title: Identification of naturally processed helper T-cell epitopes from prostate-specific membrane antigen using peptide-based in vitro stimulation.
abstract: OBJECTIVE
  There is growing evidence that CD4(+) helper T lymphocytes (HTLs) play an essential role in the induction and long-term maintenance of antitumor CTL responses. Thus, approaches to develop effective T-cell-based immunotherapy should focus in the stimulation of both CTLs and HTLs reactive against tumor-associated antigens. The present studies were performed with the purpose of identifying HTL epitopes for prostate-specific membrane antigen (PSMA) for the optimization of vaccines for prostate cancer.
  
  
  METHODS
  Synthetic peptides from regions of the PSMA sequence that were predicted to serve as HTL epitopes were prepared with use of computer-based algorithms and tested for their capacity to trigger in vitro HTL responses in lymphocytes from normal volunteers.
  
  
  RESULTS
  Our results show that 4 peptides from PSMA were effective in eliciting HTL responses. Moreover, HTL reactive to 3 of the 4 peptides were capable of reacting with naturally processed antigen in the form of freeze/thaw lysates or apoptotic cells produced from PSMA-positive LNCaP tumor cell lines.
  
  
  CONCLUSIONS
  Human HTLs are capable of effectively recognizing epitopes derived from PSMA. The information presented here should facilitate the design of improved vaccination strategies for prostate cancer.
authors: Department of Immunology, Mayo Clinic, Rochester, Minnesota55905, USA.
authors: Hiroya
authors: H
authors: Kobayashi
authors: Ryusuke
authors: R
authors: Omiya
authors: Benjamin
authors: B
authors: Sodey
authors: Mitsuru
authors: M
authors: Yanai
authors: Kensuke
authors: K
authors: Oikawa
authors: Keisuke
authors: K
authors: Sato
authors: Shoji
authors: S
authors: Kimura
authors: Satoru
authors: S
authors: Senju
authors: Yasuharu
authors: Y
authors: Nishimura
authors: Masatoshi
authors: M
authors: Tateno
authors: Esteban
authors: E
authors: Celis
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000276:immunology* / Q000378:metabolism; D017209:Apoptosis / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D043425:Glutamate Carboxypeptidase II / Q000276:immunology* / Q000378:metabolism; D000949:Histocompatibility Antigens Class II / Q000276:immunology / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology / Q000627:therapeutic use*; D011471:Prostatic Neoplasms / Q000276:immunology* / Q000628:therapy; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000166:cytology / Q000276:immunology*
chemical_list: D000954:Antigens, Surface; D018984:Epitopes, T-Lymphocyte; D000949:Histocompatibility Antigens Class II; D010446:Peptide Fragments; C473848:FOLH1 protein, human; D043425:Glutamate Carboxypeptidase II