Frequent occurrence of high affinity T cells against MELOE-1 makes this antigen an attractive target for melanoma immunotherapy

Eur J Immunol. 2010 Jun;40(6):1786-94. doi: 10.1002/eji.200940132.

Abstract

We recently showed that the infusion of tumor infiltrating lymphocytes specific for the MELOE-1 antigen was associated with a prolonged relapse-free survival for HLA-A2(+) melanoma patients who received tumor infiltrating lymphocytes therapy. Here, we characterized the MELOE-1/A2-specific T-cell repertoire in healthy donors and melanoma patients to further support an immunotherapy targeting this epitope. Using tetramer enrichment followed by multicolor staining, we found that MELOE-1-specific T cells were present in the blood of healthy donors and patients at similar frequencies (around 1 in 1x10(5) CD8(+) cells). These cells mainly displayed a naïve phenotype in 4/6 healthy donors and 3/6 patients, whereas high proportions of memory cells were observed in the remaining individuals of both groups. There was a recurrent usage of the Valpha12.1 chain for 17/18 MELOE-1-specific T-cell clones derived from healthy donors or patients, associated with diverse Vbeta chains and V(D)J junctional sequences. All clones derived from melanoma patients (9/9) were reactive against the MELOE-1(36-44) peptide and against HLA-A2(+) melanoma cell lines. This study documents the existence of a large TCR repertoire specific for the MELOE-1/A2 epitope and its capacity to give rise to antitumor CTL that supports the development of immunotherapies targeting this epitope.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Neoplasm / immunology*
  • Cell Differentiation / immunology
  • Cell Separation
  • Epitopes, T-Lymphocyte / immunology
  • Flow Cytometry
  • Humans
  • Immunotherapy / methods*
  • Lymphocytes, Tumor-Infiltrating / immunology
  • Melanoma / immunology*
  • Melanoma / therapy
  • Neoplasm Proteins / immunology*
  • Phenotype
  • Receptors, Antigen, T-Cell / immunology
  • T-Lymphocyte Subsets / cytology
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocytes / cytology
  • T-Lymphocytes / immunology*

Substances

  • Antigens, Neoplasm
  • Epitopes, T-Lymphocyte
  • MELOE-1 antigen, human
  • Neoplasm Proteins
  • Receptors, Antigen, T-Cell