CD8+ T cell targeting of tumor antigens presented by HLA-E

Sci Adv. 2024 May 10;10(19):eadm7515. doi: 10.1126/sciadv.adm7515. Epub 2024 May 10.

Abstract

The nonpolymorphic major histocompatibility complex E (MHC-E) molecule is up-regulated on many cancer cells, thus contributing to immune evasion by engaging inhibitory NKG2A/CD94 receptors on NK cells and tumor-infiltrating T cells. To investigate whether MHC-E expression by cancer cells can be targeted for MHC-E-restricted T cell control, we immunized rhesus macaques (RM) with rhesus cytomegalovirus (RhCMV) vectors genetically programmed to elicit MHC-E-restricted CD8+ T cells and to express established tumor-associated antigens (TAAs) including prostatic acidic phosphatase (PAP), Wilms tumor-1 protein, or Mesothelin. T cell responses to all three tumor antigens were comparable to viral antigen-specific responses with respect to frequency, duration, phenotype, epitope density, and MHC restriction. Thus, CMV-vectored cancer vaccines can bypass central tolerance by eliciting T cells to noncanonical epitopes. We further demonstrate that PAP-specific, MHC-E-restricted CD8+ T cells from RhCMV/PAP-immunized RM respond to PAP-expressing HLA-E+ prostate cancer cells, suggesting that the HLA-E/NKG2A immune checkpoint can be exploited for CD8+ T cell-based immunotherapies.

Publication types

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

MeSH terms

  • Acid Phosphatase
  • Animals
  • Antigen Presentation / immunology
  • Antigens, Neoplasm* / immunology
  • CD8-Positive T-Lymphocytes* / immunology
  • Cancer Vaccines / immunology
  • Cell Line, Tumor
  • Cytomegalovirus / immunology
  • HLA-E Antigens*
  • Histocompatibility Antigens Class I / immunology
  • Histocompatibility Antigens Class I / metabolism
  • Humans
  • Macaca mulatta
  • Male
  • Mesothelin

Substances

  • Acid Phosphatase
  • Antigens, Neoplasm
  • Cancer Vaccines
  • Histocompatibility Antigens Class I
  • HLA-E Antigens
  • Mesothelin
  • prostatic acid phosphatase