A Toll-like receptor 2/6 agonist reduces allergic airway inflammation in chronic respiratory sensitisation to Timothy grass pollen antigens

B Fuchs, S Knothe, S Rochlitzer, M Nassimi… - International archives of …, 2010 - karger.com
B Fuchs, S Knothe, S Rochlitzer, M Nassimi, M Greweling, HD Lauenstein, C Nassenstein…
International archives of allergy and immunology, 2010karger.com
Background: The hygiene hypothesis negatively correlates the microbial burden of the
environment with the prevalence of T helper type 2 (Th2)-related disorders, eg allergy and
asthma. This is explained by Th1 triggering through pathogen-associated molecular patterns
via Toll-like receptors (TLRs). In this study, the biological effects of a TLR2/6 agonist as a
potential treatment of allergic inflammation are explored. Methods: In a model of chronic
allergic airway inflammation induced by intranasal administration of Timothy grass pollen …
Background
The hygiene hypothesis negatively correlates the microbial burden of the environment with the prevalence of T helper type 2 (Th2)-related disorders, eg allergy and asthma. This is explained by Th1 triggering through pathogen-associated molecular patterns via Toll-like receptors (TLRs). In this study, the biological effects of a TLR2/6 agonist as a potential treatment of allergic inflammation are explored.
Methods
In a model of chronic allergic airway inflammation induced by intranasal administration of Timothy grass pollen allergen extract, early TLR agonism and/or interferon (IFN)-γ administration was compared to the therapeutic and immune-modulating effects of dexamethasone with regard to the cellular inflammation and cytokine profiles.
Results
Eosinophilic inflammation was clearly reduced by TLR2/6 agonism. This effect was also seen without simultaneous administration of IFN-γ. However, lymphocyte counts were not affected among the different treatment groups. More precise determination of the lymphocyte-mediated immune reaction showed that TLR2/6 agonism induced neither CD4+ foxp3+ regulatory T cells in draining lymph nodes nor a pronounced Th1 immune response. In contrast, dexamethasone reduced both sensitisation as well as allergic inflammation and, in addition, CD11c+ antigen-presenting cells in lymph nodes. Our data clearly point to the potential to rebalance Th2-skewed allergic immune responses by therapeutic TLR2/6 agonist administration.
Conclusion
The use of the TLR2/6 agonist is a promising therapeutic approach in diseases with an imbalance in T cell responses, such as allergy and asthma.
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