Natural T cell autoreactivity to melanoma antigens: clonally expanded melanoma-antigen specific CD8 + memory T cells can be detected in healthy humans

Cancer Immunol Immunother. 2019 May;68(5):709-720. doi: 10.1007/s00262-018-02292-7. Epub 2019 Feb 19.


We used four-color ImmunoSpot® assays, in conjunction with peptide pools that cover the sequence of tyrosinase (Tyr), melanoma-associated antigen A3 (MAGE-A3), melanocyte antigen/melanoma antigen recognized by T cells 1 (Melan-A/MART-1), glycoprotein 100 (gp100), and New York esophageal squamous cell carcinoma-1 (NY-ESO-1) to characterize the melanoma antigen (MA)-specific CD8 + cell repertoire in PBMC of 40 healthy human donors (HD). Tyr triggered interferon gamma (IFN-γ)-secreting CD8 + T cells in 25% of HD within 24 h of antigen stimulation ex vivo. MAGE-A3, Melan-A/MART-1, and gp100 also induced recall responses in 10%, 7.5%, and 2.5% of HD, respectively. At this time point, these CD8 + T cells did not yet produce GzB (granzyme B). However, they engaged in GzB production after 72 h of antigen stimulation. By this 72-h time point, 57.5% of the HD responded to at least one, and typically several, of the MA. A closer characterization of the Tyr-specific CD8 + T cell repertoire indicated that it was low-affinity, and to primarily entail a stem cell-like subpopulation. Collectively, our data reveal pre-existing endogenous T cell immunity against melanoma antigens in healthy donors, and analogous to natural autoantibodies, we have termed this "natural T cell autoreactivity".

Keywords: CD8 + T cells; ELISPOT; Melanoma antigens; PIVAC 17; Stem-cell like CD8 + T cells.

MeSH terms

  • Antigens, Neoplasm / immunology
  • Autoimmunity
  • CD8-Positive T-Lymphocytes / immunology*
  • Cell Proliferation
  • Clone Cells
  • Enzyme-Linked Immunospot Assay / methods*
  • Healthy Volunteers
  • Humans
  • Immunologic Memory
  • Interferon-gamma / metabolism
  • Lymphocyte Activation
  • MART-1 Antigen / immunology
  • Monophenol Monooxygenase / immunology*
  • Neoplasm Proteins / immunology
  • gp100 Melanoma Antigen / immunology


  • Antigens, Neoplasm
  • MAGEA3 protein, human
  • MART-1 Antigen
  • Neoplasm Proteins
  • gp100 Melanoma Antigen
  • Interferon-gamma
  • Monophenol Monooxygenase