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Inflammation Research

, Volume 47, Issue 12, pp 493–500 | Cite as

Specific signaling pathways in the regulation of TNF-α mRNA synthesis and TNF-α secretion in RBL-2H3 mast cells stimulated through the high affinity IgE receptor

  • C. Pelletier
  • C. Guérin-Marchand
  • B. Iannascoli
  • F. Marchand
  • B. David
  • A. Weyer
  • U. Blank

Abstract.

Objective: In the present study, we investigated signal transduction pathways involved in TNF-α gene expression and TNF-α secretion by mast cells stimulated through the high affinity IgE receptor (FcɛRI).¶Materials and Methods: TNF-α mRNA steady state levels and TNF-α secretion in the presence of specific pharmacological agents were monitored using rat basophilic leukemia cells (RBL-2H3) stimulated through FcɛRI. Relative amounts of TNF-α mRNA versus β-actin levels were quantified by RNase protection and RT-PCR assays. TNF-α secretion was measured by a current ELISA test.¶Results: We show that EGTA (5 mM) prevented TNF-α mRNA expression and TNF-α secretion in antigen-stimulated cells. The protein kinase C (PKC) inhibitor bisindolylmaleimide I substantially blocked TNF-α secretion at 2 μM but had only a marginal effect on TNF-α mRNA expression. The results were similar when PKC isoforms were depleted by long-term exposure to 100 nM phorbol ester (PMA). The PI 3-kinase inhibitor wortmannin blocked TNF-α secretion at low doses (EC50 = 13 nM), but only partially affected mRNA expression.¶Conclusions: Our results show that in FcɛRI-stimulated RBL-2H3 cells calcium mobilization, activation of PKC and PI 3-kinase are necessary for TNF-α secretion while for the increased TNF-α mRNA expression PKC activity is dispensable and PI 3-kinase activity only partially required.

Key words: Mast cells — Fc receptors — TNF-α— Gene regulation — RBL 

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Copyright information

© Birkhäuser Verlag, Basel, 1998

Authors and Affiliations

  • C. Pelletier
    • 1
  • C. Guérin-Marchand
    • 1
  • B. Iannascoli
    • 1
  • F. Marchand
    • 1
  • B. David
    • 1
  • A. Weyer
    • 1
  • U. Blank
    • 1
  1. 1.Institut Pasteur, Unité d'Immuno-Allergie, 25-28 rue du Dr. Roux, F-75724 Paris Cedex 15, France, Fax +33 1 40 61 33 83, e-mail: ublank@pasteur.frFR

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