title: A peptide epitope derived from the cancer testis antigen HOM-MEL-40/SSX2 capable of inducing CD4⁺ and CD8⁺ T-cell as well as B-cell responses.
abstract: BACKGROUND
  Antigen-derived HLA class I-restricted peptides can generate specific CD8(+) T-cell responses in vivo and are therefore often used as vaccines for patients with cancer. However, only occasional objective clinical responses have been reported suggesting the necessity of CD4(+) T-cell help and possibly antibodies for the induction of an effective anti-tumor immunity in vivo. The SSX2 gene encodes the cancer testis antigen (CTA) HOM-MEL-40/SSX2, which is frequently expressed in a wide spectrum of cancers. Both humoral and cellular immune responses against SSX2 have been described making SSX2 an attractive candidate for vaccine trials.
  
  
  METHODS
  SYFPEITHI algorithm was used to predict five pentadecamer peptides with a high binding probability for six selected HLA-DRB1 subtypes (*0101, *0301, *0401, *0701, *1101, *1501) which are prevalent in the Caucasian population.
  
  
  RESULTS
  Using peripheral blood cells of 13 cancer patients and 5 healthy controls, the HOM-MEL-40/SSX2-derived peptide p101-111 was identified as an epitope with dual immunogenicity for both CD4(+) helper and cytotoxic CD8(+) T cells. This epitope also reacted with anti-SSX2 antibodies in the serum of a patient with breast cancer. Most remarkably, SSX2/p101-111 simultaneously induced specific CD8, CD4, and antibody responses in vitro.
  
  
  CONCLUSIONS
  p101-111 is the first CTA-derived peptide which induces CD4(+), CD8(+), and B-cell responses in vitro. This triple-immunogenic peptide represents an attractive vaccine candidate for the induction of effective anti-tumor immunity.
authors.affiliation: José-Carreras-Center at the Department of Internal Medicine I-Build. 45.3, Saarland University Medical School, 66424 Homburg, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Neumann
authors.forename: Boris
authors.initials: B
authors.lastname: Kubuschok
authors.forename: Kubilay
authors.initials: K
authors.lastname: Ertan
authors.forename: Claudia
authors.initials: C
authors.lastname: Schormann
authors.forename: Stefan
authors.initials: S
authors.lastname: Stevanovic
authors.forename: Klaus-Dieter
authors.initials: KD
authors.lastname: Preuss
authors.forename: Werner
authors.initials: W
authors.lastname: Schmidt
authors.forename: Michael
authors.initials: M
authors.lastname: Pfreundschuh
mesh_terms: D000595:Amino Acid Sequence; D017951:Antigen Presentation; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D019496:Cancer Vaccines / Q000276:immunology* / Q000494:pharmacology*; D016022:Case-Control Studies; D018984:Epitopes, T-Lymphocyte / Q000235:genetics / Q000276:immunology*; D006684:HLA-DR Antigens / Q000276:immunology; D006801:Humans; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics / Q000276:immunology*; D009369:Neoplasms / Q000276:immunology* / Q000628:therapy; D010446:Peptide Fragments / Q000276:immunology; D012097:Repressor Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: D019496:Cancer Vaccines; D018984:Epitopes, T-Lymphocyte; D006684:HLA-DR Antigens; D009363:Neoplasm Proteins; D010446:Peptide Fragments; D012097:Repressor Proteins; C093962:synovial sarcoma X breakpoint proteins