title: Vaccination with recombinant NY-ESO-1 protein elicits immunodominant HLA-DR52b-restricted CD4+ T cell responses with a conserved T cell receptor repertoire.
abstract: OBJECTIVE
  ESO is a tumor-specific antigen with wide expression in human tumors of different histologic types and remarkable spontaneous immunogenicity. We have previously shown that specific T(H)1 and antibody responses can be elicited in patients with no detectable preexisting immune responses by vaccination with rESO administered with Montanide ISA-51 and CpG ODN 7909. The purpose of the present study was to characterize vaccine-induced ESO-specific CD4(+) T cell responses.
  
  
  METHODS
  We generated CD4(+) T cell clones from patient C2, who had the highest CD4(+) T cell response to the vaccine, and analyzed their fine specificity and HLA class II restriction to determine the recognized epitope. We then assessed the response to the identified epitope in all vaccinated patients expressing the corresponding HLA class II allele.
  
  
  RESULTS
  We found that ESO-specific CD4(+) T cell clones from patient C2 recognize peptide ESO(119-143) (core region 123-137) presented by HLA-DR52b (HLA-DRB3*0202), a MHC class II allele expressed by about half of Caucasians. Importantly, following vaccination, all patients expressing DR52b developed significant responses to the identified epitope, accounting for, on average, half of the total CD4(+) T cell responses to the 119-143 immunodominant region. In addition, analysis of ESO-specific DR52b-restricted CD4(+) T cells at the clonal level revealed significant conservation of T cell receptor usage among different individuals.
  
  
  CONCLUSIONS
  The identification of a DR52b-restricted epitope from ESO that is immunodominant in the context of vaccine-elicited immune responses is instrumental for the immunologic monitoring of vaccination trials targeting this important tumor antigen.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, CLCC René Gauducheau, Boulevard Jacques Monod, Saint Herblain, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Bioley
authors.forename: Christelle
authors.initials: C
authors.lastname: Dousset
authors.forename: Alice
authors.initials: A
authors.lastname: Yeh
authors.forename: Bo
authors.initials: B
authors.lastname: Dupont
authors.forename: Nina
authors.initials: N
authors.lastname: Bhardwaj
authors.forename: Gregory
authors.initials: G
authors.lastname: Mears
authors.forename: Lloyd J
authors.initials: LJ
authors.lastname: Old
authors.forename: Maha
authors.initials: M
authors.lastname: Ayyoub
authors.forename: Danila
authors.initials: D
authors.lastname: Valmori
mesh_terms: D000595:Amino Acid Sequence; D017951:Antigen Presentation / Q000502:physiology; D000951:Antigens, Neoplasm / Q000737:chemistry / Q000276:immunology* / Q000627:therapeutic use; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D019496:Cancer Vaccines / Q000276:immunology* / Q000627:therapeutic use; D002478:Cells, Cultured; D018604:Epitope Mapping; D006684:HLA-DR Antigens / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D016056:Immunodominant Epitopes / Q000032:analysis / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D008565:Membrane Proteins / Q000737:chemistry / Q000276:immunology* / Q000627:therapeutic use; D010446:Peptide Fragments / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology / Q000627:therapeutic use; D013379:Substrate Specificity / Q000276:immunology; D037182:T-Cell Antigen Receptor Specificity / Q000276:immunology; D014611:Vaccination / Q000379:methods
chemical_list: D000951:Antigens, Neoplasm; C104948:CTAG1B protein, human; D019496:Cancer Vaccines; D006684:HLA-DR Antigens; D016056:Immunodominant Epitopes; D008565:Membrane Proteins; D010446:Peptide Fragments; D011948:Receptors, Antigen, T-Cell; D011994:Recombinant Proteins