Inflammation Research

, Volume 54, Issue 2, pp 74–81 | Cite as

Dialyzable Leukocyte Extract differentially regulates the production of TNFα, IL-6, and IL-8 in bacterial component-activated leukocytes and endothelial cells

  • Miriam Ojeda OjedaEmail author
  • Cornelis van’t Veer
  • Celia B. Fernández Ortega
  • Manuel de J. Araña Rosainz
  • Wim A. Buurman
Original Research Paper


Objective: To investigate i) whether the Dialyzable Leukocyte Extract (DLE) modulates the production of proinflammatory cytokines in leukocytes activated by the bacterial cell wall components lipopolysaccharide (LPS), lipoteichoic acid (LTA), and peptidoglycan (PGN); ii) the effect of DLE on LPS-stimulated endothelial cells; and iii) whether the regulatory effect of DLE on inflammatory mediators is related to the modulation of Toll-like receptors (TLRs), NF-κB and cAMP signaling pathways.

Methods: Leukocytes were stimulated with LPS, LTA, and PGN in the presence of DLE. Endothelial cells were stimulated with LPS and treated with DLE. The levels of Tumor Necrosis Factor-α(TNFα), Interleukin-6 (IL-6), and IL-8 in culture supernatants were evaluated by ELISA. The expression of Toll-like receptor 2 (TLR2) and 4 (TLR4), NF-κB activity and cAMP levels were evaluated by flow cytometry, EMSA, and EIA, respectively.

Results: The addition of DLE to leukocytes stimulated with cell wall constituents suppressed the production of TNFα. However, DLE induced IL-8 release in monocytes and enhanced IL-6 and IL-8 production by activated monocytes and endothelial cells. Also, DLE induced TLR2 and TLR4 expression, and increased cAMP levels, whereas NF-κB activity was inhibited.

Conclusions: The present data indicate the differential regulation by DLE of the production of TNFα, IL-6, and IL-8 cytokines, associated with effects on TLR2 and TLR4 expression and NF-κB and cAMP activities. We suggest a putative mechanism for the biological effects of DLE in activated leukocytes and endothelial cells.

Key words.

LPS NF-kappaB cAMP inflammation TLR 



Activator protein


cAMP-responsive element-binding protein


Dialyzable Leukocyte Extract


Electrophoretic mobility shift assay


Enzyme-linked immunoabsorbent assays


Human umbilical vein endothelial cells






Lipoteichoic acid


Nuclear factor


Peripheral blood mononuclear cells






Toll-like receptor


Tumor Necrosis Factor


3′,5′-cyclic adenosine monophosphate


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Copyright information

© Birkhäuser Verlag, Basel 2005

Authors and Affiliations

  • Miriam Ojeda Ojeda
    • 1
    Email author
  • Cornelis van’t Veer
    • 2
  • Celia B. Fernández Ortega
    • 1
  • Manuel de J. Araña Rosainz
    • 1
  • Wim A. Buurman
    • 2
  1. 1.Division of Physical ChemistryCenter for Genetic Engineering and Biotechnology (CIGB)HavanaCuba
  2. 2.Department of General SurgeryUniversity of MaastrichtMaastrichtThe Netherlands

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