Extracellular purine metabolism and signaling of CD73-derived adenosine in murine Treg and Teff cells

Am J Physiol Cell Physiol. 2011 Aug;301(2):C530-9. doi: 10.1152/ajpcell.00385.2010. Epub 2011 May 18.


CD73-derived adenosine acts as potent inhibitor of inflammation, and regulatory T cells (Treg) have been shown to express CD73 as a novel marker. This study explored the role of endogenously formed adenosine in modulating NF-κB activity and cytokine/chemokine release from murine Treg and effector T cells (Teff) including key enzymes/purinergic receptors of extracellular ATP catabolism. Stimulating murine splenocytes and CD4(+) T cells with anti-CD3/anti-CD28 significantly upregulated activated NF-κB in CD73(-/-) T cells (wild type: 4.36 ± 0.21; CD73(-/-): 6.58 ± 0.75; n = 4; P = 0.029). This was associated with an augmented release of proinflammatory cytokines IL-2, TNF-α, and IFN-γ. Similar changes were observed with the CD73 inhibitor APCP (50 μM) on NF-κB and IFN-γ in wild-type CD4(+) T-cells. Treatment of stimulated CD4(+) T-cells with adenosine (25 μM) potently reduced IFN-γ release which is mediated by adenosine A2a receptors (A2aR). AMP (50 μM) also reduced cytokine release which was not inhibited by APCP. In Teff, A2aR activation (CGS21680) potently inhibited the release of IL-1, IL-2, IL-3, IL-4, IL-12, IL-13, IFN-γ, TNF-α, granulocyte-macrophage colony-stimulating factor (GM-CSF), CCL3, and CCL4. However, in Treg, CGS21680 did not alter cytokine/chemokine release. In summary, CD73-derived adenosine tonically inhibits active NF-κB in CD4(+) T-cells, thereby modulating the release of a broad spectrum of proinflammatory cytokines and chemokines. Downregulation of P2X7 and upregulation of CD73 in Treg after antigenic stimulation may be an important mechanism to maintain the ability of Treg to generate immunosuppressive adenosine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5'-Nucleotidase / antagonists & inhibitors
  • 5'-Nucleotidase / deficiency
  • 5'-Nucleotidase / genetics
  • 5'-Nucleotidase / metabolism*
  • Adenosine / metabolism*
  • Adenosine A2 Receptor Agonists / pharmacology
  • Animals
  • Cell Proliferation
  • Cells, Cultured
  • Chemokines / metabolism
  • Dose-Response Relationship, Drug
  • Enzyme Inhibitors / pharmacology
  • GPI-Linked Proteins / antagonists & inhibitors
  • GPI-Linked Proteins / deficiency
  • GPI-Linked Proteins / genetics
  • GPI-Linked Proteins / metabolism
  • Immune Tolerance* / drug effects
  • Inflammation Mediators / metabolism
  • Interferon-gamma / metabolism
  • Interleukins / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • NF-kappa B / metabolism
  • Purinergic P1 Receptor Antagonists / pharmacology
  • Receptor, Adenosine A2A / metabolism
  • Signal Transduction* / drug effects
  • T-Lymphocyte Subsets / drug effects
  • T-Lymphocyte Subsets / enzymology*
  • T-Lymphocyte Subsets / immunology
  • T-Lymphocytes, Regulatory / drug effects
  • T-Lymphocytes, Regulatory / enzymology*
  • T-Lymphocytes, Regulatory / immunology
  • Time Factors
  • Tumor Necrosis Factor-alpha / metabolism


  • Adenosine A2 Receptor Agonists
  • Chemokines
  • Enzyme Inhibitors
  • GPI-Linked Proteins
  • Inflammation Mediators
  • Interleukins
  • NF-kappa B
  • Purinergic P1 Receptor Antagonists
  • Receptor, Adenosine A2A
  • Tumor Necrosis Factor-alpha
  • Interferon-gamma
  • 5'-Nucleotidase
  • Nt5e protein, mouse
  • Adenosine