Ectopically expressed human tumor biomarker MutS homologue 2 is a novel endogenous ligand that is recognized by human γδ T cells to induce innate anti-tumor/virus immunity

J Biol Chem. 2012 May 11;287(20):16812-9. doi: 10.1074/jbc.M111.327650. Epub 2012 Mar 20.

Abstract

Human (h) MutS homologue 2, a nuclear protein, is a critical element of the DNA mismatch repair system. Our previous studies suggest that hMSH2 might be a protein ligand for TCRγδ. Here, we show that hMSH2 is ectopically expressed on a large panel of epithelial tumor cells. We found that hMSH2 interacts with both TCRγδ and NKG2D and contributes to Vδ2 T cell-mediated cytolysis of tumor cells. Moreover, recombinant human MSH2 protein stimulates the proliferation and IFN-γ secretion of Vδ2 T cells in vitro. Finally, hMSH2 expression is induced on the cell surface of Epstein-Barr virus-transformed lymphoblastoid cell lines, and the induction increases the sensitivity of these lymphoblastoid cell lines to γδ T cell-mediated cytolysis. Our data suggest that hMSH2 functions as a tumor-associated or virus infection-related antigen recognized by both Vδ2 TCR and NKG2D, and it plays a role in eliciting the immune responses of γδ T cells against tumor- and virus-infected cells. The recognition of ectopic surface-expressing endogenous antigen by TCRγδ and NKG2D may be an important mechanism of innate immune response to carcinogenesis and viral infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers, Tumor / biosynthesis
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / immunology*
  • Burkitt Lymphoma / genetics
  • Burkitt Lymphoma / immunology
  • Burkitt Lymphoma / metabolism*
  • Cell Line, Transformed
  • Cell Proliferation
  • HeLa Cells
  • Herpesvirus 4, Human / genetics
  • Herpesvirus 4, Human / immunology*
  • Herpesvirus 4, Human / metabolism
  • Humans
  • Immunity, Innate*
  • Interferon-gamma / genetics
  • Interferon-gamma / immunology
  • Interferon-gamma / metabolism
  • MutS Homolog 2 Protein / biosynthesis
  • MutS Homolog 2 Protein / genetics
  • MutS Homolog 2 Protein / immunology*
  • NK Cell Lectin-Like Receptor Subfamily K / biosynthesis
  • NK Cell Lectin-Like Receptor Subfamily K / genetics
  • NK Cell Lectin-Like Receptor Subfamily K / immunology
  • Neoplasms, Glandular and Epithelial / genetics
  • Neoplasms, Glandular and Epithelial / immunology*
  • Neoplasms, Glandular and Epithelial / metabolism
  • Neoplasms, Glandular and Epithelial / pathology
  • Receptors, Antigen, T-Cell, gamma-delta / biosynthesis
  • Receptors, Antigen, T-Cell, gamma-delta / genetics
  • Receptors, Antigen, T-Cell, gamma-delta / immunology*
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / metabolism

Substances

  • Biomarkers, Tumor
  • KLRK1 protein, human
  • NK Cell Lectin-Like Receptor Subfamily K
  • Receptors, Antigen, T-Cell, gamma-delta
  • Interferon-gamma
  • MSH2 protein, human
  • MutS Homolog 2 Protein