PKCtheta and PKA are antagonistic partners in the NF-AT transactivation pathway of primary mouse CD3+ T lymphocytes

Blood. 2006 Jun 15;107(12):4841-8. doi: 10.1182/blood-2005-10-4044. Epub 2006 Mar 2.


We here investigate the crosstalk of PKC and PKA signaling during primary CD3(+) T-lymphocyte activation using pharmacologic inhibitors and activators in combination with our established panel of PKC isotype-deficient mouse T cells in vitro. PKCtheta and PKA inversely affect the CD3/CD28-induced IL-2 expression, whereas other PKC isotypes are dispensable in this signaling pathway. Gene ablation of PKCtheta selectively results in a profound reduction of IL-2 production; however, complete abrogation of IL-2 production in these PKCtheta(-/-) T cells was achieved only by simultaneous coactivation of the cAMP/PKA pathway in CD3(+) T cells. Conversely, the reduced IL-2 production in PKC inhibitor-treated T cells can be rescued by inhibition of the cAMP/PKA pathway in wild-type but not in PKCtheta(-/-) T cells. Mechanistically, the cAMP/PKA and PKCtheta pathways converge at the level of NF-AT, as shown by DNA binding analysis. The combined increase in PKA and decrease in PKCtheta activity leads to an enhanced inhibition of nuclear NF-AT translocation. This PKCtheta/PKA crosstalk significantly affects neither the NF-kappaB, the AP-1, nor the CREB pathways. Taken together, this opposite effect between the positive PKCtheta and the negative cAMP/PKA signaling pathways appears rate limiting for NF-AT transactivation and IL-2 secretion responses of CD3(+) T lymphocytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Active Transport, Cell Nucleus / drug effects
  • Active Transport, Cell Nucleus / genetics
  • Active Transport, Cell Nucleus / immunology
  • Animals
  • CD28 Antigens / immunology
  • CD3 Complex / immunology*
  • CREB-Binding Protein / immunology
  • Cell Nucleus / immunology
  • Cells, Cultured
  • Cyclic AMP / immunology
  • Cyclic AMP-Dependent Protein Kinases
  • Gene Deletion
  • Interleukin-2 / immunology
  • Lymphocyte Activation / drug effects
  • Lymphocyte Activation / genetics
  • Lymphocyte Activation / immunology
  • Mice
  • NF-kappa B / immunology
  • NFATC Transcription Factors / immunology*
  • Protein Kinase C / antagonists & inhibitors
  • Protein Kinase C / deficiency
  • Protein Kinase C / immunology*
  • Protein Kinase Inhibitors / pharmacology
  • Protein-Serine-Threonine Kinases / antagonists & inhibitors
  • Protein-Serine-Threonine Kinases / immunology*
  • Signal Transduction / drug effects
  • Signal Transduction / genetics
  • Signal Transduction / immunology*
  • T-Lymphocytes / cytology
  • T-Lymphocytes / immunology*
  • Transcription Factor AP-1 / immunology


  • CD28 Antigens
  • CD3 Complex
  • Interleukin-2
  • NF-kappa B
  • NFATC Transcription Factors
  • Protein Kinase Inhibitors
  • Transcription Factor AP-1
  • Cyclic AMP
  • CREB-Binding Protein
  • Crebbp protein, mouse
  • Protein-Serine-Threonine Kinases
  • Cyclic AMP-Dependent Protein Kinases
  • Protein Kinase C