, Allergy and Inflammation Branch, Division of Allergy, Immunology, and Transplantation, Department of Health and Human Services, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-6601, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Minnicozzi
authors.forename: Richard T
authors.initials: RT
authors.lastname: Sawyer
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Fenton
mesh_terms: D056704:Adaptive Immunity; D000328:Adult; D000485:Allergens / Q000276:immunology*; D000818:Animals; D002648:Child; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D004847:Epithelial Cells / Q000276:immunology / Q000378:metabolism; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology* / Q000503:physiopathology; D007108:Immune Tolerance; D007113:Immunity, Innate; D007223:Infant; D007249:Inflammation / Q000276:immunology; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D051379:Mice; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism; D051192:Receptors, Pattern Recognition / Q000276:immunology* / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism; D058504:Th17 Cells / Q000276:immunology / Q000378:metabolism; D018418:Th2 Cells / Q000276:immunology / Q000378:metabolism
chemical_list: D000485:Allergens; D051192:Receptors, Pattern Recognition