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Tumour necrosis factor‐ α ‐induced expression of intercellular adhesion molecule‐1 on human eosinophilic leukaemia EoL‐1 cells is mediated by the activation of nuclear factor‐ κ B pathway
Author(s) -
Ip W. K.,
Wong C. K.,
Lam C. W. K.
Publication year - 2003
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 - 10.1046/j.1365-2222.2003.01585.x
Subject(s) - microbiology and biotechnology , tumor necrosis factor alpha , cell adhesion molecule , biology , intercellular adhesion molecule 1 , mapk/erk pathway , iκbα , icam 1 , signal transduction , cancer research , nf κb , immunology
Summary Background Intercellular adhesion molecule‐1 (ICAM‐1) has been shown to mediate the adhesion and migration of eosinophils to the site of allergic inflammation. However, molecular mechanisms regulating the expression of ICAM‐1 in eosinophils are still being elucidated. We investigated the effect of tumour necrosis factor‐alpha (TNF‐α) on ICAM‐1 expression of eosinophils. Methods The surface expression of ICAM‐1 on a human eosinophilic leukaemic cell line, EoL‐1, was assessed by immunocytochemical staining. The phosphorylation of inhibitor kappa B‐alpha (IκB‐α) and p38 mitogen‐activated protein kinase (MAPK) was detected by Western blot. Nuclear factor kappa‐B (NF‐κB) pathway‐related genes were evaluated by the cDNA expression array system, whereas the activity of NF‐κB was measured by electrophoretic mobility shift assay (EMSA). Results TNF‐α was found to induce the cell surface expression of ICAM‐1. A specific proteasome inhibitor N‐cbz‐Leu‐Leu‐leucinal (MG‐132), but not a p38 MAPK inhibitor (SB 203580), was found to suppress the TNF‐α‐induced expression of ICAM‐1 on EoL‐1 cells. The gene expressions of ICAM‐1, NF‐κB and IκBα were up‐regulated after the stimulation with TNF‐α. Further, TNF‐α was shown to induce IκB‐α phosphorylation and degradation, thereby indicating the activation of NF‐κB. In EMSA, there was a shifted NF‐κB band on TNF‐α‐treated cells with or without SB 203580, but no shifted band was observed on MG‐132‐treated cells. Conclusion In vitro studies of EoL‐1 cells, an eosinophilic leukaemic cell line, confirmed that NF‐κB plays an important role in the expression of ICAM‐1 and recruitment of eosinophils in allergic inflammation.