title: A novel CD4 T-cell epitope described from one of the cervical cancer patients vaccinated with HPV 16 or 18 E7-pulsed dendritic cells.
abstract: Previously, safety and immunogenicity of human papillomavirus type 16 (HPV16) or 18 E7-pulsed dendritic cells (DC) vaccinations were demonstrated in a dose-escalation Phase I clinical trial which enrolled ten patients diagnosed with stage IB or IIA cervical cancer (nine HPV 16-positive, one HPV 18-positive). The goal of the study was to define the T-cell epitopes of HPV 16 or 18 E7 protein in these patients in order to develop new strategies for treating HPV-associated malignancies. This was accomplished through establishing T-cell lines by stimulating peripheral blood mononuclear cells with autologous mature DC pulsed with the HPV 16 or 18 E7 protein, examining the T-cell responses using ELISPOT assays, and isolating E7-specific T-cell clones based on IFN-gamma secretion. Then, the epitope was characterized in terms of its core sequence and the restriction element. Twelve T-cell lines from eight subjects (seven HPV 16-positive, one HPV 18-positive) were evaluated. Positive T-cell responses were demonstrated in four subjects (all HPV 16-positive). All four were positive for the HPV 16 E7 46-70 (EPDRAHYNIVTFCCKCDSTLRLCVQ) region. T-cell clones specific for the E7 47-70 region were isolated from one of the subjects. Further analyses revealed a novel, naturally processed, CD4 T-cell epitope, E7 58-68 (CCKCDSTLRLC), restricted by the HLA-DR17 molecule.
authors.affiliation: Department of Microbiology and Parasitology, College of Basic Medical Sciences, China Medical University, 92 Beier Road, Heping District, Shenyang, 110001, China. xlwang@mail.cmu.edu.cn [corrected]
authors.forename: Xuelian
authors.initials: X
authors.lastname: Wang
authors.forename: Alessandro D
authors.initials: AD
authors.lastname: Santin
authors.forename: Stefania
authors.initials: S
authors.lastname: Bellone
authors.forename: Sushil
authors.initials: S
authors.lastname: Gupta
authors.forename: Mayumi
authors.initials: M
authors.lastname: Nakagawa
mesh_terms: D000595:Amino Acid Sequence; D017951:Antigen Presentation; D015704:CD4 Antigens / Q000235:genetics; D019496:Cancer Vaccines / Q000627:therapeutic use*; D003713:Dendritic Cells / Q000276:immunology*; D004305:Dose-Response Relationship, Drug; D018984:Epitopes, T-Lymphocyte / Q000235:genetics / Q000276:immunology; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D052162:Human papillomavirus 16 / Q000276:immunology*; D052161:Human papillomavirus 18 / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D009367:Neoplasm Staging; D009856:Oncogene Proteins, Viral / Q000627:therapeutic use*; D050725:Papillomavirus E7 Proteins; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology; D002583:Uterine Cervical Neoplasms / Q000188:drug therapy / Q000276:immunology
chemical_list: D015704:CD4 Antigens; D019496:Cancer Vaccines; D018984:Epitopes, T-Lymphocyte; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; C059731:oncogene protein E7, Human papillomavirus type 16