Role of activator protein 1, nuclear factor-kappaB, and nuclear factor of activated T cells in IgE receptor-mediated cytokine expression in mature human mast cells.
BACKGROUND
On activation by cross-linking the high-affinity IgE receptor (FcepsilonRI), expression of TNF-alpha, IL-3, IL-5, and IL-13 is induced in human intestinal mast cells.


OBJECTIVE
We sought to examine, for the first time, FcepsilonRI signaling in mature human mast cells.


METHODS
Mast cells were isolated from intestinal tissue and cultured in the presence of stem cell factor. The cells were treated with specific inhibitors before stimulation by means of FcepsilonRI cross-linking. Cytokine mRNA expression was analyzed by means of RT-PCR, and activation of signaling molecules was determined by means of immunocytochemistry, RT-PCR, Western blotting, and protein kinase C (PKC) assay.


RESULTS
We found that nuclear factor-kappaB (NF-kappaB), as well as c-Fos and c-Jun, the components of activator protein 1 (AP-1), are activated after FcepsilonRI cross-linking in human intestinal mast cells. Treatment of the cells with specific inhibitors revealed an involvement of NF-kappaB and nuclear factor of activated T cells, as well as the necessity of extracellular signal-regulated kinase 1/2 (ERK-1/2), PKC, and AP-1 for the induced cytokine gene expression. Consistently, we found that activation of c-Fos corresponds with the induced cytokine gene expression and that ERK-1/2, an activator of c-Fos, was activated in response to FcepsilonRI cross-linking.


CONCLUSIONS
Our data on human mast cells show that the activity of ERK-1/2, PKC, and subsequent activation of AP-1 are necessary for the FcepsilonRI-mediated cytokine expression. Nuclear factor of activated T cells and NF-kappaB seem to be necessary for the induction of TNF-alpha, IL-3, and IL-13 but are less important for the transcription of IL-5.
Department of Gastroenterology, Hepatology, and Endocrinology, Medical School of Hannover, Hannover, Germany.
Axel
A
Lorentz
Ilka
I
Klopp
Thomas
T
Gebhardt
Michael P
MP
Manns
Stephan C
SC
Bischoff
D016207:Cytokines / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000502:physiology*; D016762:Genes, fos; D016758:Genes, jun; D006801:Humans; D018793:Interleukin-13 / Q000235:genetics; D007377:Interleukin-3 / Q000235:genetics; D015848:Interleukin-5 / Q000235:genetics; D008407:Mast Cells / Q000276:immunology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000502:physiology*; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D011493:Protein Kinase C / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis; D017455:Receptors, IgE / Q000502:physiology*; D015398:Signal Transduction; D018808:Transcription Factor AP-1 / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
D016207:Cytokines; D004268:DNA-Binding Proteins; D018793:Interleukin-13; D007377:Interleukin-3; D015848:Interleukin-5; D016328:NF-kappa B; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D012333:RNA, Messenger; D017455:Receptors, IgE; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D011493:Protein Kinase C; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases