Systematic Immunotherapy Target Discovery Using Genome-Scale In Vivo CRISPR Screens in CD8 T Cells

Cell. 2019 Aug 22;178(5):1189-1204.e23. doi: 10.1016/j.cell.2019.07.044.


CD8 T cells play essential roles in anti-tumor immune responses. Here, we performed genome-scale CRISPR screens in CD8 T cells directly under cancer immunotherapy settings and identified regulators of tumor infiltration and degranulation. The in vivo screen robustly re-identified canonical immunotherapy targets such as PD-1 and Tim-3, along with genes that have not been characterized in T cells. The infiltration and degranulation screens converged on an RNA helicase Dhx37. Dhx37 knockout enhanced the efficacy of antigen-specific CD8 T cells against triple-negative breast cancer in vivo. Immunological characterization in mouse and human CD8 T cells revealed that DHX37 suppresses effector functions, cytokine production, and T cell activation. Transcriptomic profiling and biochemical interrogation revealed a role for DHX37 in modulating NF-κB. These data demonstrate high-throughput in vivo genetic screens for immunotherapy target discovery and establishes DHX37 as a functional regulator of CD8 T cells.

Keywords: CD8 T cell; DHX37; T cell effector function; adoptive transfer; breast cancer; immunotherapy; in vivo CRISPR screen; lentiCRISPR; target discovery; tumor infiltration.

Publication types

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

MeSH terms

  • Animals
  • Breast Neoplasms / pathology
  • Breast Neoplasms / therapy
  • CD8-Positive T-Lymphocytes / cytology
  • CD8-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / metabolism*
  • Cell Line, Tumor
  • Clustered Regularly Interspaced Short Palindromic Repeats / genetics
  • Cytokines / genetics
  • Cytokines / metabolism
  • Female
  • Humans
  • Immunologic Memory
  • Immunotherapy
  • Male
  • Mice
  • Mice, Knockout
  • NF-kappa B / metabolism
  • Programmed Cell Death 1 Receptor / metabolism
  • RNA Helicases / deficiency
  • RNA Helicases / genetics*
  • RNA, Guide, CRISPR-Cas Systems / metabolism
  • Transcriptome


  • Cytokines
  • NF-kappa B
  • Programmed Cell Death 1 Receptor
  • RNA, Guide, CRISPR-Cas Systems
  • Dhx37 protein, mouse
  • RNA Helicases