TLR3 in Human Eosinophils: Functional Effects and Decreased Expression during Allergic Rhinitis.
Författare
Summary, in English
Background/Aim: Viral respiratory infections are increasingly implicated in allergic exacerbations. Virus-induced activation of eosinophils through Toll-like receptors (TLRs) could be involved. The present study was designed to examine TLR3 expression in eosinophils from bone marrow (BM) and peripheral blood (PB) during symptomatic allergic rhinitis, and to evaluate the functional responsiveness of TLR3 in purified eosinophils. Methods: BM and PB samples were obtained from healthy volunteers and patients with seasonal allergic rhinitis outside and during the pollen season. Eosinophils were analyzed for TLR3 expression by flow cytometry. Polyinosinic:polycytidylic acid [poly(I:C)], an agonist for TLR3, was used to assess its functional role in purified eosinophils and the intracellular signaling pathways involved. Results: TLR3 expression was demonstrated in BM and PB eosinophils. It was higher in BM-derived than in circulating cells and it was downregulated in both compartments during symptomatic allergic rhinitis. TLR3 expression was also downregulated in the presence of interleukin (IL)-4 and IL- 5. Stimulation with poly(I:C) increased the percentage of CD11b+ cells and enhanced the secretion of IL-8, effects mediated via the p38 mitogen-activated protein kinases and nuclear factor-kappaB signaling pathways. Moreover, pretreatment with IL-5 augmented the poly(I:C)-induced IL-8 release. Conclusions: Eosinophils activated via TLR3 might be more able to home and recruit leukocytes to sites of inflammation. The decreased TLR3 expression during symptomatic allergic rhinitis and in the presence of Th2 cytokines indicates a role in allergic airway inflammation. Thus, eosinophils might function as a link between viral infections and exacerbations of allergic disease.
Avdelning/ar
- Clinical and Experimental Allergy Research
- Institutionen för kliniska vetenskaper, Malmö
- Klinisk kemi, Malmö
Publiceringsår
2010
Språk
Engelska
Sidor
118-128
Publikation/Tidskrift/Serie
International Archives of Allergy and Immunology
Volym
151
Issue
2
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Karger
Ämne
- Respiratory Medicine and Allergy
Status
Published
Forskningsgrupp
- Clinical and Experimental Allergy Research
- Clinical Chemistry, Malmö
ISBN/ISSN/Övrigt
- ISSN: 1423-0097