Internal checkpoint regulates T cell neoantigen reactivity and susceptibility to PD1 blockade

Med. 2022 Oct 14;3(10):682-704.e8. doi: 10.1016/j.medj.2022.07.008. Epub 2022 Aug 24.

Abstract

Background: Adoptive transfer of tumor-infiltrating lymphocytes (TIL) fails to consistently elicit tumor rejection. Manipulation of intrinsic factors that inhibit T cell effector function and neoantigen recognition may therefore improve TIL therapy outcomes. We previously identified the cytokine-induced SH2 protein (CISH) as a key regulator of T cell functional avidity in mice. Here, we investigate the mechanistic role of CISH in regulating human T cell effector function in solid tumors and demonstrate that CRISPR/Cas9 disruption of CISH enhances TIL neoantigen recognition and response to checkpoint blockade.

Methods: Single-cell gene expression profiling was used to identify a negative correlation between high CISH expression and TIL activation in patient-derived TIL. A GMP-compliant CRISPR/Cas9 gene editing process was developed to assess the impact of CISH disruption on the molecular and functional phenotype of human peripheral blood T cells and TIL. Tumor-specific T cells with disrupted Cish function were adoptively transferred into tumor-bearing mice and evaluated for efficacy with or without checkpoint blockade.

Findings: CISH expression was associated with T cell dysfunction. CISH deletion using CRISPR/Cas9 resulted in hyper-activation and improved functional avidity against tumor-derived neoantigens without perturbing T cell maturation. Cish knockout resulted in increased susceptibility to checkpoint blockade in vivo.

Conclusions: CISH negatively regulates human T cell effector function, and its genetic disruption offers a novel avenue to improve the therapeutic efficacy of adoptive TIL therapy.

Funding: This study was funded by Intima Bioscience, U.S. and in part through the Intramural program CCR at the National Cancer Institute.

Keywords: CISH; CRISPR; PD-1; T cell therapy; TIL; cancer; checkpoint; immunotherapy; neoantigen; preclinical research; scRNAseq.

Publication types

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

MeSH terms

  • Adoptive Transfer
  • Animals
  • Cytokines / metabolism
  • Humans
  • Immunotherapy, Adoptive / methods
  • Lymphocytes, Tumor-Infiltrating*
  • Mice
  • T-Lymphocytes*

Substances

  • Cytokines