Systematic elucidation and pharmacological targeting of tumor-infiltrating regulatory T cell master regulators

Cancer Cell. 2023 May 8;41(5):933-949.e11. doi: 10.1016/j.ccell.2023.04.003. Epub 2023 Apr 27.

Abstract

Due to their immunosuppressive role, tumor-infiltrating regulatory T cells (TI-Tregs) represent attractive immuno-oncology targets. Analysis of TI vs. peripheral Tregs (P-Tregs) from 36 patients, across four malignancies, identified 17 candidate master regulators (MRs) as mechanistic determinants of TI-Treg transcriptional state. Pooled CRISPR-Cas9 screening in vivo, using a chimeric hematopoietic stem cell transplant model, confirmed the essentiality of eight MRs in TI-Treg recruitment and/or retention without affecting other T cell subtypes, and targeting one of the most significant MRs (Trps1) by CRISPR KO significantly reduced ectopic tumor growth. Analysis of drugs capable of inverting TI-Treg MR activity identified low-dose gemcitabine as the top prediction. Indeed, gemcitabine treatment inhibited tumor growth in immunocompetent but not immunocompromised allografts, increased anti-PD-1 efficacy, and depleted MR-expressing TI-Tregs in vivo. This study provides key insight into Treg signaling, specifically in the context of cancer, and a generalizable strategy to systematically elucidate and target MR proteins in immunosuppressive subpopulations.

Keywords: TRPS1; cancer systems biology; gemcitabine; master regulator analysis; regulatory T cells; tumor immunology.

Publication types

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

MeSH terms

  • Humans
  • Lymphocytes, Tumor-Infiltrating / metabolism
  • Neoplasms* / drug therapy
  • Neoplasms* / genetics
  • Neoplasms* / metabolism
  • Proteins / metabolism
  • Repressor Proteins / metabolism
  • T-Lymphocytes, Regulatory* / metabolism

Substances

  • Proteins
  • TRPS1 protein, human
  • Repressor Proteins