Catch and Release of Cytokines Mediated by Tumor Phosphatidylserine Converts Transient Exposure into Long-Lived Inflammation

Mol Cell. 2017 Jun 1;66(5):635-647.e7. doi: 10.1016/j.molcel.2017.05.011.

Abstract

Immune cells constantly survey the host for pathogens or tumors and secrete cytokines to alert surrounding cells of these threats. In vivo, activated immune cells secrete cytokines for several hours, yet an acute immune reaction occurs over days. Given these divergent timescales, we addressed how cytokine-responsive cells translate brief cytokine exposure into phenotypic changes that persist over long timescales. We studied melanoma cell responses to transient exposure to the cytokine interferon γ (IFNγ) by combining a systems-scale analysis of gene expression dynamics with computational modeling and experiments. We discovered that IFNγ is captured by phosphatidylserine (PS) on the surface of viable cells both in vitro and in vivo then slowly released to drive long-term transcription of cytokine-response genes. This mechanism introduces an additional function for PS in dynamically regulating inflammation across diverse cancer and primary cell types and has potential to usher in new immunotherapies targeting PS and inflammatory pathways.

Keywords: IFNγ; cytokine signaling; phosphatidylserine; quantitative biology; transcriptional regulation; tumor inflammation; tumor microenvironment.

MeSH terms

  • Animals
  • Cell Communication*
  • Cell Line, Tumor
  • Coculture Techniques
  • Computational Biology
  • Computer Simulation
  • Databases, Genetic
  • Female
  • Gene Expression Profiling / methods
  • Gene Expression Regulation, Neoplastic
  • HEK293 Cells
  • Humans
  • Inflammation / genetics
  • Inflammation / immunology
  • Inflammation / metabolism*
  • Inflammation / pathology
  • Inflammation Mediators / metabolism*
  • Interferon gamma Receptor
  • Interferon-gamma / immunology
  • Interferon-gamma / metabolism*
  • Interleukin-12 / immunology
  • Interleukin-12 / metabolism
  • Interleukin-23 / immunology
  • Interleukin-23 / metabolism
  • Janus Kinases / metabolism
  • Lymphocyte Activation
  • Lymphocytes, Tumor-Infiltrating / immunology
  • Lymphocytes, Tumor-Infiltrating / metabolism*
  • Lymphocytes, Tumor-Infiltrating / pathology
  • Male
  • Melanoma, Experimental / genetics
  • Melanoma, Experimental / immunology
  • Melanoma, Experimental / metabolism*
  • Melanoma, Experimental / pathology
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Models, Biological
  • PTEN Phosphohydrolase / genetics
  • PTEN Phosphohydrolase / metabolism
  • Phosphatidylserines / immunology
  • Phosphatidylserines / metabolism*
  • Phosphorylation
  • RAW 264.7 Cells
  • Receptors, Interferon / genetics
  • Receptors, Interferon / metabolism
  • STAT1 Transcription Factor / metabolism
  • Signal Transduction
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism*
  • T-Lymphocytes / pathology
  • Thyroid Neoplasms / genetics
  • Thyroid Neoplasms / immunology
  • Thyroid Neoplasms / metabolism*
  • Thyroid Neoplasms / pathology
  • Time Factors
  • Transcription, Genetic

Substances

  • Inflammation Mediators
  • Interleukin-23
  • Phosphatidylserines
  • Receptors, Interferon
  • STAT1 Transcription Factor
  • Stat1 protein, mouse
  • Interleukin-12
  • Interferon-gamma
  • Janus Kinases
  • PTEN Phosphohydrolase
  • Pten protein, mouse