Tumor heterogeneity and clonal cooperation influence the immune selection of IFN-γ-signaling mutant cancer cells

Nat Commun. 2020 Jan 30;11(1):602. doi: 10.1038/s41467-020-14290-4.


PD-1/PD-L1 blockade can promote robust tumor regression yet secondary resistance often occurs as immune selective pressure drives outgrowth of resistant tumor clones. Here using a genome-wide CRISPR screen in B16.SIY melanoma cells, we confirm Ifngr2 and Jak1 as important genes conferring sensitivity to T cell-mediated killing in vitro. However, when implanted into mice, these Ifngr2- and Jak1-deficient tumors paradoxically are better controlled immunologically. This phenotype maps to defective PD-L1 upregulation on mutant tumor cells, which improves anti-tumor efficacy of CD8+ T cells. To reconcile these observations with clinical reports of anti-PD-1 resistance linked to emergence of IFN-γ signaling mutants, we show that when mixed with wild-type tumor cells, IFN-γ-insensitive tumor cells indeed grow out, which depends upon PD-L1 expression by wild-type cells. Our results illustrate the complexity of functions for IFN-γ in anti-tumor immunity and demonstrate that intratumor heterogeneity and clonal cooperation can contribute to immunotherapy resistance.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • B7-H1 Antigen / metabolism
  • CRISPR-Cas Systems / genetics
  • Cell Line, Tumor
  • Cell Proliferation
  • Clone Cells
  • Cytotoxicity, Immunologic
  • Genetic Heterogeneity*
  • Humans
  • Immunomodulation
  • Interferon-gamma / metabolism*
  • Lymphocytes, Tumor-Infiltrating / immunology
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Mutation / genetics*
  • Neoplasms / genetics*
  • Neoplasms / pathology*
  • Signal Transduction*
  • T-Lymphocytes / immunology


  • B7-H1 Antigen
  • Cd274 protein, mouse
  • Interferon-gamma