title: Immunological monitoring of patients with melanoma after peptide vaccination using soluble peptide/HLA-A2 dimer complexes.
abstract: To facilitate the immunologic monitoring of a peptide vaccine trial, a novel, empty dimeric HLA-A2 molecule (A2 dimer) that could be loaded with peptides was produced. The dimer comprises the extracellular domain of HLA-A2 noncovalently linked to a fusion protein consisting of human beta2-microglobulin joined to the human IgG1 Fc domain. Peptide-loaded dimer complexes were used to assess the function of peptide-specific T cells. HLA-A2 gp100 peptide dimers stimulated interferon (IFN)-gamma production by the gp100-specific TIL-1520 cell line. Gp100/A2 dimer stimulation in combination with intracellular cytokine staining was used to analyze peptide-specific T-cell responses in patients with melanoma after vaccination with the modified gp100: 209-2M peptide in adjuvant. Titration analysis of the amount of peptide-loaded dimer required to stimulate gp100-specific T cells was used to estimate the functional avidity of effector/memory CD8+ T lymphocytes. The number of peptide-specific T cells detected in the peripheral blood of vaccinated patients using this assay was comparable to the number determined by staining with fluoresceinated gp100: 209-2M HLA-A2 tetramers. IFN-gamma production by T cells was comparable after stimulation with peptide-pulsed dimers, T2 cells, or autologous dendritic cells. Peptide-loaded A2 dimers could also be used directly to stimulate T cells in the ELISPOT assay.
authors.affiliation: Robert W Franz Cancer Research Center, Earle A Chiles Research Institute, Providence Portland Medical Center, Portland, Oregon 97213, USA. hhu@providence.org
authors.forename: Hong-Ming
authors.initials: HM
authors.lastname: Hu
authors.forename: Annemieke
authors.initials: A
authors.lastname: Dols
authors.forename: Sybren L
authors.initials: SL
authors.lastname: Meijer
authors.forename: Kevin
authors.initials: K
authors.lastname: Floyd
authors.forename: Edwin
authors.initials: E
authors.lastname: Walker
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Urba
authors.forename: Bernard A
authors.initials: BA
authors.lastname: Fox
mesh_terms: D000818:Animals; D019496:Cancer Vaccines / Q000627:therapeutic use*; D015925:Cryopreservation; D003713:Dendritic Cells / Q000276:immunology; D019281:Dimerization; D015789:HLA-A2 Antigen / Q000737:chemistry* / Q000276:immunology; D006801:Humans; D020382:Interleukin-18 / Q000378:metabolism; D008545:Melanoma / Q000097:blood / Q000276:immunology / Q000628:therapy*; D008562:Membrane Glycoproteins / Q000276:immunology; D015166:Monitoring, Immunologic; D010446:Peptide Fragments / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology; D014407:Tumor Cells, Cultured; D014611:Vaccination; D022223:Vaccines, Subunit / Q000627:therapeutic use*; D058951:gp100 Melanoma Antigen
chemical_list: D019496:Cancer Vaccines; D015789:HLA-A2 Antigen; D020382:Interleukin-18; D008562:Membrane Glycoproteins; C548637:PMEL protein, human; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D022223:Vaccines, Subunit; D058951:gp100 Melanoma Antigen