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Induction of the cyclic nucleotide phosphodiesterase PDE4B is essential for LPS-activated TNF-alpha responses.


Lipopolysaccharide (LPS) stimulation of the innate immune response requires the activation of signaling cascades that culminate in the synthesis and secretion of proinflammatory cytokines. Given the inhibitory effects of phosphodiesterase (PDE) inhibitors on LPS-induced cytokine production, we have investigated LPS responses in mice deficient in PDE4 (type 4 cAMP-specific PDE)-B and PDE4D. LPS stimulation of mouse peripheral leukocytes induced PDE4B mRNA accumulation and increased PDE4 activity. This response was completely absent in mice deficient in PDE4B but not PDE4D. LPS induction of tumor necrosis factor-alpha secretion by circulating leukocytes was decreased by approximately 90% in mice deficient in PDE4B but not in mice lacking PDE4D. The impaired LPS response was evident regardless of the LPS dose used for stimulation and was associated with a more than 90% decrease in tumor necrosis factor-alpha mRNA accumulation. A decreased responsiveness to LPS was also present in other inflammatory cells, including peritoneal and lung macrophages. These findings demonstrate that PDE4B gene activation by LPS constitutes a feedback regulation essential for an efficient immune response.

Pubmed ID: 12032334


  • Jin SL
  • Conti M


Proceedings of the National Academy of Sciences of the United States of America

Publication Data

May 28, 2002

Associated Grants

  • Agency: NICHD NIH HHS, Id: HD20788

Mesh Terms

  • 3',5'-Cyclic-AMP Phosphodiesterases
  • Animals
  • Bronchoalveolar Lavage Fluid
  • Cell Line
  • Cells, Cultured
  • Cyclic Nucleotide Phosphodiesterases, Type 3
  • Cyclic Nucleotide Phosphodiesterases, Type 4
  • Gene Expression Regulation, Enzymologic
  • Genetic Vectors
  • Genomic Library
  • Humans
  • Interleukin-6
  • Leukocytes
  • Lipopolysaccharides
  • Macrophages, Peritoneal
  • Mice
  • Restriction Mapping
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription, Genetic
  • Transcriptional Activation
  • Tumor Necrosis Factor-alpha