CD73 on cancer-associated fibroblasts enhanced by the A2B-mediated feedforward circuit enforces an immune checkpoint

Nat Commun. 2020 Jan 24;11(1):515. doi: 10.1038/s41467-019-14060-x.

Abstract

CD73, an ecto-5'-nucleotidase (NT5E), serves as an immune checkpoint by generating adenosine (ADO), which suppresses immune activation through the A2A receptor. Elevated CD73 levels in tumor tissues correlate with poor clinical outcomes. However, the crucial source of CD73 activity within the tumor microenvironment remains unspecified. Here, we demonstrate that cancer-associated fibroblasts (CAFs) constitute the prominent CD73hi population in human colorectal cancers (CRCs) and two CD73- murine tumor models, including a modified CRC. Clinically, high CAF abundancy in CRC tissues correlates strongly with elevated CD73 activity and poor prognosis. Mechanistically, CAF-CD73 expression is enhanced via an ADO-A2B receptor-mediated feedforward circuit triggered by tumor cell death, which enforces the CD73-checkpoint. Simultaneous inhibition of A2A and A2B pathways with CD73-neutralization synergistically enhances antitumor immunity in CAF-rich tumors. Therefore, the strategic and effective targeting of both the A2B-mediated ADO-CAF-CD73 feedforward circuit and A2A-mediated immune suppression is crucial for improving therapeutic outcomes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5'-Nucleotidase / metabolism*
  • Adenosine / metabolism
  • Adenosine A2 Receptor Antagonists / pharmacology
  • Animals
  • Cancer-Associated Fibroblasts / drug effects
  • Cancer-Associated Fibroblasts / metabolism*
  • Cancer-Associated Fibroblasts / pathology
  • Cell Line, Tumor
  • Colorectal Neoplasms / immunology*
  • Colorectal Neoplasms / metabolism
  • Colorectal Neoplasms / pathology*
  • Disease Progression
  • Drug Synergism
  • Hematopoietic Stem Cells / metabolism
  • Humans
  • Lymphocytes, Tumor-Infiltrating / metabolism
  • Mice, Inbred C57BL
  • Models, Biological
  • Neutralization Tests
  • Receptor, Adenosine A2B / metabolism*
  • Transcriptome / genetics
  • Treatment Outcome
  • Tumor Microenvironment
  • Up-Regulation

Substances

  • Adenosine A2 Receptor Antagonists
  • Receptor, Adenosine A2B
  • 5'-Nucleotidase
  • Adenosine