Characterization of CD8+ T-cell responses in the peripheral blood and skin injection sites of melanoma patients treated with mRNA electroporated autologous dendritic cells (TriMixDC-MEL)

Biomed Res Int. 2013:2013:976383. doi: 10.1155/2013/976383. Epub 2013 Jan 3.

Abstract

Treatment of melanoma patients with mRNA electroporated dendritic cells (TriMixDC-MEL) stimulates T-cell responses against the presented tumor-associated antigens (TAAs). In the current clinical trials, melanoma patients with systemic metastases are treated, requiring priming and/or expansion of preexisting TAA-specific T cells that are able to migrate to both the skin and internal organs. We monitored the presence of TAA-specific CD8(+) T cells infiltrating the skin at sites of intradermal TriMixDC-MEL injection (SKILs) and within the circulation of melanoma patients treated in two clinical trials. In 10 out of fourteen (71%) patients screened, CD8(+) T cells recognizing any of the four TAA presented by TriMixDC-MEL cellular vaccine were found in both compartments. In total, 30 TAA-specific T-cell responses were detected among the SKILs and 29 among peripheral blood T cells, of which 24 in common. A detailed characterization of the antigen specificity of CD8(+) T-cell populations in four patients indicates that the majority of the epitopes detected were only recognized by CD8(+) T cells derived from either skin biopsies or peripheral blood, indicating that some compartmentalization occurs after TriMix-DC therapy. To conclude, functional TAA-specific CD8(+) T cells distribute both to the skin and peripheral blood of patients after TriMixDC-MEL therapy.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Neoplasm / immunology*
  • Biopsy
  • CD8-Positive T-Lymphocytes / immunology*
  • Cancer Vaccines / therapeutic use*
  • Cell Movement
  • Dendritic Cells / transplantation*
  • Electroporation
  • Epitopes / immunology
  • Humans
  • Melanoma / therapy*
  • Neoplasm Metastasis
  • Pilot Projects
  • Recurrence
  • Skin / metabolism
  • Skin Neoplasms / therapy*

Substances

  • Antigens, Neoplasm
  • Cancer Vaccines
  • Epitopes