title: Peptide-specific CD8+ T-cell evolution in vivo: response to peptide vaccination with Melan-A/MART-1.
abstract: Monitoring of CD8+ T-cell responses in cancer patients during peptide vaccination is essential to provide useful surrogate markers and to demonstrate vaccine efficacy. We have longitudinally followed CD8+ T-cell responses in 3 melanoma patients who were immunized with peptides derived from Melan-A/MART-1. Recombinant HLA-A2 tetramers loaded with the naturally presented Melan-A/MART-1 nonamer peptide (AAGIGILTV) and the Melan-A/MART-1 analog (ELAGIGILTV) were used in combination with phenotypical analysis for different T-cell subsets including naive T cells, effector T cells, "true memory" T cells and "memory effector" T cells, based on CD45RA/RO and CCR7-expression. At least in a single patient, T cells binding to the AAGIGILTV epitope were detected in naive, precursor (CD45RA+/CCR7+) CD8+ T cells, and CD8+ T cells binding to the analog ELAGIGILTV peptide were identified in the terminally differentiated (CD45RA+/CCR7-) T-cell subset. Molecular and functional analysis of tetramer-binding T cells revealed that the T-cell receptor (TCR) repertoire was oligo/polyclonal in AAGIGILTV-reactive T cells, but different and restricted to a few TCR clonotypes in ELAGIGILTV-reactive T cells prior to vaccination. The TCR repertoire reactive with Melan-A/MART-1 peptide epitopes was broadened during vaccination and exhibited a different profile of cytokine release after specific stimulation: tetramer-binding T cells from 2/3 patients secreted granulocyte/macrophage colony-stimulating factor (GM-CSF) and interferon-gamma but not interleukin-2 (IL-2) in response to Melan-A/MART-1 peptides. In the third patient, tetramer-binding T cells secreted IL-2 exclusively. Our results show that T-cell responses to peptide vaccination consist of different T-cell subsets associated with different effector functions. Complementary analysis for TCR CDR3 and cytokine profiles may be useful to define the most effective CD8+ T-cell population induced by peptide vaccination.
authors.affiliation: Medizinische Klinik II, Hämatologie-Onkologie, Krankenhaus Nordwest, Frankfurt, Germany.
authors.forename: Elke
authors.initials: E
authors.lastname: Jäger
authors.forename: Hauni
authors.initials: H
authors.lastname: Höhn
authors.forename: Artje
authors.initials: A
authors.lastname: Necker
authors.forename: Reinhold
authors.initials: R
authors.lastname: Förster
authors.forename: Julia
authors.initials: J
authors.lastname: Karbach
authors.forename: Kirsten
authors.initials: K
authors.lastname: Freitag
authors.forename: Claudia
authors.initials: C
authors.lastname: Neukirch
authors.forename: Chiara
authors.initials: C
authors.lastname: Castelli
authors.forename: Russell D
authors.initials: RD
authors.lastname: Salter
authors.forename: Alaxander
authors.initials: A
authors.lastname: Knuth
authors.forename: Markus J
authors.initials: MJ
authors.lastname: Maeurer
mesh_terms: D018528:ATP-Binding Cassette Transporters; D000911:Antibodies, Monoclonal / Q000378:metabolism; D000951:Antigens, Neoplasm / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D019496:Cancer Vaccines / Q000627:therapeutic use*; D022801:Complementarity Determining Regions / Q000032:analysis; D005434:Flow Cytometry; D015789:HLA-A2 Antigen / Q000276:immunology; D006801:Humans; D058965:MART-1 Antigen; D008545:Melanoma / Q000276:immunology / Q000628:therapy*; D009363:Neoplasm Proteins / Q000276:immunology*; D009842:Oligopeptides / Q000276:immunology*; D010641:Phenotype; D011485:Protein Binding; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D012878:Skin Neoplasms / Q000276:immunology / Q000628:therapy*; D014407:Tumor Cells, Cultured; D014611:Vaccination; D022223:Vaccines, Subunit
chemical_list: D018528:ATP-Binding Cassette Transporters; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D019496:Cancer Vaccines; C109399:Cdr3 protein, Candida albicans; D022801:Complementarity Determining Regions; D015789:HLA-A2 Antigen; D058965:MART-1 Antigen; C548667:MLANA protein, human; D009363:Neoplasm Proteins; D009842:Oligopeptides; D011948:Receptors, Antigen, T-Cell; D022223:Vaccines, Subunit