title: Adjuvant immunization of HLA-A2-positive melanoma patients with a modified gp100 peptide induces peptide-specific CD8+ T-cell responses.
abstract: OBJECTIVE
  To measure the CD8+ T-cell response to a melanoma peptide vaccine and to compare an every-2-weeks with an every-3-weeks vaccination schedule.
  
  
  METHODS
  Thirty HLA-A2-positive patients with resected stage I to III melanoma were randomly assigned to receive vaccinations every 2 weeks (13 vaccines) or every 3 weeks (nine vaccines) for 6 months. The synthetic, modified gp100 peptide, g209-2M, and a control peptide, HPV16 E7, were mixed in incomplete Freund's adjuvant and injected subcutaneously. Peripheral blood mononuclear cells obtained before and after vaccination by leukapheresis were analyzed using a fluorescence-based HLA/peptide-tetramer binding assay and cytokine flow cytometry.
  
  
  RESULTS
  Vaccination induced an increase in peptide-specific T cells in 28 of 29 patients. The median frequency of CD8+ T cells specific for the g209-2M peptide increased markedly from 0.02% before to 0.34% after vaccination (P <.0001). Eight patients (28%) exhibited peptide-specific CD8+ T-cell frequencies greater than 1%, including two patients with frequencies of 4.96% and 8.86%, respectively. Interferon alfa-2b-treated patients also had significant increases in tetramer-binding cells (P <.0001). No difference was observed between the every-2-weeks and the every-3-weeks vaccination schedules (P =.59).
  
  
  CONCLUSIONS
  Flow cytometric analysis of HLA/peptide-tetramer binding cells was a reliable means of quantifying the CD8+ T-cell response to peptide immunization. This assay may be suitable for use in future trials to optimize different vaccination strategies. Concurrent interferon treatment did not inhibit the development of a peptide-specific immune response and vaccination every 2 weeks, and every 3 weeks produced similar results.
authors.affiliation: Earle A. Chiles Research Institute, Robert W. Franz Cancer Research Center, Providence Portland Medical Center, 4805 NE Glisan St, 5F40, Portland, OR 97213-2967, USA. josmith@providence.org
authors.forename: John W
authors.initials: JW
authors.lastname: Smith
authors.forename: Edwin B
authors.initials: EB
authors.lastname: Walker
authors.forename: Bernard A
authors.initials: BA
authors.lastname: Fox
authors.forename: Daniel
authors.initials: D
authors.lastname: Haley
authors.forename: Ketura P
authors.initials: KP
authors.lastname: Wisner
authors.forename: Teri
authors.initials: T
authors.lastname: Doran
authors.forename: Brenda
authors.initials: B
authors.lastname: Fisher
authors.forename: Lisa
authors.initials: L
authors.lastname: Justice
authors.forename: William
authors.initials: W
authors.lastname: Wood
authors.forename: John
authors.initials: J
authors.lastname: Vetto
authors.forename: Holden
authors.initials: H
authors.lastname: Maecker
authors.forename: Annemiek
authors.initials: A
authors.lastname: Dols
authors.forename: Sybren
authors.initials: S
authors.lastname: Meijer
authors.forename: Hong-Ming
authors.initials: HM
authors.lastname: Hu
authors.forename: Pedro
authors.initials: P
authors.lastname: Romero
authors.forename: W Gregory
authors.initials: WG
authors.lastname: Alvord
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Urba
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D019496:Cancer Vaccines / Q000008:administration & dosage*; D005260:Female; D005434:Flow Cytometry; D005453:Fluorescence; D005620:Freund's Adjuvant / Q000008:administration & dosage; D015789:HLA-A2 Antigen / Q000032:analysis*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D007937:Leukapheresis; D008297:Male; D008545:Melanoma / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000008:administration & dosage* / Q000009:adverse effects; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000008:administration & dosage* / Q000009:adverse effects; D010455:Peptides; D010865:Pilot Projects; D012878:Skin Neoplasms / Q000276:immunology*; D016896:Treatment Outcome; D058951:gp100 Melanoma Antigen
chemical_list: D019496:Cancer Vaccines; D015789:HLA-A2 Antigen; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; C548637:PMEL protein, human; D010455:Peptides; C548638:g209-2M melanoma peptide; D058951:gp100 Melanoma Antigen; D007371:Interferon-gamma; D005620:Freund's Adjuvant