Gp100 Peptide Vaccine for Intraocular Melanoma

Abstract

Purpose: : Melanoma cells express the protein gp100. The effectiveness of immunotherapy based on gp100 peptide vaccination was tested in a well established intraocular B16F10 eye melanoma model.

Methods: : C57Bl/6 mice were adoptively transferred with T cell receptor-transgenic, human gp100 specific CD8+ T lymphocytes (pmel). Mice received a total of 4 subcutaneous injections with gp100 peptide, starting 2 weeks before tumor inoculation. Immunostimulatory cream containing the TLR-7 ligand Imiquimod (Aldara^TM) was applied at the injection site. Some mice were additionally treated with IL-2 i.v. One week after the second vaccination, B16F10 melanoma cells were inoculated in the anterior chamber of the mouse eye. Tumor growth was followed with binocular microscopy and scored semi-quantitatively.

Results: : Tumor growth in the group treated with adoptive transfer of CD8+ cells, gp100 vaccination and Aldara showed a delay in tumor growth. Adding IL-2 intravenously one week before tumor inoculation prevented growth of a B16F10 tumor in the anterior chamber of the eye.

Conclusions: : Immunotherapy consisting of pmel cells, gp100 peptide vaccination and Aldara^TM cream delays tumor growth in the eye. Additional treatment with IL-2 induces complete protection against tumor growth of a B16F10 tumor in the anterior chamber of the eye of a C57/Bl6 mouse.

Keywords: oncology • immunomodulation/immunoregulation • tumors