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Differential up‐regulation of neurotrophin receptors and functional activity of neurotrophins on peripheral blood eosinophils of patients with allergic rhinitis, atopic dermatitis and nonatopic subjects
Author(s) -
Raap U.,
Deneka N.,
Bruder M.,
Kapp A.,
Wedi B.
Publication year - 2008
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1111/j.1365-2222.2008.03035.x
Subject(s) - neurotrophin , nerve growth factor , tropomyosin receptor kinase a , low affinity nerve growth factor receptor , neurotrophin 3 , immunology , receptor , medicine , trk receptor , brain derived neurotrophic factor , tropomyosin receptor kinase b , neurotrophic factors , endocrinology
Summary Background Recent studies suggest that neurotrophins have a pivotal role in neuroimmune interactions. Indeed, in contrast to nonatopic subjects (NA), neurotrophins have been shown to be increased in atopic diseases such as allergic rhinitis (AR) and atopic dermatitis (AD). Aim The aim of the study was to assess the functional role of nerve growth factor (NGF), brain‐derived neurotrophic factor (BDNF), neurotrophin (NT)‐3 and ‐4 and the expression of pan‐neurotrophin receptor (p75 NTR ) and tyrosine kinase (trk)A, ‐B and ‐C on peripheral blood eosinophils in AR, AD and NA. Methods Peripheral blood eosinophils of patients with AR, AD and NA were purified by CD16 negative selection (purity>98%). Neurotrophin receptor expression was analysed by FACS analysis. Apoptosis test (FACS analysis) and chemotactic index (modified Boyden chamber assay) were assessed after stimulation with BDNF, NT‐3/‐4 and NGF. Results The expression of trkA‐C and p75 NTR was significantly higher in AD>AR>NA ( P <0.05–0.001). Apoptosis was significantly inhibited by BDNF, NGF, NT‐3 in AD ( P <0.05–0.001), by NT‐3/‐4 and NGF in AR ( P <0.05–0.01) and by NT‐3 ( P <0.05–0.01) in NA eosinophils. Chemotaxis was significantly induced by BDNF and NT‐3/4 ( P <0.01–0.001) in AD peripheral blood eosinophils. Conclusion Neurotrophin receptor expression and neurotrophin functional activity was greatest in AD>AR>NA. AD eosinophils are pre‐activated and may therefore better respond to neurotrophins. With this study, we provide new pathophysiologic insights into atopic diseases with a functional role of neurotrophins in peripheral blood eosinophils in AD and AR.