title: Identification of novel immunogenic human leukocyte antigen-A 2402-binding epitopes of human papillomavirus type 16 E7 for immunotherapy against human cervical cancer.
abstract: BACKGROUND
  A study was undertaken to identify new immunogenic human leukocyte antigen (HLA)-A 2402-restricted epitopes from human papillomavirus (HPV) type 16 E7 protein for immunotherapy against cervical cancer.
  
  
  METHODS
  Synthetic overlapping peptides were screened by measuring the frequency of CD8(+) cytotoxic T lymphocytes (CTLs) producing intracellular interferon-γ (IFN-γ) using flow cytometry and were validated in SiHa cells with a Cr release cytotoxicity assay. In vivo antitumor effects of peptide-sensitized peripheral blood mononuclear cells (PBMCs) and isolated CD8(+) CTLs were evaluated using BALB/c nude mice with SiHa cell xenotransplants.
  
  
  RESULTS
  Among 14 overlapping 15-amino acid peptides, E7(61-75) (CDSTLRLCVQSTHVD) and E7(67-81) (LCVQSTHVDIRTLED) induced significantly higher IFN-γ production (P < .05) and showed higher in vitro cytotoxicity against SiHa cells than did cells sensitized with the negative control. To determine the exact HLA-A 2402-restricted epitopes, a total of 25 overlapping 9- or 10-amino acid peptides spanning E7(61-75) and E7(67-81) were synthesized. E7(61-69) (CDSTLRLCV) and E7(67-76) (LCVQSTHVDI) induced significantly greater IFN-γ production as well as increased in vitro cytotoxicity against SiHa cells compared with those of other peptides and the negative control (P < .01), and the antitumor effects of these peptide-sensitized PBMCs were induced by CD8(+) CTLs. E7(61-69) -sensitized and E7(67-76) -sensitized PBMCs and isolated CD8(+) CTLs showed a much greater suppression of tumor growth in vivo compared with that of control groups treated with PBS (P < .01). The authors also confirmed the synergistic antitumor effect of cisplatin followed by E7(67-76) -sensitized PBMCs in vivo.
  
  
  CONCLUSIONS
  E7(61-69) and E7(67-76) were identified as novel HPV type 16 E7 epitopes for HLA-A 2402, which could be used for immunotherapy against cervical cancer.
authors.affiliation: Department of Laboratory Medicine, Yonsei University Medical College, Seoul, Republic of Korea.
authors.forename: Sunphil
authors.initials: S
authors.lastname: Jang
authors.forename: Young Tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Hye Won
authors.initials: HW
authors.lastname: Chung
authors.forename: Kyoung-Ryul
authors.initials: KR
authors.lastname: Lee
authors.forename: Jong-Baeck
authors.initials: JB
authors.lastname: Lim
authors.forename: Kyungwon
authors.initials: K
authors.lastname: Lee
mesh_terms: D002945:Cisplatin / Q000627:therapeutic use; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D005260:Female; D059871:HLA-A24 Antigen / Q000276:immunology*; D052162:Human papillomavirus 16 / Q000276:immunology*; D006801:Humans; D016219:Immunotherapy, Adoptive; D050725:Papillomavirus E7 Proteins / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D002583:Uterine Cervical Neoplasms / Q000276:immunology / Q000628:therapy* / Q000821:virology
chemical_list: D018984:Epitopes, T-Lymphocyte; D059871:HLA-A24 Antigen; D050725:Papillomavirus E7 Proteins; C059731:oncogene protein E7, Human papillomavirus type 16; D002945:Cisplatin