Tissue-specific abundance of interferon-gamma drives regulatory T cells to restrain DC1-mediated priming of cytotoxic T cells against lung cancer

Immunity. 2023 Feb 14;56(2):386-405.e10. doi: 10.1016/j.immuni.2023.01.010. Epub 2023 Feb 2.

Abstract

Local environmental factors influence CD8+ T cell priming in lymph nodes (LNs). Here, we sought to understand how factors unique to the tumor-draining mediastinal LN (mLN) impact CD8+ T cell responses toward lung cancer. Type 1 conventional dendritic cells (DC1s) showed a mLN-specific failure to induce robust cytotoxic T cells responses. Using regulatory T (Treg) cell depletion strategies, we found that Treg cells suppressed DC1s in a spatially coordinated manner within tissue-specific microniches within the mLN. Treg cell suppression required MHC II-dependent contact between DC1s and Treg cells. Elevated levels of IFN-γ drove differentiation Treg cells into Th1-like effector Treg cells in the mLN. In patients with cancer, Treg cell Th1 polarization, but not CD8+/Treg cell ratios, correlated with poor responses to checkpoint blockade immunotherapy. Thus, IFN-γ in the mLN skews Treg cells to be Th1-like effector Treg cells, driving their close interaction with DC1s and subsequent suppression of cytotoxic T cell responses.

Keywords: T cell dysfunction; T cell priming; Th1-like effector regulatory T cells; anti-tumor immunity; cross-presenting dendritic cells; cytotoxic T cells; interferon-gamma; non-small cell lung cancer; regulatory T cells; tissue-specific immunity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • CD8-Positive T-Lymphocytes
  • Humans
  • Interferon-gamma
  • Lung Neoplasms*
  • T-Lymphocytes, Cytotoxic
  • T-Lymphocytes, Regulatory*

Substances

  • Interferon-gamma
  • IFNG protein, human