Defining a role for ambient TLR ligand exposures in the genesis and prevention of allergic diseases

• Published in: Seminars in immunopathology Vol. 30; no. 1; pp. 53 - 62
• Main Authors: Tse, Kevin, Horner, Anthony A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.02.2008; Springer Nature B.V
• Subjects: Allergens; Allergens - immunology; Allergies; Animals; Asthma; Biomedical and Life Sciences; Biomedicine; Dendritic Cells - immunology; Dermatitis, Atopic - immunology; Disease; Dust - immunology; Endotoxins - analysis; Endotoxins - immunology; Environmental Exposure; Farms; Humans; Hypersensitivity - immunology; Hypersensitivity - metabolism; Hypersensitivity - prevention & control; Hypotheses; Immunology; Internal Medicine; Ligands; Livestock; Meta-analysis; Pets; Review; Rhinitis; Toll-Like Receptors - immunology; Toll-Like Receptors - metabolism; Allergy; Environment; Endotoxin; Hygiene Hypothesis; Toll-like receptor
• ISSN: 1863-2297; 1863-2300
• DOI: 10.1007/s00281-007-0098-8

Environmental variables responsible for the increasing allergic disease burden observed in developed countries over the last century have yet to be adequately characterized. Meta-analyses of epidemiological studies presented in the first half of this paper demonstrate a correlation between farm-associated exposures (i.e., livestock, pets, unpasteurized milk, and endotoxin) and a reduction in allergic risk during childhood. Laboratory investigations discussed in the second half of the paper characterize the intrinsic immunostimulatory activities of living environments. Considered together, experimental findings presented herein suggest a novel paradigm by which early life home exposures to microbial products and other allergen-nonspecific immunostimulants modify allergic risk.