Antitumour activity mediated by CD4+ cytotoxic T lymphocytes against MHC class II-negative mouse hepatocellular carcinoma induced by dendritic cell vaccine and interleukin-12

Immunology. 2005 Aug;115(4):451-61. doi: 10.1111/j.1365-2567.2005.02179.x.


When BALA/c mice with BNL hepatocellular carcinoma (HCC) were treated with dendritic cells fused with BNL cells (DC/BNL) and recombinant murine interleukin (IL)-12, tumour development was significantly suppressed, whereas treatment with either DC/BNL or IL-12 alone did not show a tumour-suppressive effect. Antitumour activity induced by DC/BNL + IL-12 was abrogated by depletion of CD4+ T cells, but not by depletion of CD8+ T cells or natural killer cells. Splenic CD4+ T cells and CD8+ T cells from DC/BNL-treated mice showed cytotoxic activity against BNL cells after 3 days of incubation with DC/BNL, although BNL cells do not express major histocompatibility complex (MHC) class II molecules even after treatment with interferon (INF)-gamma. Furthermore, CD4+ T cells killed syngeneic-irrelevant CT26 cells and even allogeneic Hepa1-6 cells. This cytotoxicity was blocked by concanamycin A, but not by an anti-Fas ligand (FasL) monoclonal antibody, indicating that cytotoxic activity was mediated by perforin. Immunofluorescence microscopy demonstrated that abundant CD4+ T cells and MHC class II-positive macrophages, but not CD8(+) T cells, had infiltrated tumour tissue in mice treated with DC/BNL + IL-12. Flow cytometric analysis of tumour-infiltrating cells in mice treated with DC/BNL + IL-12 showed increases in CD4+ T cells and MHC class II+ CD11b+ cells but not in CD8+ T cells or MHC class I+ CD11b+ cells. Our results suggest that, in BNL-bearing mice treated with DC/BNL + IL-12, tumour macrophages activated by INF-gamma produced by IL-12-stimulated T cells might present BNL tumour antigens and activate DC/BNL-primed CD4+ cytotoxic T lymphocytes (CTLs) in a MHC class II-dependent manner, leading to perforin-mediated bystander killing of neighbouring MHC class II-negative tumour cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Neoplasm / immunology
  • Apoptosis / immunology
  • CD4-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / immunology
  • Cancer Vaccines / immunology*
  • Carcinoma, Hepatocellular / immunology*
  • Cell Line, Tumor
  • Cytotoxicity, Immunologic / immunology
  • Dendritic Cells / immunology*
  • Fas Ligand Protein
  • Female
  • Flow Cytometry / methods
  • Histocompatibility Antigens Class II / immunology*
  • Interleukin-12 / immunology*
  • Killer Cells, Natural / immunology
  • Liver Neoplasms, Experimental / immunology*
  • Membrane Glycoproteins / immunology
  • Mice
  • Mice, Inbred BALB C
  • Perforin
  • Pore Forming Cytotoxic Proteins
  • Spleen / immunology


  • Antigens, Neoplasm
  • Cancer Vaccines
  • Fas Ligand Protein
  • Fasl protein, mouse
  • Histocompatibility Antigens Class II
  • Membrane Glycoproteins
  • Pore Forming Cytotoxic Proteins
  • Perforin
  • Interleukin-12