Altered intracellular sorting signals do not influence the efficacy of genetic melanoma vaccines incorporating helper determinants in mice.

Abstract

BACKGROUND:

A genetic melanoma vaccine consisting of cDNA encoding the model self-antigen tyrosinase-related protein 2 (TRP2) fused in-frame to the immunogenic enhanced green fluorescent protein (EGFP) was able to break immune tolerance and stimulate CD8+ T cells in vivo. In the present study we investigated whether alteration of the intracellular antigen localization as a result of the linkage with immune-enhancing helper proteins affects the resulting immune response.

METHODS:

Expression plasmids and recombinant adenoviruses were constructed encoding various fusion proteins with different intracellular sorting signals which direct the antigen to the cytosol, the endoplasmic reticulum or the endosomal compartments. Genetic immunization of C57BL/6 mice was performed with all constructs using particle-bombardment of the skin and injection of recombinant adenoviruses. The resulting immune response was analyzed using ELISPOT and tumor rejection assays.

RESULTS:

Induction of TRP2-specific CD8+ T cells in vivo and autoimmune-mediated destruction of melanocytes in the bombarded area of the skin were observed with all constructs expressing fusion proteins between TRP2 and EGFP. Importantly, injections of the different recombinant adenoviruses all mediated protective immunity against transplanted B16 melanoma cells.

CONCLUSIONS:

Altered intracellular sorting signals do not significantly influence the efficacy of genetic melanoma vaccines incorporating helper determinants in our model system. These results further support the concept that linkage of immunogenic helper sequences can be successfully applied for antigen-specific immunotherapy of melanoma and provide a scientific basis for the translation of this strategy in future clinical applications.

• Authors: Jürgen Brück, Julia Steitz, Dennis Strand, Thomas Tüting
• Journal: The journal of gene medicine (J Gene Med) Vol. 7 Issue 5 Pg. 613-20 (May 2005) ISSN: 1099-498X [Print] England
• PMID: 15580620 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright (c) 2004 John Wiley & Sons, Ltd.

Chemical References

• CD4 Antigens
• Cancer Vaccines
• Recombinant Fusion Proteins
• enhanced green fluorescent protein
• Green Fluorescent Proteins
• Intramolecular Oxidoreductases
• dopachrome isomerase

Topics

• Animals
• Autoimmunity
• CD4 Antigens (genetics)
• Cancer Vaccines (administration & dosage)
• Genetic Therapy (methods)
• Genetic Vectors (administration & dosage)
• Green Fluorescent Proteins (genetics, immunology)
• Immunization
• Intramolecular Oxidoreductases (genetics, immunology)
• Melanoma, Experimental (immunology, prevention & control, therapy)
• Mice
• Mice, Inbred C57BL
• Protein Transport
• Recombinant Fusion Proteins (genetics, immunology, pharmacokinetics)
• Skin Neoplasms (immunology, prevention & control, therapy)
• T-Lymphocytes, Helper-Inducer (immunology)