Vaccines targeting tumor blood vessel antigens promote CD8(+) T cell-dependent tumor eradication or dormancy in HLA-A2 transgenic mice

J Immunol. 2012 Feb 15;188(4):1782-8. doi: 10.4049/jimmunol.1101644. Epub 2012 Jan 13.

Abstract

We have recently shown that effective cytokine gene therapy of solid tumors in HLA-A2 transgenic (HHD) mice lacking murine MHC class I molecule expression results in the generation of HLA-A2-restricted CD8(+) T effector cells selectively recognizing tumor blood vessel-associated pericytes and/or vascular endothelial cells. Using an HHD model in which HLA-A2(neg) tumor (MC38 colon carcinoma or B16 melanoma) cells are not recognized by the CD8(+) T cell repertoire, we now show that vaccines on the basis of tumor-associated blood vessel Ags (TBVA) elicit protective Tc1-dependent immunity capable of mediating tumor regression or extending overall survival. Vaccine efficacy was not observed if (HLA-A2(neg)) wild-type C57BL/6 mice were instead used as recipient animals. In the HHD model, effective vaccination resulted in profound infiltration of tumor lesions by CD8(+) (but not CD4(+)) T cells, in a coordinate reduction of CD31(+) blood vessels in the tumor microenvironment, and in the "spreading" of CD8(+) T cell responses to alternate TBVA that were not intrinsic to the vaccine. Protective Tc1-mediated immunity was durable and directly recognized pericytes and/or vascular endothelial cells flow-sorted from tumor tissue but not from tumor-uninvolved normal kidneys harvested from these same animals. Strikingly, the depletion of CD8(+), but not CD4(+), T cells at late time points after effective therapy frequently resulted in the recurrence of disease at the site of the regressed primary lesion. This suggests that the vaccine-induced anti-TBVA T cell repertoire can mediate the clinically preferred outcomes of either effectively eradicating tumors or policing a state of (occult) tumor dormancy.

Publication types

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

MeSH terms

  • Animals
  • Antigens, Neoplasm / immunology
  • Blood Vessels / immunology*
  • CD8-Positive T-Lymphocytes / immunology*
  • Cancer Vaccines / administration & dosage
  • Cancer Vaccines / immunology*
  • Cell Line, Tumor
  • Endothelial Cells / immunology*
  • Genes, MHC Class I
  • HLA-A2 Antigen / genetics
  • HLA-A2 Antigen / immunology*
  • Lymphocyte Activation / immunology
  • Melanoma, Experimental / blood supply
  • Melanoma, Experimental / immunology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Neoplasms, Experimental / blood supply
  • Neoplasms, Experimental / immunology*
  • Pericytes / immunology*
  • Platelet Endothelial Cell Adhesion Molecule-1 / immunology
  • T-Lymphocytes, Cytotoxic / immunology
  • Tumor Microenvironment / immunology

Substances

  • Antigens, Neoplasm
  • Cancer Vaccines
  • HLA-A2 Antigen
  • Platelet Endothelial Cell Adhesion Molecule-1