Genetic immunization with a melanocytic self-antigen linked to foreign helper sequences breaks tolerance and induces autoimmunity and tumor immunity

Gene Ther. 2002 Feb;9(3):208-13. doi: 10.1038/sj.gt.3301634.

Abstract

Mechanisms maintaining peripheral tolerance to self-antigens present a major obstacle for the development of antigen-specific melanoma vaccines, presumably because self-antigens are not able to stimulate a CD4 T-helper response. Using the melanosomal enzyme tyrosinase-related protein 2 (TRP2) expressed by melanocytes and most melanoma cells as a model self-antigen, we investigated whether linkage with a foreign immunogenic protein providing strong CD4 helper sequences would be able to circumvent tolerance and enhance the induction of antigen-specific tumor immunity. We found that genetic immunization of mice with cDNA encoding a fusion protein between enhanced green fluorescent protein (EGFP) from jellyfish and autologous murine TRP2 (EGFP.mTRP2) resulted in the stimulation of TRP2-reactive T cells in vivo. Importantly, immunization with EGFP.mTRP2 effectively protected mice against metastatic growth of B16 melanoma in the lungs and was associated with fur depigmentation as a sign of autoimmune-mediated destruction of melanocytes. Our results show that tumor vaccines consisting of self-antigens linked to immunogenic helper sequences can be successfully applied to the immunotherapy of melanoma and provide a scientific basis for the translation of this strategy in future clinical investigations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autoimmunity
  • CD4 Antigens / genetics
  • CD8 Antigens / genetics
  • Cancer Vaccines / administration & dosage*
  • Genetic Therapy / methods*
  • Genetic Vectors / administration & dosage*
  • Green Fluorescent Proteins
  • Intramolecular Oxidoreductases / genetics*
  • Luminescent Proteins / genetics
  • Melanoma, Experimental / immunology
  • Melanoma, Experimental / therapy*
  • Mice
  • Mice, Knockout
  • Recombinant Fusion Proteins / genetics
  • T-Lymphocytes, Helper-Inducer / immunology*

Substances

  • CD4 Antigens
  • CD8 Antigens
  • Cancer Vaccines
  • Luminescent Proteins
  • Recombinant Fusion Proteins
  • Green Fluorescent Proteins
  • Intramolecular Oxidoreductases
  • dopachrome isomerase