The SWI/SNF chromatin remodeling complexes BAF and PBAF differentially regulate epigenetic transitions in exhausted CD8+ T cells

Immunity. 2023 Jun 13;56(6):1320-1340.e10. doi: 10.1016/j.immuni.2023.05.008.

Abstract

CD8+ T cell exhaustion (Tex) limits disease control during chronic viral infections and cancer. Here, we investigated the epigenetic factors mediating major chromatin-remodeling events in Tex-cell development. A protein-domain-focused in vivo CRISPR screen identified distinct functions for two versions of the SWI/SNF chromatin-remodeling complex in Tex-cell differentiation. Depletion of the canonical SWI/SNF form, BAF, impaired initial CD8+ T cell responses in acute and chronic infection. In contrast, disruption of PBAF enhanced Tex-cell proliferation and survival. Mechanistically, PBAF regulated the epigenetic and transcriptional transition from TCF-1+ progenitor Tex cells to more differentiated TCF-1- Tex subsets. Whereas PBAF acted to preserve Tex progenitor biology, BAF was required to generate effector-like Tex cells, suggesting that the balance of these factors coordinates Tex-cell subset differentiation. Targeting PBAF improved tumor control both alone and in combination with anti-PD-L1 immunotherapy. Thus, PBAF may present a therapeutic target in cancer immunotherapy.

Keywords: BAF; CRISPR-Cas9 screen; PBAF; SWI/SNF; T cell exhaustion; T cell memory; chromatin remodelling complexes; epigenetics; immunotherapy.

Publication types

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

MeSH terms

  • CD8-Positive T-Lymphocytes*
  • Cell Differentiation
  • Chromatin
  • Chromatin Assembly and Disassembly*
  • Epigenesis, Genetic

Substances

  • Chromatin