title: gp100/pmel17 and tyrosinase encode multiple epitopes recognized by Th1-type CD4+T cells.
abstract: CD4+ T cells modulate the magnitude and durability of CTL responses in vivo, and may serve as effector cells in the tumour microenvironment. In order to identify the tumour epitopes recognized by tumour-reactive human CD4+ T cells, we combined the use of an HLA-DR4/peptide binding algorithm with an IFN-gamma ELISPOT assay. Two known and three novel CD4+ T cell epitopes derived from the gp 100/pmel17 and tyrosinase melanocyte-associated antigens were confirmed or identified. Of major interest, we determined that freshly-isolated PBMC frequencies of Th1-type CD4+ T recognizing these peptides are frequently elevated in HLA-DR4+ melanoma patients (but not normal donors) that are currently disease-free as a result of therapeutic intervention. Epitope-specific CD4+ T cells from normal DR4+ donors could be induced, however, after in vitro stimulation with autologous dendritic cell pulsed with antigens (peptides or antigen-positive melanoma lysates) or infected with recombinant vaccinia virus encoding the relevant antigen. Peptide-reactive CD4+ T cells also recognized HLA-DR4+ melanoma cell lines that constitutively express the relevant antigen. Based on these data, these epitopes may serve as potent vaccine components to promote clinically-relevant Th1-type CD4+ T cell effector function in situ.
authors.affiliation: Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
authors.forename: L S
authors.initials: LS
authors.lastname: Kierstead
authors.forename: E
authors.initials: E
authors.lastname: Ranieri
authors.forename: W
authors.initials: W
authors.lastname: Olson
authors.forename: V
authors.initials: V
authors.lastname: Brusic
authors.forename: J
authors.initials: J
authors.lastname: Sidney
authors.forename: A
authors.initials: A
authors.lastname: Sette
authors.forename: Y L
authors.initials: YL
authors.lastname: Kasamon
authors.forename: C L
authors.initials: CL
authors.lastname: Slingluff
authors.forename: J M
authors.initials: JM
authors.lastname: Kirkwood
authors.forename: W J
authors.initials: WJ
authors.lastname: Storkus
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology; D002460:Cell Line; D003713:Dendritic Cells / Q000276:immunology / Q000821:virology; D000939:Epitopes / Q000235:genetics / Q000276:immunology*; D005260:Female; D015804:HLA-DR4 Antigen / Q000276:immunology / Q000378:metabolism; D006801:Humans; D008297:Male; D008545:Melanoma / Q000235:genetics / Q000276:immunology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D008875:Middle Aged; D008969:Molecular Sequence Data; D014442:Monophenol Monooxygenase / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D009842:Oligopeptides / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D011485:Protein Binding; D011506:Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D018417:Th1 Cells / Q000166:cytology / Q000276:immunology*; D014407:Tumor Cells, Cultured; D014616:Vaccinia virus / Q000235:genetics / Q000254:growth & development; D058951:gp100 Melanoma Antigen
chemical_list: D000939:Epitopes; D015804:HLA-DR4 Antigen; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D009842:Oligopeptides; C548637:PMEL protein, human; D011506:Proteins; D058951:gp100 Melanoma Antigen; D014442:Monophenol Monooxygenase